Effect of silencing of long non-coding RNA HOTAIR on radiosensitivity of rectal adenocarcinoma cell lines

Abstract

Objective To investigate the effect of long non-coding RNA HOX transcript antisense RNA (lncRNA HOTAIR) on the cell proliferation, radiosensitivity and apoptosis of the rectal adenocarcinoma cell lines SW480 and HCT116 in vitro. Methods The expression levels of lncRNA HOTAIR in the rectal adenocarcinoma cell lines (SW480 and HCT116) were assessed by real-time quantitative PCR (RT-qPCR). Silencing of HOTAIR by RNA interference was performed to explore its roles in cell proliferation, radiosensitivity and apoptosis. After treatment with irradiation at a gradient dose, the cell viability was measured and the rate of cell apoptosis was tested. Results Compared with the human rectal epithelial cell lines, the expression of lncRNA HOTAIR was significantly higher in the rectal adenocarcinoma cell lines. The colonic assay demonstrated that the sensitizing enhancement ratios (SERs) were 1.58 and 1.33 for the cells transfected with HOTAIR siRNA in SW480 and HCT116 cell line compared with the control isRNA transfection group. In vitro silencing of lncRNA HOTAIR could enhance the apotosis rate and radiosensitivity of the rectal adenocarcinoma cell line SW480. Conclusion The expression level of lncRNA HOTAIR is correlated with the cellular radiosensitivity, which is probably a parameter for predicting the radiosensitivity of rectal adenocarcinoma cells. Radiotherapy combined with HOTAIR-siRNA can significantly inhibit the cell proliferation, induce cell apoptosis and enhance the radiosensitivity. Key words: Rectal neoplasm; LncRNA HOTAIR; Radiosensitivity; Cell proliferation; Apoptosis