脂解激活脂蛋白受体LSR调控胆固醇稳态促进上皮性卵巢癌侵袭转移的机制研究

Ovarian cancer is the most lethal gynecological carcinoma and up to 75% newly diagnosed patients accompanied with metastasis to abdominopelvic cavity. Dysregulation of lipid metabolism is the variable prognosis factor of ovarian cancer, but the functional molecular mechanism is not very clear. Previously, we found that LSR was expressed significantly higher in cancer tissues than normal ovarian tissues and predicted a poor prognosis. Knockdown of LSR inhibited the invasive ability of ovarian cancer cells both in vitro and in vivo, and overexpression of LSR showed the opposite results, suggesting the oncogenic roles of LSR in the invasion and metastasis of ovarian cancer. However, the functional mechanism was largely unknown. Based on previous findings, we proposed a scientific hypothesis: "LSR might activate EGFR/AKT/SREBP-1/STARD3 pathway to regulate cholesterol homeostasis to enhance invasion and metastasis ability of ovarian cancer ". In order to verify the hypothesis, we will apply gene expression database, human clinical resource, human ovarian cancer cells and ovarian cancer model in situ, to profoundly reveal the role of LSR in ovarian cancer invasion. We will go further to clarify the molecular mechanisms underlying LSR mediated EGFR/AKT/SREBP-1/STARD3 pathway to dysregulate cholesterol homeostasis, and to provide lipoprotein receptor LSR as a new theoretical evidence to diagnose and treat ovarian cancer.

卵巢癌是病死率最高的妇科恶性肿瘤，多达75%初诊患者已有盆腹腔内播撒。脂质代谢是影响卵巢癌预后的可变因素，但分子机制远未阐明。我们的预实验结果提示脂蛋白受体LSR在卵巢癌组织中表达上调并且提示预后不良,干扰LSR表达显著抑制卵巢癌细胞侵袭能力，而过表达LSR则结果相反。说明LSR在卵巢癌侵袭转移中起重要作用，但其作用机制还需进一步探讨。基于前期结果，课题组提出假说：LSR可能通过调控EGFR/AKT/SREBP-1/STARD3通路影响胆固醇稳态，导致卵巢癌侵袭转移的发生。为了验证这一假说，本研究将通过基因表达数据库、人类临床资源、卵巢癌细胞系和原位卵巢癌模型，深入研究LSR在卵巢癌侵袭转移中的重要作用，明确LSR通过调控EGFR/AKT/SREBP-1/STARD3通路影响胆固醇稳态促进侵袭转移的作用机制。本研究将从LSR这个新视点为卵巢癌诊治提供理论基础。

为阐明脂解激活脂蛋白受体（LSR）调控胆固醇稳态促进上皮性卵巢癌侵袭转移的机制，本课题通过基因表达数据库、人类临床资源和原位卵巢癌模型，采用生物信息学、全外显子测序、临床资料分析、Western blot、Real-time PCR、腺病毒载体转染、RNA干扰、过表达等手段，从分子、细胞、组织及动物水平等层次，对LSR参与脂代谢调节卵巢癌发生发展及中国人群卵巢癌基因特点、生殖预后等进行了初步研究。首先通过卵巢癌组织对比正常卵巢组织构建组织芯片，从蛋白水平评估LSR与预后的关系、LSR蛋白表达位置及LSR与其互作蛋白RIPK4的关系探究；进而利用Western blot和Real-time PCR技术筛选LSR高/低表达的卵巢癌细胞系，构建稳转干扰/过表达LSR细胞株，并研究不同血脂情况时在体外、体内层面的侵袭能力；接着采用CHIP-PCR实验和荧光素酶报告基因实验确定转录因子YY1与LSR的结合及其结合位点；最后利用LSR功能缺失和回复实验及其干扰、抑制通路研究，确定信号通路调节胆固醇代谢的下游分子机制。综合上述结果，本研究从脂质代谢这个新视点为揭示卵巢癌侵袭转移的机制奠定基础，同时也为卵巢癌诊治提供了理论新思路，相关研究发表SCI论文4篇，待发表SCI论文2篇。此外，为探究LSR作为一种卵巢标志物进进行诊断和预后评估的可行性，前期在检测方法的构建方面进行了探究，提出了多种检测方法，获得相关专利授权3项。通过课题的设计和实施，培养了在职博士生1名、硕士生3名，且均已取得相应学位。项目投入经费21万元，支出21万元，各项支出基本与预算相符。