肝癌微环境参与经导管肝动脉化疗栓塞治疗抵抗的机制研究

The hepatoma microenviroment plays an important role in occurrence and development of hepatomas. There are two important characteristics of hepatoma microenviroment: inflammation and ischemia. Transhepatic Arterial Chemotherapy And Embolization (TACE) is a common clinical therapy for hepatomas. However, the overall curative effect of TACE is poor. Our previous research indicated that some indexes of hepatoma microenviroment, such as inflammatory classifications, fibrosis degrees and hypoxic levels, foreshow the bad prognosis of patients after TACE. This fact indicates hepatoma microenviroment related factors may be involved in resisting TACE. But the specific mechanisms are only partially understood. According to the characteristics of hepatoma microenvironments, our study project aims to screen out the posssibe key cells, cytokines and ischemia related factors by using patients’ records and their clinical samples of HCC. Furthermore, we would verify the impact of above-mentioned factors (key cells, cytokines and ischemia related factors) on hepatoma cells’ features: adapted to hypoxic and undernourished microenviroment and resisting chemotherapy. Based on the above study, we wanna verify the mechanisms of the chemotherapy-resistant of hepatoma cells by intervening site-specifically in microenviroment related factors. Eventually, to develop new embolization agents of TACE for promoting curative effect by analyzing the correlation between microenviroment related factors and prognosis of TACE.

肝癌微环境在肝癌发生发展中发挥重要作用，炎症和缺血是肝癌微环境的两大重要特征。经导管肝动脉化疗栓塞（TACE）是肝癌常用的治疗手段，但总体疗效不理想。我们前期研究发现，肝癌微环境相关指标如炎症评级、纤维化程度及缺氧水平等较高的患者行TACE治疗后多预后不良，提示肝癌微环境相关因素可能参与了TACE治疗抵抗，但具体机制尚不明确。本课题拟利用肝癌临床标本及病例资料，针对肝癌微环境炎症及缺血特征，筛选可能参与TACE治疗抵抗的关键细胞、因子及缺血相关因素；再通过体内外实验验证上述细胞、因子及缺血相关因素对肝癌细胞适应缺氧缺营养微环境及化疗抵抗能力的影响；在此基础上通过对微环境相关因素的靶向干预明确微环境诱导肝癌细胞产生TACE治疗抵抗的机制；最后在临床分析微环境相关指标与TACE治疗预后的相关性, 探索形成新的TACE栓塞剂。预期结果有助于为提高肝癌TACE治疗效果提供新的理论依据和治疗策略。

肝癌发生与肝前体细胞（HPCs）异常激活和分化密切相关，我们解析了促进肝前体细胞激活和异常分化的肿瘤微环境，并且阐明了详细的作用机制，针对关键的作用靶点，我们设计了可有效抑制肝癌发生的治疗策略。利用TCGA公共数据库、原发性肝癌动物模型和临床肝癌标本，采用组织芯片和单细胞测序技术对肝癌微环境进行解析。结果发现，肝癌炎症微环境中巨噬细胞和中性粒细胞的数量及其相关趋化轴与肝癌患者术后生存期负相关。在此基础上研究了巨噬细胞和中性粒细胞的CCL2/CCR2和CXCLs/CXCR2趋化轴抑制剂干预炎症微环境对肝癌TACE治疗疗效的影响。结果显示CCL2/CCR2和CXCLs/CXCR2趋化轴抑制剂单独和联合使用均可显著提高大鼠肝癌TACE治疗的效果，抑制肝癌的大小和数量，降低炎症反应和肝损伤水平，延长肝癌大鼠的生存期。TNF-α是肝脏炎症微环境中重要的炎症因子，我们发现TNF-R2 通过 hnRNPK 调节 YAP 的转录活性。hnRNPK直接结合并稳定目标基因YAP 以促进其转录，在HPCs的恶性转化过程中发挥重要作用。由于肝脏中存在大量巨噬细胞，利用其吞噬特性，我们制备了靶向巨噬细胞含化疗药物及诱发巨噬细胞死亡药物的脂质体，一方面可以使化疗药物在肝脏中富集，另一方面可以通过诱发巨噬细胞死亡达到缓释化疗药物和抑制肿瘤发生的双重作用。上述治疗策略可有效抑制肝癌发生发展。另外，我们也探索了通过靶向杀伤HPCs预防肝癌发生和复发的新方案。凋亡HPCs来源的细胞外囊泡中包含死亡信号，被肝癌起始细胞摄取后能杀死肝癌起始细胞，从而抑制肝癌发生或复发。我们的研究发现为临床的肝癌患者TACE治疗提供了有效的治疗策略。