Gao Ying, Wei Guangyan, Yu Hua, Li Shuping, Tang Yuhao, Yue Xin, Chen Yong, Zhan Meixiao, Wu Jian
Department of Radiation Oncology, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China.
Cancer Center, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China.
Cell Death Differ. 2025 Apr;32(4):689-701. doi: 10.1038/s41418-024-01411-5. Epub 2024 Nov 12.
Radiotherapy (RT) is one of the main therapies for hepatocellular carcinoma (HCC), but its effectiveness has been constrained due to the resistance effect of radiation. Thus, the factors involved in radioresistance are evaluated and the underlying molecular mechanisms are also done. In this present study, we identified Integrin β6 (ITGB6) as a potential radioresistant gene through an integrative analysis of transcriptomic profiles, proteome datasets and survival using HCC cases treated with IR. We show that ITGB6 functionally contributed to radioresistance by activating autophagy through a series of in vitro and in vivo methods, such as clonogenic assays, autophagy flux (LC3B-GFP-mCherry reporter) analysis and a subcutaneous transplantation model. Mechanically, ITGB6 binds to Annexin A2 (ANXA2) and enhanced its stability by competitively antagonizing proteasome mediated ANXA2 degradation, thereby promoting autophagy and radioresistance. Notably, HCC radioresistance was significantly improved by either blocking ITGB6 or autophagy, but the combination was more effective. Importantly, ITGB6/ANXA2 axis triggered autophagic program endowed HCC cells with radioresistant activity in a radiated patient-derived xenograft (PDX) model and hydrodynamic injection in liver-specific Itgb6-knockout mice, further supported by clinical evidence. Together, our data revealed that ITGB6 is a radioresistant gene stabilizing the autophagy regulatory protein ANXA2, providing insights into the biological and potentially clinical significance of ITGB6/ANXA2 axis in radiotherapy planning of HCC.
放射治疗（RT）是肝细胞癌（HCC）的主要治疗方法之一，但其有效性因辐射抗性作用而受到限制。因此，对涉及辐射抗性的因素进行了评估，并对潜在的分子机制也进行了研究。在本研究中，我们通过对接受放疗的HCC病例的转录组图谱、蛋白质组数据集和生存率进行综合分析，确定整合素β6（ITGB6）为潜在的辐射抗性基因。我们通过一系列体外和体内方法，如克隆形成试验、自噬通量（LC3B-GFP-mCherry报告基因）分析和皮下移植模型，表明ITGB6通过激活自噬在功能上促进了辐射抗性。从机制上讲，ITGB6与膜联蛋白A2（ANXA2）结合，并通过竞争性拮抗蛋白酶体介导的ANXA2降解来增强其稳定性，从而促进自噬和辐射抗性。值得注意的是，阻断ITGB6或自噬均可显著提高HCC的辐射抗性，但联合使用更为有效。重要的是，在辐射的患者来源异种移植（PDX）模型和肝特异性Itgb6基因敲除小鼠的水动力注射中，ITGB6/ANXA2轴触发的自噬程序赋予HCC细胞辐射抗性活性，临床证据进一步支持了这一点。总之，我们的数据表明ITGB6是一个稳定自噬调节蛋白ANXA2的辐射抗性基因，为ITGB6/ANXA2轴在HCC放疗计划中的生物学和潜在临床意义提供了见解。
