Chen Jian-Xia, Yi Xi-Juan, Gao Shan-Xia, Sun Jin-Xia
Department of Reproductive Medicine, Linyi Central Hospital, Linyi City, Shandong, China.
Gen Physiol Biophys. 2020 Jul;39(4):319-330. doi: 10.4149/gpb_2020011.
Aim of this study was to investigate the possible regulatory effect of the programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) signaling pathway on Tregs in ovarian cancer. Immunohistochemistry was used to detect the expression of PD-L1 and PD-1 and the presence of FOXP3+ Tregs in ovarian cancer. Then, ovarian cancer HO8910 cells were subjected to transfection with PD-L1 siRNA in vitro. CCK-8, Transwell and wound healing assays were performed to detect the biological behaviors of ovarian cancer cells. Human T-cells isolated from human peripheral blood were cocultured with HO8910 cells, which were divided into the Control, TGF-β, and TGF-β+ anti-PD-L1 groups. The proportion of differentiated Tregs was detected by flow cytometry. Mouse models of ovarian cancer were established, and PD-L1 antibody therapy was administered. Tumor growth and Treg recruitment were observed. PD-L1, PD-1 and FOXP3+ Tregs were found in ovarian cancer tissue. Patients with tumors with an advanced stage and low differentiation and lymph node metastasis had significantly higher levels of PD-1, PD-L1 and FOXP3+ Tregs. After transfection with PD-L1 siRNA, HO8910 cells showed a significant reduction in PD-L1 expression, proliferation, migration and invasion. After T-cells were cocultured with ovarian cancer cells, the TGF-β+ anti-PD-L1 group showed a substantial decline in the differentiation of T-cells into Tregs compared with the TGF-β group. Moreover, mice in the anti-PD-L1 group had significantly reduced tumor growth rates, Treg proportions in the tumor microenvironment, and FOXP3 expression.
本研究的目的是探讨程序性死亡蛋白-1（PD-1）/程序性死亡配体-1（PD-L1）信号通路对卵巢癌中调节性T细胞（Tregs）的潜在调节作用。采用免疫组织化学法检测卵巢癌中PD-L1和PD-1的表达以及FOXP3+ Tregs的存在情况。然后，在体外对卵巢癌HO8910细胞进行PD-L1 siRNA转染。进行CCK-8、Transwell和伤口愈合试验以检测卵巢癌细胞的生物学行为。将从人外周血中分离的人T细胞与HO8910细胞共培养，HO8910细胞分为对照组、转化生长因子-β（TGF-β）组和TGF-β + 抗PD-L1组。通过流式细胞术检测分化的Tregs比例。建立卵巢癌小鼠模型并给予PD-L1抗体治疗。观察肿瘤生长和Treg募集情况。在卵巢癌组织中发现了PD-L1、PD-1和FOXP3+ Tregs。肿瘤分期晚、低分化且有淋巴结转移的患者，其PD-1、PD-L1和FOXP3+ Tregs水平显著更高。用PD-L1 siRNA转染后，HO8910细胞的PD-L1表达、增殖、迁移和侵袭均显著降低。T细胞与卵巢癌细胞共培养后，与TGF-β组相比，TGF-β + 抗PD-L1组T细胞向Tregs的分化显著下降。此外，抗PD-L1组小鼠的肿瘤生长速率、肿瘤微环境中Treg比例和FOXP3表达均显著降低。
