Wang Yifan, Hu Jingguo, Sun Yu, Song Bo, Zhang Yan, Lu Yusong, Ma Haitao
The First Affiliated Hospital of Soochow University, Department of Thoracic Surgery, Suzhou 215006, China.
Affiliated Hospital of Chengdu University, Department of Thoracic Surgery, Chengdu 610081, China.
Evid Based Complement Alternat Med. 2022 Sep 25;2022:5983959. doi: 10.1155/2022/5983959. eCollection 2022.
Despite non-small cell lung cancer (NSCLC) treatment is proved to be effective using PD-L1 monoclonal antibody (PD-L1 MAb), it is commonly seen in immune-related adverse events reported. We aimed to explore metformin synergized with PD-L1 MAb in treating NSCLC and its potential molecular mechanism. In mice, the transplantable lung cancer models were established and a co-culture system of CD8+T cells and LLC cells was constructed. The anti-tumor effect was assessed by xenograft tumor growth, proliferation signal Ki67 expression, and MTT assays. Immunohistochemistry and western blot assays were also conducted to determine tumor immune response as well as mechanism investigation. The results indicated that tumor volume and cell proliferation were markedly inhibited following metformin synergized with PD-L1 MAb which was more effective than either single metformin or PD-L1 MAb. The cytokines TNF-, IL-2, and IFN- secretion in CD8+ T cells was significantly increased, and the immune response was enhanced by metformin synergized with PD-L1 MAb. Further, the WB results implied that metformin synergized with PD-L1 MAb could activate the AMPK pathway and inhibit mTOR. AMPK inhibitor (Compound C) was added, and the results showed that the anti-tumor effect was reduced in metformin + PD-L1 MAb + CC than in metformin + PD-L1 MAb which indicates the metformin synergized with PD-L1 MAb efficacy was AMPK pathway dependent. In conclusion, metformin synergized with PD-L1 MAb has better efficacy against NSCLC than metformin or PD-L1 MAb alone in an AMPK-dependent way and facilitates increasing CD8+ T cell infiltration and enhancing tumor immune response.
尽管已证明使用程序性死亡受体配体1单克隆抗体（PD-L1 MAb）治疗非小细胞肺癌（NSCLC）是有效的，但免疫相关不良事件仍屡见不鲜。我们旨在探讨二甲双胍与PD-L1 MAb联合治疗NSCLC及其潜在分子机制。在小鼠中，建立可移植肺癌模型，并构建CD8+T细胞与LLC细胞的共培养体系。通过异种移植瘤生长、增殖信号Ki67表达及MTT试验评估抗肿瘤效果。还进行了免疫组化和蛋白质印迹试验以确定肿瘤免疫反应及机制研究。结果表明，二甲双胍与PD-L1 MAb联合使用后，肿瘤体积和细胞增殖受到显著抑制，其效果优于单独使用二甲双胍或PD-L1 MAb。CD8+T细胞中细胞因子TNF-、IL-2和IFN-的分泌显著增加，二甲双胍与PD-L1 MAb联合增强了免疫反应。此外，蛋白质印迹结果表明，二甲双胍与PD-L1 MAb联合可激活AMPK通路并抑制mTOR。加入AMPK抑制剂（化合物C）后，结果显示二甲双胍+PD-L1 MAb+CC组的抗肿瘤效果低于二甲双胍+PD-L1 MAb组，这表明二甲双胍与PD-L1 MAb联合的疗效依赖于AMPK通路。总之，二甲双胍与PD-L1 MAb联合使用对NSCLC的疗效优于单独使用二甲双胍或PD-L1 MAb，其通过依赖AMPK的方式促进CD8+T细胞浸润增加并增强肿瘤免疫反应。
