IL-6对肝癌干细胞耐药索拉菲尼的调控机制

Sorfenib is a multikinase inhibitor and the only FDA-approved therapeutic agent for advanced hepatocellular carcinoma (HCC). However, this agent only has a limited therapeutic benefit as it extends the median survival to just 8-12 weeks. Most patients develop adaptive resistance soon after drug withdrawal. A better understanding of the molecular mechanisms governing Sorafenib resistance is essential for developing novel strategies to improve the treatment outcome. Our preliminary studies suggest that liver cancer stem cells (LCSCs) may play a major role in mediating resistance to anti-angiogenic therapy, and the major pro-inflammatory cytokine interleukin 6 (IL-6) may be a key regulator for the biological properties of LCSCs. We hypothesize that LCSCs are a key cell type responsible for the treatment resistance to Sorafenib, and IL-6 plays a critical role in regulating LCSCs. In this project, we aim to (1) identify and characterize the key subtype of LCSCs responsible for treatment resistance to Sorafenib; (2) explore the key molecular pathways involved in the regulatory role of IL-6 on LCSCs; and (3) evaluating the therapeuitc potential of combinatorial use of IL-6 blockade with Sorafenib in HCC. The data generated by the studies planed in this project will be invaluable in facilitating a rational design of the drugs targeting LCSCs in order to improve the therapeutic outcomes for patients with advanced HCC.

多种激酶血管生成抑制剂索拉菲尼是目前唯一被FDA批准治疗进展期肝癌的分子靶向药物，但经该药治疗的患者其中位生存期仅有8-12周，耐药已成为其临床应用的瓶颈。本项目前期研究显示，肝癌干细胞在抗血管生成治疗方面起到了重要作用，而IL-6作为索拉菲尼反应的生物标记物，与肝癌干细胞耐药密切相关。因此，本项目通过建立耐药HCC细胞株，利用干细胞标记物分选出耐药肝癌干细胞，明确该类型细胞中IL-6通路表达谱；并通过调节这些干细胞中IL-6的信号，观察对肝癌干细胞生物学特性的影响，特别是对干细胞成瘤性的影响，阐释IL-6对肝癌干细胞耐药索拉菲尼的调控机制；建立NOD/SCID小鼠皮下移植瘤模型和DEN诱导肝癌模型，通过阻断IL-6通路，验证肝癌干细胞依赖IL-6通路产生耐药性这一假设。本项目将为肝癌合理用药和新药研发提供可靠的科学依据。

本研究首先建立耐药索拉菲尼的HCC细胞株，利用建立的耐药 HCC 细胞株，通过干细胞标记物分选出耐药肝癌干细胞（LCSCs），明确该类型细胞中 IL-6 通路表达谱；通过刺激或阻断 IL-6，检测干细胞标记物、干性标记物等表达水平的变化，分析体外和体内肿瘤细胞生物学行为的改变，阐释 IL-6 对 LCSCs 耐药抗血管生成药物的调控机制；建立 NOD/SCID小鼠皮下移植瘤模型和 DEN 诱导肝癌模型，通过阻断 IL-6 通路，验证 LCSCs 依赖 IL-6 通路产生耐药性这一假设，并尝试通过阻断 IL-6 联合索拉非尼改善对肝癌的疗效。现已成功建立耐药索拉菲尼HCC细胞株，即Huh7和PLC/PRF/5两种耐药细胞系，并对其进行了相关实验，证明了耐药株与对照细胞株之间明显的差异。LCSCs分选正在进行，分选成功后在一年内实施下一步实验以明确该类型细胞中 IL-6 通路表达谱。拟为肝癌合理用药和新药研发提供可靠的科学依据，有利于提高肝癌的治疗水平。