UNC5D新型胞内裂解片段调控MZF1促凋亡转录促进膀胱癌细胞外源性调亡机制的研究

Identification of effective signaling pathways for inducing bladder cancer cell death has become an important frontier subject in the field of molecular oncology. Our recent work indicated a novel mechanism for favoring pro-apoptotic transcriptional regulation of E2F1 by the intracellular cleavage fragment of the dependence receptor UNC5D , which translocated into the nucleus and interacted with E2F1 upon intrinsic apoptotic stimulation. Further investigations showed that novel intracellular cleavage fragment of UNC5D generated upon extrinsic apoptotic stimuli , could translocate into the nucleus , interact with MZF1 to transactivate the death ligands and UNC5D, and induce apoptosis in bladder cancer cells. In this project, we aimed to further investigate the role of functional complex of novel intracellular cleavage fragment of UNC5D with MZF1 in extrinsic apoptosis pathway through a series of molecular biology methods such as Co-Immunoprecipitation, luciferase reporter assay, Chromatin Immunoprecipitation assay and DNA microarray. Furthermore, in vivo experiments from animals and clinical samples would be conducted to support the hypothesis that the novel intracellular fragment of UNC5D as transcription co-activator may enhance extrinsic apoptosis mediated by TNF α by forming a functional interaction with MZF1 to promote selective transactivation of the pro-apoptotic target genes. The findings of this study may provide novel insights in demonstrating the direct relation of active form of dependence receptors by enzymes with classical apoptosis pathway, illustrating the mechanism of selective transactivation for some transcription factors with multiple biological functions, and effective solutions to solve failure of apoptosis induced by extrinsic apoptotic stimuli.

鉴定有效诱导膀胱肿瘤细胞死亡的信号通路已成为分子肿瘤学领域的重要前沿课题。申请者最近的工作揭示了依赖性受体UNC5D在内源性凋亡刺激下产生胞内裂解片段，直接入核调控E2F1促凋亡转录的新颖机制。前期结果进一步提示UNC5D在外源性凋亡刺激下产生了新型的胞内裂解片段，该片段入核后可结合转录因子MZF1，活化死亡配体及UNC5D转录, 诱导膀胱癌细胞凋亡。本研究拟通过免疫共沉淀、荧光素酶报告基因分析、染色质免疫沉淀及DNA微阵列等分子生物学方法，并结合体内动物实验与临床标本检测结果，力图证明UNC5D胞内裂解段作为转录共激活子调控MZF1选择性促凋亡转录功能，增强TNF α介导的外源性凋亡的假说。本研究阐明了以UNC5D为代表的依赖性受体酶切活化形式与经典凋亡信号通路间的直接联系，为具有多重生物学功能的转录因子靶基因选择机制研究提供了新思路，也为解决外源性凋亡诱导失效的难题提供了有效方案。

鉴定有效诱导膀胱肿瘤细胞死亡的信号通路已成为分子肿瘤学领域的重要前沿课题。申请者最近的工作揭示了依赖性受体 UNC5D 在内源性凋亡刺激下产生胞内裂解片段，直接入核调控 E2F1 促凋亡转录的新颖机制。前期结果进一步提示 UNC5D 在外源性凋亡刺激下产生了新型的胞内裂解片段，该片段入核后可结合转录因子 MZF1，活化死亡配体及 UNC5D转录, 诱导膀胱癌细胞凋亡。本研究拟通过免疫共沉淀、荧光素酶报告基因分析、染色质免疫沉淀及 DNA 微阵列等分子生物学方法，并结合体内动物实验与临床标本检测结果，力图证明 UNC5D 胞内裂解段作为转录共激活子调控 MZF1 选择性促凋亡转录功能，增强 TNF α介导的外源性凋亡的假说。本研究阐明了以 UNC5D 为代表的依赖性受体酶切活化形式与经典凋亡信号通路间的直接联系，为具有多重生物学功能的转录因子靶基因选择机制研究提供了新思路，也为解决外源性凋亡诱导失效的难题提供了有效方案。