肝癌协定方逆转NK细胞功能低下治疗乙肝相关肝癌的机制研究

NK cells often exhibited reduced infiltration and impaired functional activities in patients with chronic HBV infection (CHB) or hepatocellular carcinoma (HCC). NK-cell-based therapeutic strategies are becoming increasingly attractive. We found Ganaixieding decoction (GAXD) had a potential therapeutic effect in tumor model of human HBV-related HCC in nude mice: suppression of cell proliferation and angiogenesis as well as HBV replication. We also found GAXD inhibited the activation of STAT3. Studies suggest that blockage of STAT3 in hepatocellular carcinoma cells augments NK cell functions via reversing HCC–induced immune suppression. So, we suppose that GAXD may reverse the immune tolerance of NK cells in the tumor microenvironment, and reactivate the immunological function of NK cells, thus enhancing the therapeutic effect on HBV- related HCC. In this study, we try to clarify the molecular mechanism of GAXD on NK cells, and whether NK cells play a key role in GAXD.

慢性乙肝感染和肝癌患者体内NK细胞的功能受到明显抑制，改善和提高NK细胞的功能成为治疗这类肝脏疾病的新的突破口。申请人将临床经验药方肝癌协定方（GAXD）应用于乙肝相关肝癌移植瘤裸鼠模型，观察到GAXD有效抑制肿瘤增殖和血管增生，并清除病毒，而且发现GAXD抑制了STAT3信号通路的活化。已知抑制肝癌细胞中的STAT3可以激活肝癌微环境中NK细胞的活性，从而逆转肿瘤诱导的免疫逃逸。因而，我们推测GAXD可能对肝脏富集的NK细胞有调节作用，通过逆转肿瘤微环境诱导的NK细胞功能低下发挥作用。本课题拟构建DEN诱导的HBV转基因小鼠模型，并设计了体外细胞模型，检测与NK细胞免疫功能活性调节相关的关键分子的变化，逐步深入探讨GAXD是否能逆转乙肝相关肝癌微环境中NK细胞的功能低下并阐明其分子机制，还通过NK细胞清除实验明确NK细胞是否在GAXD的治疗中起着关键作用。

本课题探讨基于STAT3信号通路的肝癌协定方（GAXD）是否能逆转乙肝相关肝癌的微环境中NK细胞功能低下并阐明机制，从而解答中药复方对机体免疫系统的具体调控机制并为临床应用提供数据支持。我们在细胞水平上证实了GAXD含药血清改变了HepG2.2.15细胞表面NK细胞相关配体的表达，从而增强了NK92细胞对HepG2.2.15细胞的杀伤活性；在动物模型上证实了GAXD治疗后抑制了Hepa1-6肿瘤的生长，瘤内NK细胞的比例和活化水平明显增强，当清除NK细胞后，GAXD抑制Hepa1-6肿瘤生长的疗效消失。本课题的研究成果拓深了中医药在免疫调节方面的研究，特别是当一些化疗药、靶向药引起免疫功能抑制或受损时，与之联用，从而发挥中医药整体治疗和辨证施治的优势。