Field of the invention
[0001] The present invention relates to the fields of genetics and oncology and provides
methods for predicting and identifying tumors of epithelial origin. Specifically,
the present invention relates to a novel method of predicting tumor initiation, tumor
progression and/or carcinomas, the method comprising detecting genetic abnormality
associated with tumors of epithelial origin. The present invention further relates
to a novel method of identifying an individual with potential for developing carcinoma,
the method comprising detection of genetic abnormalities. The present invention also
relates to a method of predicting the progression of carcinomas and the transformation
thereof to an aggressive variant, the method comprising detection of genetic abnormalities,
which indicate the probability to develop carcinoma. The present invention also relates
to a use of specific chromosomal region, a gene or a fragment thereof, and/or genetic
markers for predicting tumor initiation, tumor progression and/or carcinoma. The present
invention also relates to a use of specific chromosomal region or a gene or a fragment
thereof in therapy, for the development of therapy and for the preparation of a medicament
for treating tumors of epithelial origin.
Background of the invention
[0002] Cancer is a complex disease in which several genetic and epigenetic abnormalities
have accumulated. A varying number of genetic changes are needed prior to occurrence
of a somatically developed tumor. Available data indicate that the development of
solid tumors is dependent on combination of deletions and amplifications of multiple
chromosome segments (
Mertens et al. Cancer Res 57: 2765-2780, 1997;
Mitelman et al. Nature Genet, 15: 417-474, 1997). Over 90% of all human neoplasia is derived from epithelia. Thus, epithelial cells
play an important role in physiological and pathophysiological conditions. Carcinomas
are malignant tumors derived from epithelial cells. The most common carcinomas include
the common forms of breast, prostate, lung and colorectal cancer.
[0003] Colorectal cancer is the third most common cancer worldwide with an estimated one
million new cases annually (
Parkin et al. CA Cancer J Clin 55: 74-108, 2005). The average lifetime risk in industrialized countries is approximately 5%, and
almost half of those affected will die of their disease (
Burt, Gastroenterology 119: 837-853, 2000). Colorectal cancer develops via a benign precursor lesion, polyp, and is preventable
through polypectomy. It is estimated that 30% of the population have colonic polyps,
and the incidence of polyps increases with age. Thus, screening colonoscopies in average
asymptomatic individuals have revealed neoplastic (adenomatous) polyps in 12% of individuals
of 40-49 years of age (
Imperiale TF et al. NEJM 346: 1781-1785, 2002), and in 58% among 50-59 year-old individuals (
Mehran A et al. Surg Endosc 17: 1974-1977, 2003). Certain inherited disorders, which account for some 5-10% of the total colorectal
cancer burden, are associated with an increased number of polyps (familial adenomatous
polyposis, FAP) or an elevated tendency to malignant progression (hereditary nonpolyposis
colorectal cancer, HNPCC) (
Lynch and de la Chapelle, N Engl J Med 348: 919-932, 2003).
[0004] Survival is closely related to the stage at diagnosis, even in patients who have
already developed malignant disease: over 90% of patients with local cancer are alive
after 5 years as opposed to less than 10% of those with metastatic disease (
Burt, Gastroenterology 119: 837-853, 2000). Colorectal carcinomas are notoriously resistant to both chemotherapy and radiotherapy
and most patients for whom surgery alone is not curative are doomed to die of their
disease (Globcan, International Agency for Research on Cancer. Available at http:/www-dep.iarc.fr/,
2002). It is therefore vital to be able to identify individuals with an increased
risk as early as possible to enable efficient cancer prevention or curative treatment.
[0005] Colorectal cancer development via benign precursors along with the accumulation of
genetic changes is one of the best-known examples of multistep carcinogenesis (
Chung DC, Gastroenterology 119: 854-865, 2000, and below). This multistep evolutionary nature of colorectal cancer provides excellent
opportunities for early cancer detection and prevention. Colorectal cancers arise
as a result of stepwise accumulation of mutations at the nucleotide level and/or at
the gross chromosomal level. The overwhelming majority of colorectal cancers display
one of the two major genomic instability phenotypes, microsatellite instability (MSI)
or chromosomal instability (CIN) (
Abdel-Rahman et al. Proc. Natl. Acad. Sci. USA 98: 2538-2543, 2001). The current literature includes a multitude of biomarkers of potential use in colorectal
cancer risk assessment or early detection of this cancer; however, clinical validation
is mostly lacking (
Umar and Srivastava, Dis Markers 20: 87-96, 2004).
[0006] Currently, histology serves as a main predictor, with multiplicity of adenomas, high-grade
dysplasia, villous features, and large size (over 1 cm), for increased cancer risk
(
Winawer et al. Gastroenterology 130: 1872-1885, 2006). Therefore, predictors of advanced pathology would be useful, for both adenomas
and cancer, to be able to assign an appropriate risk category for each patient. Biomarkers
that could serve as predictors of a tendency to cancer progress would be highly welcome.
[0007] Lung cancer is a leading cause of cancer-related deaths worldwide, with approximately
1.2 million deaths annually (Ferlay
et al. 2001, GLOBOCAN2000: Cancer Incidence, Mortality and Prevalence Worldwide, Version
1.0 IARC CancerBase No. 5. Lyon, IARCPress). Up to 95 percent of lung cancers are
smoking related and thus, DNA adducts have a key role in carcinogenesis.
[0009] Malignancies of the lung can be divided based on the histological characteristics
into small cell (SCLC) and non-small cell lung cancers (NSCLC), the latter consisting
mainly of epidermoid carcinoma and adenocarcinoma. Recent studies have shown the genetic
background to be different among these cancer types (
Kaminski et al. Chest 125 (5 Suppl): 111 S-5S, 2004,
Fong et al. Thorax 58: 892-900, 2003). However, it is assumed that over 20 genetic or epigenetic abnormalities are needed
before clinically evident lung cancer. Typically, in lung carcinomas, multiple chromosome
aberrations can be observed indicating genomic instability. Novel tumor markers would
explain the pathogenesis of cancer and therefore, improve the effect of therapies
and survival in lung cancers.
[0010] Diagnostics longs for single markers or a panel of markers for general screening
of cancers. For example, prostate specific antigen (PSA) is secreted by the cells
of the prostate gland and elevated levels of PSA are used as a marker for prostate
tumors.
[0011] Several other markers for epithelial tumors are available but their use is hampered
from their nonspecificity: These markers are often elevated also in other conditions
than malignancy, such as in inflammatory lesions. Such markers, that have been used
in the clinics but that do not meet the requirement of specificity and/or sensitivity
are, for instance the following: tumor-derived colon-specific antigen (tCSA), carcinoembryonic
antigen (CEA), alpha-fetoprotein (AFP), pregnancy-specific beta-glycoprotein 1 (SP1),
human placental lactogen (HPL), human beta chorionic gonadotrophin (beta-HCG), transferrin
(TF) and ferritin (FE).
[0012] It is of highest importance to develop new methods, which enable early identification
of patients with an increased risk to develop aggressive carcinoma to enable efficient
cancer prevention. There is also a need for a clinically useful method that could
serve as a predictor of a carcinoma progressing tendency. Also, additional means for
the development of new guidelines for the initiation and follow-up of cancer therapy
are greatly needed.
[0013] Schneider, B. G. et al., J. Clin Pathol: Mol Pathol 2003; 56: 141-149 describe regions of allelic imbalance in the distal portion of chromosome 12q and
suggest that these regions may contain tumor suppressor genes important in the development
of gastric cancer. Specifically, by mapping extended regions of homozygosity (ERHs)
in gastric cancer cell lines and sites of allelic imbalance (AI) in primary gastric
adenocarcinomas the authors identified three regions that contain putative supressor
genes at chromosome 12 between microsatellite markers D12S1667 and D12S88 (region
A), D12607 and D12S78 (region B), and D12S342 and D12S324 (region C). No supressor
genes are mentioned for region A, which locates near the chromosomal region 12q21.2
identified in the present application to contain genetic aberrations that are specific
for tumors of epithelial origin.
[0014] International patent publication
WO2005/118869 discloses a method to determine if a patient is afflicted with cancer or at risk
for developing cancer. In the method the copy number of a minimal common region (MCR)
in a subject sample are compared to a normal copy number of the MCR, wherein said
MCR is selected from the group of 54 MCRs listed in Table 1. These MCRs are of a megabase
size and are neither structurally nor functionally defined. One of the regions is
12q21-q24.33, wherein DUSP6 is named as candidate gene encoding a protein of the dual
specificity protein phosphatase subfamilly. The specific chromosomal region 12q21.2
is not mentioned, nor is the
NAV3 gene. Table 4 of
WO2005/118869 lists a large number of gene markers present in the MCRs containing a deletion, including
at chromosome 12, but fails to mention
NAV3. Similarly, in Table 5 the gene markers present in the MCRs, containing an amplification,
do not include
NAV3.
[0015] Chromosome 12q21 aberrations, specifically neuron navigator 3
(NAV3) gene aberrations, have been identified in neuroblastomas and cutaneous T-cell lymphoma
(CTCL). Four of 10 primary neuroblastomas studied by Coy et al. showed reduced or
absent expression of
NAV3, and three of them had homozygous deletions of both alleles (
Coy JF et al. Gene 290: 73-94, 2002). In CTCL, a deletion or a translocation of
NAV3 gene was associated with a point mutation in the remaining allele only in one of
7 patients studied (
Karenko L et al. Cancer Res 65: 8101-8110, 2005 and
EP1476567 A1). In pancreatic carcinomas, chromosome 12q21 aberrations were identified by microsatellite
analysis. Loss of heterozygosity (LOH) was detected with markers D12S1684 and D12S1708,
which border a chromosomal region comprising
NAV3 gene (
Kimura M et al. Cancer Res 58: 2456-60, 1998). However, the chromosomal region described in the article by Kimura
et al. is large and neither the specific region nor the NAV3 gene was observed to be linked
to pancreatic carcinoma. On the contrary, this application describes chromosomal abnormalities
that are specific for tumors of epithelial origin, in the specific chromosomal region.
