rs11671784 G/A and rs895819 A/G polymorphisms inversely affect gastric cancer susceptibility and miR-27a expression in a Chinese population.
BACKGROUND
rs895819 and rs11671784 are 2 SNPs in miR-27a that can influence the expression of mature miRNA. However, their role in gastric cancer development is still not well understood. This study aimed to determine whether these 2 polymorphisms are associated with gastric cancer risk in a Chinese population and how they influence the expression of miR-27a.


METHODS
This was a case-control study and recruited 278 gastric cases and 278 healthy matched controls. Genotyping of these 2 SNPs among the participants were performed to assess their association with gastric cancer risk. Tumor samples from 59 patients who had physical resection were used for qRT-PCR analysis of miR-27a expression. To further valid the effects of these 2 SNPs, findings of previous studies were pooled to generate integrated evidence.


RESULTS
Individuals with rs895819 G variants exhibited significantly increased risk of gastric cancer, while subjects with rs11671784 A variants had significantly reduced gastric cancer risk. Among the patients, rs895819 G variants were moderately associated with lymphatic invasion and lymph node metastasis, while rs11671784 A variants were associated with significantly reduced risk of lymphatic invasion. qRT-PCR results demonstrated rs895819 polymorphism contributed to an aberrant process from pri-miR-27a to pre-miR-27a, but rs11671784 did not affect the transcription and post-transcription processes of the miR-27a gene. The subsequent meta-analysis largely confirmed the effects of these 2 SNPs on gastric cancer risk.


CONCLUSIONS
rs895819 and rs11671784 inversely affect gastric cancer risk and the influence was closely related to their effects on miR-27a expression.
Department of Gastroenterology, Yantai Shan Hospital, Yantai, Shangdong, China (mainland).
Bo
B
Song
Department of Gastroenterology, Yantai Shan Hospital, Yantai, Shangdong, China (mainland).
Ge
G
Yan
Department of General Surgery, Huashan Hospital, Fudan University, Shanghai, China (mainland).
Hankun
H
Hao
Department of Radiology, Central hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China (mainland).
Bei
B
Yang
D044466:Asian People / Q000235:genetics*; D002681:China; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D008875:Middle Aged; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000235:genetics* / Q000473:pathology
C531388:MIRN27 microRNA, human; D035683:MicroRNAs