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Schematic representation of chromosome 16q deletion in HCC cases presenting partial, interstitial LOH and putative homozygous deletions. Markers are shown from centromer (on the left) to the telomere according to the Genethon genetic map. Each vertical line represents a tumor sample. Black, white and gray circles represent LOH, retention of heterozygosity and nonpolymorphic genotyping results, respectively. The critical region de®ned by genotyping is indicated on the left side
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Loss of heterozygosity (LOH) represents the most frequent genetic alteration observed in hepatocellular carcinoma (HCC). Chromosome 16q is of particular interest as it exhibits LOH in 29% of HCC tumors and is frequently lost in breast, prostate, ovarian and gastric carcinomas. We genotyped 157 HCC tumors for 17 microsatellite markers distributed on...
Contexts in source publication
Context 1
... contrast, deletion of 16q was partial in two cases (CHC040 and CHCC050), encompassing the telomeric part of the chromosome. In two additional cases, CHC162 and CHC092, the deletion was interstitial (Figure 1). Data collected from these 43 heterozygous deletions pointed to a common region of deletion located within a 6 cM interval, bounded by D16S518 and D16S504. ...
Context 2
... panel of 17 polymorphic microsatellite markers distributed on chromosome 16q was selected from the LMS2 panel (Perkin-Elmer) and from the Genethon database ( Figure 1). PCR ampli®cations were performed using primers described in the Genethon database and following the ampli®cation procedure described in Bluteau et al. (1999). ...
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Using 21 microsatellite polymorphic markers spanning both p and q arms, we have performed detailed deletion mapping on chromosome 9 in 18 primary nasopharyngeal carcinomas. All 18 tumors were informative at multiple loci. Eleven of the 18 cases (61%) demonstrated allelic deletion of chromosome 9. Among these 11, 6 cases are likely to be tumors with...
Loss of heterozygosity studies have been used to identify chromosomal regions which are frequently deleted and thus indicate areas which may harbor tumor suppressor genes. As a result, both the WT1 gene located in chromosome 11p13 and an unidentified gene(s) within chromosome 11p15 have been implicated in Wilms' tumorigenesis. Cytogenetic and linka...
Loss of heterozygosity at chromosome arm 16q is a frequent event in human prostate cancer. In this study, loss of heterozygosity at 16q was studied in 44 prostate cancer patients exhibiting various clinical features. Fifteen polymorphic polymerase chain reaction (PCR) markers were used to identify the separately deleted areas and the findings were...
Citations
... WW domain-containing oxidoreducatase (WWOX) gene resides in one of the most common fragile sites known as FRA16D, a region that is altered in many types of cancer [3][4][5] . Frequent homozygous deletions were reported at this region in aflatoxin B1 exposed HCC 6 , suggesting that it might harbor a tumor suppressor. In particular, WWOX expression is absent or reduced in most of the derived liver cancer cell lines 7 . ...
... Several studies have suggested that the WWOX gene functions as a tumor suppressor in liver cancer 3,4,7 . Early evidence has revealed the existence of frequent homozygous deletions at chromosome 16q23, where WWOX resides, in aflatoxin B1 exposed HCC 6 . In another study, expression of both WWOX and FHIT, another tumor suppressor located in a fragile site, appeared to be correlated and downregulated in liver tissues in a carcinogen-specific manner 49 . ...
... Our findings also suggest that WWOX loss is an important contributor for HCC promotion as earlier hits are required for HCC initiation. WWOX expression could be altered by environmental cues 6,49 or in consequence of microRNA dysregulation 15 or even as a result of genetic variations in WWOX 50 . If these alterations were combined with western HFD then our findings indicate that HCC risk increases. ...