[0016] Novel biomarkers for providing more effective and early diagnosis of potentially
aggressive tumors as well as identifying tumors susceptible to targeted therapies
are warranted. The present invention provides one solution for predicting or identifying
tumor and carcinoma progression. The present invention also discloses a tool for evaluating
clinical aggressiveness of epithelial tumors and patient survival. Furthermore, the
invention provides a new therapeutic target for carcinoma prevention or therapy.
Brief description of the invention
[0017] The object of the invention is thus to provide novel methods and means for diagnosing,
staging and monitoring of patients having cancer, such methods and means allowing
an early diagnosis of the disease.
[0018] Another object of the invention is to provide novel methods and means for predicting
tumor initiation, tumor progression and/or carcinoma.
[0019] Another object of the invention is to provide novel methods and means for identification
of individuals with an increased risk to develop carcinomas, such methods and means
being specific and reliable and allowing identification as early as possible.
[0020] Yet another object of the invention is to provide novel methods and means for the
prediction of the progression of carcinomas and the transformation to an aggressive
form, such methods and means allowing a timely therapeutic intervention, which may
be life-saving.
[0021] Still another object of the invention is to provide novel methods and means for the
development of new guidelines for the initiation and follow-up of therapeutic interventions
as well as for the development of new treatment modalities for cancers, such methods
and means prolonging the remission stage of the disease and introducing new possibilities
for combating the disease and for the recovery of the patient.
[0022] Still another object of the invention is to provide novel biomarkers useful in early
detection of the cancer as well as cancer risk assessment.
[0023] The present invention relates to a novel method for prediction of tumor initiation,
tumor progression and/or carcinomas, characterized by detecting the presence or the
absence of genetic abnormalities at 12q21.2 in a neuron navigator 3 (NAV3) gene or
a fragment thereof, the presence of said genetic abnormalities being associated with
tumors of epithelial origin, in a biological sample. In other words, the genetic abnormalities
indicate the presence of epithelial tumors or an initiation or progression of tumors
of epithelial origin and/or carcinoma.
[0024] The present invention further relates to a novel method for identifying an individual
with potential for developing carcinoma of epithelial origin, the method comprising
detection of genetic abnormalities at 12q21.2 in a neuron navigator 3 (NAV3) gene
or a fragment therof, said genetic abnormalities being associated with tumors of epithelial
origin. That is, the genetic abnormalities indicate tumors of epithelial origin with
potential for developing carcinoma.
[0025] The present invention further relates to a novel method of predicting the progression
of carcinomas of epithelial origin and/or the transformation thereof to an aggressive
variant, characterized by detecting genetic abnormalities at 12q21.2 in a neuron navigator
3 (NAV3) gene or a fragment therof, wherein abnormalities indicate the probability
to develop carcinoma.
[0026] The present invention also relates to the use of the
NAV3 gene or a fragment thereof for predicting tumor initiation, tumor progression and/or
carcinoma, genetic abnormalities in the
NAV3 gene indicating tumors of epithelial origin.
[0027] The present invention also relates to the use of genetic markers at 12q21.2, for
predicting tumor initiation, tumor progression and/or carcinoma, characterized by
detecting the presence or absence of genetic abnormalities, said genetic abnormalities
at 12q21.2 in
NAV3 gene or in a fragment thereof indicating tumors of epithelial origin. Said genetic
abnormalities are associated with tumors of epithelial origin and/or carcinoma.
[0028] The present invention also describes the use of a specific chromosomal region 12q21.2,
specifically the
NAV3 gene, a fragment thereof or a gene product thereof in therapy, for the development
of therapy or for the preparation of a medicament for treating tumors of epithelial
origin.
Brief description of the drawings
[0029] In the following the invention will be described in greater detail by means of preferred
embodiments with reference to the attached drawings, in which
Figure 1 shows a LOH observed at the chromosome 12 microsatellite D12S1708 in both
adenoma (middle) and carcinoma (bottom) as compared to their matching normal tissue
(top).
Figure 2 shows a MSI observed at the chromosome 12 microsatellite D12S1708 in the
carcinoma (bottom) compared to its matching normal tissue (top). The adenoma (middle)
is MSS.
Figure 3 shows single nucleotide primer extension, (SnuPE) showing LOH in a carcinoma
(bottom) as compared to its matching normal (top).
Figure 4 shows a karyotype of the true malignant lung carcinoma cells of a patient
with CTCL and SCLC.
Figure 5a shows the result of NAV3-specific FISH with breast cancer metastases. Black bars indicate the amount of polyploidy
in studied cells and grey bars indicate the amount of NAV3 deleted cells. Results are shown as percentage of total cell count.
Figure 5b shows typical cells of breast cancer metastases with NAV3 deletion. Green signals indicate centromeres and red signals NAV3 copies.
Figure 6 shows comparison of NAV3 FISH results from normal colon and colon cancer samples. NAV3 FISH analysis included both normal colon and CRC samples from the same patient (n=36).
Mean values (%) of normal colon (grey bars) and colon cancer (black bars) are shown.
Detailed description of the invention
[0030] It has been found that abnormalities at 12q21.1-q21.31, specifically 12q21.2, are
associated with tumors of epithelial origin.
[0031] Chromosome 12q21.1-q21.31 aberrations, specifically 12q21.2 aberrations, more specifically
NAV3 gene aberrations, have been found to have role in the development of epithelial originated
tumors.
[0032] The present invention is based on a method for detecting genetic abnormalities at
12q21.1-q21.31, specifically 12q21.2, associated with tumors of epithelial origin,
excluding carcinoma of pancreas.
[0033] Specifically, genetic abnormalities at chromosomal position 12q21.1-q21.31, specifically
12q21.2, affect
NAV3 gene or a fragment thereof.
[0034] Specifically, genetic abnormalities are detected in
NAV3 gene or a fragment thereof.
[0035] In one preferred embodiment of the method of the invention the tumor of epithelial
origin is an adenoma and/or a carcinoma.
[0036] In another preferred embodiment of the method of the invention the location of the
tumor of epithelial origin is colon, rectum, lung, urinary bladder, breast, squamous
or basal cells. In other words, the epithelial tumor is a colon tumor, rectum tumor,
lung tumor, urinary bladder tumor, breast tumor, squamous cell tumor or a basal cell
tumor. In the large intestine, the colorectal tumors can be either adenocarcinomas
or premalignant adenomas or polyps, in the urinary bladder the tumor can be transitional
epithelial polyps with poor differentiation or overt transitional carcinomas, the
breast tumors can be either ductal carcinomas or acinar carcinomas and in the skin,
the tumors can be either basaliomas or epidermoid carcinomas (also called squamous
cell carcinoma or spinocellular carcinoma). In the lung, the tumor can be either epidermoid
carcinoma or adenocarcinomas.
[0037] In a further preferred embodiment of the method of the invention the genetic abnormalities
are determined by the loss of heterozygosity (LOH) of
NAV3 gene or a fragment thereof, wherein LOH of
NAV3 is indicative of tumor progression.
[0038] In a further preferred embodiment of the method of the invention the genetic abnormalities
of
NAV3 gene are determined in haploid, diploid and/or polyploid cells.
[0039] In a further preferred embodiment of the method of the invention the tumor cells
are microsatellite stable (MSS) or microsatellite instable (MSI).
[0040] In a further preferred embodiment of the method of the invention the tumor of epithelial
origin is other than carcinoma of pancreas.
[0041] The present invention is also based to the use of chromosomal region 12q21.1-q21.31,
specifically 12q21.2,
NAV3 gene or a fragment thereof, and/or markers at 12q21.1-q21.31, specifically 12q21.2,
associated with tumors of epithelial origin.
[0042] In one preferred embodiment the markers at 12q21.1-q21.31 include D12S1684, D12S326,
D12S1708 and/or rs1852464.
[0043] In one preferred embodiment the markers at 12q21.2 include D12S326 and/or rs1852464.
[0044] As used herein the expression "genetic abnormality" refers to the presence of a translocation,
deletion, amplification, inversion or another defect at 12q21.1-q21.31, specifically
at 12q21.2.
[0045] As used herein the expression "deletion" refers to the absence of a nucleotide or
nucleotides and/or an exon or exons in the gene sequence which absence adversely affects
the function of the gene. The expression also refers to the absence of the gene fragment,
gene or the chromosomal fragment containing the gene.
[0046] As used herein the expression "another defect" refers to any genetic alteration,
such as a substitution, an addition, polymorphism, insertion, inversion etc., which
is associated with tumors of epithelial origin.
[0047] As used herein the expression "loss of heterozygosity (LOH)" refers to the loss of
a single parent's contribution to part of the cell's genome. LOH can be considered
as an event to unmask a mutant allele of a gene which may play a role in suppressing
tumor formation. Thus, LOH is an important marker for tumor initiation or progression.
[0048] As used herein the expression "BLOH" refers to borderline LOH, meaning that one of
the alleles in the tumor sample has 25%-39% signal reduction compared to its matching
normal.
[0049] As used herein the expression "translocation" refers to transfer of chromosomal regions
between non-homologous chromosomes.
[0050] As used herein the expression "amplification" refers to gain of genetic material
such as a gene fragment, a gene or the chromosomal fragment containing the gene.
[0051] As used herein the expression "tumor" refers to an abnormal mass of tissue due to
abnormal excess of cells divisions or lack of normal cell death. Tumors may be benign
or malignant, in other words not cancerous or cancerous. Tumors include such as adenomas,
carcinomas or polyps.
[0052] As used herein the expression "adenoma" refers to a noncancerous tumor.
[0053] As used herein the expression "carcinoma" refers to a cancer of epithelial origin.
