Single-Nucleotide Polymorphisms of the MSH2 and MLH1 Genes, Potential Molecular Markers for Susceptibility to the Development of Basal Cell Carcinoma in the Brazilian Population

Comprehensive investigating of MMR gene in hepatocellular carcinoma with chronic hepatitis B virus infection in Han Chinese population

Hepatocellular carcinoma associated with chronic hepatitis B virus infection seriously affects human health. Present studies suggest that genetic susceptibility plays an important role in the mechanism of cancer development. Therefore, this study focused on single nucleotide polymorphisms (SNPs) of MMR genes associated with HBV-HCC. Five groups of participants were included in this study, which were healthy control group (HC), spontaneous clearance (SC), chronic hepatitis B group (CHB), HBV-related liver cirrhosis group (LC) and HBV-related hepatocellular carcinoma group (HBV-HCC). A total of 3128 participants met the inclusion and exclusion criteria for this study. 20 polymorphic loci on MSH2, MSH3 and MSH6 were selected for genotyping. There were four case-control studies, which were HC vs. HCC, SC vs. HCC, CHB vs. HCC and LC vs. HCC. We used Hardy-Weinberg equilibrium test, unconditional logistic regression, haplotype analysis, and gene-gene interaction for genetic analysis. Ultimately, after excluding confounding factors such as age, gender, smoking and drinking, 12 polymorphisms were found to be associated with genetic susceptibility to HCC. Haplotype analysis showed the risk haplotype GTTT (rs1805355_G, rs3776968_T, rs1428030_C, rs181747_C) was more frequent in the HCC group compared with the HC group. The GMDR analysis showed that the best interaction model was the three-factor model of MSH2-rs1981928, MSH3-rs26779 and MSH6-rs2348244 in SC vs. HCC group (P=0.001). In addition, we found multiplicative or additive interactions between genes in our selected SNPs. These findings provide new ideas to further explore the etiology and pathogenesis of HCC. We have attempted to explain the molecular mechanisms by which certain SNPs (MSH2-rs4952887, MSH3-rs26779, MSH3-rs181747 and MSH3-rs32950) affect genetic susceptibility to HCC from the perspectives of eQTL, TFBS, cell cycle and so on. We also explained the results of haplotypes and gene-gene interactions. These findings provide new ideas to further explore the etiology and pathogenesis of HCC.

Multiple primary melanoma in association with other personal and familial cancers

BACKGROUND

Multiple primary melanoma (MPM) is known to be associated with familial melanoma. However, the association between MPM and other personal and familial cancers is not well documented. The objective of this study was to evaluate the association between MPM and personal history of other cancers or cancer history among first-degree relatives (FDRs).

METHODS

We performed a retrospective case-control study including cases with gender-matched MPM and single primary melanoma (SPM) at a 1:2 ratio from the University of Pittsburgh Cancer Institute Melanoma Center Biological Sample and Nevus Bank. The associations between MPM and other cancers were evaluated using univariable and multivariable logistic regression models.

RESULTS

In total, 378 patients (44.2% men; median age 52 years) were enrolled, including 252 with SPM and 126 with MPM. In comparison to patients with SPM, patients with MPM were more likely to have squamous cell carcinoma (odds ratio [OR] 1.95, 95% confidence interval [CI] 1.001-3.79, p = 0.047) and prostate cancer (OR 2.72, 95% CI 1.07-7.01, p = 0.034). FDRs of patients with MPM had higher prevalence of melanoma (OR 2.37, 95% CI 1.31-4.28, p = 0.004) and prostate cancer (OR 2.92, 95% CI 1.47-6.14, p = 0.002) but not other cancers. In multivariable analysis, the association remained significant between MPM and squamous cell carcinoma (OR 2.18, 95% CI 1.08-4.39, p = 0.028), prostate cancer (OR 2.85, 95% CI 1.09-7.54, p = 0.032), FDR history of melanoma (OR 2.37, 95% CI 1.31-4.29, p = 0.004), and FDR history of prostate cancer (OR 3.26, 95% CI 1.59-6.83, p = 0.001).

CONCLUSIONS

Patients with MPM have a higher prevalence of personal and FDR histories of nonmelanoma skin cancers and prostate cancer.

