长链非编码RNA EGOT通过招募hnRNPH1促进pre-SUMF1选择性剪切提高乳腺癌细胞对紫杉醇敏感性的分子机制研究

紫杉醇耐药是乳腺癌一线化疗失败的主要原因，但是分子机制并不完全清楚。申请人对乳腺癌新辅助样本行转录组测序，识别lncRNA EGOT在紫杉醇敏感的病人中显著上调表达。敲降EGOT，溶酶体自噬降低，紫杉醇敏感性降低。后续测序明确EGOT靶基因SUMF1，后者催化硫酸酯酶活性，增强溶酶体功能；RNA pull-down初步揭示EGOT与选择性剪切蛋白hnRNPH1结合。敲降hnRNPH1，成熟SUMF1 mRNA降低。同时，初步揭示KDM3A/B介导H3K27ac激活EGOT转录表达。因此，提出KDM3A/B-H3K27ac-EGOT-hnRNPH1-pre-SUMF1轴促进SUMF1表达，增强溶酶体自噬，提高乳腺癌细胞对紫杉醇的敏感性科学假说。项目将整合临床样本、质谱、RIP、RNA pull-down、ChIP等实验手段，多层面、多角度系统研究，阐明分子机制，为解决紫杉醇耐药提供重要线索。

Paclitaxel resistance of breast cancer cell is the major cause leading to the failure of first line chemotherapy. However, the mechanism is still in dark. Our previous study confirmed that lncRNA EGOT was upregulated in breast cancer patients with high sensitivity to paclitaxel. Furthermore, we found that EGOT knockdown reduced lysosomal autophagy and paclitaxel sensitivity of breast cancer cell in vitro. Further studies indicate that EGOT may exhibit its function via promoting alternative splicing of pre-SUMF1 by scaffolding hnRNPH1. In addition, EGOT itself can be transcriptionally activated by KDM3A/B mediated H3K27ac modification. To confirm this hypothesis, integration analysis of breast cancer tissues in bio bank, RNA pull-down, mass spectrometric analysis, RIP and ChIP assays would be applied to explore the potential mechanism by which EGOT enhancing lysosomal autophagy sensitizes paclitaxel cytotoxicity via promoting alternative splicing of pre-SUMF1 by scaffolding hnRNPH1 in human breast cancer, offering a vital clue to overcome paclitaxel resistance.