[0054] As used herein the expression "epithelial" refers to the cells that line the internal
and external surfaces of the body.
[0055] As used herein the expression "tumors of epithelial origin" refers to tumors, which
arise from epithelial cells. The tumors of epithelial origin include such as breast,
colorectal, lung, urinary bladder, breast, squamous cell, basal cell, prostate, gastric,
esophagus and mouth/tongue tumors.
[0056] Epithelial tumors arise from epithelium, the specified set of cells that cover organs
and surfaces of the body. Epithelium can be simple, such as the one cell layer epithelium
covering part of respiratory tract, mammary gland ducts and ductuli or intestine,
or can be stratifies, composed of several layers of cells, such as is found in the
upper layer of skin or in the urinary bladder. The epithelium of the skin is keratinizing,
meaning that while the basal cells of the epidermis, covering skin are round and proliferate,
the uppermost cells are flattened, non-dividing and their cytoplasm is filled with
keratin fibres. The urinary epithelium, on the other hand, is not keratinizing but
even here, the basally located cells are round while the cells located closer to the
surface are flattened and thus, this type of epithelium is called transitional.
[0057] As used herein the expression "indicating tumors of epithelial origin" refers to
that the presence or high probability or possibility of epithelial tumors is shown
or described or proved or evidenced.
[0058] As used herein the expression "aggressive variant" refers to a cancer, which grows
fast and possibly metastasizes.
[0059] As used herein the expressions "fragment" or "functional fragment" refer to a part
of
NAV3 gene, which is detectable in the methods of the invention such as LOH-analysis or
FISH-methods.
[0060] As used herein the expression "gene product" refers to a mRNA, protein or to any
product achieved directly or indirectly from the gene.
[0061] Neuron navigator 3 (
NAV3 or
POMFIL1) gene is a member of a recently identified human gene family, which shows homology
to the
unc-53, an axonguidance gene from
Caenorhabditis elegans (
Maes et al. Genomics 80: 21-30, 2002). It also shares homologous sequences with human RAINB1 (retinoic acid inducible
in neuroblastoma cells) a mammalian homologue of unc-53 (
Merrill et al. PNAS 99: 3422-3427, 2002). By structure prediction NAV3 has calponin-like domains and SH3 binding sites suggestive
of a role in cell signaling (
Coy JF et al. Gene 290: 73-94, 2002 and
Maes et al. Genomics 80: 21-30, 2002)
NAV3 consists of 39 exons and its expression, based on mRNA detection, is largely restricted
to the brain tissue (
Maes et al. Genomics 80: 21-30, 2002).
NAV3 was shown to produce transcripts encoding proteins of different lengths and it may
be subject to tissue-specific alternative splicing. NAV3 is structrally a helicase
and exonuclease, resembling Wemer and Bloom syndrome proteins with the role in maintaining
stability of chromosomes (
Coy JF et al. Gene 290: 73-94, 2002,
Maes et al. Genomics 80: 21-30, 2002). Subcellularly, NAV3 has been reported to locate in nuclear pre complexes (
Coy JF et al. Gene 290: 73-94, 2002) and might have a role in nuclear transport, kinetochore formation and cell cycle
control (
Fahrenkrog B and Aebi U, Nat Rev Mol Cell Biol 4: 757-66, 2003). Thus, NAV3 could be a non-classical haploinsufficient tumour suppressor (
Sherr CJ, Cell 116: 235-46, 2004).
[0062] In the present invention, genetic abnormalities at 12q21.1-q21.31, specifically 12q21.2,
were studied by LOH analysis for colorectal adenomas, carcinomas lung cancers and
urinary bladder cancer. Fluorescence
in situ hybridization (FISH) was also utilized for colon tumors, breast cancer, basal cell
carcinoma (BCC) and squamous cell carcinoma (SCC), and comparative genomic hybridization
(CGH) for lung cancers in order to scrutinize chromosomal position 12q21.1-q21.31,
specifically 12q21.2.
[0063] All the microsatellite markers (D12S1684, D12S326, D12S1708) as well as the SNP marker
(the intragenic
NAV3 rs1852464) showed LOH at 12q21.1-q21.31 in adenomas and carcinomas of colorectum.
In urinary bladder cancer samples, at least borderline LOH was detected with said
four markers. Microsatellite markers also showed LOH in lung cancers. Furthermore,
FISH revealed loss of 12q21 in colon tumors and both loss and gain of 12q21 in breast
cancers, basal cell carcinoma and squamous cell carcinoma. CGH revealed loss of 12q21
in one lung cancer. Thus, loss or gain of
NAV3 appears as a marker of tumors originating from epithelia.
[0064] In addition, colorectal adenomas and carcinomas arising in the same patient showed
NAV3 LOH suggesting that adenoma patients will develop carcinomas through
NAV3 LOH. Poor differentiation was observed in an adenoma with
NAV3 LOH and the size of
NAV3 LOH adenomas tended to be greater than of those without LOH.
[0065] We have now observed, that the chromosomal abnormalities, found in epithelial tumors,
in fact do occur in tumors arising in all different types of epithelium. Thus, the
basaliomas (also called carcinoma basocellulare or basal cell carcinomas) are formed
from the cells normally located in the most basal part of epidermis. On the other
hand, the squomous cells carcinoma (also called carcinoma squamocellulare or spinocellular
carcinoma), are formed from the more distally located cells and this tumor often show
keratinisation, a feature characteristic for the keratinizing cells. Carcinomas of
breast and colorectal carcinomas are examples of malignant tumors arising from simple
epithelium, having only one layer of cells normally, but even here, the original benign
epithelium contains differentiated cell types, such as exocrine cells of the mammary
gland, secreting either milk or mucus, or mucus secreting Goblet cells in the gut
epithelium.
[0066] Epithelial tumors can be benign, premalignant or overtly malignant. We did observe
the chromosomal abnormality described in more detail in this application mostly in
malignant tumours, carcinomas but also in some of the premalignant conditions, such
as large adenomas of colon or rectum.
[0067] Because genetic abnormalities were associated with tumors of epithelial origin, the
presence of those abnormalities indicate the initiation, progression and/or presence
of tumors of epithelial origin or the development, progression and/or presence of
carcinomas. Therefore, it is possible to diagnose or identify the patients who have
the tumor of the epithelial origin or carcinoma by detecting the presence of said
aberrations in a biological sample. It is also possible to diagnose or identify the
patients whose tumors are likely to progress or develop or transform to an aggressive
variant by detecting the presence of said aberrations. The biological samples from
the patients or suspected patients can be screened for the presence of said genetic
abnormalities.
[0068] According to the method of the present invention, the presence or absence of genetic
abnormalities can be detected from a biological sample by any known detection method
suitable for detecting translocations, deletions, insertions etc. Such methods are
easily recognized by those skilled in the art and include fluorescence
in situ hybridisations, such as multi-colour fluorescence in situ hybridisations, multi-fluor
in situ-hybridisation (MFISH), spectral karyotyping (SKY), Combined binary ratio labelling
(COBRA), colour changing karyotyping (CCK). In comparative genomic hybridization (CGH)
the genetic changes are classified as DNA gains and losses. CGH reveals a characteristic
pattern that includes aberrations at chromosomal and subchromosomal levels. The conventional
G-banding techniques can also be used in cases were the coarse detection of gains,
losses or translocations is regarded as sufficient. Preferable methods are those suitable
for use in clinical laboratories.
[0069] According to one preferred embodiment of the present invention, which takes advantage
of the identification of
NAV3 gene in tumors of epithelial origin, the presence or absence of the
NAV3 gene or an equivalent or a fragment thereof can be detected from a biological sample
by any known detection method suitable for detecting a gene expression (or copy number),
i.e. methods based on detecting the copy number of the gene (or DNA) and/or those
based on detecting the gene expression products (mRNA or protein). Such methods are
easily recognized by those skilled in the art and include conventional polymerase
chain reaction (PCR)-methods, RT-PCR,
in situ hybridisations, such as FISH, mRNA
in situ hybridisation, Northern analysis, Southern and Western analyses, immunohistochemistry,
and other immunoassays, such as ELISA. Preferable methods are those suitable for use
in routine clinical laboratories.
[0070] According to another preferred embodiment of the present invention, which takes advantage
of the LOH analysis for detecting abnormalities of
NAV3 gene, deletion, gene conversion, mitotic recombination and chromosome loss can be
detected. LOH in cancers can be identified by the presence of heterozygosity at a
genetic locus in germline DNA and the absence of heterozygosity at the same locus
in the tumor cells.
[0071] According to another preferred embodiment of the present invention, which takes advantage
of the markers suitable for detecting abnormalities of
NAV3 gene, markers include any biological markers such as microsatellite markers, SNP-markers,
any probes, primers or antibodies associated with
NAV3 gene. Numerous methods are suitable for analysing nucleic acids for the presence
of specific sequence variations such as polymorphisms, SNP's, insertions or deletions.
Allelic variants can be discriminated for example by enzymatic methods, electrophoretic
methods, and physical methods. These methods include for example single strand conformation
polymorphism (SSCP), heteroduplex analysis, fragment analysis, DNA sequencing, minisequencing,
primer extension methods, microarrays, mass spectrometry and denaturing high performance
liquid chromatography (DHPLC). PCRs are often used in analyzing specific sequence
variations or exploited in combination with aforementioned methods.
[0072] In the method of the invention, the biological sample can be any suitable tissue
sample, such as biopsy from the epithelial tissue or lymph node or a metastatic tumor
lesion in any body organ or whole blood. The biological sample can be, if necessary,
pretreated in a suitable manner known to those skilled in the art.
