Objective: To investigate the effect of microRNA(miR)⁃221 in proliferation of tongue squamous cell carcinoma(TSCC) cells in vitro and in vivo.
Methods: The UM1 cell line was transfected with miR⁃221 inhibitor, and qRT⁃PCR analysis was used to detect the expression level of miR⁃221 in UM1 cell line after transfection. MTS assay was performed to analyze the effect of miR-221 on proliferation after transfection. Western blot analysis was used to demonstrate the metastasis associated proteins after transfection. Tumorigenesis model in nude mice was performed to analyze the effect of miR-221 on proliferation of UM1 cell line after transfection in vivo. Data were analyzed using the Statistical Package for the Social Science (SPSS), Version 19.0. For all statistical analyses, P<0.05 was considered statistically significant.
Results: Ectopic transfection of the miR-221 inhibitor to the UM1 cell led to decrease inmiR-221 expression (P<0.01); after transfection, the proliferation rate of UM1 cell was reduced (P<0.05); the expression level of E-Cadherin in cells was increased, while that of the MMP2, MMP9, Vimentin were decreased. The results of the subcutaneous xenograft model in nude mice showed that low-expression of miR-221 led to decrease in tumorigenesis ability (P< 0.01). Immunohistochemical staining showed that E-Cadherin was increased, and MMP2, MMP9, Vimentin were decreased.
Conclusion: miR-221 gene silencing could suppress the proliferation of TSCC in vitro and in vivo.