Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0677930 (primary tumor)
 20,210 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Germline mutations in the BRCA1 and BRCA2 genes confer a high lifetime risk of developing breast and other cancers; however, remarkable differences exist regarding disease manifestation in mutation carriers. It has been suggested that other genetic and/or environmental factors modify not only the appearance but also the age of onset and type of tumor in BRCA1/2-associated cases. The aim of the present study was to investigate the role of two p53 polymorphisms (c.97-147ins16bp and c.215c>g, p.Arg72Pro) as potential modifiers. For this purpose we investigated the possible association between the two polymorphisms and disease status in 447 BRCA1/2 mutation carriers belonging to 170 Spanish breast and/or ovarian cancer families. Genotype and haplotype analyses revealed that the presence of a specific haplotype carrying the allele without the 16-bp insertion and the variant allele for the Arg72Pro (No Ins-72Pro haplotype) was associated with an earlier age of onset in BRCA2 mutation carriers. We found an increased risk of developing a first primary tumor (breast or ovarian) before 35 years of age for individuals who carried at least one No Ins-72Pro haplotype (OR: 2.69; 95% CI: 1.15-6.29; P=0.022). We confirmed these data by a functional study in which we compared different p53 genotypes in relation to their apoptotic response after cell treatment with a cytotoxic drug (AraC). Our results revealed a decrease in p53 apoptotic rate associated with the No Ins-72Pro haplotype.
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PMID:A haplotype containing the p53 polymorphisms Ins16bp and Arg72Pro modifies cancer risk in BRCA2 mutation carriers. 1641 81

The clinical value of prostate-specific antigen (PSA)-positive circulating tumor cells (CTCs) is still a matter of debate and it is also still unclear if these CTCs actually represent the primary tumor. Therefore, we isolated PSA-positive CTCs from the peripheral blood of patients suffering from multifocal cancers and did genetic profiling of each cancer focus by a multiplex PCR-based microsatellite analysis (D7S522, D8S522, NEFL, D10S541, D13S153, D16S400, D16S402, D16S422, and D17S855). In 17 of 20 prostate cancer cases, the loss of heterozygosity (LOH) pattern of the CTCs was identical with only one focus of the primary tumor. Moreover, in six cases, the LOH pattern suggested that smaller foci, down to 0.2 cm3, might deliver CTCs. Interestingly, the highest number of LOHs was observed at the marker D10S541 (85%), the PTEN gene, which was observed much less frequently in unifocal prostate cancer (48%). Furthermore, the infrequently occurring LOH in the BRCA1 gene (38%) was found in four of the five cases where a biochemical recurrence was seen within 3 years after prostatectomy. Therefore, the data might support the assumption that CTCs in prostate cancer are derived from distinct foci of a primary tumor. The size of the tumor focus is not related to the delivery of cells. Although the number of cases that were investigated in this study was small, it might be suggested that the LOH at distinct markers such as D10S541 and D17S855 represent the genes PTEN and BRCA1, which might be associated with the occurrence of CTCs in the peripheral blood of patients as well as an early biochemical recurrence.
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PMID:Asynchronous growth of prostate cancer is reflected by circulating tumor cells delivered from distinct, even small foci, harboring loss of heterozygosity of the PTEN gene. 1698 34

The question of whether p73 is a tumor suppressor gene, is not yet answered with full confidence. The lack of spontaneous tumor formation in p73 null mice and infrequent p73 mutations seen in a variety of cancers analyzed would straightaway negate its role as a primary tumor suppressor gene. However, accumulating evidence suggest that p73 gene and its target genes are hypermethylated in the cancer of lymphoid origin. Here I discuss some facts and thoughts that support the idea that p73 could still be a tumor suppressor gene. The tumor suppressor network in which p73 appears to be a participant involves E2F1, JunB, INK4a/p16, ARF/p19, p57kip2 and BRCA1. Knock out of each gene in E2F-1-p73-JunB-p16INK4a network of tumor suppressor proteins result in lymphoma/leukemia formation. Further, I tried to explain why lymphomas are not seen in p73 null mice and why p73 gene is not prone to frequent mutation.
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PMID:Some facts and thoughts: p73 as a tumor suppressor gene in the network of tumor suppressors. 1740 86

