The polymorphisms of MSH6 gene are associated with AIDS progression in a northern Chinese population

Association of APEX1 and XRCC1 Gene Polymorphisms With HIV-1 Infection Susceptibility and AIDS Progression in a Northern Chinese MSM Population

Background: Some studies have shown that the base excision repair (BER) pathway has an effect on HIV-1 replication. APEX1 and XRCC1 as key BER genes may affect DNA repair capacity. However, the roles of single nucleotide polymorphisms (SNPs) in APEX1 and XRCC1 and their impact on HIV-1 infection and AIDS progression remain unclear.

Methods: A custom-designed 48-Plex SNPscan Kit was used for detection of single nucleotide polymorphisms. 601 HIV-1-infected men who have sex with men (MSM) and 624 age-matched healthy individuals were recruited in northern China. Four SNPs (rs1130409, rs1760944, rs2307486 and rs3136817) in APEX1 gene and three SNPs (rs1001581, rs25487 and rs25489) in XRCC1 gene were genotyped. The generalized multifactor dimension reduction (GMDR) method was used to identify the SNP-SNP interactions.

Results: In this study, rs1130409 G allele, rs1001581 C allele and rs25487 C allele were associated with a higher risk of HIV-1 infection susceptibility (p = 0.020, p = 0.007 and p = 0.032, respectively). The frequencies of APEX1 haplotype TT and XRCC1 haplotype CT showed significant differences between cases and controls (p = 0.0372 and p = 0.0189, respectively). Interestingly, stratified analysis showed that the frequency of rs1001581 C allele was significantly higher in AIDS patients with the CD4⁺ T-lymphocyte count <200 cells/μl than those with >200 cells/μl (p = 0.022). Moreover, significant gene-gene interactions among rs1130409, rs1001581 and rs25487 were identified by GMDR (p = 0.0107). Specially, individuals with five to six risk alleles have a higher susceptibility to HIV-1 infection than those with zero to two risk alleles (p < 0.001).

Conclusion:APEX1 and XRCC1 gene polymorphisms were associated with the susceptibility to HIV-1 infection and AIDS progression in MSM populations in northern China.

Association between polymorphisms in MRE11 and HIV-1 susceptibility and AIDS progression in a northern Chinese MSM population

BACKGROUND

Previous studies reported that DNA damage repair (DDR) genes may play an important role in HIV-1 infection. The MRE11 gene, a member of the MRN complex, plays an essential part in the homologous recombination pathway, which is one of the classical DDR pathways. Previous reports have demonstrated that MRE11 has an effect on HIV-1 replication. However, the role of SNPs in the MRE11 gene and their impact on HIV-1 infection and AIDS progression remain unknown.

METHODS

In this study, 434 MSM HIV-1-infected patients in northern China and 431 age-matched healthy controls were enrolled. Five SNPs (rs2155209, rs10831234, rs13447720, rs601341 and rs11020803) at the MRE11 gene were genotyped. Another series of cases (409 MSM HIV-1-infected patients) and controls (403 age-matched healthy males) were recruited as the validation set.

RESULTS

In our study, rs10831234 showed differences in allele frequencies between cases and controls (P = 0.005). Additionally, there was an association between rs10831234 and HIV-1 infection susceptibility in dominant and additive models (P = 0.005 and P = 0.006, respectively). All significant associations were replicated in the validation set, and the associations were still significant after Bonferroni correction for multiple testing when the two data sets were combined. Furthermore, in haplotype association analyses between the case and control groups, the frequencies of the haplotypes Crs11020803Crs10831234 and Trs11020803Trs10831234 showed significant differences (P = 0.0181 and P = 0.0068, respectively).

CONCLUSIONS

We demonstrated that the MRE11 rs10831234-T allele may confer increased risk of HIV-1 infection.

Inhibitory effect of MSH6 gene silencing in combination with cisplatin on cell proliferation of human osteosarcoma cell line MG63

Osteosarcoma (OS) is one of the most common primary bone malignancies, with the survival rate of patients with OS remaining low. Therefore, we conducted this study to identify the potential role combination of both MSH6 gene silencing and cisplatin (DDP) plays in OS cell proliferation and apoptosis. Microarray-based gene expression profiling was used to identify the differentially expressed genes (DEGs) in patients with OS, as well as microRNAs (miRNAs) that regulate the candidate gene. OS tissues from 67 patients with OS along with normal tissues from 24 amputee patients were collected for detection of the positive expression of mutS homolog 6 (MSH6) protein, mRNA, and protein expressions of c-myc, cyclin D1, l-2, B-cell lymphoma 2 (Bcl-2), Stathmin, proliferating cell nuclear antigen (PCNA), and Bcl-2-associated X (Bax). Moreover, after MSH6 silencing and DDP were treated on the selected human OS cell line MG63 with the highest expression of MSH6, cell viability, cell cycle distribution, and apoptosis were detected. The microarray analysis showed that MSH6 was upregulated in OS chip data. Furthermore, silencing MSH6 combined with DDP reduced expressions of c-myc, cyclin D1, Bcl-2, Stathmin, and PCNA, and elevated Bax expression, whereas inhibiting OS cell viability, impeding cell cycle distribution, and inducing apoptosis. In conclusion, our preliminary results indicated that the combination of MSH6 gene silencing coupled with DDP may have a better effect on the inhibition of OS cell proliferation and promote apoptosis, potentially providing targets for the OS treatment.

Rs2303428 of MSH2 Is Associated with Hepatocellular Carcinoma Prognosis in a Chinese Population

The defects of DNA repair genes may lead to genomic instability and cancer. As an important DNA mismatch repair gene that maintains genomic stability from DNA replication errors, genetic variants of mutS homolog 2 (MSH2) are associated with some cancers. In this study, 1021 hepatocellular carcinoma (HCC) cases and 1021 non-HCC controls from Guangxi were included to explore the association between MSH2 single-nucleotide polymorphisms (SNPs) and HCC. Among the eight MSH2 SNPs, only genotype distribution of rs2303428 was significantly different from HCC and non-HCC patients (p < 0.05). Moreover, CT, TT, and CT/TT genotype of rs2303428 could increase HCC risk [OR (95% CI) = 1.758 (1.195-2.657), 1.846 (1.213-2.896), and 1.823 (1.219-2.763), respectively] and decrease the survival time of HCC patients [codominant, HR (95% CI) = 1.267 (1.046-1.535); dominant, HR (95% CI) = 1.675 (1.162-2.414)]. In addition, rs2303428 was found to interact with HBV infection and family history to increase HCC risk by gene-environment analysis (p < 0.05). Finally, multivariate COX regression analysis showed that rs2303428, tumor number, tumor staging, and metastasis had a significant influence on HCC prognosis. Our results provide MSH2 SNP, rs2303428, as a new prognostic biomarker for HCC patients.