The relationship between polymorphisms of XRCC5 genes with astrocytoma prognosis in the Han Chinese population

Circular RNA XRCC5 aggravates glioma progression by activating CLC3/SGK1 axis via recruiting IGF2BP2

BACKGROUND

Increasing evidences have reported the critical roles of circular RNA (circRNA) in gliomas. Whereas, the role of circXRCC5 in glioma and its underlying molecular mechanism has not been reported.

METHODS

The RNA transcripts and protein levels were detected using qRT-PCR, immunohistochemistry (IHC) and in situ hybridization (ISH) assays. Cell proliferation was characterized by CCK-8 and clone formation assays. The formation of NLRP3-inflammasomes was identified using immunofluorescence (IF) and Western blot assays. The cytokines were determined using immunosorbent assay (ELISA) and Western blot assays. The molecular interactions were validated using RIP and pull-down assays.

RESULTS

circXRCC5 was over-expressed in glioma and positively related to the shorter survival rate, advanced TNM stage and larger tumor volume. circXRCC5 knockdown inhibited cell proliferation and NLRP3-mediated inflammasome activation of glioma cells. Subsequently, we found that circXRCC5 maintained mRNA stability of CLC3 by binding to IGF2BP2. Furthermore, CLC3 accelerated SGK1 expression via PI3K/PDK1/AKT pathway. The rescue experiments showed that both overexpression of CLC3 or SGK1 dramatically alleviated circXRCC5 knockdown-induced inhibition of cell proliferation and NLRP3-mediated inflammasome activation of glioma cells. In vivo, our study proved that circXRCC5 accelerated glioma growth by regulating CLC3/SGK1 axis.

CONCLUSION

Our data concluded that circXRCC5 formed a complex with IGF2BP2 to regulate inflammasome activation and tumor growth via CLC3/SGK1 axis.

Association of Polymorphisms in NHEJ Pathway Genes with HIV-1 Infection and AIDS Progression in a Northern Chinese MSM Population

Background and Aims

Men who have sex with men (MSM) are at high risk of HIV infection. The nonhomologous end joining (NHEJ) pathway is the main way of double-stranded DNA break (DSB) repair in the higher eukaryotes and can repair the DSB timely at any time in cell cycle. It is also indicated that the NHEJ pathway is associated with HIV-1 infection since the DSB in host genome DNA occurs in the process of HIV-1 integration. The aim of the present investigation was to evaluate associations of single-nucleotide polymorphisms (SNPs) in NHEJ pathway genes with susceptibility to HIV-1 infection and AIDS progression among MSM residing in northern China.

Methods

A total of 481 HIV-1 seropositive men and 493 HIV-1 seronegative men were included in this case-control study. Genotyping of 22 SNPs in NHEJ pathway genes was performed using the SNPscan™ Kit.

Results

Positive associations were observed between XRCC6 rs132770 and XRCC4 rs1056503 genotypes and the susceptibility to HIV-1 infection. In gene-gene interaction analysis, significant SNP-SNP interactions of XRCC6 and XRCC4 genetic variations were found to play a potential role in the risk of HIV-1 infection. In stratified analysis, XRCC5 rs16855458 was significantly associated with CD4+ T cell counts in AIDS patients, whereas LIG4 rs1805388 was linked to the clinical phases of AIDS patients.

Conclusions

NHEJ gene polymorphisms can be considered to be risk factors of HIV-1 infection and AIDS progression in the northern Chinese MSM population.

High expression of NPM1 via the Wnt/β-catenin signalling pathway might predict poor prognosis for patients with prostate adenocarcinoma

Prostate adenocarcinoma (PRAD) occurs only in males and has a higher incidence rate than other cancers. NPM1 is a nucleocytoplasmic shuttling protein that participates in the development of multiple tumours. The aim of this research was to explore the effect of the upregulation or downregulation of the NPM1 protein on the malignancy of prostate cancer and its possible signalling pathway. Prostate adenocarcinoma cell lines were used in this study, including RWPE-1, PC3, LNCap, and 22RV1 cells. Our research revealed that NPM1 was widely expressed in the PRAD cell lines, as determined by Western blotting, and that the levels of NPM1 protein were positively correlated with the degree of malignancy of the PRAD cell lines. Through interference and overexpression experiments, we found that PC3 cells growth was inhibited after NPM1 knockdown and that this inhibition was partly reversed by CTNNB1 overexpression; in contrast, PC3 cells growth was promoted after NPM1 overexpression, and this promotion was partly reversed by CTNNB1 knockdown, suggesting that NPM1 and CTNNB1 play important roles in the progression of prostate cancer cells via the Wnt/β-catenin signalling pathway. NPM1 may serve as an important biomarker and candidate therapeutic for patients with prostate cancer.

