MCM6预测肝癌索拉非尼耐药的价值及相关机制研究

Acquired resistance is a major limitation of hepatocellular carcinoma (HCC) treatment with the sorafenib. The Mini-chromosome maintenance protein 6 (MCM6) is essential for DNA replication initiation and elongation in eukaryotic cells. ..Our previous study found that MCM6 acts as an oncogene in the development of HCC and subsequently regulates metastasis in HCC. Our preliminary study further indicated that late stage HCC patients with low MCM6 expression benefit more from the treatment of sorafenib. RNA-seq sequencing proves that MCM6 could activate MAPK /ERK signal pathway. Thus, we hypothesized that MCM6 regulates sorafenib resistance via MAPK /ERK pathway in hepatocellular carcinoma. ..In this project, multiple methods including whole transcriptome sequencing and Co-Immunoprecipitation will be used to explore whether the expression pattern of single MCM6 or with other proteins involved in its signal pathway could predict sorafenib resistance in HCC cells. For further validatition, orthotopic mouse mode were established to investigate the changes of MCM6 during sorafenib treatment in vivo. Moreover, a clinical study will be performed to further verify the relationship between the expression of MCM6 in HCC and efficacy of sorafenib. The correlation of MCM6 mRNA expression in serum with HCC sorafenib resistance will also be propectively studied. ..The study in this grant proposal will contribute to elucidate the mechanism of sorafenib resistance in HCC. Moreover, a predictive model by dynamically monitoring serum MCM6 changes may greatly help to establish an noninvasive detection platform to screen the occurance of acquired resistance during sorafenib treatment. Thus may improve the molecular targeting treatment by individual genotyping.

晚期肝癌对索拉非尼耐药是影响疗效的严峻问题。MCM6是DNA复制延伸的关键蛋白。前期研究证明MCM6能促进肝癌细胞的侵袭转移；血清MCM6与术后早期复发相关。近期预实验发现：索拉非尼在MCM6低表达肝癌患者中的疗效明显优于高表达患者；转录组测序证实索拉非尼耐药株中MCM6对MAPK/ERK通路激活起正调控作用。据此推测MCM6通过MAPK/ERK信号通路影响肝癌索拉非尼耐药。本项目拟采用RNA-seq、CO-IP等技术分析MCM6单独或联合其信号通路相关蛋白在索拉非尼耐药中的预测价值；其次建立裸鼠皮下、肝原位移植瘤模型，验证MCM6对索拉非尼敏感性的影响；最后结合临床样本分析组织及血清中MCM6与索拉非尼耐药的关系。本项目将从新的视角揭示肝癌索拉非尼耐药机理；同时，外周血无创检测MCM6，将为未来转化研究—构建耐药动态监测平台提供有力的数据支持，使基因分型基础上的个体化靶向治疗更趋精准。

原发性肝癌肿瘤相关致死率高，极易发生肝内复发和肝外远处转移，其中肺转移占据了肝外转移的一半以上，是影响肝癌患者长期生存的主要因素。尽管针对肝癌的靶向治疗的发展已经有效地治疗原位病灶，但对发生肺转移的患者收效甚微。肿瘤转移是一个多步骤的复杂过程不仅受多种分子通路的调控也与机械微环境密切相关。本研究中我们发现细胞迁移诱导透明质酸结合蛋白(CEMIP)是一种重要的力学相关因子，它通过激活肺成纤维细胞(LFs)、促进胶原蛋白的产生增加肺基质硬度，并诱导肺转移前生态位形成。肺基质硬度的增加可促进转移灶血管生成。特发性肺间质纤维化(IPF)的一线用药吡非尼酮，可抑制由CEMIP介导的TGF-β1/Smad信号通路激活，从而降低肺转移灶硬度。两者联合用药可增强索拉非尼的抗血管生成作用。此外，通过临床样本的验证得出CEMIP有望成为肝癌肺转移潜在的力学标志物和治疗靶点。抗血管生成联合抗纤维化治疗或可成为肝癌肺转移的破局之路。.. 我们的研究针对肝癌患者数量众多，异质性明显，目前关于肺转移尚无有效治疗手段这样一个临床问题，从肿瘤力学微环境这一角度，帮助临床医生理解为什么不同肝癌患者在肺转移转归方面表现出巨大差异。基于转移灶微环境的表型表征，对肝癌患者进行风险分层。为以抗纤维化药物为代表的肿瘤力学治疗开辟新的道路，同时也有助于提高抗血管生成药物索拉非尼在肝癌肺转移中的治疗地位。