ERAD抑制剂调节肿瘤细胞凋亡的表观遗传学机制研究

内质网相关蛋白降解(endoplasmic reticulum-associated protein degradation, ERAD)通路对于维持细胞稳态至关紧要。我们在研究中发现， ERAD抑制剂调节肿瘤细胞凋亡，其机制整合了ERstress 和表观遗传学原理：ERAD抑制剂抑制蛋白降解，引发ERstress, 破坏细胞内泛素平衡，使组蛋白去泛素化，解除其对前凋亡基因Noxa的转录抑制，利于 转录因子ATF4募集到Noxa的转录启动区。本项目拟进一步研究H2A.Z泛素化对Noxa启动区H2A-H2A.Z异型核小体稳定性的调节，利用 ChIP-seq 技术在全基因组范围内检测这个异型核小体的分布及对ATF4募集的影响，并结合免疫共沉淀和蛋白质谱技术寻找泛素化H2A.Z伴侣蛋白和辅助因子。对于ERAD抑制剂调节肿瘤细胞凋亡的表观遗传学机制的深入研究，可为开发新的高效抗肿瘤药物提供理论基础

The endoplasmic reticulum‑associated degradation (ERAD) pathway is essential for cancer cell homeostasis. We previously found ERAD inhibitors activated pro-apoptosis gene NOXA via an unanticipated mechanism that integrate ER stress response with an epigenetic mechanism to induce cell death. First, ERAD inhibitors block protein degradation and trigger ER stress. Second，the accumulation of ubiqitinated protein in cells lead to ubiquitn stress. Downregulation of histone ubiquitination relieve its inhibition on NOXA transcription and facilite recruiting transcriptional factor ATF4 to Noxa promoter. In this study, we will further discuss the role of ubiquitinated-H2A.Z on the stability of H2A-H2A.Z heterotypic nucleosomes located in Noxa promoter region . We will also use ChIP–seq to analysis the genome-wide distribution of H2A-H2A.Z heterotypic nucleosomes and investigate how they affect the recruitment of transcriptional factor ATF4 to Noxa promoter region. Finally, with the protein immunoprecipitation and mass spectrometry, we will identifify the cofactors of ubquitinated H2A.Z. These results will establish a novel connection between epigenetic mechanism and cancer cell apoptosis, and it might open a new window for cancer therapy.