MUC1 rs4072037 polymorphism is associated with decreased risk of gastric cancer: a meta-analysis

Family-based exome sequencing combined with linkage analyses identifies rare susceptibility variants of MUC4 for gastric cancer

Genome-wide association studies of gastric cancer (GC) cases have revealed common gastric cancer susceptibility loci with low effect size. We investigated rare variants with high effect size via whole-exome sequencing (WES) of subjects with familial clustering of gastric cancer. WES of DNAs from the blood of 19 gastric cancer patients and 36 unaffected family members from 14 families with two or more gastric cancer patients were tested. Linkage analysis combined with association tests were performed using Pedigree Variant Annotation, Analysis, and Search Tool (pVAAST) software. Based on the logarithm of odds (LOD) and permutation-based composite likelihood ratio test (CLRT) from pVAAST, MUC4 was identified as a predisposing gene (LOD P-value = 1.9×10-5; permutation-based P-value of CLRT ≤ 9.9×10-9). In a larger cohort consisting of 597 GC patients and 9,759 healthy controls genotyped with SNP array, we discovered common variants in MUC4 regions (rs148735556, rs11717039, and rs547775645) significantly associated with GC supporting the association of MUC4 with gastric cancer. And the MUC4 variants were found in higher frequency in The Cancer Genome Atlas Study (TCGA) germline samples of patients with multiple cancer types. Immunohistochemistry indicated that MUC4 was downregulated in the noncancerous gastric mucosa of subjects with MUC4 germline missense variants, suggesting that loss of the protective function of MUC4 predisposes an individual to gastric cancer. Rare variants in MUC4 can be novel gastric cancer susceptibility loci in Koreans possessing the familial clustering of gastric cancer.

Association between the MUC1 rs4072037 Polymorphism and Risk of Gastric Cancer and Clinical Outcomes

Purpose

Mucin 1 (MUC1) was identified as a gastric cancer (GC) susceptibility gene by genome-wide association studies in Asians and candidate gene studies in Europeans. This study aimed to investigate the association between the MUC1 rs4072037 polymorphism and GC in terms of the Lauren classification and long-term clinical outcomes.

Materials and Methods

A total of 803 patients with GC and 816 unrelated healthy controls were enrolled in the study. The association between the MUC1 rs4072037 variant and GC histological types and clinical outcomes, including tumor recurrence and prognosis was investigated.

Results

The major A allele of rs4072037 was associated with increased GC risk (P<0.05). In subtype analysis, the association was most significant for diffuse-type GC (P<0.05) and in a dominant model (P<0.05), whereas there was no association with intestinal-type GC (P>0.05). Cox proportional hazards analysis revealed the heterozygote AG rs4072037 allele as an independent risk factor influencing tumor recurrence and disease-related death in diffuse-type GC (P<0.05). but not in intestinal-type GC (P>0.05).

Conclusions

The exonic single nucleotide polymorphism rs4072037 in MUC1 was associated with diffuse-type GC and was an independent risk factor influencing tumor recurrence and disease-related death in diffuse-type GC.

Genetic polymorphisms and gastric cancer risk: a comprehensive review synopsis from meta-analysis and genome-wide association studies

Objective

In the past few decades, more than 500 reports have been published on the relationship between single nucleotide polymorphisms (SNPs) on candidate genes and gastric cancer (GC) risk. Previous findings have been disputed and are controversial. Therefore, we performed this article to summarize and assess the credibility and strength of genetic polymorphisms on the risk of GC.

Methods

We used Web of Science, PubMed, and Medline to identify meta-analyses published before July 30th, 2018 that assessed associations between variants on candidate genes and the risk of GC. Cumulative epidemiological evidence of statistical associations was assessed combining Venice criteria and a false-positive report probability (FPRP) test.

Results

Sixty-one variants demonstrated a significant association with GC risk, whereas 29 demonstrated no association. Nine variants on nine genes were rated as presenting strong cumulative epidemiological evidence for a nominally significant association with GC risk, including APE1 (rs1760944), DNMT1 (rs16999593), ERCC5 (rs751402), GSTT1 (null/presence), MDM2 (rs2278744), PPARG (rs1801282), TLR4 (rs4986790), IL-17F (rs763780), and CASP8 (rs3834129). Eleven SNPs were rated as moderate, and 33 SNPs were rated as weak. We also used the FPRP test to identify 13 noteworthy SNPs in five genome-wide association studies.

Conclusions

Sixty-one variants are significantly associated with GC risk, and 29 variants are not associated with GC risk; however, five variants on five genes presented strong evidence for an association upgraded from moderate. Further study of these variants may be needed in the future. Our study also provides referenced information for the genetic predisposition to GC.