Genetic variants in miRNA machinery genes associated with clinicopathological characteristics and outcomes of gastric cancer patients

Background: Polymorphisms in miRNA machinery genes have been proved to be related to risk or survival of several kinds of cancers, but the results are controversial and the role of these polymorphisms in gastric cancer remains uncertain. In our study, we investigated the association between five genetic variants in miRNA machinery genes (DICER, RAN, XPO5 [name of the gene]) and clinical outcomes in Chinese gastric cancer patients. Methods: A total of 96 patients with stage IB-III gastric cancer treated with radical gastrectomy and adjuvant chemotherapy of oxaliplatin and fluorouracils were analyzed. The MassARRAY MALDI-TOF system was used to determine the genotypes. Results: DICER rs3742330 AG+GG genotype was associated with more advanced T stage compared to AA genotype (P=0.009). More patients with XPO5 rs2257082 CC genotype had poorly differentiated tumors compared with CT+TT genotype carriers. After adjustment by age, sex, differentiation, T stage, and lymph node status, XPO5 rs2257082 CC genotype carriers were found to have worse disease-free survival than CT+TT genotype carriers (adjusted HR 3.099; 95% CI 1.270, 7.564; P=0.013), carriers of RAN rs14035 CC genotype had higher three-year OS rate than carriers of CT+TT genotype (adjusted HR 3.174; 95% CI 1.010, 9.973; P=0.048). Conclusions: These results indicated that genetic variants in miRNA machinery genes might be associated with the clinicopathological features and prognosis of completely resected gastric cancer patients.