Liver cancer is one of the most lethal malignancies with very poor prognosis once diagnosed. The most common form of liver cancer is hepatocellular carcinoma (HCC). The WW domain-containing oxidoreductase (WWOX) is a large gene that is often perturbed in a wide variety of tumors, including HCC. WWOX has been shown to act as a tumor suppressor modulating cellular metabolism via regulating hypoxia-inducible factor 1α (HIF-1α) levels and function. Given that WWOX is commonly inactivated in HCC, we set to determine whether specific targeted deletion of murine Wwox affects liver biology and HCC development. WWOX liver-specific knockout mice (WwoxΔHep) showed more potent liver regeneration potential and enhanced proliferation as compared with their control littermates. Moreover, WWOX deficiency in hepatocytes combined with diethylnitrosamine treatment increased the tumor burden, which was associated with increased HIF1α levels and target gene transactivation. Inhibition of HIF1α by systemic treatment with digoxin significantly delayed HCC formation. Our work suggests that WWOX inactivation has a central role in promoting HCC through rewiring of cellular metabolism and modulating proliferation.
... Loss of chromosome 16q, and particularly 16q23 has been reported in different cancers [132][133][134]. In melanoma, different studies have shown loss of chro-mosome16q [6,135]. ...
Background:
Skin melanocytes can give rise to benign and malignant neoplasms. Discrimination of an early melanoma from an unusual/atypical benign nevus can represent a significant challenge. However, previous studies have shown that in contrast to benign nevi, melanoma demonstrates pervasive chromosomal aberrations.
Objective:
This substantial difference between melanoma and benign nevi can be exploited to discriminate between melanoma and benign nevi.
Methods:
Array-comparative genomic hybridization (aCGH) is an approach that can be used on DNA extracted from formalin-fixed paraffin-embedded (FFPE) tissues to assess the entire genome for the presence of changes in DNA copy number. In this study, high resolution, genome-wide single-nucleotide polymorphism (SNP) arrays were utilized to perform comprehensive and detailed analyses of recurrent copy number aberrations in 41 melanoma samples in comparison with 21 benign nevi.
Results:
We found statistically significant copy number gains and losses within melanoma samples. Some of the identified aberrations are previously implicated in melanoma. Moreover, novel regions of copy number alterations were identified, revealing new candidate genes potentially involved in melanoma pathogenesis.
Conclusions:
Taken together, these findings can help improve melanoma diagnosis and introduce novel melanoma therapeutic targets.
... On the other hand, the fixation process used for the FFPE tissues could cause DNA fragmentation, damage or fusion, thus leading to a false-negative result. Additionally, considering that loss of chromosome frequently occurred in many cancers can result in genomic chromosomal instability [14][15][16], it implies that the loss of the reference gene loci in the tumor may cause a false-positive elevated ratio of MET:AP3B1 in ddPCR, rather than high MET copy number. ...
Purpose:
The analysis of MET gene copy number (CN) has been considered to be a potential biomarker to predict the response to MET-targeted therapies in various cancers. However, the current standard methods to determine MET CN are SNP 6.0 in the genomic DNA of cancer cell lines and fluorescence in situ hybridization (FISH) in tumor models, respectively, which are costly and require advanced technical skills and result in relatively subjective judgments. Therefore, we employed a novel method, droplet digital PCR (ddPCR), to determine the MET gene copy number with high accuracy and precision.
Methods:
The genomic DNA of cancer cell lines or tumor models were tested and compared with the MET gene CN and MET/CEN-7 ratio determined by SNP 6.0 and FISH, respectively.
Results:
In cell lines, the linear association of the MET CN detected by ddPCR and SNP 6.0 is strong (Pearson correlation = 0.867). In tumor models, the MET CN detected by ddPCR was significantly different between the MET gene amplification and non-amplification groups according to FISH (mean: 15.4 vs 2.1; P = 0.044). Given that MET gene amplification is defined as MET CN >5.5 by ddPCR, the concordance rate between ddPCR and FISH was 98.0%, and Cohen's kappa coefficient was 0.760 (95% CI, 0.498-1.000; P <0.001).
Conclusions:
The results demonstrated that the ddPCR method has the potential to quantify the MET gene copy number with high precision and accuracy as compared with the results from SNP 6.0 and FISH in cancer cell lines and tumor samples, respectively.