We assessed molecular markers such as BRCA1, K-ras, p53, Bcl-2, Bcl-XL, Survivin and telomerase activity in untreated ovarian cancer tissue samples, ascitic cells and normal ovarian tissues and gathered insights into their correlation with each other and also with apoptotic index. The expression of these proteins was analyzed by Western blotting and immunohistochemistry. Apoptotic index was determined by TUNEL assay and telomerase activity was measured by PCR-ELISA kit. p53, Bcl-2, Bcl-XL, K-ras and Survivin were found to be over expressed in tumors and ascitic cells as compared to normal controls whereas there was no significant difference in expression of BRCA1. A significantly higher telomerase activity and lower apoptotic index in tumors as compared to controls was observed. p53 positively correlated with Bcl-2, Bcl-XL, K-ras and Survivin expression and also clinical stage of the disease. A positive correlation between Survivin and Bcl-2, Bcl-XL was seen. Apoptotic Index, telomerase activity and BRCA1 expression showed no correlation with any of the parameters. Our study confirms the fact that multiple gene interactions govern the pathogenesis of ovarian cancer, and analyzing ascitic cells of ovarian cancer patients may help to delineate molecular profile of the primary tumor.
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PMID:Role of apoptotic regulators in human epithelial ovarian cancer. 1761 99

Although ovarian carcinomas with mutated BRCA1 or BRCA2 are sensitive to platinum compounds, such carcinomas eventually develop platinum resistance. Previously, we showed that acquired resistance to cisplatin in BRCA2-mutated tumors can be mediated by secondary intragenic mutations in BRCA2 that restore the wild-type BRCA2 reading frame. Here, we show that secondary mutations of BRCA1 also occur in BRCA1-mutated ovarian cancer with platinum resistance. We evaluated nine recurrent BRCA1-mutated ovarian cancers previously treated with platinum compounds, including five with acquired platinum resistance, one with primary platinum resistance, and three with platinum sensitivity. Four of the six recurrent platinum-resistant tumors had developed secondary genetic changes in BRCA1 that restored the reading frame of the BRCA1 protein, whereas none of the three platinum-sensitive recurrent tumors developed BRCA1 sequence alterations. We immunohistochemically confirmed restored expression of BRCA1 protein in two cases with secondary mutations. Intriguingly, the case with primary platinum resistance showed back mutation of BRCA1 in the primary tumor and showed another secondary mutation in the recurrent tumor. Our results suggest that secondary mutations in BRCA1 can mediate resistance to platinum in BRCA1-mutated ovarian tumors.
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PMID:Secondary BRCA1 mutations in BRCA1-mutated ovarian carcinomas with platinum resistance. 1841 25

The existence of several model systems with which to investigate a particular disease is advantageous for researchers. This is especially true for ovarian cancer, which, due to its complex and heterogeneous nature, inherently requires a large number of model systems. Here, we report a new ovarian serous adenocarcinoma cell line, designated YDOV-157, and characterized via post genomics and post proteomics. In this study, primary culture of tumor cells from ascites was performed and the cells were immortalized up to at least 60 passages in vitro. We studied the morphologies, cell proliferation, BRCA1/2 mutations, tumorigenesis capacity, and chemosensitivity of YDOV-157. Using a cDNA microarray, differentially expressed genes were identified and some of them were validated. Using proteomic analysis, we identified proteins that were differentially expressed in YDOV-157. The newly derived cell line, designated YDOV-157, grew as a monolayer and the doubling time was 102 h. When transplanted into nude mice, it initiated the formation of tumor masses with microscopic findings identical to those of the primary tumor. Chemosensitivity test showed that paclitaxel induced the highest chemosensitivity index. In microarray analysis, 2,520 probes were differently expressed, compared to human ovarian surface epithelial cells (HOSEs). In SYBR Green real-time PCR, the expression of E2F2 (P = 0.040) and CRABP2 genes (P = 0.030) was significantly higher in the ovarian cancer cell lines than in HOSEs. Furthermore, proteomic analysis showed that expression of 28 spots was significantly altered between YDOV-157 and HOSE. In conclusion, the newly derived YDOV-157 cell line may be an important research resource for studying cancer cell biology and should also be very useful for developing new strategies that inhibit cancer cell growth and progression.
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PMID:Genomic and proteomic characterization of YDOV-157, a newly established human epithelial ovarian cancer cell line. 1868 96

The role of polarity signaling in cancer metastasis is ill defined. Using two three-dimensional culture models of mammary epithelial cells and an orthotopic mouse model of breast cancer, we reveal that Par6 signaling, which is regulated directly by TGFbeta, plays a role in breast cancer metastasis. Interference with Par6 signaling blocked TGFbeta-dependent loss of polarity in acini-like structures formed by non-transformed mammary cells grown in three-dimensional structures and suppressed the protrusive morphology of mesenchymal-like invasive mammary tumor cells without rescuing E-cadherin expression. Moreover, blockade of Par6 signaling in an in vivo orthotopic model of metastatic breast cancer induced the formation of ZO-1-positive epithelium-like structures in the primary tumor and suppressed metastasis to the lungs. Analysis of the pathway in tissue microarrays of human breast tumors further revealed that Par6 activation correlated with markers of the basal carcinoma subtype in BRCA1-associated tumors. These studies thus reveal a key role for polarity signaling and the control of morphologic transformation in breast cancer metastasis.
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PMID:A role for the TGFbeta-Par6 polarity pathway in breast cancer progression. 1966 98

