Department of Thoracic Surgery, The Second Clinical Medical College (Shenzhen People's Hospital), Jinan University, Shenzhen, Guangdong 518020, P.R. China.
Oncol Rep. 2020 Jun;43(6):1906-1914. doi: 10.3892/or.2020.7547. Epub 2020 Mar 17.
Circulating tumor cells (CTCs) that are shed from the primary tumor invade the blood stream or surrounding parenchyma to form new tumors. The present study aimed to explore the underlying mechanism of cisplatin resistance in lung adenocarcinoma CTCs and provide clinical treatment guidance for lung cancer treatment. CTCs from the blood samples of 6 lung adenocarcinoma patients were treated with different concentrations of cisplatin along with A549 and H1299 cells. The sensitivity of CTCs to cisplatin was explored by detecting the inhibitory rate via CCK‑8 assay. The related molecular mechanism was investigated by western blot analysis. miR‑10a expression was detected using quantitative real‑time PCR (RT‑qPCR). The relationship between miR‑10a and phosphatidylinositol‑4,5‑bisphosphate 3‑kinase catalytic subunit α (PIK3CA) was verified and further confirmed by luciferase reporter assay, western blotting and RT‑qPCR assay. The results revealed that CTCs exhibited lower cisplatin sensitivity than A549 and H1299 cells. Moreover, CTCs treated with cisplatin demonstrated higher miR‑10a expression and lower PIK3CA expression than that in A549 and H1299 cells (P<0.01). Expression of phosphoinositide 3‑kinase (PI3K) and protein kinase B (Akt) phosphorylation were also decreased in A549 and H1299 cells compared with CTCs after cisplatin treatment. PIK3CA is a target of miR‑10a, and both miR‑10a overexpression and PIK3CA knockdown obviously decreased the sensitivity of A549 and H1299 cells to cisplatin as well as the expression of PI3K and phosphorylation of Akt. PIK3CA overexpression attenuated the cisplatin resistance of A549 and H1299 cells induced by miR‑10a. In conclusion, miR‑10a suppressed the PI3K/Akt pathway to strengthen the resistance of CTCs to cisplatin via targeting PIK3CA, providing a new therapeutic target for lung cancer treatment.
循环肿瘤细胞（CTCs）从原发性肿瘤脱落，侵入血液或周围实质，形成新的肿瘤。本研究旨在探讨肺腺癌 CTC 顺铂耐药的潜在机制，为肺癌治疗提供临床治疗指导。用不同浓度的顺铂处理来自 6 例肺腺癌患者血液样本中的 CTCs，并用 CCK-8 法检测 CTCs 对顺铂的敏感性。通过 Western blot 分析研究相关分子机制。采用实时定量 PCR（RT-qPCR）检测 miR-10a 的表达。通过荧光素酶报告实验、Western blot 和 RT-qPCR 验证和进一步证实 miR-10a 与磷脂酰肌醇-4,5-二磷酸 3-激酶催化亚单位α（PIK3CA）之间的关系。结果表明，CTCs 对顺铂的敏感性低于 A549 和 H1299 细胞。此外，与 A549 和 H1299 细胞相比，顺铂处理的 CTCs 表现出更高的 miR-10a 表达和更低的 PIK3CA 表达（P<0.01）。与 CTCs 相比，用顺铂处理后 A549 和 H1299 细胞中的磷酸肌醇 3-激酶（PI3K）和蛋白激酶 B（Akt）磷酸化表达也降低。PIK3CA 是 miR-10a 的靶基因，miR-10a 过表达和 PIK3CA 敲低明显降低了 A549 和 H1299 细胞对顺铂的敏感性以及 PI3K 和 Akt 磷酸化的表达。PIK3CA 过表达减弱了 miR-10a 诱导的 A549 和 H1299 细胞对顺铂的耐药性。总之，miR-10a 通过靶向 PIK3CA 抑制 PI3K/Akt 通路，增强 CTCs 对顺铂的耐药性，为肺癌治疗提供了新的治疗靶点。