Correlation of MSH2 exonic deletions and protein downregulation with breast cancer biomarkers and outcome in Pakistani women/patients

Mismatch repair (MMR) pathway is one of the underlying mechanisms of predisposition to breast cancer (BC). The present study explored the association of MSH2 exonic deletions, respective survival analysis, protein structure prediction, transcription profiling, and expression analysis with BC risk. Genotyping analysis of 493 BC cases and 387 controls confirmed the association of two MSH2 exonic deletions, i.e., exon 3 (OR:6.4, CI = 3.4-12.1) and 9 (OR:7.8, CI = 4.1-14.8) with BC risk. In order to confirm the phenotypic-genotypic relationship, we have performed MSH2 transcriptomic (p < 0.05) and protein expression analysis (OR:30, CI = 4-230) which further confirmed its downregulation/loss in BC biopsy samples highlighting potential role in the onset of breast carcinogenesis. Additionally, we have presented that MSH2 mutations can alter the expression profile of other BC associated biomarkers like ER, PR, CK-7, GATA-3, and E-cadherin. Subsequently, the effect of exonic deletions on secondary structure of protein has shown missing of beta and alpha helices in their protein products via in-silico analysis. However, loss of exon 3 results in the altered core protein structure leading to dysfunction protein, possible cause of BC development. No association of MSH2 exonic deletions with survival statistics was observed conceivably due to the shorter follow-up time. Thus, our results at genetic, transcriptomic, and proteomic levels confirmed the downregulated MSH2, emphasizing its potential contribution in MMR mechanisms for breast tumorigenesis. In conclusion, MSH2 deficiency may cause breast cancer development and progression.

Association between SNPs and Loss of Methylation Site on the CpG island of the Promoter Region of the Smoothened Gene, Potential Molecular Markers for Susceptibility to the Development of Basal Cell Carcinoma in the Brazilian Population

Objective:

Perform genotyping of SNPs in the promoter region of the SMO gene in BCC samples from patients from northeastern Brazil, and to determine if there is an association of these SNPs of the gene in question with the susceptibility to the development of the BCC.

Methods:

100 samples of paraffined tissue from patients with histopathological diagnosis of BCC and 100 control samples were analyzed for each polymorphism by a newly developed genotyping method, the Dideoxy Single Allele Specific – PCR. The software Bioestat - version 5.3 and Haploview 4.2 were used for the statistical analysis. For all tests a P-value <0.05 was considered significant.

Results:

The SNP rs538312246 is the Hardy-Weinberg equilibrium, therefore, it did not present significant association with the BCC (X² =2.343 and P<0.158). However, the CpG-SNPs rs375350898 and rs75827493 were significantly associated to the BCC in the analyzed samples (X² = 27,740/21,500 and P <0001), the SNP rs75827493 showed a significant association with the BCC of the nodular subtype (P <0.0069). Therefore, our results suggest that SNPs rs375350898 and rs75827493 are potential molecular markers for susceptibility to BCC.

Conclusion:

The ability to detect SNP in a population, especially in promoter regions, has profoundly changed human genetic studies. This study allowed the understanding of the relationship between the presence of SNPs in CpG islands of the promoter region of the SMO gene can modify the methylation pattern and provide susceptibility to BCC in the population.

Conventional Versus Giant Basal Cell Carcinoma, a Review of 57 Cases: Histologic Differences Contributing to Excessive Growth

Background:

Giant basal cell carcinoma (GBCC) is defined as a basal cell carcinoma (BCC) exceeding 5 cm in size. While these tumors impart significant morbidity due to local tissue destruction and have a higher rate of metastatic disease than their conventional (smaller) counterparts, reasons for their large size remain unclear. While theories relating to neglect or faster growth rate are often invoked; to date, there has not been a comprehensive evaluation of the histologic features of these large tumors that may contribute to their size.

Methods:

Histologic features of GBCCs (n = 29) were evaluated and compared to those of conventional BCC (n = 28). Available clinical demographic data were also reviewed.

Results:

GBCCs, in addition to overall larger size, more often were thicker, displayed ulceration, and showed a more infiltrative growth pattern than their conventional counterparts. These rare tumors also displayed an insignificant increased propensity for a brisk host immune response, and the infiltrate significantly more often included clusters of plasma cells.

Conclusions:

Most histologic features seen in GBCCs likely reflect their large size. Histologic features alone are unlikely to explain the size of these rare tumors. The possibility of an altered host immune response contributing to the growth of these tumors requires further investigation.