虫草素对EGFR/T790M突变非小细胞肺癌的抑制作用及分子机制研究

Mounting evidences showed that the most intractable problem in NSCLC treatment is drug resistance caused by the T790M mutation in EGFR kinase domain. Therefore，it is imperative to seek for novel EGFR inhibitors to conquer this problem. Traditional Chinese medicine is a treasure trove gifted by nature to cure disease. Cordyceps sinensis（Berk.）Sacc is a valuable medicine used for lung cancer treatment in clinical trials. Our group have focused on this medicine and studied its chemical components. Cordycepin, one of the active constituents of Cordyceps, attracted our attention for its chemical structure is similar as ATP. Furthermore, it was found that cordycepin could inhibit the proliferation and induce apoptosis of human lung cancer cell H1975 via regulating EGFR signaling pathway. And MTT assay and molecular docking results exhibited that the inhibitor potency of cordycepin on H1975/T790M was better than that of H1975 cells. Taken together, these results implied that cordycepin may be a good inhibitor directly binding to the ATP pocket of EGFR/T790M to conquer the resistance. In this proposal, we aim to investigate the molecular mechanism and target of cordycepin. Both cell model and xenograft model of T790M-positive NSCLC will be used to investigate the therapeutic efficacy. To elucidate the accurate molecular mechanism of inhibitor effect, flow cytometry, Western blot analysis and Trans well will be employed to test the cell cycle, apoptosis and the expression level of EGFR and other key molecules. Finally, molecular trapping and drug affinity responsive target stability will be used to study the molecular target. Our findings will not only elucidate the therapeutic efficacy and the molecular mechanism of cordycepin, but also give a new choice in clinical trials. And it is also provided the scientific evidence for the development of novel EGFR inhibitors.

EGFR/T790M继发突变耐药是现阶段NSCLC治疗的难点。课题组研究发现虫草素可通过调控EGFR信号通路抑制肺癌细胞H1975的增殖并诱导凋亡。MTT和分子对接结果表明虫草素对H1975/T790M的抑制活性高于H1975，提示虫草素可能通过直接靶向EGFR/T790M起作用，改善T790M突变导致的耐药问题，但具体机制尚未明确。本项目拟通过细胞实验和移植瘤模型研究虫草素对NSCLC/T790M的抑制作用；采用Real-Time PCR、Western blot等技术研究虫草素对NSCLC/T790M细胞周期、凋亡和侵袭的影响，明确分子机制；最后用分子捕获和DARTS技术研究虫草素作用靶点，阐明虫草素是否通过直接靶向EGFR/T790M，改善T790M继发突变耐药。本项目研究成果不仅为NSCLC/T790M患者提供了新的治疗思路，而且为虫草素的开发利用提供了科学依据。