... The fluorescence intensities of signals in blood leukocytes decreased after AFB1 treatment in the most cases, indicating deletions in 8p21.2 and 15q11.2. Earlier in AFB1-exposed hepatocellular carcinoma's cases homozygous deletions at different loci were reported [33] including chromosome regions 8p23 and 15q25-26 adjacent to the areas studied in our work [34][35][36]. ...
Aflatoxin B1 (AFB1) is a mycotoxin produced by Aspergillus spec. The latter are worldwide contaminants of food with mutagenic and carcinogenic activities in animals and humans. AFB1 was shown to have deleterious effects on metabolism of eukaryotes in many model systems, including the ability to inhibit DNA replication. An agent that disturbs DNA replication may also have the potential to induce de novo DNA copy number variations (CNVs).
Blood samples of three clinically healthy carriers were treated in vitro with AFB1 and chromosome preparations were subjected to parental origin determination fluorescence in situ hybridization (pod-FISH). Probes able to visualize CNVs in 8p21.2 and 15q11.2 were applied. In this setting here for the first time an influence of AFB1 on molecular-cytogenetically detectable CNVs could be shown.
The obtained results indicate that: (i) pod-FISH is a single cell directed, sensitive and suitable method for the analysis of mutagen induced CNVs, (ii) AFB1 has the potential to induce in vitro instability of known CNVs in human leukocytes.
... One recently described polymorphism of the WWOX gene is based on the transversion of a cytosine to a guanine at base position 844 in the coding sequence. 102,103 Additionally, chromatin was found to exert an influence on WWOX expression by histone methylation and acetylation. The K562 cell line, characterized by almost undetectable level of WWOX mRNA, was grown in medium supplemented with inhibitors of methylation and deacetylation, resulting in an elevated number of aberrant and wild-type WWOX transcripts being observed. ...
WWOX gene is located in FRA16D, the highly affected chromosomal fragile site. Its tumor suppressor activity has been proposed on a basis of numerous genomic alterations reported in chromosome 16q23.3-24.1 locus. WWOX is affected in many cancers, showing as high as 80% loss of heterozygosity in breast tumors. Unlike most tumor suppressors impairing of both alleles of WWOX is very rare. Despite cellular and animal models information on a WWOX role in cancer tissue is limited and sometimes confusing. This review summarizes information on WWOX in human tumors.
© 2015 by the Society for Experimental Biology and Medicine.
... Many studies suggested that the risk factors related to liver cancer are alcohol abuse, smoking, exposure to aflatoxins, sex, ethnicity, as well as infection by hepatitis B (HBV) and C viruses (HCV) [11][12][13]. Whereas heavy alcohol intake is the main cause of cirrhosis, long-term exposure to aflatoxins and HBV and/or HCV infection increase the frequency of liver cancer development and HCC [14][15][16][17]. For further reading on the epidemiology of liver cancer see [13,18,19]. ...
The liver acts as a hub for metabolic reactions to keep a homeostatic balance during development and growth. The process of liver cancer development, although poorly understood, is related to different etiologic factors like toxins, alcohol, or viral infection. At the molecular level, liver cancer is characterized by a disruption of cell cycle regulation through many molecular mechanisms. In this review, we focus on the mechanisms underlying the lack of regulation of the cell cycle during liver cancer, focusing mainly on hepatocellular carcinoma (HCC). We also provide a brief summary of novel therapies connected to cell cycle regulation.
