MiR-106b Promotes Cell Migration And Invasion Targeting Smad7 In Esophageal Squamous Cell Carcinoma Via EMT

Objective: To investigate the effects of mi R-106 b and its regulation on Smad7 protein expression in the esophageal squamous cell carcinoma(ESCC). Methods: Specimens of ESCC and normal tissues were collected from 90 Kazakh‘s ESCC patients, the prtotein expression of Smad7 was examined by immunohistochemistry(IHC). KYSE150 cell was transfected with mi R-106 b and KYSE450 cell was transfected with mi R-106b-inhibition,the expression of mi R-106 b, Smad7 m RNA, EMT-associated markers were detected by Quantitative RT-PCR(q RT-PCR).Smad7 protein, EMT-associated proteins were measured by Western blot and cell proliferation was detected using MTT assay.In addition, cell migration, invasion ability and apoptosis were evaluated by Wound healing assay, Transwell assay and Flow Cytometry after transfection. To determine the possible target gene of mi R-106 b, Western blot analysis and Luciferase reporter gene assays were performed. Results: The positive rate of Smad7 expression in paired normal adjacent tissues(NATs) was significantly higher than carcinoma tissues of patients with ESCC(P<0.05), while Smad7 expression was correlated with metastasis of Lymph node(P<0.05). Overexpression mi R-106 b showed that cell proliferation and ability of migration, invasion was obviously increased in esophageal cancer KYSE150(P<0.05), and resulted in the decrease of Smad7 protein levels. Furthermore, expression of E-Cadherin was significantly lower in the group of transfected with mi R-106 b than that in control(P<0.05).Meanwhile, expression of N-Cadherin was higher(P<0.05). On the contrary, down-regulation of mi R-106 b was inhibited in cell proliferation and migration, invasion(P<0.05), and resulted in the increase of Smad7 protein levels. The EMT markers were definitely negative with mi R-106 b. Luciferase experiment shows that Smad7 was derectly regulated by mi R-106 b. Conclusion: Mi R-106 b and Smad7 were involved in ESCC carcinogenesis. In ESCC the protein expression Smad7 was down-regulated by mi R-106 b in post-transcription level. The present data revealed that mi R-106 b was involved in the cell proliferation, migration and invasion.