title: MicroRNA-340 promotes the tumor growth of human gastric cancer by inhibiting cyclin G2.
abstract: Aberrant expression and function of microRNAs (miRNAs) play a critical role in the development and progression of various human cancers including gastric cancer. However, the clinical significance and underlying mechanisms of miR-340 remain largely unknown in gastric cancer. In the present study, we demonstrated that the expression of miR-340 was aberrantly elevated in both gastric cancer tissues and cells. Moreover clinical association analyses disclosed that the elevated level of miR-340 was significantly associated with unfavorable clinicopathological characteristics of the gastric cancer patients, such as poor differentiation, large tumor size and advanced tumor-node-metastasis (TNM) stage. Gastric cancer patients with high expression of miR-340 had prominently shorter overall survival and disease-free survival. Functionally, forced expression of miR-340 promoted cell viability, proliferation, colony formation and cell cycle progression in the SGC-7901 cells, while miR-340 silencing reduced cell viability, proliferation, colony formation and cell cycle progression in MGC-803 cells. Furthermore, in vivo experiments indicated that miR-340 knockdown suppressed the tumor growth of MGC-803 cells. Notably, alteration of miR-340 expression affected the luciferase activity of wild-type 3'-UTR of cyclin G2 (CCNG2) and regulated CCNG2 abundance in gastric cancer cells, indicating that CCNG2 is a direct target of miR-340. Moreover, CCNG2 knockdown eradicated the effects of miR-340 silencing on gastric cancer cells. In conclusion, our data suggest that miR-340 may potentially serve as a novel prognostic biomarker and therapeutic target for gastric cancer.
authors.affiliation: Department of Hepatobiliary Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, P.R. China.
authors.forename: Guozhi
authors.initials: G
authors.lastname: Yin
authors.affiliation: Department of General Surgery, Hanzhong Central Hospital, Hanzhong 723000, P.R. China.
authors.forename: Huayou
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Department of Hepatobiliary Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, P.R. China.
authors.forename: Yumo
authors.initials: Y
authors.lastname: Xue
authors.affiliation: Department of Hepatobiliary Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, P.R. China.
authors.forename: Bowen
authors.initials: B
authors.lastname: Yao
authors.affiliation: Department of General Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, P.R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
mesh_terms: D002453:Cell Cycle / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000235:genetics*; D002470:Cell Survival / Q000235:genetics; D056767:Cyclin G2 / Q000235:genetics*; D018572:Disease-Free Survival; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D020868:Gene Silencing / Q000502:physiology; D006801:Humans; D008207:Lymphatic Metastasis / Q000235:genetics / Q000473:pathology; D008297:Male; D035683:MicroRNAs / Q000235:genetics*; D008875:Middle Aged; D013274:Stomach Neoplasms / Q000235:genetics* / Q000473:pathology*; D047368:Tumor Burden / Q000235:genetics
chemical_list: C101593:CCNG2 protein, human; D056767:Cyclin G2; C570046:MIRN340 microRNA, human; D035683:MicroRNAs