... Whenever available, whole blood or buffy coat from the same patients was used as a normal control. PC3, DU145, and LNCaP cells were obtained from American Type Culture Collection Inc. (Manassas, VA) in 2000, 2001 , and 2007, respectively . The genomes of these cell lines were tested for short tandem repeat DNA profiling on eight different loci (CSF1PO, D13S317, D16S539, D5S818, D7S820, THO1, TPOX, and vWA) of the genomes by PCR using the following sets of primers: CSF1PO, 5=-AACCTGAGTCTGCCAAGGAC- TAGC-3= and 5=-TTCCACACACCACTGGCCATCTTC-3=; D13S317, 5=-ACAGAAGTCTGGGATGTGGA-3= and 5=-GCC- CAAAAAGACAGACAGAA-3=; D16S539, 5=-GATCCCAA- GCTCTTCCTCTT-3= and 5=-ACGTTTGTGTGTGCATCTGT-3=; D5S818, 5=-GGGTGATTTTCCTCTTTGGT-3= and 5=-TGATTC- CAATCATAGCCACA-3=; D7S820, 5=-TGTCATAGTTTAGA- ACGAACTAACG-3= and 5=-CTGAGGTATCAAAAACTCA- GAGG-3=; TH01, 5=-GTGGGCTGAAAAGCTCCCGATTAT-3= and 5=-ATTCAAAGGGTATCTGGGCTCTGG-3=; TPOX, 5=- ACTGGCACAGAACAGGCACTTAGG-3= and 5=-GGAGGA- ACTGGGAACCACACAGGT-3=; and vWA, 5=-CCCTAGTG- GATGATAAGAATAATCAGTATG-3= and 5=-GGACAGAT- GATAAATACATAGGATGGATGG-3=. These cell lines were authenticated because the short tandem repeat profiles of the cell lines have a perfect match with those published by American Type Culture Collection Inc. ...
The prediction of prostate cancer clinical outcome remains a major challenge after the diagnosis, even with improved early detection by prostate-specific antigen (PSA) monitoring. To evaluate whether copy number variation (CNV) of the genomes in prostate cancer tumor, in benign prostate tissues adjacent to the tumor (AT), and in the blood of patients with prostate cancer predicts biochemical (PSA) relapse and the kinetics of relapse, 241 samples (104 tumor, 49 matched AT, 85 matched blood, and 3 cell lines) were analyzed using Affymetrix SNP 6.0 chips. By using gene-specific CNV from tumor, the genome model correctly predicted 73% (receiver operating characteristic P = 0.003) cases for relapse and 75% (P < 0.001) cases for short PSA doubling time (PSADT, <4 months). The gene-specific CNV model from AT correctly predicted 67% (P = 0.041) cases for relapse and 77% (P = 0.015) cases for short PSADT. By using median-sized CNV from blood, the genome model correctly predicted 81% (P < 0.001) cases for relapse and 69% (P = 0.001) cases for short PSADT. By using median-sized CNV from tumor, the genome model correctly predicted 75% (P < 0.001) cases for relapse and 80% (P < 0.001) cases for short PSADT. For the first time, our analysis indicates that genomic abnormalities in either benign or malignant tissues are predictive of the clinical outcome of a malignancy.
... In our analysis of 16q23.3-24.1 region we did not find any evidence for LOH in the two studied WWOXassociated loci in CRC. We used two STS (sequence-tagged site) markers (D16S3096 and D16S518) which are most often afflicted by hemizygous deletions in all kinds of cancers, for instance: breast ductal carcinoma in situ lesions [16], breast cancer metastases [25], hepatocellular carcinoma [26], non-small cell lung cancer [27], oesophageal squamous cell carcinoma [28], gastric carcinoma [29], but none of the STS markers displayed LOH in our set of colorectal cancer samples. We also tested the status of methylation in the promoter region of WWOX gene, presumably resulting in lowered WWOX expression, which was shown in several studies [11,22]. ...