[0073] In therapy, restoration of the normal function of the
NAV3 gene can be used. This may be reached by enhancing the expression of functionally
homologous genes, by introducing an intact
NA V3 gene or by using an altered form of the
NAV3 gene or antisense oligonucleotide against the
NAV3 in any technique presently available for gene therapy to prevent the progression
of a proliferating disease. In particular, tumor cell growth may be slowed down or
even stopped by such therapy. Such techniques include the
ex vivo and
in situ therapy methods, the former comprising transducing or transfecting an intact or altered
NA V3 gene (or its functional domains) in a recombinant or peptide form or as antisense
oligonucleotides or in a vector to the patient, and the latter comprising inserting
the altered gene or oligonucleotide into a carrier, which is then introduced into
the patient. Depending on the disease to be treated, a transient cure or a permanent
cure may be achieved. Alternatively, monoclonal or humanized antibodies or peptides
binding to the NAV3 protein or to the fusion gene generated as a result of the translocation,
can be used to suppress the function of the altered NAV3 protein and thus tumor cell
growth may be slowed down or even stopped. Antibodies against NAV3 could also be used
to carry other agents, such as cytotoxic substances, to the cancer cells over-expressing
the
NAV3 gene. Such agents could then be used to kill specifically the cancer cells.
[0074] Understanding the genetic aberrations or the chromosomal changes, especially those
associated with the tumor initiation will contribute to early diagnosis of cancer
and treatment of patients. The present invention discloses for the first time the
role of
NAV3 LOH in epithelial tumors. The present invention also discloses that when
NAV3 LOH is observed in colorectal adenomas it is likely that such patient will develop
carcinomas through
NAV3 LOH as well.
[0075] Detection of deletions or other defects of the
NAV3 gene as described in the present invention, allows thus earlier identification of
patients with an increased risk to develop aggressive cancer and enables efficient
cancer prevention and development of novel diagnostic and follow-up of carcinomas,
such as colorectal or lung cancer. Discovery of genetic abnormalities of
NAV3 in epithelial tumors also opens new possibilities in the advancement of therapies
thereof.
[0076] The following examples are given for further illustration of the invention.
[0077] It will be obvious to a person skilled in the art that, as the technology advances,
the inventive concept can be implemented in various ways. The invention and its embodiments
are not limited to the examples described below but may vary within the scope of the
claims.
Example 1
a) NAV3 loss of heterozygosity (LOH) analysis using microsatellite markers
[0078] Histology of the formalin-fixed paraffin-embedded tissue samples was verified by
a histopathologist. Tumors, adenomas or normal areas were dissected out to get pure
normal or at least 50% ratio of carcinoma or adenoma tissue for the DNA preparation
according to a standard protocol. Paraffin embedded sections were cut at 10 µm thickness
and DNA was purified from these following standard protocols (
Isola et al. Am J Pathol 145: 1301-1308, 1994).
[0079] LOH analysis was performed for
NAV3 gene. Three microsatellite markers spanning the
NAV3 gene locus at 12q21.1-q21.31 and surrounding the gene from both directions (physical
distances between loci in mega-bases according to http://www.ensembl.org are given
in parentheses) were chosen: pter D12S1684 -(0.8 Mb)- D12S326 -(0.2 Mb)- NAV3 -(3.8
Mb)- D12S1708 qter. The DNA samples were amplified by polymerase chain reaction (PCR)
using the following primers: D12S1684F 5'cctgcatgcctcagttatga3', D12S1684R 5'aacaagccataccagtcagg3',
D12S326F 5'accaggctcccctaaaagtg3', D12S326R 5'agaatgaccagacccacagg3', D12S1708F 5'gggaacttatgtcaaggctagga3',
D12S1708R 5'gatctagtgctcaagaggttttcaa3'. PCR reactions were performed in 25-µl reaction
volume containing 75-150 ng of template DNA, GeneAmp 10x PCR buffer (Applied Biosystems),
0.2 mM of dNTP Mix (GE Healthcare Biosciences Ab), 0.8 umol of each primer, and 1,5
U of AmpliTaq polymerase (AB). The following PCR cycles were used for amplification:
94°C for 3 minutes, 35 cycles of 94°C for 30 seconds denaturation, annealing temperature
of 60°C for 30 seconds, and 72°C for 45 seconds extension. Final extension was 72°C
for 5 minutes. The forward primers were fluorescently labeled with FAM and PCR fragments
were run on the ABI3730 sequencer/genotyper and results analysed using GeneMapper
v3 software (Applied Biosystems).
b) NAV3 loss of heterozygosity (LOH) analysis using single nucleotide primer extension, SnuPE
[0080] The DNA was prepared as above.
[0081] A non-radioactive method was used to quantify the relative expression of the two
NAV3 alleles in patients heterozygous for the coding A/G polymorphism (rs1852464) within
exon 19 of the
NAV3 gene. The heterozygosity for rs1852464 is up to 0.493 in the Caucasians/Europeans
making it a highly useful marker. The extension reaction of SNuPE is based on the
incorporation of a single ddNTP that is selected to allow differential extension of
a labeled primer annealed close to the polymorphic site.
[0082] Matching tumor and normal genomic DNA samples from the same individuals were first
PCR amplified using primers rs1852464F 5' CCTGCTATTTTCATCTTTCAAGC 3' and rs1852464R
5' GGCTGGGATGCTGTTTGAG 3' to yield a 130 bp PCR fragment containing the A/G polymorphism.
PCR reactions were performed in 25-µl reaction volume containing 60-100 ng of template
DNA, GeneAmp 10x PCR buffer (Applied Biosystems), 0.2 mM of dNTP Mix (GE Healthcare
Biosciences Ab), 0.4 µM of each primer, and 1.5 U of AmpliTaq polymerase (AB). The
following PCR cycles were used for amplification: 94°C for 3 minutes, 35 cycles of
94°C for 30 seconds denaturation, annealing temperature of 56°C for 30 seconds, and
72°C for 45 seconds extension. Final extension was 72°C for 5 minutes. The PCR product
was subsequently purified by Exonuclease I (10 U/µl) and SAP (Shrimp alkaline phosphatase,
2 U/µl) (ExoSAP-IT, Amersham Biosciences) according to the manufacturer's instructions.
[0083] PCR Extension was performed using a fluorescently labeled extension primer 5' GATGCTGTTTGAGCGCATCATGCTGGGCCC
3' and a nucleotide mix containing the stopping nucleotide ddCTP in place of the normal
cytosin. PCR Extensions were performed in 20-µl reaction volume containing 2 µl of
purified PCR product, Thermo Sequenase Reaction Buffer (GE Healthcare Biosciences
Ab), 50 µM of each dATP, dGTP, dTTP, and ddCTP (GE Healthcare Biosciences Ab), 0.2
µM of SNuPE primer, and 6,4 U of Thermo Sequenase DNA Polymerase (GE Healthcare Biosciences
Ab). The following PCR cycles were used for extension reactions: 95°C for 2 minutes,
25 cycles of 95°C for 20 seconds denaturation, annealing temperature of 56°C for 20
seconds, and 70°C for 40 seconds extension. Final extension was 70°C for 10 minutes.
This yielded extension products of: 43 bp and 49 bp depending on whether G or A is
present in the template. The products of the primer extension reaction were run on
the ABI3730 sequencer/genotyper and results analysed using GeneMapper v3 software
(Applied Biosystems).
c) Interpretation of LOH results
Example 2
a) NAV3 LOH analysis of colorectal tumor series
[0085] Three series (designated here A, B and C) were examined:
Series A: Consecutive series of 56 colorectal carcinomas and 21 adenomas (total no
= 77) from 59 patients. Adenomas and carcinomas arising in the same patients were
available in 10 out of the 59 cases. Judged only by the instability at the three chromosome
12 microsatellite loci examined, all of the adenomas were MSS while 14 of the 56 carcinomas
showed MSI at one or more marker(s) (25%).
Series B: Well-characterized series of familial colorectal tumors that tested negative
for mismatch repair gene germline mutations. This consisted of 18 MSS carcinomas,
1 MSI carcinoma and 4 MSS adenomas (total number = 23 tumors). This series has previously
been characterized for the common molecular changes in colorectal carcinogenesis.
Series C: Well-characterized series of MSI-colorectal cancers arising in HNPCC families
with proven MMR gene germline mutations (total number = 24 tumors).
[0086] Corresponding normal samples were mostly from normal mucosae blocks or, when these
were not available, from other normal body tissues available from the patients (eg.
lymph nodes, appendix or blood).
[0087] Microsatellite instability, MSI, refers to genome-wide length variation of microsatellites,
which are short tandem nucleotide tracts within the DNA, as a result of a failure
in DNA mismatch repair, whereas microsatellite stable, MSS, refers to constant length
of microsatellites, in other words lack of length variation of microsatellites caused
by a failure in DNA mismatch repair.
[0088] The LOH analysis was performed as described in Example 1.
[0089] The results obtained from all series examined are summarized in Table 1. Table 2
gives the results for each marker tested separately. Of special note that, using the
intragenic
NAV3 SNP rs1852464 as a strictly specific marker for LOH at
NA V3 exon 19, the available data so far shows a frequency of 7/20 (35%) for
NAV3 loss at this site in MSS tumors. These 7 tumors included 6 already implicated by
the microsatellite markers while in only one case BLOH was seen at the rs1852464 SNP
but not at the flanking microsatellite loci. Out of the 31 tumors that showed LOH/BLOH
by microsatellite markers in series A, 23 were non informative or are still pending,
leaving 8 cases for comparison with SNuPE. Of these 8 cases, 6 showed concordant
NAV3 loss at the SNP rs1852464.
