Effect of lncRNA MEG3 on radiosensitivity of nasopharyngeal carcinoma cells by down-regulating miR-7-5p expression

Objective To investigate the effect and underlying mechanism of lncRNA MEG3 on the radiosensitivity of nasopharyngeal carcinoma cells. Methods this experiment, overexpression control group, MEG3 overexpression group, miR-NC inhibition group, miR-7-5p inhibition group, overexpression control+ 4 Gy group, MEG3 overexpression+ 4 Gygroup, miR-NC inhibition+ 4 Gy group, miR-7-5p inhibition+ 4 Gy group, MEG3 overexpression+ miR-NC overexpression group, MEG3 overexpression+ miR-7-5p overexpression group were established. The expression of miR-7-5p and MEG3 was detected by qRT-PCR. The radiosensitivity of nasopharyngeal carcinoma cells was measured by clone formation assay. Cell apoptosis was assessed by flow cytometry. The fluorescence activity was evaluated by dual luciferase reporter assay. Results MEG3 was lowly expressed in nasopharyngeal carcinoma tissues and cells. Overexpression of MEG3 and inhibition of miR-7-5p expression increased the radiosensitivity of nasopharyngeal carcinoma cells and promoted radiation-induced cell apoptosis. MEG3 could targetedly regulate the miR-7-5p expression. Overexpression of miR-7-5p reversed the effect of overexpression of MEG3 on the sensitization of nasopharyngeal carcinoma cells and the promotion of apoptosis induced by radiation exposure. Conclusions Overexpression of MEG3 increases the radiosensitivity of nasopharyngeal carcinoma cells and promotes radiation-induced cell apoptosis. The mechanism may be related to the down-regulation of miR-7-5p expression. Key words: lncRNA MEG3; miR-7-5p; Nasopharyngeal carcinoma cell line; Radiosensitivity; Apoptosis