Radiotherapy Department, Changzhou Tumor Hospital Affiliated to Soochow University, China.
Adv Clin Exp Med. 2021 Feb;30(2):173-181. doi: 10.17219/acem/130599.
Radioresistance is a huge obstacle in radiotherapy of non-small cell lung cancer (NSCLC) and how to raise radiosensitivity is an urgent issue.
In this study, we investigated the role and molecular mechanism of sodium new houttuyfonate (SNH) in regulation of radiosensitivity of NSCLC cells.
The Cell Counting Kit-8 (CCK-8) was used to measure cell viabilities of NSCLC cell lines A549 and HCC827 after a treatment with SNH (0 mM, 0.1 mM and 0.3 mM). It examined cytotoxicity induced by X-ray (0 Gy, 1 Gy, 2 Gy, 4 Gy, 6 Gy, and 8 Gy) after SNH (0.3 mM) treatment, while flow cytometry was used for apoptosis detection use. Expression of miR-147a or signal transducer and activator of transcription (STAT3) in selected cell lines was assessed through real-time quantitative polymerase chain reaction (RT-qPCR). The CCK-8 was then applied to measure cytotoxicity in cells with miR-147a upregulation or STAT3 suppression under irradiation apoptosis changes were detected with flow cytometry. Thereafter, binding conditions between miR-147a and STAT3 were checked using luciferase reporter assays. Expressions of STAT3 in A549 transfected by siNC, siSTAT3, and by siSTAT3 and miR-147a mimics were checked using RT-qPCR and the phosphorylation of STAT3 was observed using enzyme-linked immunosorbent assay (ELISA).
The SNH treatment significantly suppressed cell viabilities and increased apoptosis of lung cancer cells. Cytotoxicity and apoptosis in A549 cells were both enhanced after SNH treatment and raised as the dosages of X-ray grew. MiR-147a presented lower expression in lung cancer cells and was upregulated by SNH, which further contributed to higher cell apoptosis after irradiation. STAT3 directly bound miR-147a and was more expressed in NSCLC cells. Inhibited phosphorylation of STAT3 promoted apoptosis in A549 cells after X-ray exposure. Overexpressed miR-147a inactivated STAT3 signaling, adding to cell apoptosis after irradiation.
SNH-induced miR-147a increased radiosensitivity of A549 cells through inactivation of STAT3 pathway.
放射抵抗是非小细胞肺癌（NSCLC）放射治疗的巨大障碍，如何提高放射敏感性是一个迫切需要解决的问题。
本研究旨在探讨钠新虎杖苷（SNH）在调节 NSCLC 细胞放射敏感性中的作用及其分子机制。
采用细胞计数试剂盒-8（CCK-8）检测 SNH（0 mM、0.1 mM 和 0.3 mM）处理后 NSCLC 细胞系 A549 和 HCC827 的细胞活力。检测 SNH（0.3 mM）处理后 X 射线（0 Gy、1 Gy、2 Gy、4 Gy、6 Gy 和 8 Gy）诱导的细胞毒性，同时采用流式细胞术检测细胞凋亡情况。采用实时定量聚合酶链反应（RT-qPCR）检测选定细胞系中 miR-147a 或信号转导和转录激活因子 3（STAT3）的表达。然后，采用 CCK-8 检测 miR-147a 上调或 STAT3 抑制下照射后细胞的细胞毒性，采用流式细胞术检测细胞凋亡变化。然后，通过荧光素酶报告基因检测检查 miR-147a 与 STAT3 之间的结合情况。采用 RT-qPCR 检测 siNC、siSTAT3 及 siSTAT3 和 miR-147a 模拟物转染 A549 后的 STAT3 表达，采用酶联免疫吸附试验（ELISA）检测 STAT3 磷酸化。
SNH 处理显著抑制肺癌细胞的活力并增加其凋亡。SNH 处理后 A549 细胞的细胞毒性和凋亡均增强，且随着 X 射线剂量的增加而升高。miR-147a 在肺癌细胞中的表达较低，SNH 可上调其表达，进一步促进照射后细胞凋亡。STAT3 直接与 miR-147a 结合，在 NSCLC 细胞中表达较高。抑制 STAT3 的磷酸化可促进 A549 细胞在 X 射线照射后的凋亡。转染 miR-147a 可使 STAT3 信号失活，增加照射后细胞凋亡。
SNH 诱导的 miR-147a 通过失活 STAT3 通路增加 A549 细胞的放射敏感性。