Table 1. NAV3 LOH and BLOH results in different series
| |
MSS carcinoma |
MSI carcinoma |
MSS adenoma |
| Series A (n=77)* |
22/42 (52%) |
1/8 (13%)* |
8/21 (38%) |
| Series B (n=23) |
12/18 (67%) |
0/1 (0%) |
3/4 (75%) |
| Series C (n=24) |
|
5/24 (21%) |
|
| Total |
34/60 (57%) |
6/33 (18%) |
11/25 (44%) |
| * The MSI carcinoma in Series A consisted of 14 cancer of which 6 were non informative |
Table 2. NAV3 LOH and BLOH results for each marker
| |
D12S1684 |
D12S326 |
D12S1708 |
SnuPE @rs1852464 |
| A-MSS carcinoma |
14/37 |
13/33 |
7/29 |
9/23* |
| A-MSI carcinoma |
0/3 |
0/2 |
1/4 |
0/7* |
| A-MSS adenoma |
4/21 |
6/19 |
3/16 |
0/8* |
| B-MSS carcinoma |
6/13 |
6/12 |
2/10 |
4/8 |
| B-MSI carcinoma |
0/1 |
0/1 |
0/1 |
1/1 |
| B-MSS adenoma |
1/4 |
1/2 |
1/3 |
0/1 |
| C-MSI carcinoma |
3/5 |
0/6 |
2/11 |
0/15 |
| Totals: |
|
|
|
|
| All MSS carcinoma |
20/50 (40%) |
19/45 (42%) |
9/39 (23%) |
13/31 (42%) |
| All MSI carcinoma |
3/9 (33%) |
0/9 (0%) |
3/16 (19%) |
1/23 (4%) |
| All MSS adenoma |
5/25 (20%) |
7/21 (33%) |
4/19 (21%) |
0/9 (0%) |
| Total all tumors |
28/84 (33%) |
26/75 (35%) |
16/74 (22%) |
14/63 (22%) |
| * NOTE: As usual LOH frequencies were calculated for informative cases only. SNuPE
test was uninformative due to constitutional homozygosity in 9 carcinomas (8 MSS,
1 MSI) and in all 6 adenomas that showed LOH by chromosome 12 microsatellites examined.
This chance occurrence of homozygosity at the rs1852464 will make it risky to compare
the available data by microsatellites versus SNuPE. |
2b) LOH analysis of colorectal adenomas and carcinomas arising in the same patient
[0090] Adenomas and carcinomas arising in the same patients were available in 10 out of
the 59 cases in series A. The analysis was performed as described in Example 1.
[0091] In 4 of these 10 patients the adenomas showed LOH or BLOH and in 3 of these 4 cases
the matching carcinomas were informative and have mostly similar pattern of LOH/BLOH
(Table 3). This suggests that when
NAV3 LOH is observed in adenomas it is likely that such patient will develop carcinomas
through
NAV3 LOH as well.
Table 3. LOH results of adenomas and carcinomas arising in the same patient
| Case no |
Tumor |
D12S1684 |
D12S326 |
D12S1708 |
SnuPE @rs1852464 |
| 1 |
Ca |
BLOH (0.73) |
no |
no |
|
| |
Ad |
BLOH (0.67) |
no |
no |
|
| |
Ad |
ND |
BLOH (0.74) |
LOH |
|
| 2 |
Ca |
no |
LOH |
no |
|
| |
Ad |
no |
BLOH (0.68) |
no |
|
| |
Ad |
no |
LOH |
no |
|
| 3 |
Ca |
no |
no |
no |
|
| |
Ad |
no |
no |
no |
|
| |
Ad |
no |
no |
no |
|
| 4 |
Ca |
BLOH (0.75) |
homozygous |
no |
|
| |
Ad |
no |
homozygous |
no |
|
| 5 |
Ca |
MSI |
MSI |
MSI |
homozygous |
| |
Ad |
no |
no |
no |
|
| 6 |
Ca |
no |
no |
BLOH (0.66) |
|
| |
Ca |
no |
no |
BLOH (0.66) |
|
| |
Ad |
no |
no |
no |
|
| 7 |
Ca |
no |
no |
homozygous |
|
| |
Ad |
no |
no |
homozygous |
|
| 8 |
Ca |
no |
homozygous |
homozygous |
|
| |
Ad |
no |
homozygous |
homozygous |
|
| 9 |
Ca |
MSI |
MSI |
?MSI |
homozygous |
| |
Ad |
BLOH (0.73) |
no |
homozygous |
|
| 10 |
Ca |
LOH |
LOH |
LOH |
|
| |
Ad |
LOH |
LOH |
LOH |
|
2c) Morphological and histological features of colorectal tumors carrying NAV3 LOH
[0092] The occurrence of LOH in the adenomas tended to be associated to cases, which by
standard criteria were considered to be at risk to cancer development. Out of five
adenomas with LOH, the mean diameter was more than 9 mm and thus, close to the critical
level of 1 cm, while in the other five cases without LOH, the mean diameter was less
than 6 mm (Table 4). Furthermore, in the adenomas with LOH, one out of five showed
poor differentiation while the differentiation degree in the LOH negative cases was
always high.
Table 4. LOH analysis with markers D12S1684, D12S326 and D12S1708 of ten cases with
tubular adenomas of colon and rectum. Differentiation was graded from 1 (highly differentiated)
to 3 (poor differentiation). Size was given as the diameter in millimeters.
| Case |
D12S1684 |
D12S326 |
D12S1708 |
Differentiation* |
Size** |
| 1 |
Complete LOH |
LOH |
LOH |
1 |
15 |
| 2 |
No |
BLOH |
No |
2 |
10 |
| 3 |
No |
BLOH |
No |
1 |
8 |
| 4 |
BLOH |
No |
No |
1 |
7 |
| 5 |
No |
LOH |
No |
1 |
7 |
| 6 |
No |
No |
No |
1 |
7 |
| 7 |
No |
No |
No |
1 |
6 |
| 8 |
No |
Homozygous |
Homozygous |
1 |
5 |
| 9 |
No |
No |
No |
1 |
5 |
| 10 |
No |
No |
No |
1 |
5 |
* Differentiation degree 1-3
** Size in millimeters |
Example 3
NAV3 deletion in colorectal tumors detected by FISH
Samples
[0093] Samples for the FISH (fluorescence in-situ hybridization) assay were prepared from
18 randomly selected colorectal carcinoma cases from series A (described in Example
2a) and from seven cases with skin samples obtained from patients suffering from chronic
eczema, a non-malignant inflammatory lesion as a negative control. All tissue samples
had been processed by routine formalin fixation and embedded in paraffin.
Preparation of nuclei from paraffin embedded tissue
[0094] 50 µm sections were cut from formalin-fixed paraffin embedded tissue. After deparaffinization
each section was digested with protease XXIV (Sigma) at +37°C for 30 minutes. After
enzymatic digestion, nuclei were pelleted by centrifugation at 2000 g for 10 minutes
and diluted in 0.1 M Tris-HCl, 0.07 M NaCl, pH 7.2. Nuclear suspension was pipetted
on objective slides and dried over night at room temperature. The slides were fixed
with 0.01% paraformaldehyde for 4 minutes at room temperature, followed by dehydration
with graded ethanol (70%, 85%, 100%). Slides were stored at -70°C.
Labeling of probes with Fluorescein-12-dUTP and with Alexa-594-5-dUTP
[0095] Three bacterial artificial chromosome (BAC) clones specific to
NAV3 DNA (RP11-494K17, RP11-36P3 and RP11-136F16; Research Genetics Inc., Huntsville,
AL, USA) were labeled with Alexa-594-5-dUTP (Invitrogen) and the chromosome 12 centromere
probe (pA12H8) was labeled with Fluorescein-12-dUTP (Roche) using nick translation
(
Hyytinen E et al. Cytometry, 16: 93-99, 1994). For each labeling reaction 1-2 µg DNA was used in total reaction volume of 50 µl.
4 µl of each labeled BAC and centromere probes were mixed together with human COT1
DNA (Invitrogen) and precipitated with sodium acetate and ethanol. Precipitated probe
mix was diluted into hybridization buffer (15% w/v dextran sulphate, 70% formamide
in SSC, pH 7.0) and denatured at +76°C for 10 minutes.
FISH with nuclei extracted from paraffin embedded tissue
[0096] Slides were pretreated with 1 M sodium thiocyanate at +80°C for 5 minutes and washed
with 2 x SSC three times for 5 minutes. After washing slides were treated with 50%
glycerol, 0.1 x SSC at +90°C for 6 minutes, with 2 x SSC for 3 minutes and with distilled
water three times for 2 minutes. Slides were denatured in 70% formamide, 2 x SSC at
+87°C for 7 minutes. After denaturation the slides were dehydrated with graded ethanol
(70%, 85%, 100%) and digested enzymatically with proteinase K (Sigma; 8 µg/ml in 20
mM Tris-HCl, pH 7.5, 2 mM CaCl
2) at +37°C for 7 minutes. After digestion slides were dehydrated and 10 µl of denatured
probe mix was pipetted on slides. Hybridisation was carried out overnight at +37°C.
Slides were washed three times with 1.5 M Urea, 0.1 x SSC at +45°C for 10 minutes,
once with 0.1 x SSC for 10 minutes and 4 x SSC for 5 minutes, followed by three washes
with PN buffer (0.1 M sodium phosphate buffer, pH 8.0, 0.1% NP-40). Finally, slides
were rinsed with distilled water, air dried and mounted in Vectashield Mounting Medium
with DAPI (Vector).
Analysis and results
[0097] Slides were analysed using Olympus BX 50, Tokyo, Japan, equipped with filter set
8300 and tripleband exciter 83103x (Chroma Technology Corp., Brattleboro, VT, USA)
and a cooled CCD camera (Sensi Cam, PCO, Computer Optics, Kelheim, Germany) combined
to a computer (Dell GX280, Limerick, Ireland) with software Image pro Plus (Media
Cybernetics, Silver Spring, MD, USA). Fifty cells were analysed from each case and
the cells were grouped as normal if having two labels for chromosome 12 centromere
and two for the
NAV3. Polyploid cells had three or more centromere labels.
