Effect of miR-374b-5p targeting RECK gene on xenogenic human gastric cancer in nude mice / 肿瘤

ABSTRACT

Objective: To investigate the role of microRNA-374b-5p (miR-374b-5p) and its target gene reversion-inducing-cysteine-rich protein with Kazal motifs (RECK) in occurrence and development of gastric cancer. Methods: The human gastric cancer MGC-803 cells were used to establish BABL/c nude mice model bearing xenografts of MGC-803 cells. The mice were randomly divided into three groups when the volume of the xenograft reaching about 60 mm3: blank control group (n = 5), negative control (NC) group (transfecion with miR-374b-5p NC-inhibitor every four days) (n = 5) and miR-374b-5p inhibitor group (transfecion with miR-374b-5p inhibitor every four days) (n = 5). The growth of the xenografts was observed. The mice in each group were sacrificed three days after the end of last transfection (on the 35th day after transplantation of MGC-803 cells). The pathological features of the xenografts were observed by hematoxylin-eosin (HE) staining. The expression level of miR-374b-5p in xenografts in nude mice after transfection was determined by real-time fluorogenic quantitative-PCR (RFQ-PCR). The Luciferase Activity Assay was used to determine whether miR-374b-5p was targeting RECK gene. The expressions of RECK mRNA and protein were detected with RFQ-PCR and immunohistochemistry, respectively. Results: The tumor xenograft volume of miR-374b-5p inhibitor group was significantly smaller than those of the blank control group and NC group since the 9th day after transfection (since the 23th day after the beginning of transplantation) (P < 0.05), but the xenograft volume of the blank control group and the NC group had no significant difference. Pathological results indicated that the degree of malignancy of xenografts in miR-374b-5p inhibitor group was lower than those of the other two groups. The expression level of miR-374b-5p in miR-374b-5p inhibitor group was significantly lower than those in the other two groups (both P < 0.05). The miR-374b-5p directly targeting RECK gene was proved by Luciferase Activity Assay. The mRNA and protein expressions of RECK in miR-374b-5p inhibitor group were both significantily higher than those in the other two groups (all P < 0.05). Conclusion: miR-374b-5p may play as an oncogene in the occurrence and development of gastric cancer through RECK pathway.