Objective:To evaluate the effect of long-chain non-coding RNA MEG3(LncRNA MEG3) on the radiosensitivity of cervical cancer cells, and to explore its underlying mechanism.Methods:The expression of LncRNA MEG3 in cervical cancer cells was detected by qRT-PCR. In the overexpression control group (transfected with pcDNA 3.1), LncRNA MEG3 overexpression group (transfected with pcDNA 3.1-LncRNA MEG3), miR-NC inhibition group (transfected with anti-miR-NC), miR-181a-5p inhibition group (transfected with anti-miR-181a-5p), LncRNA MEG3+ miR-NC overexpression group (co-transfected with pcDNA3.1-LncRNA MEG3 and anti-miR-NC), LncRNA MEG3+ miR-181a-5p overexpression group (co-transfected with pcDNA 3.1-LncRNA MEG3 and anti-miR-181a-5p), all plasmids were transfected into SiHa cells by liposome method. The cell survival fraction was assessed by colony formation assay. The cell apoptosis rate was evaluated by flow cytometry. The cell fluorescence activity was assessed by dual luciferase reporter assay. The expression levels of PTEN, p-Akt and Akt proteins were detected by Western blot.Results:Compared with the radiosensitive group, the expression of LncRNA MEG3 was significantly down-regulated in radiation-resistant cervical cancer tissues ( P<0.05), and its expression level was positively correlated with the sensitivity of cervical cancer cells. Overexpression of LncRNA MEG3 or inhibition of miR-181a-5p could significantly enhance the irradiation sensitivity and promote the apoptosis of cervical cancer cell line SiHa (both P<0.05). The fluorescence activity of wild-type LncRNA MEG3 cells was inhibited by miR-181a-5p. Overexpression of miR-181a-5p reversed the irradiation sensitization and pro-apoptosis effect of LncRNA MEG3 and the regulation of the PTEN/Akt signaling pathway on cervical cancer cell. Conclusion:LncRNA MEG3 can enhance the sensitivity of cervical cancer cells to radiation exposure, probably by targeting the miR-181a-5p and regulating the PTEN/Akt signaling pathway, which will provide a new direction for improving clinical prognosis of cervical cancer patients.

Objective:To investigate whether lncRNA LINC00909 affected the radiosensitivity of colorectal cancer cells by targeting miR-548-3p.Methods:The expression levels of LINC00909 and miR-584-3p in colorectal cancer and adjacent tissues were detected by qRT-PCR. The colorectal cancer cells SW480 and SW620 were cultured in vitro, and transfected with si-NC, si-LINC00909, miR-NC, miR-584-3p mimics, si-LINC00909, and anti-miR-NC and si-LINC00909, and anti-miR-584-3p, respectively. The cells were irradiated with a dose of 4 Gy. The cell survival fraction and sensitization enhancement ratio (SER) were detected by clone formation assay. Cell proliferation was detected by MTT assay. Cell migration and invasion were assessed by Trans well chamber assay. The targeting relationship between LINC00909 and miR-584-3p was confirmed by dual luciferase reporter assay. The effect of interfering with the expression of LINC00909 or inhibiting the expression of miR-584-3p on the weight of the xenograft tumor after irradiation was evaluated by subcutaneous xenograft experiment in nude mice. Results:The expression level of LINC00909 in colorectal cancer tissues was significantly up-regulated ( P<0.05), whereas the expression level of miR-584-3p was significantly down-regulated ( P<0.05). After interfering with the expression of LINC00909 or miR-584-3p overexpression, the cell survival fraction score was significantly reduced ( P<0.05), the SERs were 2.017 and 1.762, and cell proliferation, migration and invasion were suppressed (all P<0.05). Dual luciferase reporter assay confirmed that LINC00909 could target and bind to miR-584-3p. After interfering with the expression of LINC00909, the weight of the transplanted tumor was significantly reduced ( P<0.05), whereas the weight of the transplanted tumor was significantly increased after co-transfection with anti-miR-584-3p ( P<0.05). Conclusion:Interfering with the expression of LINC00909 can inhibit the proliferation, migration and invasion ability of colorectal cancer cells by up-regulating the expression of miR-548-3p, thereby enhancing the cell radiosensitivity.