MicroRNA-214 Targets GALNT7 In Gastric Adenocarcinoma Cells

[Objective]MicroRNAs(miRNAs)are a class of small non-coding RNAs that post-transcriptionally regulate gene expression.MiRNAs are involved in many physiological and pathological progresses.Accumulated evidences indicate that special miRNAs may function as oncogenes or tumor suppressors and play a critical role in cancer initiation and progression by negatively regulating their target genes.We investigated the expression of miR-214 in gastric adeno carcinoma and its influence on biological behavior of gastric adenocarcinoma cells.Meanwhile,a new direct target gene of miR-214 was identified and the biological role of target gene was explored in gastric adenocarcinoma cells.[Methods]Real-time PCR was used to detect the differential expression of miR-214 in human gastric adenocarcinoma and adjacent normal tissues.The function of miR-214 was enhanced or decreased in human gastric adenocarcinoma cell line MGC803 and the changes of cell phenotypes were determined by MTT colorimetric assay,colony formation assay,in vitro scratch assay,cell adhesion assay and transwell invasion assay.Subsequently,the candidate target gene of miR-214 was predicted by the bioinformatics analysis,and was validated by fluorescent reporter experiment.Furthermore,the mRNA levels and protein levels of target gene in gastric adenocarcinoma cancer cells overexpressed miR-214 were detected with real-time PCR and Western blot.Finally,the function of target gene was inhibited in human gastric adenocarcinoma cell line MGC803 and the changes of cell phenotypes were detected by colony formation assay,cell adhesion assay and transwell invasion assay.[Results]The expression of miR-214 in human gastric adenocarcinoma tissues was lower than in adjacent normal tissues.We found that overespression of miR-214 suppressed the proliferation activity,heterotypic adhesion and invasion capability of MGC803 cell.Subsequently,the fluorescent reporter experiment confirmed that miR-214 can directly bind to mRNA 3'UTR of a candidate target gene GALNT7 and negatively regulate its expression.After overexpression of miR-214 in gastric adenocarcinoma cells,mRNA level and protein level of GALNT7 were both decreased.Finally,we found that both the heterotypic adhesion ability and invasion capability of MGC803 cell were reduced after knockdown of GALNT7.These results consistented with those obtained from overexpression of miR-214.[Conclusions]These results demonstrated that miR-214 expression is lower in human gastric adenocarcinoma than matched adjacent normal tissues and miR-214 functions as a tumor suppressor gene and can suppress heterotypic adhesion ability and invasion capability of gastric adenocarcinoma cell through negatively regulating the target gene GALNT7 directly.The elucidation of a new target gene of miR-214 in gastric adenocarcinoma helps us to further understand cancer initiation and progression,and may provide new clues to therapy study of cancer.