Investigation of ATG16L1 rs2241880 Polymorphism with Cancer Risk: A Meta-Analysis

Autophagy-related genes polymorphism in hepatitis B virus-associated hepatocellular carcinoma: A systematic review

BACKGROUND

Chronic hepatitis B (CHB) virus is the most common risk factor for developing liver malignancy. Autophagy is an essential element in human cell maintenance. Several studies have demonstrated that autophagy plays a vital role in liver cancer at different stages. In this systematic review, we intend to investigate the role of polymorphism and mutations of autophagy-related genes (ATGs) in the pathogenesis and carcinogenesis of the hepatitis B virus (HBV).

MATERIALS AND METHODS

The search was conducted in online databases (Web of Science, PubMed, and Scopus) using Viruses, Infections, Polymorphism, Autophagy, and ATG. The study was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria.

RESULTS

The primary search results led to 422 studies. By screening and eligibility evaluation, only four studies were relevant. The most important polymorphisms in hepatocellular carcinoma were rs2241880 in ATG16L1, rs77859116, rs510432, and rs548234 in ATG5. Furthermore, some polymorphisms are associated with an increased risk of HBV infection including, rs2241880 in ATG16L1 and rs6568431 in ATG5.

CONCLUSION

The current study highlights the importance of rs2241880 in ATG16L1 and rs77859116, rs510432, and rs548234 in ATG5 for HBV-induced HCC. Additionally, some mutations in ATG16L1 and ATG5 were important in risk of HBV infection. The study highlights the gap of knowledge in the field of ATG polymorphisms in HBV infection and HBV-induced HCC.

ELSSI: parallel SNP-SNP interactions detection by ensemble multi-type detectors

With the development of high-throughput genotyping technology, single nucleotide polymorphism (SNP)-SNP interactions (SSIs) detection has become an essential way for understanding disease susceptibility. Various methods have been proposed to detect SSIs. However, given the disease complexity and bias of individual SSI detectors, these single-detector-based methods are generally unscalable for real genome-wide data and with unfavorable results. We propose a novel ensemble learning-based approach (ELSSI) that can significantly reduce the bias of individual detectors and their computational load. ELSSI randomly divides SNPs into different subsets and evaluates them by multi-type detectors in parallel. Particularly, ELSSI introduces a four-stage pipeline (generate, score, switch and filter) to iteratively generate new SNP combination subsets from SNP subsets, score the combination subset by individual detectors, switch high-score combinations to other detectors for re-scoring, then filter out combinations with low scores. This pipeline makes ELSSI able to detect high-order SSIs from large genome-wide datasets. Experimental results on various simulated and real genome-wide datasets show the superior efficacy of ELSSI to state-of-the-art methods in detecting SSIs, especially for high-order ones. ELSSI is applicable with moderate PCs on the Internet and flexible to assemble new detectors. The code of ELSSI is available at https://www.sdu-idea.cn/codes.php?name=ELSSI.

Autophagy mediates ER stress and inflammation in Helicobacter pylori-related gastric cancer

Autophagy is a cellular degradation mechanism, which is triggered by the bacterium Helicobacter pylori. A single nucleotide polymorphism (SNP) in the autophagy gene ATG16L1 (rs2241880, G-allele) has been shown to dysregulate autophagy and increase intestinal endoplasmic reticulum (ER) stress. Here, we investigate the role of this SNP in H.pylori-mediated gastric carcinogenesis and its molecular pathways. ATG16L1 rs2241880 was genotyped in subjects from different ethnic cohorts (Dutch and Australian) presenting with gastric (pre)malignant lesions of various severity. Expression of GRP78 (a marker for ER stress) was assessed in gastric tissues. The effect of ATG16L1 rs2241880 on H.pylori-mediated ER stress and pro-inflammatory cytokine induction was investigated in organoids and CRISPR/Cas9 modified cell lines. Development of gastric cancer was associated with the ATG16L1 rs2241880 G-allele. Intestinal metaplastic cells in gastric tissue of patients showed increased levels of ER-stress. In vitro models showed that H.pylori increases autophagy while reducing ER stress, which appeared partly mediated by the ATG16L1 rs2241880 genotype. H.pylori-induced IL-8 production was increased while TNF-α production was decreased, in cells homozygous for the G-allele. The ATG16L1 rs2241880 G-allele is associated with progression of gastric premalignant lesions and cancer. Modulation of H.pylori-induced ER stress pathways and pro-inflammatory mediators by ATG16L1 rs2441880 may underlie this increased risk.