Women with BRCA1 and BRCA2 mutations have an elevated risk of breast cancer and ovarian cancer, but also of developing second primary breast cancer. BRCA1/2 mutation carriers with breast cancer must choose between breast conservation (BCT) and mastectomy (M) yet data on outcomes are limited. The purpose of this study is to compare long-term outcome following BCT and M in BRCA1/2 carriers. 655 women with BRCA1/2 mutations diagnosed with breast cancer and treated with BCT (n = 302) or M (n = 353) were identified and underwent follow-up to assess local, regional, and systemic recurrence. Local failure as first failure was significantly more likely in those treated with BCT compared to M, with a cumulative estimated risk of 23.5 vs. 5.5%, respectively, at 15 years (P < 0.0001); 15-year estimates in carriers treated with BCT and chemotherapy was 11.9% (P = 0.08 when compared to M). Most events appeared to be second primary cancers rather than failure to control the primary tumor. The risk of contralateral breast cancer was high in all groups, exceeding 40%, but was not statistically significantly different by use of adjuvant radiotherapy (RT) or not, suggesting no added risk from scatter RT at 10 and 15 years. There were no differences seen in regional or systemic recurrences between the BCT and M groups, and no difference in overall survival. In conclusion, BRCA1/2 mutation carriers with breast cancer have similar survival whether treated with M or BCT. However, women undergoing BCT have an elevated risk of a second in-breast event that is significantly reduced in the presence of chemotherapy. Contralateral breast cancer events are very common.
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PMID:Local therapy in BRCA1 and BRCA2 mutation carriers with operable breast cancer: comparison of breast conservation and mastectomy. 2041 23

The aim of this study was to verify whether histopathological features of extratumoral and of primary tumor breast tissue could play a role in identifying patients with familial characteristics. We examined the clinicopathological features of 504 patients with sporadic or familial breast cancer stratified for risk of BRCA mutation. Patients with a higher risk of being carrier of BRCA gene mutations were significantly associated with tumor poor differentiation (p=0.003), positive lymph node invasion (p=0.02) and presence of vascular peritumoral invasion (p=0.008). Among the extra-tumoral lesions, only the epithelial proliferative lesions were related to higher mutation risk both in the overall series and familial patients (p<0.0001 and p=0.003, respectively). Interestingly, a significant difference in terms of high mutation risk was observed in usual ductal hyperplasia lesions (UDH), (p=0.002). We suggest that vascular peritumoral invasion and UDH lesions could predict a higher mutation risk of BRCA1 and BRCA2 genes and help in individuating patient candidates to further molecular analysis.
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PMID:Histological features of extratumoral breast lesions as a predictive factor of familial breast cancer. 2042 20

The goal was to determine recurrent or second primary status for late stomal malignancies, 16 and 17 years post-total laryngectomy in two laryngeal squamous cell carcinoma (LSCC) patients, based on DNA methylation signatures and HPV typing. Adopting a literature review based definition of late stomal recurrences as new primaries at the site of the stoma or neopharynx occurring >5 years after total laryngectomy, we employed a multi-gene candidate approach to examine promoter methylation in 24 tumor suppressor genes and PCR-based assays for HPV status offered additional insights into whether the late stomal tumors post-total laryngectomy were related or not. The primary tumor for Patient 1 was negative for HPV but had aberrant hypermethylation of APC, MLH1 and BRCA1. The stomal biopsy 17-years later showed presence of HPV-16 without any methylated genes. In Patient 2, HPV-11 and promoter methylation of APC identified in the primary tumor was also observed in the stomal malignancy 16 years post-total laryngectomy. Additional information provided by molecular typing for HPV and methylation markers underscored Patient 1's and 2's late stomal presentation as most likely a second primary and recurrence, respectively. DNA methylation markers are particularly advantageous because DNA methylation is an early event in tumorigenesis, and the epigenetic modification, 5-methylcytosine, is a stable marker. Molecular marks to discern genetic heterogeneity or relatedness of stomal malignancies several years post-total laryngectomy can provide clues to their status as either second primaries or likely recurrences. Our results support the hypothesis that a subset of stomal recurrences after total laryngectomy represents second primary tumors.
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PMID:Molecular characterization of late stomal recurrence following total laryngectomy. 2122 33


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