半乳糖凝集素-3通过Wnt/β-Catenin通路调控上皮性卵巢癌转移及化疗敏感性的研究

Severe metastatic implants and chemotherapy resistance are two major causes for treatment failure in epithelial ovarian carcinoma (EOC), however, the specific mechanism is still not clear yet. In our previous study, we have found that Galectin-3 can have an influence on metastatic capability of ovarian cancer cells, and on chemotherapy sensitivity. By regulating the expression of Gal-3, β-catenin would change respectively. Moreover, there was a positive correlation in regards to the expressions of Gal-3 and β-catenin in the EOC tissues. These findings suggested that Gal-3 may function via the Wnt/β-catenin pathway in EOC。Based on our previous works, We will use Co-Immunoprecipitation, westernblot and immunofluorescence to explore the mechanism of Gal-3 regulation on metastatic capability, chemotherapy sensitivity through Wnt/β-Catenin. Nude mice of EOC model were used to verify the mechanism of Gal-3 regulation on metastatic capability, chemotherapy sensitivity. This study will help to clarify the mechanism of Gal-3 promoting metastatic capability and chemotherapy sensitivity in EOC, and it will provide new theoretical base and target for accurate treatment of EOC.

广泛种植性转移和化疗耐药是上皮性卵巢癌治疗失败的主要原因，但具体机制却仍不清楚。我们前期研究发现调控半乳糖凝集素-3（Gal-3）能影响卵巢癌细胞的转移能力与化疗敏感性，并引起β-Catenin相应变化，且在组织标本中，Gal-3与β-Catenin表达成正相关，提示Gal-3可能通过Wnt/β-Catenin通路起作用。本研究拟在前期研究的基础上，采用免疫共沉淀、westernblot和免疫荧光等技术，研究Gal-3如何通过Wnt/β-Catenin通路调控上皮性卵巢癌细胞转移能力和对卡铂/紫杉醇的敏感性，构建Gal-3过表达和低表达的上皮性卵巢癌裸鼠模型，验证Gal-3通过Wnt/β-Catenin通路调控其转移能力和对卡铂/紫杉醇敏感性的机制。本研究有助于阐明Gal-3促进卵巢癌发展和化疗耐药的机理，将为实现上皮性卵巢癌的精准治疗提供新的理论依据以及靶点。

卵巢癌是致死率最高的妇科恶性肿瘤，以铂为基础的化疗是目前的一线治疗方案，广泛种植性转移和化疗耐药是上皮性卵巢癌治疗失败的主要原因，但具体机制却仍不清楚。通过研究，我们发现Gal-3通过Wnt/β-catenin通路调控上皮性卵巢癌转移和化疗敏感性。1）临床样本提示：Gal-3在卵巢癌患者中与β-catenin表达具有相关性（r=0.304，P=0.001），前者为卵巢癌铂耐药和复发的独立风险因素，而后者为复发的独立风险因素。Gal-3高表达患者总生存率较差。2）Gal-3在上皮性卵巢癌中为癌基因，调控其表达可影响卵巢癌细胞侵袭、凋亡、增殖及化疗敏感性，WB实验发现上调Gal-3的卵巢癌细胞中Wnt通路关键蛋白表达上调，且耐药蛋白ABCG2升高，抗凋亡蛋白bcl2和Bax增多，在下调Gal-3的卵巢癌细胞中观察到相反结果。在上调Gal-3的卵巢癌中通过小分子XAV969抑制Wnt/β-catenin通路后，上调Gal-3的促侵袭以及铂耐药的作用被逆转，表明Gal-3是通过Wnt/β-catenin调控卵巢癌细胞的生物学特性。Co-IP试验提示Gal-3与β-catenin蛋白可相互结合。3）裸鼠成瘤实验进一步验证了上述结果，对瘤体中Wnt下游分子进行IHC，发现β-catenin、c-myc、cyclinD1与Gal-3表达呈正相关，同时，高表达Gal-3的肿瘤细胞出现EMT。4）进一步基因芯片寻找差异基因后发现：下调Gal-3显著影响卵巢癌细胞PIK3-Akt、FoxO、MAPK、Her2及胰岛素相关通路分子的表达。其相关的下游机制可能涉及细胞周期重分布、细胞凋亡和自噬。本研究阐明了Gal-3促进卵巢癌转移和化疗耐药的机理，可能为实现上皮性卵巢癌的精准治疗提供新的理论依据以及靶点。