Isoforms of autophagy-related proteins: role in glioma progression and therapy resistance

Autophagy is the process of recycling and utilization of degraded organelles and macromolecules in the cell compartments formed during the fusion of autophagosomes with lysosomes. During autophagy induction the healthy and tumor cells adapt themselves to harsh conditions such as cellular stress or insufficient supply of nutrients in the cell environment to maintain their homeostasis. Autophagy is currently seen as a form of programmed cell death along with apoptosis and necroptosis. In recent years multiple studies have considered the autophagy as a potential mechanism of anticancer therapy in malignant glioma. Although, subsequent steps in autophagy development are known and well-described, on molecular level the mechanism of autophagosome initiation and maturation using autophagy-related proteins is under investigation. This article reviews current state about the mechanism of autophagy, its molecular pathways and the most recent studies on roles of autophagy-related proteins and their isoforms in glioma progression and its treatment.

Genetic associations between CYP24A1 polymorphisms and predisposition of cancer: A meta-analysis

BACKGROUND

CYP24A1 polymorphisms may affect predisposition of cancer, but the results of published studies remain inconclusive. Therefore, the authors conducted this meta-analysis to more robustly assess relationships between CYP24A1 polymorphisms and the predisposition of cancer by pooling the findings of published studies.

MATERIALS AND METHODS

A comprehensive literature search of PubMed, Embase, Web of Science, Wanfang, and CNKI was endorsed by the authors to identify eligible studies; 17 studies were finally found to be eligible for pooled meta-analysis.

RESULTS

The pooled meta-analysis results showed that genotypic frequencies of the rs4809960 polymorphism among cancerous patients and controls of Caucasian ethnicity differed significantly, and genotypic frequencies of the rs6022999 polymorphism among cancerous patients and controls of Asian ethnicity also differed significantly. Moreover, we found that genotypic frequencies of the rs2585428 polymorphism among patients with prostate cancer and controls differed significantly, and genotypic frequencies of the rs6068816 polymorphism among patients with prostate cancer/breast cancer and controls also differed significantly.

CONCLUSIONS

This meta-analysis suggests that the rs4809960 polymorphism may affect the predisposition of cancer in Caucasians, and the rs6022999 polymorphism may affect the predisposition of cancer in Asians. Moreover, the rs2585428 polymorphism may affect the predisposition of prostate cancer, while the rs6068816 polymorphism may affect the predisposition of prostate cancer and breast cancer.

LncRNA growth arrest-special 5 polymorphisms and predisposition to cancer: A meta-analysis

AIM

The lncRNA growth arrest-special 5 (GAS5) is a critical tumor suppressor lncRNA, and its expression level has been found to be decreased in many types of cancers. So GAS5 polymorphisms are also likely to influence predisposition to many types of malignant diseases. Nevertheless, the relationships between GAS5 polymorphisms and cancer are still controversial. Thus, the authors designed this meta-analysis to get a more statistically reliable conclusion.

METHODS

The authors searched PubMed, Embase, and Web of Science for eligible studies. A total of 12 eligible studies involving 8693 cancer cases and 10,805 controls were pooled and analyzed in this meta-analysis.

RESULTS

Among GAS5 polymorphisms, only GAS5 rs145204276 insertion/deletion polymorphism could be analyzed in a meta-analysis with regard to predisposition to cancer since no any other GAS5 polymorphisms were explored by at least two individual genetic association studies. All eligible studies were found to be of Asian origin. Although the overall pooled meta-analysis results did not show any significant associations between rs145204276 insertion/deletion polymorphism and a predisposition to cancer, rs145204276 insertion/deletion polymorphism was demonstrated to be significantly associated with a predisposition to gastric cancer (dominant comparison: P<0.0001; recessive comparison: P=0.005; over-dominant comparison: P=0.0003; over-dominant comparison: P<0.0001) in Asians in further subgroup analyses.

CONCLUSIONS

This meta-analysis demonstrated that GAS5 rs145204276 insertion/deletion polymorphism was associated with a predisposition to gastric cancer in Asians. Nevertheless, considering that this positive finding was only based on three eligible studies from the same area, future studies with larger sample sizes in other populations are still warranted to test the robustness of our findings.