Meifang Huang1,1, Tianqian Li1,1, Qing Wang1, Chongxin Li1, Huahua Zhou1, Shengyi Deng1, Zengbo Lv1, Yongmei He1, Bo Hou2, Guangying Zhu3,4,5. 1. Department of Oncology, The First People's Hospital of Qujing/The Qujing Affiliated Hospital of Kunming Medical University, Qujing, Yunnan, China. 2. Department of Thoracic Surgery, The First People's Hospital of Qujing/The Qujing Affiliated Hospital of Kunming Medical University, Qujing, Yunnan, China. 3. Department of Radiation Oncology, Center of Respiratory Medicine, China-Japan Friendship Hospital, Beijing, China. 4. Institute of Respiratory Medicine, Chinese Academy of Medicine Sciences, Beijing, China. 5. National Center for Respiratory Disease, Beijing, China.
Abstract
BACKGROUND: Radiotherapy is one of main useful therapies in non-small cell lung cancer (NSCLC). Nevertheless, the underlying mechanism between NSCLC cell radiosensitivity and effective treatment remains unclear. OBJECTIVE: The aim is to explore the relationship between circular (circ) RNA and NSCLC cell radiosensitivity. METHODS: CircRNA plasmacytoma variant translocation 1 (PVT1) and microRNA (miR)-1208 expression in NSCLC cells were assessed using quantitative reverse transcriptase PCR (qRT-PCR). NSCLC cells were transfected with si-PVT1 or miR-1208 inhibitor and then exposed to irradiation. Cellular biology behaviors were detected using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), Terminal deoxynucleotidyl transferase dUTP Nick-End Labeling (TUNEL), colony formation, invasion and western blot. Additionally, binding between circPVT1 and miR-1208 was testified by dual-luciferase reporter and RIP assay. RESULTS: CircPVT1 was upregulated in NSCLC cells after irradiation treatment. Silencing circPVT1 induced inhibition of NSCLC cell growth and invasion, accompanied by cell apoptosis and γ-H2AX expression. Moreover, NSCLC cell proliferation and invasion was further inhibited by irradiation treatment in circPVT1-silenced cells, indicating a strong radiosensitivity of NSCLC cells. CircPVT1 functions as a competing endogenous RNA of miR-1208. Silencing miR-1208 reversed NSCLC cell sensitivity response to irradiation and activated PI3K/AKT/mTOR pathway in circPVT1-silenced cells. CONCLUSIONS: Silencing circPVT1 enhanced radiosensitivity of NSCLC cells by sponging miR-1208.
BACKGROUND: Radiotherapy is one of main useful therapies in non-small cell lung cancer (NSCLC). Nevertheless, the underlying mechanism between NSCLC cell radiosensitivity and effective treatment remains unclear. OBJECTIVE: The aim is to explore the relationship between circular (circ) RNA and NSCLC cell radiosensitivity. METHODS: CircRNA plasmacytoma variant translocation 1 (PVT1) and microRNA (miR)-1208 expression in NSCLC cells were assessed using quantitative reverse transcriptase PCR (qRT-PCR). NSCLC cells were transfected with si-PVT1 or miR-1208 inhibitor and then exposed to irradiation. Cellular biology behaviors were detected using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), Terminal deoxynucleotidyl transferase dUTP Nick-End Labeling (TUNEL), colony formation, invasion and western blot. Additionally, binding between circPVT1 and miR-1208 was testified by dual-luciferase reporter and RIP assay. RESULTS: CircPVT1 was upregulated in NSCLC cells after irradiation treatment. Silencing circPVT1 induced inhibition of NSCLC cell growth and invasion, accompanied by cell apoptosis and γ-H2AX expression. Moreover, NSCLC cell proliferation and invasion was further inhibited by irradiation treatment in circPVT1-silenced cells, indicating a strong radiosensitivity of NSCLC cells. CircPVT1 functions as a competing endogenous RNA of miR-1208. Silencing miR-1208 reversed NSCLC cell sensitivity response to irradiation and activated PI3K/AKT/mTOR pathway in circPVT1-silenced cells. CONCLUSIONS: Silencing circPVT1 enhanced radiosensitivity of NSCLC cells by sponging miR-1208.