NAV3 deletion was defined when the number of centromere labels was higher than the number
of
NAV3 labels. A few cells had one centromere and one
NAV3 label; this was taken as a technical artifact. The results (Table 5) show clearly
that the samples from the colon carcinomas have a high frequency of polyploidy and
that these cells often show deletion of one or more of the
NAV3 alleles.
Table 5. Number of normal cells, polyploidy cells and cells with NAV3 deletion in samples from colorectal carsinoma patients and from inflammatory skin
lesions. Fifty cells per case were calculated.
| Sample |
Number of cells counted |
normal 2/2 cell, * |
all polyploid cells (>2 cen), ** |
cen>nav cells, *** |
1 cen 1 nav, **** |
| Case C1, colon carsinoma |
50 |
28 |
14 |
5 |
2 |
| Case C2, colon carsinoma |
50 |
31 |
6 |
11 |
3 |
| Case C3, colon carsinoma |
50 |
29 |
10 |
8 |
7 |
| Case C4, colon carsinoma |
50 |
27 |
17 |
9 |
2 |
| Case C5, colon carsinoma |
50 |
22 |
15 |
20 |
2 |
| Case C6, colon carsinoma |
50 |
19 |
18 |
7 |
5 |
| Case C7, colon carsinoma |
50 |
31 |
5 |
6 |
7 |
| Case C8, colon carsinoma |
50 |
21 |
21 |
11 |
5 |
| Case C9, colon carcinoma |
50 |
16 |
30 |
10 |
2 |
| Case C10, colon carsinoma |
50 |
18 |
16 |
16 |
7 |
| Case C11, colon carsinoma |
50 |
19 |
18 |
8 |
4 |
| Case C12, colon carsinoma |
50 |
23 |
18 |
10 |
0 |
| Case C13, colon carsinoma |
50 |
34 |
1 |
3 |
5 |
| Case C14, colon carsinoma |
50 |
19 |
18 |
8 |
4 |
| Case C15, colon carsinoma |
50 |
23 |
18 |
10 |
5 |
| Case C16, colon carsinoma |
50 |
24 |
11 |
8 |
3 |
| Case C17, colon carsinoma |
50 |
28 |
12 |
6 |
3 |
| Case C18, colon carsinoma |
50 |
24 |
14 |
12 |
3 |
| |
|
|
|
|
|
| Case S1, skin, eczema |
50 |
42 |
1 |
2 |
3 |
| Case S2, skin, eczema |
50 |
43 |
1 |
3 |
3 |
| Case S3, skin, eczema |
50 |
47 |
1 |
0 |
2 |
| Case S4, skin, eczema |
50 |
42 |
0 |
2 |
5 |
| Case S5, skin, eczema |
50 |
44 |
1 |
3 |
2 |
| Case S6, skin, eczema |
50 |
38 |
3 |
3 |
9 |
| Case S7, skin, eczema |
50 |
41 |
2 |
2 |
3 |
* = Normal number (2 and 2) of centromere and NAV3 labels per cell
** = More than 2 centromere labels per cell
*** = Number of centromere labels more than NAV3 labels per cell
**** = one centromere and one NAV3 label per cell |
Example 4
NAV3 LOH analysis of lung tumors
[0098] Archival paraffin-embedded samples of five patients with lung cancer without any
evidence of other organ involvement or other concomitant cancer were examined. Three
of the lung cancer samples were SCLC and two epidermoid carcinomas. Microdissection
and PCR amplification for the lung cancer cell samples and their corresponding normal
lung tissue samples were performed according to the following protocol.
[0099] Sections of 5-µm were cut from the samples using a microtome and mounted onto a 1,35
µm thin polyethylene membrane (P.A.L.M. Microlaser Technologies, Bemried, Germany)
attached to a glass slide. Tissue sections were then deparaffinized and stained with
hematoxylin as described before (
Stoecklein et al. Am J Pathol 161: 43-51, 2002). For morphological control hematoxylin-eosin staining was made according to standard
protocol. Areas of malignant cells covering 200000 µm
2 were laser capture microdissected using the P.A.L.M. Laser-Microbeam system (P.A.L.M.
Microlaser Technologies). Thereafter, proteinase K digestion was performed and the
DNA was amplified with SCOMP as previously described (
Klein et al. Proc Natl Acad Sci USA 96: 4494-9, 1999 and
Stoecklein et al. Am J Pathol 161: 43-51, 2002). The success of amplification was PCR-tested for microsatellite markers D5S500 and
D17S1161, as previously described (
Klein et al. Proc Natl Acad Sci USA 96: 4494-9, 1999 and
Stoecklein et al. Am J Pathol 161: 43-51, 2002).
[0100] The five lung cancer cases were analysed successfully for LOH according to the method
described in Example 1 a. Of these five lung cancers, one was uninformative for all
three markers that were used, but loss of heterozygosity was found in two of the four
other cases (Table 6).
Table 6. NAV3 LOH in lung cancers.
| Case |
D12S326 (closer to NAV3) |
D12S1708 |
D12S1684 |
| EC normal |
OK-heterozygous |
homozygous |
?? |
| EC tumor |
NO |
Homozygous |
?? |
| SCLC normal |
OK-heterozygous |
homozygous |
homozygous |
| SCLC tumor |
LOH |
?? |
?? |
| EC normal |
OK-heterozygous |
OK-heterozygous |
OK-heterozygous |
| EC tumor |
NO |
LOH |
LOH |
| SCLC normal |
Homozygous |
homozygous |
homozygous |
| SCLC tumor |
homozygous |
homozygous |
?? |
| SCLC normal |
homozygous |
OK-heterozygous |
homozygous |
| SCLC tumor |
homozygous |
NO |
homozygous |
?? means non-interpretable pattern
NO = no LOH
SCLC = small cell lung cancer
EC = epidermoid carcinoma of the lung |
Example 5
CGH-analysis of lung tumors
[0101] Lung cancer samples of twelve patients were used for CGH. These twelve patients were
also diagnosed with CTCL.
[0102] CGH was performed according to the protocol published by Klein
et al. 1999 with the modifications described by Stoecklein
et al. 2002 (
Klein et al. Proc Natl Acad Sci USA 96: 4494-9, 1999 and
Stoecklein et al. Am J Pathol 161: 43-51, 2002). Briefly, microdissected and proteinase K digested DNA was digested with Mse I restriction
enzyme (BioLabs) resulting in DNA fragments with an average length of 256 bp, adaptors
were ligated to the 5' overhangs, and DNA fragments were amplified by polymerase chain
reaction. The amplified DNA was then labeled with digoxigenin-dUTP (Roche) and similarly
processed aliquots of reference DNA obtained from peripheral blood mononuclear cells
of healthy volunteers with biotin-dUTP (Roche). The labeled probes were hybridized
on normal male metaphase slides for 2-3 nights. After posthybridization washes, metaphases
were viewed under a fluorescence microscope and three-color digital images were captured
using an epifluorescence microscope (Axioplan imagining 2, Carl Zeiss AG, Oberkochen,
Germany) equipped with a CCD camera using statistical limits for green to red ratios
to determine DNA copy number gains and losses. Eight to twelve metaphases were included
in the analysis for each case. As an internal control, normal male and female DNA
were cohybridized and only differences in sex chromosomes were identified.
[0103] In tumor cells of one lung cancer patient, loss of 12q21 was shown by CGH (Figure
4). Karyotype of the patient with SCLC and CTCL represent typical changes for SCLC:
losses of 3p, 5q, 8p, 10q, and 13q, as well as gains of 5p, and 19q. Some other typical
SCLC aberrations (17p loss, and 8q gain) are absent. Findings characteristic for CTCL
include e.g. losses of 10q/10, and 13, and gains of 4q, 7, 17q/17, and 18, which all
can be demonstrated in this case. Interestingly, loss of 12q21 was also evident.
Example 6
NAV3 deletions in urinary bladder cancer
Tissue samples
[0104] Samples from 16 patients diagnosed to have a transitional epithelial carcinoma of
the urinary bladder were selected for the study. The samples were routinely fixed
in neutral formalin and embedded in paraffin. 1-3 sections of 50 microns thickness
were cut and the nuclei were isolated as described in Example 3.
Probe labeling
[0105] Two bacterial artificial chromosome (BAC) clones specific to
NAV3 DNA (RP11-36P3 and RP11-136F16; Research Genetics Inc., Huntsville, AL, USA) were
labeled with Alexa594-5-dUTP (Invitrogen) and the chromosome 12 centromere probe (pA12H8;
American Type Cell Culture) was labeled with Alexa488-5-dUTP (Invitrogen) using nick
translation (Hyytinen et al. 1994). 50-75 ng of each labeled BAC and 30 ng of centromere
probe were mixed together with 1 µg of human COT1 DNA (Invitrogen) and precipitated
with sodium acetate and ethanol. Precipitated probe mix was diluted into 10 µl of
hybridization buffer (15% w/v dextran sulphate, 70% formamide in 2 x SSC, pH 7.0).
Fluoresence in situ hybridisation
[0106] Nuclei slides were pretreated with 1 M sodium thiocyanate at +80°C for 5 minutes
and washed with 2 x SSC three times for 5 minutes at room temperature. After washing,
slides were treated with 50% glycerol, 0.1 x SSC at +90°C for 6 minutes, with 2 x
SSC for 3 minutes and with distilled water three times for 2 minutes. Slides were
digested enzymatically with proteinase K (Sigma; 8µg/ml in 20 mM Tris-HCl, pH 7.5,
2 mM CaCl
2) at +37°C for 8 minutes. After dehydration and air drying probe mix was pipetted
on slides and slides were denatured for 6 min at +85°C on a hot plate. Hybridisation
was carried out for 48 hr at +37°C. Slides were washed three times with 1.5 M Urea,
0.1 x SSC at +47°C for 10 minutes, once with 0.1 x SSC for 10 minutes at +47°C, followed
by three washes with PBS, 0.1 % NP-40 at room temperature. Finally, slides were rinsed
with distilled water, air dried and mounted in Vectashield Mounting Medium with 4',6-diamino-2
phenylindole dihydrochloride (DAPI; Vector).
