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.

放疗 （RT） 是肝细胞癌 （HCC） 的主要疗法之一，但由于放疗的耐药作用，其有效性受到限制。因此，评估了涉及放射抗性的因素，并完成了潜在的分子机制。在本研究中，我们通过对转录组学谱、蛋白质组数据集和使用经 IR 治疗的 HCC 病例的生存率进行综合分析，确定整合素 β6 （ITGB6） 是一种潜在的放射抗性基因。我们表明，ITGB6 通过一系列体外和体内方法激活自噬，如克隆形成测定、自噬通量 （LC3B-GFP-mCherry 报告基因） 分析和皮下移植模型，在功能上促进了放射抗性。在机械上，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，从而促进自噬和放射抗性。值得注意的是，通过阻断 ITGB6 或自噬，HCC 放射耐药性得到显著改善，但联合使用更有效。重要的是，ITGB6/ANXA2 轴触发自噬程序在辐射患者来源的异种移植物 （PDX） 模型中赋予 HCC 细胞放射抗性活性，并在肝脏特异性 Itgb6 敲除小鼠中进行流体动力学注射，进一步得到临床证据的支持。总之，我们的数据揭示了 ITGB6 是一种稳定自噬调节蛋白 ANXA2 的放射抗性基因，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。