PGAM1在晚期肺腺癌吉非替尼继发耐药中的作用及其机制

In recent years, therapies for advanced lung adenocarcinoma patients with EGFR - TKI acquired resistance have been a hotspot in the field of lung cancer research. Cancer cells mainly depend on aerobic glycolysis for proliferation. To inhibit tumor glycolysis may improve the EGFR - TKI efficacy and reverse TKI acquired resistance. However, the questions of whether the glycolysis relevant enzymes affect TKI effects and what’s the mechanism have not yet been elucidated. PGAM1 is one of the important enzymes in the glycolytic pathway. Studies have shown that it plays an important role in tumor progression. Our preliminary work found that lactate production and PGAM1 activity were significantly inhibited in TKI-sensitive lung cancer cell line followed by gefitinib treatment. In contrast, TKI-resistant cell line had relatively higher PGAM1 activity and lactate concentration after TKI medication. Hence, we speculate that lung cancers with acquired resistance to TKI gradually upregulate aerobic glycolysis after continuous TKI treatment to support the growth of drug-resistant cancer cells by providing beneficial metabolic environment, and PGAM1 may be involved in this process, to inhibit PGAM1 may improve the efficacy of TKI. This project plans to knockdown PGAM1 gene expression in TKI-resistant lung cancer cell lines, to explore the role of PGAM1 in lung cancer TKI secondary resistance and the mechanisms of regulation through the assays of MTT, glycolysis level test and animal experiments. The implementation of this study will help to provide a new regimen for the treatment of patients with TKI acquired resistances from the perspective of cancer metabolism.

肺腺癌EGFR-TKI继发耐药是目前肺癌研究的热点和难点。肿瘤细胞主要依赖有氧糖酵解方式进行代谢。抑制肿瘤糖酵解途径有可能提高TKI疗效，但糖酵解相关酶如何影响TKI对EGFR突变肺癌的作用及其机制至今未阐明。PGAM1是糖酵解途径中重要的酶之一，其在肿瘤进展中发挥重要作用。我们的前期工作发现TKI敏感肺癌细胞在吉非替尼作用后乳酸及PGAM1活性均显著下降；而耐药细胞在吉非替尼作用后乳酸含量以及PGAM1活性均无明显变化。因此，我们推测TKI无法抑制耐药肺癌的糖酵解代谢，后者能促进耐药细胞的生长，而PGAM1可能参与这一过程，抑制PGAM1可能提高TKI的疗效。本课题拟通过基因敲除技术降低耐药肺癌细胞系PGAM1表达，行细胞增殖抑制实验、糖酵解水平检测以及动物实验等探讨PGAM1在肺癌TKI继发耐药中的作用和调节机制，从肿瘤代谢角度认识肺癌EGFR-TKI耐药，为耐药肺癌治疗提供新的思路。

肺腺癌EGFR-TKI继发耐药是目前肺癌研究的热点和难点。肿瘤细胞主要依赖有氧糖酵解方式进行代谢。抑制肿瘤糖酵解途径有可能提高TKI疗效，但糖酵解相关酶如何影响EGFR-TKI对EGFR突变肺癌的作用及其机制至今未阐明。PGAM1是糖酵解途径中重要的酶之一，其在肿瘤进展中发挥重要作用。我们的前期工作发现TKI敏感肺癌细胞在吉非替尼作用后乳酸及PGAM1活性均显著下降；而耐药细胞在吉非替尼作用后乳酸含量以及PGAM1活性均无明显变化。因此，我们推测EGFR-TKI无法抑制耐药肺癌的糖酵解代谢，后者能促进耐药细胞的生长，而PGAM1可能参与这一过程，抑制PGAM1可能提高TKI的疗效。本课题通过基因敲除技术降低耐药肺癌细胞系PGAM1表达，经细胞增殖抑制实验、糖酵解水平检测，western blot以及动物实验等PC9GR细胞中mTOR通路活化，后者上调了PGAM1表达，增加肿瘤细胞糖酵解水平，通过降低TKI耐药的PC9GR细胞中PGAM1表达，可提高细胞对吉非替尼的敏感性，部分纠正吉非替尼的耐药，延缓肿瘤细胞增殖。这一结果帮助人们从肿瘤代谢角度认识肺癌EGFR-TKI耐药，为耐药肺癌治疗方法的探索提供了新的思路。