Identification of an IFN-β-associated gene signature for the prediction of overall survival among glioblastoma patients

Background

Brain glioblastoma multiforme (GBM) is the most common primary malignant intracranial tumor. The prognosis of this disease is extremely poor. While the introduction of β-interferon (IFN-β) regimen in the treatment of gliomas has significantly improved the outcome of patients; The mechanism by which IFN-β induces increased TMZ sensitivity has not been described. Therefore, the main objective of the study was to elucidate the molecular mechanisms responsible for the beneficial effect of IFNβ in GBM.

Methods

Messenger RNA expression profiles and clinicopathological data were downloaded from The Cancer Genome Atlas (TCGA) GBM and GSE83300 dataset from the Gene Expression Omnibus. Univariate Cox regression analysis and lasso Cox regression model established a novel 4-gene IFN-β signature (peroxiredoxin 1, Sec61 subunit beta, X-ray repair cross-complementing 5, and Bcl-2-like protein 2) for GBM prognosis prediction. Further, GBM samples (n=50) and normal brain tissues (n=50) were then used for real-time polymerase chain reaction experiments. Gene set enrichment analysis (GSEA) was performed to further understand the underlying molecular mechanisms. Pearson correlation was applied to calculate the correlation between the long non-coding RNAs (lncRNAs) and IFN-β-associated genes. An lncRNA with a correlation coefficient |R²|>0.3 and P<0.05 was considered to be an IFN-β-associated lncRNA.

Results

Patients in the high-risk group had significantly poorer survival than patients in the low-risk group. The signature was found to be an independent prognostic factor for GBM survival. Furthermore, GSEA revealed several significantly enriched pathways, which might help explain the underlying mechanisms. Our study identified a novel robust 4-gene IFN-β signature for GBM prognosis prediction. The signature might contain potential biomarkers for metabolic therapy and treatment response prediction for GBM patients.

Conclusions

In the present study, we established a novel IFN-β-associated gene signature to predict the overall survival of GBM patients, which may help in clinical decision making for individual treatment.

Elevated XRCC5 expression level can promote temozolomide resistance and predict poor prognosis in glioblastoma

Drug resistance and disease recurrence are important contributors for the poor prognosis of glioblastoma multiforme (GBM). Temozolomide (TMZ), the standard chemotherapy for GBM treatment, can methylate DNA and cause the formation of double-strand breaks (DSBs). X-ray repair cross complementing 5 (XRCC5), also known as Ku80 or Ku86, is required for the repair of DSBs. The present study identified novel determinants that sensitize cells to TMZ, using an array-based short hairpin (sh)RNA library. Then, cBioportal, Oncomine, and R2 databases were used to analyze the association between gene expression levels and clinical characteristics. Subsequently, lentiviral shRNA or pCMV was used to knockdown or overexpress the gene of interest, and the effects on TMZ sensitivity were determined using a MTT assay and western blot analysis. TMZ-resistant cells were also established and were used in in vitro and in vivo experiments to analyze the role of the gene of interest in TMZ resistance. The results indicated that XRCC5 was effective in enhancing TMZ cytotoxicity. The results from the bioinformatics analysis revealed that XRCC5 mRNA expression levels were associated with clinical deterioration and lower overall survival rates. In addition, XRCC5 knockdown could significantly increase TMZ sensitivity in GBM cells, while XRCC5 overexpression caused the cancer cells to be resistant to TMZ. Both the in vivo and in vitro experiments showed that TMZ treatment could induce expression of XRCC5 in TMZ-resistant cells. Taken together these findings suggested that XRCC5 could be a promising target for GBM treatment and could also be used as a diagnostic marker for refractory GBM.

