Department of Radiation Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China; Center of Interventional Radiology and Vascular surgery, Department of Radiology, Zhongda hospital, Southeast university, Nanjing 210009, China.
Department of Radiation Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
Gene. 2021 Feb 5;768:145261. doi: 10.1016/j.gene.2020.145261. Epub 2020 Oct 22.
Radiotherapy is one of the primary therapeutic modalities for patients diagnosed esophageal squamous cell carcinoma(ESCC). Previous studies have shown that chemotherapy resistance could be linked with the overexpression vascular ATPases(V-ATPase) subunits genes. However, it is unknown whether V-ATPase subunits genes play a role in radiotherapy resistance. The aim of this study was to investigate the effect of the ATP6V1C1 in radiotherapy resistance. siRNA and plasmids were used to transfect low expression of ATP6V1C1 in TE13 (human ESCC cell) and high expressed in ECA109 (human ESCC cell), respectively. To observe proliferation, radiosensitivity, apoptosis and DNA-damage response, colony formation assays, EDU assays, flow cytometry and γH2AX assay were used with or without radiation exposure, separately. The quantities of the autophagosomes and autolysosomes by immunofluorescence were calculated. Autophagic microstructure were discovered by transmission electron microscopy, and the study also repeated in vivo by nude mice. Western blot assay was applied to prove changes in relative proteins. We found that suppressing ATP6V1C1 increased the sensitivity of ESCC cells after RT. Silencing ATP6V1C1 with IR suppressed the tumor growth and promoted autophagy. Besides, the underlying mechanism of ATP6V1C1, which is not fatally disrupted, is that ATP6V1C1 with ionizing radiation (IR)decreased apoptosis and inhibited autophagy may by activating mTOR signaling to suppress radiosensitivity for ESCC cells. Thus, we first reported that the ATP6V1C1 may represent a potential radiotherapeutic target by effect on radiation sensitivity for ESCC.
放射治疗是诊断为食管鳞状细胞癌（ESCC）患者的主要治疗方式之一。先前的研究表明，化疗耐药性可能与血管三磷酸腺苷酶（V-ATPase）亚基基因的过度表达有关。然而，V-ATPase 亚基基因是否在放射治疗耐药性中起作用尚不清楚。本研究旨在探讨 ATP6V1C1 在放射治疗耐药性中的作用。使用 siRNA 和质粒分别转染 TE13（人 ESCC 细胞）中低表达的 ATP6V1C1 和 ECA109（人 ESCC 细胞）中高表达的 ATP6V1C1。通过无辐射暴露和有辐射暴露分别进行集落形成试验、EDU 试验、流式细胞术和 γH2AX 试验，观察增殖、放射敏感性、细胞凋亡和 DNA 损伤反应。通过免疫荧光法计算自噬体和自溶体的数量。通过透射电子显微镜观察自噬的微观结构，并在裸鼠体内重复该研究。应用 Western blot 试验证明相对蛋白的变化。我们发现，抑制 ATP6V1C1 可增加 ESCC 细胞在 RT 后的敏感性。用 IR 沉默 ATP6V1C1 可抑制肿瘤生长并促进自噬。此外，ATP6V1C1 并非致命性破坏的潜在机制是，ATP6V1C1 与电离辐射（IR）一起降低细胞凋亡并抑制自噬，可能通过激活 mTOR 信号通路抑制 ESCC 细胞的放射敏感性。因此，我们首次报道，ATP6V1C1 通过影响 ESCC 细胞的辐射敏感性，可能成为放射治疗的潜在靶点。