The WWOX gene is a tumour suppressor gene affected in various types of malignancies. Numerous studies showed either loss or reduction of the WWOX expression in variety of tumours, including breast, ovary, liver, stomach and pancreas. Recent study demonstrated that breast cancer patients exhibiting higher WWOX expression showed significantly longer disease-free survival in contrast to the group with lower relative WWOX level. This work was undertaken to show whether similar phenomena take place in colon tumours and cell lines. To assess the correlation of WWOX gene expression with prognosis and cancer recurrence in 99 colorectal cancer patients, we performed qRT-PCR analysis. We also performed analysis of WWOX promoter methylation status using MethylScreen method and analysis of loss of heterozygosity (LOH) status at two WWOX-related loci, previously shown to be frequently deleted in various types of tumours. A significantly better disease-free survival was observed among patients with tumours exhibiting high level of WWOX (hazard ratio = 0.39; p = 0.0452; Mantel-Cox log-rank test), but in multivariate analysis it was not an independent prognostic factor. We also found that although in colorectal cancer WWOX expression varies among patients and correlates with DFS, the exact mode of decrease in this type of tumour was not found. We failed to find the evidence of LOH in WWOX region, or hypermethylation in promoter regions of this gene. Although we provide the evidence for tumour-suppressive role of WWOX gene expression in colon, we were unable to identify the molecular mechanism responsible for this.
... However, loss of heterozygosity on chromosome 16q at the fragile site FRA16D was found in 29% of HCC and an association between 16q lack and R249S mutation affecting the p53 gene was determined in HCC samples from patients exposed to aflatoxin B1 [160] . Decreased or absent expression of WWOX was observed in cell lines derived from human HCCs [161] . WWOX protein is able to interact with other proteins, in particular with p73 protein [162,163] . ...
A few signaling pathways are driving the growth of hepatocellular carcinoma. Each of these pathways possesses negative regulators. These enzymes, which normally suppress unchecked cell proliferation, are circumvented in the oncogenic process, either the over-activity of oncogenes is sufficient to annihilate the activity of tumor suppressors or tumor suppressors have been rendered ineffective. The loss of several key tumor suppressors has been described in hepatocellular carcinoma. Here, we systematically review the evidence implicating tumor suppressors in the development of hepatocellular carcinoma.
... Briefly, high incidence of LOH is demonstrated in primary tumors, including carcinomas from liver (28.7%) [44], breast (81.8%) [45], esophagus [squamous cell carcinoma (SCC), 38.9%] [46], lung (non-small cell lung cancer, 37%) [47], pancreas (26.7%) [48] and stomach (30.8%) [49]. Homozygous deletion of the WWOX gene in primary tumors is rare. ...
... In one esophageal SCC, T!C transition at the second nucleotide of codon 291 causes leucine to proline substitution [46]. However, genetic polymorphisms for the WWOX gene are frequently shown in normal and clinical samples [44,[47][48][49]51]. ...
... Environmental factors contribute to genetic alterations [25,41,52,53]. Aflatoxin B1 [44], UV-light exposure and tobacco smoking [50] have been implicated in the alterations of WWOX gene in the carcinogenesis of hepatocellular carcinoma and oral SCC. mRNA alternative splicing causes codon deletions at the SDR domain (Box 1). Aberrant WWOX transcripts have been noted in breast cancer (32-55%) [22,45,54], ovarian tumors [55], esophageal SCC (5.6%) [46], oral SCC (35%) [50], lung cancer (26%) [47], hematopoietic neoplasia (12%) [51], pancreatic adenocarcinoma (6.7%) [48], gastric carcinoma (12%) [49] and non-small cell lung cancer (63.6%) [56]. ...
Common fragile site gene WWOX encodes a candidate tumor suppressor WW domain-containing oxidoreductase. Alteration of this gene, along with dramatic downregulation of WWOX protein, is shown in the majority of invasive cancer cells. Ectopic WWOX exhibits proapoptotic and tumor inhibitory functions in vitro and in vivo, probably interacting with growth regulatory proteins p53, p73 and others. Hyaluronidases regulate WWOX expression, increase cancer invasiveness and seem to be involved in the development of hormone-independent growth of invasive cancer cells. Estrogen and androgen stimulate phosphorylation and nuclear translocation of WWOX, although binding of WWOX to these sex hormones is unknown. We propose that suppression of WWOX expression by overexpressed hyaluronidases might contribute in part to the development of hormone independence in invasive cancer.
