GLS1高表达的MDSCs介导非小细胞肺癌患者AZD9291原发耐药的功能和机制研究

三代EGFR-TKI AZD9291治疗非小细胞肺癌(NSCLC)的原发耐药机制不明｡研究表明MDSC参与肿瘤化疗耐药｡申请人前期发现AZD9291原发耐药患者MDSC中GLS1表达上调,且免疫抑制功能增强｡GLS1是谷氨酰胺代谢关键酶,可通过α-KG/mTOR/NF-κB通路调控细胞因子释放｡预实验提示MDSC通过IL-23激活IL-23R/STAT3/RORγ信号促进肿瘤存活｡故推测GLS1通过α-KG/mTOR信号促进MDSCs的免疫抑制功能,同时促进MDSC分泌IL-23调控肺癌细胞IL-23R/STAT3/RORγ信号进而影响AZD9291的敏感性｡本项目拟借助慢病毒过表达和敲减系统,结合细胞共培养､骨髓过继转移和PDX模型,从动物､细胞和分子水平阐明GLS1高表达MDSC促进AZD9291耐药的机制,为AZD9291不应答患者提供更个体化免疫联合靶向治疗策略及预后评估指标｡

The third-generation EGFR-TKI targeting drug AZD9291 has been approved for the treatment of non-small cell lung cancer (NSCLC), but there are still some patients who showed no response to it, and the mechanism of this primary resistance remains unclear. Studies have shown that myeloid-derived suppressor cells (MDSC) are involved in chemotherapy resistance in cancer patients. We found that the expression of GLS1 was up-regulated in MDSC of patients with primary AZD9291 resistance, which also showed stronger immunosuppressive function. GLS1 is a key enzyme in glutamine metabolism, and its downstream α-KG can regulate the release of cytokines through the mTOR/NF-κB pathway. It has been reported that MDSC activates IL-23R /STAT3/RORγ signaling by IL-23 to promote the survival of tumor cells. Therefore, we speculate that GLS1 enhanced mTOR signal to promote the immunosuppressant function of MDSCs through α-KG, while GLS1 promoted IL-23, a cytokine secreted by MDSC, to regulate IL-23R/STAT3/RORγ signaling in NSCLC cells by α-KG/mTOR signaling, thereby affecting the sensitivity of patients to AZD9291. With the application of lentivirus overexpression/knockout system and corresponding knockout mice, combined with the cell co-culture system, bone marrow adoptional metastasis and allograft model of human tumor, this project intends to elucidate the mechanism of MDSC function regulated by GLS1 at animal, cellular and molecular levels, as well as the mechanism of MDSC in AZD9291 resistance of NSCLC patients. This project innovatively revealed the function of GLS1 in MDSC cells, which is conducive to providing a more detailed personalized treatment strategy combined immunotherapy with targeted drugs for AZD9291 non-responsive NSCLC patients, and also provides a new indicator for prognosis evaluation.