肺癌相关MSC通过重塑肺癌细胞三羧酸循环上调α酮戊二酸促进肺癌EMT与干性的机制研究

肿瘤EMT与干性导致肿瘤进展、复发转移和治疗耐受。肿瘤微环境与肿瘤EMT以及干性密切相关，肿瘤代谢调控表观是新兴领域，其在肿瘤EMT与干性中研究尚浅。我们前期建立肺癌相关MSCs（LC-MSCs）稳定诱导肺癌EMT与干性的共培养模型，通过RNA测序发现肺癌细胞三羧酸循环重塑上调的α酮戊二酸（αKG）直接促进肺癌EMT与干性，且降低组蛋白甲基化水平。我们认为：LC-MSCs提供的肿瘤微环境通过重塑肺癌细胞三羧酸循环上调αKG水平，从而促进肺癌EMT与干性。本项目将以LC-MSCs与肺癌细胞共培养模型为基础，通过分子生物学、质谱代谢组学、表观遗传学等研究手段重点研究αKG调控组蛋白去甲基化促进肺癌EMT与干性的分子机制，并在临床样本中验证，评价靶向异柠檬酸脱氢酶以降低αKG治疗肺原位移植瘤的疗效，以期揭示肿瘤微环境通过改变肿瘤代谢调控表观遗传从而促进肿瘤EMT与干性的分子机制。

Tumor epithelial–mesenchymal transition (EMT) and stemness lead to tumor progression, recurrence, metastasis and treatment tolerance. Tumor microenvironment is closely related to EMT and stemness. Metabolism regulated epigenetics is a new field in tumor study. However, its influence on EMT and stemness is little known. We established a co-culture model of lung cancer-associated mesenchymal stem cells (LC-MSCs) and lung cancer cells, in which the characteristics of EMT and stemness was induced stably in tumor cells. The result of RNA sequencing showed that alpha ketoglutarate (αKG), upregulated by tricarboxylic acid (TCA) cycle remodeled in lung cancer cells, directly promoted EMT and stemness of lung cancer cells, and decreased histone methylation level. As a result, we hypothesize that the tumor microenvironment provided by LC-MSCs can upregulate αKG level by remodeling the TCA cycle of lung cancer cells, thus promoting EMT and stemness of lung cancer. Based on the co-culture model of LC-MSCs and lung cancer cells, the present project will focus on the molecular mechanism of αKG regulating histone demethylation to promote EMT and stemness of lung cancer by means of molecular biology, mass spectrometry-based metabonomics and epigenetics. We will also confirm this mechanism in lung cancer samples from patients and evaluated the efficacy of targeting isocitrate dehydrogenase to reduce αKG in the treatment of orthotopic lung transplantation tumor model. Our study will reveal the molecular mechanism of tumor microenvironment promoting EMT and stemness by altering tumor metabolism and then epigenetic modulation.