Effect of lentivirus-mediated expression of RNF2 gene on the proliferation and migration of esophageal carcinoma cells following X-ray radiotherapy

Objective To examine the effect of X-ray radiotherapy on cell proliferation, migration, apoptosis, and cell cycle of human esophageal carcinoma ECA-109 cells following RNA interference (RNAi)-mediated downregulation of RNF2 gene expression. Methods The level of RNF2 mRNA expression in the human esophageal carcinoma cell line ECA-109 was determined using RT-PCR. Cell proliferation of ECA-109 was measured by MTT assay, and the changes in RNF2 protein expression in ECA-109-R cells were determined using Western blot. The changes in cell cycle and cell apoptosis at different time points following radiation were analyzed by flow cytometry, and the effect of transduction on cell migration was examined using Transwell migration assay. Data were subjected to an analysis of variance with repeated measurement design. Results The mean mRNA and protein levels of RNF2 in ECA-109 cells were significantly increased in a dose-dependent manner in the radiation group than in the control group (P 0.05). The Transwell migration assay showed that the number of migrating cells following 3.5 h of radiation was significantly lower in the ECA-109-R group than in the ECA-109 and ECA-109-N groups (P<0.01). The percentage of G2/M phase cells in each group was significantly lower following 6 Gy radiation compared to that in the corresponding untreated group (P<0.01), and the percentage of G2/M phase cells was significantly lower in the ECA-109-R group than in the ECA-109 and ECA-109-N groups (P<0.05). Furthermore, cell apoptosis following radiation was also significantly higher in the ECA-109-R group than in the ECA-109 and ECA-109-N groups (P<0.01). Conclusions RNAi-mediated downregulation of RNF2 expression in esophageal carcinoma cells can reduce cell proliferation and cell migration, rescue post-radiation G2/M cell cycle arrest, promote cell apoptosis, and increase radiosensitivity. Key words: RNF2 gene; Cell proliferation; Apoptosis; Cell cycle; Esophageal carcinoma cell line