线粒体损伤对sorafenib诱导细胞凋亡的调控

Sorafenib can induce apoptosis or cell growth inhibition in tumor cells. Currently，as a small molecule compound,sorafenib is the only clinic drug that has been able to be used to treat advanced liver cancer and has shown potential efficiency.However, it has been shown not all the patients are suitable to accept sorafenib treatment since the tumors are not sensitive to sorafenib administration. In addition, high dosage of drug not only increases the economy burden, but also rusults in severe side-effects which has significantly blocked its therapeutical valuation. Our study will systematically investigate the molecullar mechanism underlying the apoptosis induced by sorafenib in liver tumor cells. We will analyze the mechanisms underlying the differrent response of liver tumor cells to sorafenib and find out the bio-marker molecule that can determin whether tumor cells are sensitive to sorafenib. Our primary experimental data have shown that some cultured liver tumor cells are sensitive to sorafenib-induced apoptosis, whereas, the others are not. Meanwhile, we observed that this differentiation may be related to mitochondria fragmentation injury. Our future work will aim to analyze the mechanism of how sorafenib induces mitochondria fragmentation injury, to test the regulation function of mitochondria in sorafenib- induced apoposis at both cell and molecule levles. We struggle to investigate how to sensitize liver tumor cells to sorafenib-induced cell death through mitochondira pathway.

Sorafenib可以诱导肿瘤细胞凋亡或生长抑制，是目前临床唯一一种可以用于有效治疗晚期肝癌的小分子药物。但临床工作发现部分肝癌患者对sorafenib敏感性差，治疗效果不明显。高剂量用药不但给增加了患者的经济负担，而且引起严重的副作用。我们认为阐明sorafenib诱导肝癌细胞凋亡的分子机制，从中找到可以决定肿瘤细胞对sorafenib诱导细胞凋亡是否敏感的标志性分子，将极大的推动该药物治疗肝癌的临床应用。初步实验结果显示不同肝癌细胞系对sorafenib诱导的细胞凋亡敏感性存在明显差异，这种差异与sorafenib能否诱导肿瘤细胞内线粒体片段化损伤有关。在此基础上，我们将进一步研究sorafenib可以诱导线粒体片段化损伤的分子机理。在细胞和分子水平上分析线粒体对Sorafenib诱导细胞凋亡信号的调控作用，并深入探讨通过线粒体途径增敏Sorafenib诱导肝癌细胞凋亡的可能性。

本研究利用体外培养的肝癌细胞和正常肝脏细胞，在细胞和分子水平上进行了初步预实验，初步阐明了线粒体融合分裂蛋白OPA1在介导Sorafenib选择性杀伤肿瘤细胞时发挥信号分选功能：1. 索拉菲尼能够诱导体外培养的细胞凋亡，但是细胞凋亡敏感性存在一定的差异。与正常培养的离体肝细胞相比，肝癌细胞对索拉菲尼更加敏感。2. 索拉菲尼能够在肝癌细胞内诱导线粒体形态发生变化，即产生过度片段化。3. 线粒体分裂融合分裂蛋白表达图谱发现线粒体膜融合蛋白OPA1被急剧下调。4. 可以初步在体外完成线粒体分离工作。为进一步研究线粒体对索拉菲尼的响应奠定初步基础。5. 完成了OPA1质粒表达载体的构建，转染了肝癌细胞和正常细胞，并获得稳定表达的细胞系。 6. 初步研究发现，OPA1基因沉默后细胞对索拉菲尼诱导的细胞凋亡更加敏感。上述实验结果已经初步证实了我们提出的Sorafenib诱导的细胞线粒体损伤在肝癌细胞死亡的发生发挥应答功能。