PKCα与UNC5B相互作用调控膀胱癌细胞药物敏感性的分子机制

PKCα is a member of Protein kinase C (PKC) family and involved in the regulation of apoptosis and drug resistance in bladder cancer cells. A proto-oncogene named netrin-1 can activate PKCα, then lead to the proliferation of tumor cells and reduce their sensitivity to cisplatin. UNC5B is one of netrin-1 dependence receptors and plays a role in the induction of tumor cell apoptosis. The previous studies showed that: Netrin-1 and UNC5B were expressed in bladder carcinoma and participate in the cellular apoptosis. The bladder cancer cells were treated with PKC inhibitor and activator and also transfected with PKC siRNA, we found that netrin-1/UNC5B signaling pathway was closely related to PKCα activation state. However, the mutual relation of PKCα, netrin-1 and UNC5B, and how PKCα participates in netrin-1/UNC5B signal pathway in bladder carcinoma and regulates cisplatin resistance are not clear. In this study, by combination of the basic with the clinics, we intend to perform specific research on the mutual relation of PKCα, netrin-1 and UNC5B to clarify the molecular mechanisms of netrin-1/UNC5B signal pathway PKCα participated in the regulation of cisplatin resistance, providing new ideas of molecular targeted therapy for bladder carcinoma.

蛋白激酶C（PKC）家族中的PKCα参与调控膀胱癌细胞的凋亡和耐药。原癌基因netrin-1可活化PKCα促进肿瘤细胞增殖并且降低顺铂的化疗敏感性。UNC5B是netrin-1依赖性受体之一，具有诱导肿瘤细胞凋亡作用。前期工作结果显示：netrin-1/UNC5B在膀胱癌中存在表达并参与癌细胞凋亡；对膀胱癌细胞给予PKC抑制剂及激活剂和转染PKC siRNA，发现netrin-1/UNC5B与PKCα活化状态密切相关。然而PKCα和netrin-1以及UNC5B的相互关系，PKCα是如何参与netrin-1/UNC5B信号通路调控膀胱癌细胞对顺铂耐药的分子机制尚不明确。本研究拟采用基础和临床相结合的手段，进行PKCα和netrin-1及UNC5B三者相互关系的研究，阐明PKCα参与netrin-1/UNC5B信号通路调控膀胱癌细胞对顺铂耐药的分子机制，为膀胱癌的分子靶向治疗提供新的思路。

我们之前的研究发现PKC可以激活Netrin-1的表达和Netrin-1信号通路的活性，本研究组继而研究了PKC是否能够通过调控Netrin-1信号通路增加膀胱癌细胞耐药性。用PKC激活剂PMA处理BIU-87细胞24小时并且在敲除Netrin-1的细胞中用PKC激活剂。用PKC抑制剂alphoatin C处理膀胱癌细胞系T24，并且在敲除Netrin-1的细胞中使用PKC抑制剂。在这些细胞中使用cisplatin顺铂（5μg/ml）处理24小时。我们分别检测了膀胱癌细胞的细胞存活，细胞凋亡，细胞凋亡相关蛋白caspase-3和cleaved caspase-3的表达情况，从而验证了在膀胱癌化疗过程中，Netrin-1通过拮抗UNC5B参与PKCα介导的顺铂耐药。项目资助发表SCI论文2篇，核心论文3篇，待发表SCI论文1篇。培养硕士2名，均已取得硕士学位。项目投入23万元，支出19.4406万元，各项支出基本与预算相符。剩余经费3.5594万元，剩余经费计划用于本项目研究后续支出。