MiR-106a induces peritoneal metastasis through acting on TIMP2 in human gastric cancer cell BGC-823 / 西安交通大学学报(医学版)

ABSTRACT

Objective To investigate the induction of microRNA (microRNA-106a,miR-106a)on the peritoneal metastasis of human gastric cancer cell BGC-823 by regulating matrix metalloproteinase inhibitor 2 (tissue inhibitor of metalloproteinases 2,TIMP2).Methods Human gastric cancer cell line BGC-823 was cultured to the logarithmic growth phase. The cells were divided into three groups: BGC-823, BGC-823/anti-miR-106a (antagomir)and BGC-823/negative control.Real-time PCR was used to identify the effect of antagomir.Transwell assay was used to detect the cell migratory and invasive abilities of these three groups in vitro .With small incision, the cells were injected into the abdominal cavity of nude mice to prepare a xenograft model.The animals were divided into two groups:miR-antagomir and miR-NC.The tumor growth in the nude mice was generally observed and estimated.Immunohistochemistry and Western blot methods were used to detect the expression of metastasis-associated protein TIMP2 on the several abdominal organs.Results The expression level of miR-106a was down- regulated in BGC-823/anti-miR-106a group,with the fold change of 0.05±0.01,which was significantly different from that in NC group (t=-18.001,P＜0.001).In vitro exogenously silencing of miR-106a gene,the numbers of invasive and migratory cells in BGC-823/anti-miR-106a group were both significantly lower than those in BGC-823 and BGC-823/negative control groups (P＜0.001).In vivo xenograft model showed that the down-regulation of miR-106a weakened the peritoneal metastasis ability of BGC-823 cells in nude mice abdominal cavity,which was reflected by the decrease of tumor number and tumor size.With the inhibition of miR-106a,the expression of TIMP2 in miR-antagomir group was significantly higher than that in miR-NC group (P＜0.05).Conclusion BGC-823 cell has the tumorigenicity in nude mice.Silencing of miR-106a inhibits gastric cancer cell metastasis, which suggests that it has the oncogenic function.MiR-106a may induce the strengthened peritoneal metastasis ability of BGC-823 cell through acting on TIMP2.