The Influence of NDRG1 Single Nucleotide Polymorphisms on Glioma Risk and Prognosis in Chinese Han Population

Glioma is a highly fatal malignant tumor with a high recurrence rate, poor clinical treatment effect, and prognosis. We aimed to determine the association between single nucleotide polymorphisms (SNPs) of NDRG1 and glioma risk and prognosis in the Chinese Han population. 5 candidate SNPs were genotyped by Agena MassARRAY in 558 cases and 503 controls; logistic regression was used to analyze the relationship between SNPs and glioma risk. We used multi-factor dimensionality reduction to analyze the interaction of 'SNP-SNP'; the prognosis analysis was performed by log-rank test, Kaplan-Meier analysis, and Cox regression model. Our results showed that the polymorphisms of rs3808599 was associated with the reduction of glioma risk in all participants (OR 0.41, p = 0.024) and the participants ≤ 40 years old (OR 0.30, p = 0.020). rs3802251 may reduce glioma risk in all participants (OR 0.79, p = 0.008), the male participants (OR 0.68, p = 0.033), and astrocytoma patients (OR 0.81, p = 0.023). rs3779941 was associated with poor glioma prognosis in all participants (HR = 2.59, p = 0.039) or astrocytoma patients (HR = 2.63, p = 0.038). We also found that the key factors for glioma prognosis may include surgical operation, radiotherapy, and chemotherapy. This study is the first to find that NDRG1 gene polymorphisms may have a certain association with glioma risk or prognosis in the Chinese Han population.

Clinical and Genetic Risk Prediction of Subsequent CNS Tumors in Survivors of Childhood Cancer: A Report From the COG ALTE03N1 Study

Purpose Survivors of childhood cancer treated with cranial radiation therapy are at risk for subsequent CNS tumors. However, significant interindividual variability in risk suggests a role for genetic susceptibility and provides an opportunity to identify survivors of childhood cancer at increased risk for these tumors. Methods We curated candidate genetic variants from previously published studies in adult-onset primary CNS tumors and replicated these in survivors of childhood cancer with and without subsequent CNS tumors (82 participants and 228 matched controls). We developed prediction models to identify survivors at high or low risk for subsequent CNS tumors and validated these models in an independent matched case-control sample (25 participants and 54 controls). Results We demonstrated an association between six previously published single nucleotide polymorphisms (rs15869 [ BRCA2], rs1805389 [ LIG4], rs8079544 [ TP53], rs25489 [ XRCC1], rs1673041 [ POLD1], and rs11615 [ ERCC1]) and subsequent CNS tumors in survivors of childhood cancer. Including genetic variants in a Final Model containing age at primary cancer, sex, and cranial radiation therapy dose yielded an area under the curve of 0.81 (95% CI, 0.76 to 0.86), which was superior ( P = .002) to the Clinical Model (area under the curve, 0.73; 95% CI, 0.66 to 0.80). The prediction model was successfully validated. The sensitivity and specificity of predicting survivors of childhood cancer at highest or lowest risk of subsequent CNS tumors was 87.5% and 83.5%, respectively. Conclusion It is possible to identify survivors of childhood cancer at high or low risk for subsequent CNS tumors on the basis of genetic and clinical information. This information can be used to inform surveillance for early detection of subsequent CNS tumors.

Combination of AQP1 and β-catenin expression is an independent prognosis factor in astrocytoma patients

Previous research usually focused on single protein or gene in tumor development, actually highly heterogeneous nature and different signaling pathways largely contribute to tumor progression and tumor patients’ outcomes. Therefore, using combinatorial biomarkers to evaluate the prognostic features and guide management is gradually accepted and urgently needed. β-catenin is a well-known crucial factor in astrocytoma progression and it is involved in aquaporin1 (AQP1) mediated cell migration. In this study, we revealed the function of AQP1 in astrocytoma progression and provided the first clinical evidence that AQP1 expression was positively correlated with β-catenin. Furthermore, we proved the functional role of AQP1/β-catenin pathway in astrocytoma progression. More importantly, we discovered that combination of AQP1 and β-catenin expression was an independent prognosis factor for astrocytoma patients and it was a better survival predictor than either AQP1 or β-catenin alone. In conclusion, our study provided a novel more precise prognostication for predicting astrocytoma prognosis based on combinatorial analysis of AQP1 and β-catenin expression.