[0107] FISH results were evaluated using Olympus BX51 microscope (Tokyo, Japan) equipped
with a 60X oil immersion objective and a triple bandpass filter for simultaneous detection
of Alexa488, Alexa594 and DAPI (Chroma Technology Corp., Brattleboro, VT, USA). 200
nuclei were analysed from each case and the nuclei were grouped as normal if having
two labels for chromosome 12 centromere and two for the
NAV3. Polyploid nuclei had three or more centromere labels.
NAV3 deletion was defined when the number of centromere labels was higher than the number
of
NAV3 labels and
NAV3 amplification was defined when the number of
NAV3 labels was higher than centromere labels. The analyses were done blinded to the diagnosis
or sample identity by two independent analysers.
NAV3 LOH analysis using microsatellite markers
[0108] For LOH assay (loss of heterozygocity), DNA coming both from normal tissue of the
patient as well as from the tumor samples was extracted from the 10 µm thick paraffin
embedded sections following standard methods (
Isola et al. Am J pathol 145: 1301-1308, 1994). Analysis was performed as described in Example 1a.
Results
[0109] The results concerning the LOH (and borderline LOH; BLOH) as well as the status of
NAV3 copy number in the FISH assay are shown in Table 7. 7 out of 17 urinary bladder cancer
samples (40%) showed LOH/BLOH with at least one of the markers used in the study.
20 out of 64 (30%) alleles were homozygous and could not be analyzed using LOH method.
In FISH analysis, 3 out of 15 samples (20%) showed
NAV3 deletion.
NAV3 gene duplication (amplification) was seen with 20% of samples. One of the samples
had both
NAV3 deletion and amplification. Two samples were not analyzed for
NAV3 copy number changes due to poor quality of the sample.
Table 7. NAV3 LOH and FISH analysis results in urinary bladder cancer
| Case no |
D12S1684 |
D12S326 |
D12S1708 |
SnuPE@ rs1852464 |
NAV3 aberration (by FISH) |
| 1 |
No |
No |
No |
No |
- |
| 2 |
BLOH |
LOH |
Homozygous |
Homozygous |
deletion |
| 3 |
No |
BLOH |
No |
No |
- |
| 4 |
No |
BLOH |
No |
Homozygous |
deletion |
| 5 |
No |
No |
No |
No |
deletion and amplification |
| 6 |
BLOH |
BLOH |
No |
No |
- |
| 7 |
No |
Homozygous |
No |
Homozygous |
amplification |
| 8 |
No |
Homozygous |
Homozygous |
Homozygous |
NA |
| 9a |
No |
No |
No |
BLOH |
- |
| 9b |
No |
LOH |
No |
No |
amplification |
| 10 |
BLOH |
BLOH |
BLOH |
Homozygous |
deletion |
| 11 |
No |
No |
No |
Homozygous |
- |
| 12 |
No |
Homozvqous |
Homozygous |
Homozygous |
- |
| 13 |
Homozygous |
No |
Homozygous |
Homozygous |
- |
| 14 |
No |
No |
Homozygous |
No |
- |
| 15 |
No |
Homozygous |
Homozygous |
No |
NA |
| 16 |
No |
No |
No |
Homozygous |
amplification |
| No of postive findings |
3/17, 1 non informative |
6/17, 4 non informative |
1/17, 6 non informative |
1/17, 9 non informative |
7/15, 2 samples not analysed (NA) |
Example 7
NAV3 deletion in breast cancer
Tissue samples
[0110] We studied the occurrence of
NAV3 deletions in breast cancer by selecting sentinel lymph nodes from four patients operated
upon for breast cancer as a study material. Touch preparates were performed from freshly
obtained lymph nodes or from frozen material and stored at -70°C until used for
NAV3 FISH analysis.
Probe labeling
[0111] Two bacterial artificial chromosome (BAC) clones specific to
NAV3 DNA (RP11-36P3 and RP11-136F16; Research Genetics Inc., Huntsville, AL, USA) were
labeled with Alexa594-5-dUTP (Invitrogen) and the chromosome 12 centromere probe (pA12H8;
American Type Cell Culture) was labeled with Alexa488-5-dUTP (Invitrogen) using nick
translation (Hyytinen et al. 1994). 50-75 ng of each labeled BAC and 10 ng of centromere
probe were mixed together with 1 µg of human COT1 DNA (Invitrogen) and precipitated
with sodium acetate and ethanol. Precipitated probe mix was diluted into 10 µl of
hybridization buffer (15% w/v dextran sulphate, 70% formamide in 2 x SSC, pH 7.0).
Fluorescence in situ hybridisation
[0112] Slides were fixed with 4% paraformaldehyde in PBS for 1 minute on ice. After PBS
washes, slides were digested enzymatically with proteinase K (Sigma; 0.66 µg/ml in
20 mM Tris-HCl, pH 7.5, 2 mM CaCl
2) at +37°C for 6 minutes. After dehydration and air drying probe mix was pipetted
on slides and slides were denatured for 5 min at +75°C on a hot plate. Hybridisation
was carried out for 24 hr at +37°C. Slides were washed three times with 1.5 M Urea,
0.1 x SSC at +47°C for 10 minutes, once with 0.1 x SSC for 10 minutes at +47°C, followed
by three washes with PBS, 0.1% NP-40 at room temperature. Finally, slides were rinsed
with distilled water, air dried and mounted in Vectashield Mounting Medium with 4',6-diamino-2
phenylindole dihydrochloride (DAPI; Vector).
[0113] FISH results were evaluated using Olympus BX51 microscope (Tokyo, Japan) equipped
with a 60X oil immersion objective and a triple bandpass filter for simultaneous detection
of Alexa488, Alexa594 and DAPI (Chroma Technology Corp., Brattleboro, VT, USA). All
cancer cells found from the sample were analysed from each case and the cells were
grouped as normal if having two labels for chromosome 12 centromere and two for the
NAV3. Polyploid cells had three or more centromere labels.
NAV3 deletion was defined when the number of centromere labels was higher than the number
of
NAV3 labels and
NAV3 amplification was defined when the number of
NAV3 labels was higher than centromere labels. The analyses were done blinded to the diagnosis
or sample identity by two independent analyzers.
Results
[0114] The results are shown in table 8 and Figures 5a and 5b. Four cases were analyzed
and all cancer cells found from the samples were counted from each case. Cells were
grouped as normal if having two labels for chromosome 12 centromere and two for the
NAV3. Polyploid cells had three or more centromere labels (>2cen).
NAV3 deleted cells contained higher number of centromere labels than
NAV3 labels (cen>nav) and
NAV3 amplified cells had higher number of
NAV3 labels than centromere labels (cen<nav).
[0115] All four cases showed cells that contained abnormal copy numbers of centromeres and/or
NAV3. In addition to
NAV3 deletion (less than two copies of the
NAV3 signal in FISH), number of cells with polyploidy (more than two copies of chromosome
12 centromere) and
NAV3 amplification (more than two copies of
NAV3 signal) was analyzed and recorded. In one case (case number 2) polyploidy with less
extensive
NAV3 deletion was observed, while in the remaining three cases polyploidy was associated
with the loss of a
NAV3 allele.
[0116] In Figure 5a, black bars indicate the amount of polyploidy in studied cells and grey
bars indicate the amount of
NAV3 deleted cells. Results are shown as percentage of total cell count. In Figure 5b,
typical cancer cells show
NAV3 deletion. Green signals indicate centomeres and red signals
NAV3 copies.
Table 8. NAV3 FISH results with breast cancer samples
| Case |
1 |
2 |
3 |
4 |
| No of counted cancer cells |
20 |
69 |
52 |
55 |
| % Normal cells |
0 |
14.5 |
19 |
23.5 |
| % Polyploid cells |
100 |
84 |
77 |
74.5 |
| % NAV3 amplified cells |
10 |
6 |
0 |
2 |
| % NAV3 deleted cells |
90 |
6 |
77 |
71 |
| Primary cell type (cen+NAV3) |
4+2 |
4+4 |
4+2 |
4+2 |
[0117] It is noteworthy that while it was difficult or even impossible to find the malignant
breast cancer cells in the lymph node touch preparate using just routine light microscopy,
this task became very simple after the
NAV3 alleles were marked with the specific fluorescence probe. Even single cells, in the
middle of thousands of normal lymphocytes, could be identified with clear copy number
changes and as a rule, these cells also showed the characteristic atypical nuclei
of cancer cell. Such abnormal cells would have been extremely difficult to identify
with light microscopy.
Example 8
NAV3 copy number changes in basal cell carcinoma (BCC) and squamous cell carcinoma (SCC)
Tissue samples
[0118] Samples from 14 patients diagnosed to have a basal cell carcinoma and 5 patients
with squamous cell carcinoma were selected for the study. The samples were routinely
fixed in neutral formalin and embedded in paraffin. 1-3 sections of 50 microns thickness
were cut and the nuclei were isolated as described in Example 3.
Fluorescence in situ hybridization
[0119] Probe labeling and FISH analysis were performed as described in example 6.
Results
[0120] NAV3 FISH analysis results of BCC and SCC samples are shown in Table 9. 3 out of 14 (21
%) of the BCC samples showed
NAV3 deletion with deletion range of 6-11 % of the total cell count. In addition, three
of the samples (21 %) showed
NAV3 gene duplication (amplification range 8-11 %). One out of five (20%) of SCC samples
indicated
NAV3 deletion (12%).
