Liu Xueke, Xu Wei, Li Lele, Zhang Zhenyong, Lu Mei, Xia Xiaoping
Department of Clinical Laboratory, the Fourth Affiliated Hospital of School of Medicine, and International School of Medicine, International Institutes of Medicine, Zhejiang University, Yiwu, China, 322000.
Int J Med Sci. 2024 Jul 9;21(10):1814-1823. doi: 10.7150/ijms.84320. eCollection 2024.
BMS-1166, a PD-1/PD-L1 inhibitor, inhibits the binding of PD-L1 to PD-1, restores T cell function, and enhances tumor immune response. However, mutations in the tumor suppressor or impaired cellular signaling pathways may also lead to cellular transformation. In this study, the SW480 and SW480R cell lines were used as the model to elucidate the treatment with BMS-1166, BEZ235, and their combination. MTT and colony-formation assays were used to evaluate cell proliferation. Wound-healing assay was used to assess cell migration. Cell cycle and apoptosis were analyzed by flow cytometry. The phosphorylation level of the key kinases in the PI3K/Akt/mTOR and MAPK pathways, PD-L1, and the protein levels related to the proliferation, migration, and apoptosis were assessed using western blotting. BEZ235 enhanced BMS-1166-mediated cell proliferation and migration inhibition in SW480 and SW480R cells and promoted apoptosis. Interestingly, the downregulation of the negative regulator PTEN raised the PD-L1 level, which was abolished by the inhibition of Akt. BMS-1166 promoted PI3K, Akt, mTOR, and Erk phosphorylation. However, the combination of BEZ235 with BMS-1166 suppressed the expression of PI3K, p-Akt, p-mTOR, and p-Erk in SW480 and SW480R cells compared to BMS-1166 or BEZ235 single treatment by inhibiting the binding of PD1 to PD-L1. PD-1 binds to PD-L1 and activates the PI3K/mTOR and MAPK pathways, which might be the molecular mechanism of acquired resistance of CRC to BMS-1166. The combination of the two drugs inhibited the phosphorylation of PI3K, Akt, and Erk in the PI3K/mTOR and MAPK pathway, i.e., BEZ235 enhanced the BMS-1166 treatment effect by blocking the PI3K/mTOR pathway and interfering with the crosstalk of the MAPK pathway. Therefore, these findings provide a theoretical basis for BMS-1166 combined with BEZ235 in the trial treatment of colorectal cancer.
BMS-1166是一种PD-1/PD-L1抑制剂，可抑制PD-L1与PD-1的结合，恢复T细胞功能，并增强肿瘤免疫反应。然而，肿瘤抑制基因的突变或细胞信号通路受损也可能导致细胞转化。在本研究中，使用SW480和SW480R细胞系作为模型来阐明BMS-1166、BEZ235及其联合用药的治疗效果。采用MTT法和集落形成试验评估细胞增殖。采用伤口愈合试验评估细胞迁移。通过流式细胞术分析细胞周期和凋亡情况。使用蛋白质印迹法评估PI3K/Akt/mTOR和MAPK通路中关键激酶的磷酸化水平、PD-L1以及与增殖、迁移和凋亡相关的蛋白质水平。BEZ235增强了BMS-1166对SW480和SW480R细胞增殖和迁移的抑制作用，并促进了细胞凋亡。有趣的是，负调节因子PTEN的下调提高了PD-L1水平，而抑制Akt可消除这种作用。BMS-1166促进了PI3K、Akt、mTOR和Erk的磷酸化。然而，与BMS-1166或BEZ235单药治疗相比，BEZ235与BMS-1166联合用药通过抑制PD1与PD-L1的结合，抑制了SW480和SW480R细胞中PI3K、p-Akt、p-mTOR和p-Erk的表达。PD-1与PD-L1结合并激活PI3K/mTOR和MAPK通路，这可能是结直肠癌对BMS-1166获得性耐药的分子机制。两种药物联合使用抑制了PI3K/mTOR和MAPK通路中PI3K、Akt和Erk的磷酸化，即BEZ235通过阻断PI3K/mTOR通路并干扰MAPK通路的串扰增强了BMS-1166的治疗效果。因此，这些发现为BMS-1166联合BEZ235用于结直肠癌的试验治疗提供了理论依据。
