程序性细胞死亡蛋白6（PDCD6）与卵巢癌细胞化疗敏感性的关系及其机制研究

Ovarian epithelial cancer is the leading killer among all gynecological malignancies. The prognosis of ovarian cancer is closely related to chemotherapy sensitivity. Some genes such as BRCA1 and BRCA2 or factors associated with proliferation and apoptosis are reported to affect chemotherapy sensitivity. Programmed cell death 6 (PDCD6) was first described as a pro-apoptotic protein. Recently we found that knockdown of PDCD6 expression by RNA interference (RNAi) surpressed the apoptosis and decreased the chemotherapy sensitivity in ovarian cancer cell lines SKOV-3 and OVCAR-3. Little is known about the relationship between PDCD6 and chemotherapy sensitivity. The purpose of the present study was to find out (a) the expression of PDCD6 in ovarian tumor tissue samples,(b) the relationship between PDCD6 and chemotherapy sensitivity in ovarian cancer cell lines,(c) the long non-coding RNA (lncRNA) which can mediate the expression of PDCD6 and its function,(d) the ubiquitin ligase which can degrade the protein of PDCD6,and (e) the effective drug or factor which can regulate the expression of PDCD6 and improve the chemotherapy sensitivity.

卵巢癌是致死率最高的妇科肿瘤。卵巢癌的预后与其化疗敏感性密切相关。研究表明，与卵巢癌发病相关的一些分子，如BRCA1、BRCA2，或与细胞增殖、凋亡相关的因子的表达异常，均可影响卵巢癌化疗敏感性。程序性细胞死亡蛋白6（PDCD6），是一种凋亡相关蛋白，近来本人发现干扰PDCD6表达后卵巢癌细胞的凋亡下降，化疗敏感性也显著降低。目前PDCD6与卵巢癌化疗敏感性的研究甚少，为此本课题拟：①检测卵巢组织标本中PDCD6的表达与化疗药物敏感性及预后的关系；②构建PDCD6的干扰和过表达质粒，转染卵巢癌细胞后，验证其与化疗敏感性的关系；③通过长链非编码RNA(lncRNA)芯片寻找可能调控PDCD6的lncRNA，验证并了解其调控方式；④探讨PDCD6蛋白的降解机制，了解其是否通过泛素化途径降解；⑤筛选出有效调控PDCD6表达的药物或分子,为提高化疗敏感性和改善治疗效果提供新的线索和依据。

目的：卵巢癌是致死率最高的妇科肿瘤。在卵巢癌患者中我们经常发现黄体生成素（LH）异常升高，这也预示着LH与卵巢癌的发生发展存在的一定关联。根据报道，LH能抑制卵巢癌细胞的凋亡。程序性细胞死亡蛋白6（PDCD6），又称之为凋亡相关蛋白2（ALG-2），是凋亡发生过程中的重要因子。因此本课题拟研究在卵巢癌中LH是否能抑制PDCD6的表达，以及LH是否能通过PDCD6抑制卵巢癌细胞的凋亡及其与化疗的关系。.方法：流式细胞仪检测LH和顺铂应用后细胞凋亡的改变。Western blotting和实时定量PCR检测PDCD6的表达情况。同时也检测相应信号传导通路的改变。动物实验进一步验证体外实验的结果。.结果：我们的研究结果发现LH能减少顺铂引起的细胞凋亡。另外LH能减少卵巢癌细胞中的PDCD6的表达。进一步的研究发现LH是通过PI3K/AKT 和 p44/42 MAPK信号传导通路抑制PDCD6表达的。动物实验发现LH能削弱顺铂的抗肿瘤作用。.结论：LH可以通过相关的信号传导通路抑制PDCD6从而减少卵巢癌细胞的凋亡，可见LH可以通过抑制凋亡影响卵巢癌的化疗敏感性。