Table 9. NAV3 FISH results with BCC and SCC samples
| Case |
Normal cells (% of total cell count) |
Polyploid cells (% of total cell count) |
NAV3 amplified cells (% of total cell count) |
NAV3 deleted cells (% of total cell count) |
| BCC1 |
87 |
3 |
NA |
2 |
| BCC2 |
87 |
4 |
NA |
4 |
| BCC3 |
77 |
14 |
9 |
4 |
| BCC4 |
85 |
4 |
5 |
7 |
| BCC5 |
84 |
3 |
8 |
4 |
| BCC6 |
90 |
2 |
3 |
4 |
| BCC7 |
85 |
7 |
4 |
2 |
| BCC8 |
75 |
20 |
5 |
3 |
| BCC9 |
88 |
2 |
7 |
1 |
| BCC10 |
NA |
2 |
NA |
1 |
| BCC11 |
NA |
NA |
NA |
1 |
| BCC12 |
NA |
NA |
NA |
1 |
| BCC13 |
NA |
17 |
5 |
11 |
| BCC14 |
NA |
7 |
11 |
6 |
| SCC1 |
89 |
4 |
4 |
2 |
| SCC2 |
90 |
6 |
3 |
2 |
| SCC3 |
94 |
2 |
2 |
2 |
| SCC4 |
81 |
4 |
NA |
3 |
| SCC5 |
NA |
9 |
NA |
12 |
Example 9
NAV3 copy number changes in colon cancer
Samples and NAV3 FISH analysis
[0121]
a) Two MSS-type colorectal adenocarcinoma cell lines [CCL-230 (SW403) and CCL-228
(SW480)] and two normal colon cell lines [CRL-1539 (CCD-33Co) and CRL-1541 (CCD-112CoN)]
were ordered from American Type Culture Collection (LGC Promochem AB, Boras, Sweden)
and grown at +37°C following manufacturer's instructions. 50 000-100 000 cells were
spun down onto the Super Frost Plus slide using cytocentrifuge. Slides were air-dried,
fixed with acetone and stored at -70°C until used for NAV3 FISH analysis. Probe labeling and FISH analysis were similar to breast cancer samples
in Example 7.
b) For metaphase preparations colorectal adenocarcinoma cell lines CCL-248, SW403,
SW480, RKO, DLD, HCA7, LIM1215 and LOVO (American Type Culture Collection, LGC Promochem
AB, Boras, Sweden) were grown following ATCC's instructions.
Cells were treated with hypotonic KCI-solution, fixed with acetone-methanol (1:3)
and the cell suspension was dropped on objective slides to make conventional chromosome
preparations.
Purified DNA of pA12H8 (centromere 12, plasmid from ATTC, purified as above or according
to Karenko L et al. J Invest Dermatol 108: 22-29, 1997) and purified DNA of RP11-136F16 and BAC RP11-36P3 (Karenko L et al. Cancer Res 65: 8101-8110, 2005), were labelled with nick-translation with FITC-dUTP (NEN Life Science products,
Inc, Boston, MA US), Alexa-594-dUTP (Invitrogen Molecular Probes, Leiden, Netherlands),
biotin-dATP (Gibco BRL, Gaithersburg, MD, USA) or digoxigenin-dUTP (Roche, Mannheim,
Germany). Centromere probe (e.g. 1-5 ng) labelled with FITC or biotin and one or two
BAC-probes were mixed and precipitated by adding 1/10 volume 3M sodium acetate and
2 x volume 100% ethanol, and centrifuged. The supernatant was discarded, the pellet
was allowed to dry, after which the DNA was dissolved in a mixture consisting of 50%
formamide, and 10% dextran sulphate, 2 x SSC, pH7 and optionally Cot-1 DNA (e.g. 125ng;
Gibco BRL, Gaithersburg, MD, USA), called here probe mixture. Target metaphases on
slides were denatured in for 2 to 3 minutes in 70% formamide / 2 x SSC solution (pH
7.0) at 70 to 73°C, and dehydrated in 70%, 85%, and 100% ethanol, and treated with
proteinase K (1 µg/ml, Sigma Chemical Co, St Louis, MO, USA) in 20 mM Tris/2mM CaCl2 (pH 7.5) buffer for 7.5 minutes at 37°C, and dehydrated as above. The probe mixture
was denatured for 5 minutes in 70°C, and applied to pretreated slides on a warm plate
(37°C), sealed under a coverslip with Rubber Cement (Starkey Chemical Co, LaGrange
IL USA) and allowed to hybridize in a humid chamber (37°C) for 2 to 3 days. The slides
were washed 3 times with 50% formamide in 2 x SSC, pH 7, 4 x SSC, and 0.1 x SSC, all
at 45°C, and with 4 x SSC, 2 x SSC and PBS at room temperature. After the posthybridization
washes, the biotinylated probe was visualised with avidin-FITC (green, Vector Laboratories,
Burlingame, CA, USA) and the digoxigenin labeled probe was visualised with anti-digoxigenin
antibody made in sheep conjugated with rhodamine (red, Roche, Mannheim, Germany).
The slides were counterstained with DAPI and mounted in Vectashield (bothVector Laboratories,
Burlingame, CA, USA).
The air-dried preparations were fixed with 0.1% paraformaldehyde and dried in ethanol
series (70%, 85%, 100%).
The metaphases were photographed with UV-microscope (Axioplan imagining 2, Zeiss,
Germany) and analysed using the computer program Isis of MetaSystems GmbH with MFISH-program
module.
c) Samples from 36 patients diagnosed to have a MSS-type of colorectal adenocarcinoma,
14 patients with MSI-type of colorectal adenoma and 19 patients with adenoma tubulare
were selected for the study. In addition, 58 normal colon mucosa samples were included
in the study as a reference material. The samples were routinely fixed in neutral
formalin and embedded in paraffin. 1-3 sections of 50 microns thickness were cut and
the nuclei were isolated as described in Example 3. NAV3 specific FISH assay was performed as described in Example 6.
Results
[0122] a) FISH analysis results of interphase cells of colon cancer cell lines (SW 403 and
SW480) are shown in table 10. Both cancer cell lines showed dominating 3 centromeres
2 NAV3 -type of deletion in almost all of the cells studied. Normal colon cell lines
did not show any
NAV3 gene copy number changes.
Table 10. NAV3 FISH results with colon cancer cell lines
| Cell line |
Normal cells (2cen2NAV3) (% of cells studied) |
Polyploid cells (cen>2) (% of cells studied) |
NAV3 deleted cells (cen>NAV3) (% of cells studied) |
| SW403 |
5 |
95 |
92 |
| SW480 |
4 |
96 |
92 |
b) FISH analysis results of metaphase cells of colon cancer cell lines (CCL-248, SW
403, SW480, RKO, DLD, HCA7, LIM1215 and LOVO) are shown in table 11.
NAV3 deletion was detected in a great majority of metaphase cells in two MSS cell lines
(CCL-248, SW 403). Also MSI cell line RKO showed plenty of
NAV3 deletions. Plenty of
NAV3 amplifications were detected in cell line DLD (MSI). Also line SW480 (MSS) showed
more centromere signals than
NAV3 signals. Some
NA V3 deletions were detected in cell line HCA7.
Table 11. NAV3 FISH results of metaphase cells with colon cancer cell lines
| Cell line |
Type |
Probe |
NAV3 deleted cells (cen>NAV3) (% of cells studied) |
NAV3 amplified cells (cen<NAV3) (% of cells studied) |
| CCL-248 |
MSS |
36P3 |
9/10 (90%) |
0/10 (0%) |
| SW 403 |
MSS |
36P3 |
6/7 (86%) |
0/7 (0%) |
| SW480 |
MSS |
36P3 |
2/10 (20%) |
2/10 (20%) |
| RKO |
MSI |
136F16 |
12/29 (41%) |
0/29 (0%) |
| |
|
36P3 |
6/14 (43%) |
0/14 (0%) |
| |
|
both |
3/7 (43%) |
0/7 (0%) |
| DLD |
MSI |
136F16 |
0/8 (0%) |
8/8 (100%) |
| |
|
36P3 |
0/8 (0%) |
8/8 (100%) |
| |
|
both |
0/2 (0%) |
2/2 (100%) |
| HCA7 |
MSI |
136F16 |
2/10 (20%) |
0/10 (0%) |
| |
|
36P3 |
0/6 (0%) |
0/6 (0%) |
| |
|
both |
0/13 (0%) |
0/13 (0%) |
| LIM1215 |
MSI |
136F16 |
0/2 (0%) |
0/2 (0%) |
| |
|
36P3 |
0/10 (0%) |
0/10 (0%) |
| |
|
both |
0/15 (0%) |
0/15 (0%) |
| LOVO |
MSI |
both |
0/1 (0%) |
0/1 (0%) |
c) NAV3 FISH assay with nuclei extracted from paraffin embedded patient samples indicated
NAV3 copy number changes in 31% of MSS-type colorectal adenocarcinoma samples, 7%
of MSI-type of colorectal adenocarcinoma (1 sample out of 14) and in 16% of adenoma
tubulare samples. Results are shown in table 12. Figure 6 shows comparison of
NAV3 FISH results from normal colon samples and MSS-type of colorectal adenocarcinoma.
Cancer cells are different from normal colon mucosal cells in terms of polyploidy
and
NAV3 copy number.
Table 12. NAV3 FISH analysis results using different colon samples. In each sample, 200 cells were
analyzed. NAV3 deleted cells contain higher number of centromere labels than NAV3 labels and NAV3 amplified cells higher number of NAV3 labels than centromere labels.
| Colon sample |
Samples with aberrant NAV3 |
Deletion range (% of cells studied) |
Amplification range (% of cells studied) |
| CRC, MSS |
11/36 |
5-41 |
8-28 |
| CRC, MSI |
1/14 |
7.5 |
- |
| Adenoma tubulare |
3/19 |
7-11 |
8 |
| Normal colon |
0/58 |
- |
- |