以往的研究主要集中在肿瘤细胞在免疫逃逸中的变化,而对肿瘤微环境(tumor microenvironment, TME)对免疫逃逸的影响知之甚少。肿瘤相关成纤维细胞(tumor-associated fibroblasts, TAFs)是TME的重要组成部分,具有特殊的生理生化特性,但其具体机制尚不清楚。为了研究TAF对胃癌细胞PD-L1表达的影响,通过transwell将胃癌细胞株MNK45、SGC7901与TAFs非接触共培养1、3、7 d。采用qRT-PCR和流式细胞仪检测PD-L1 mRNA和蛋白表达。然后选择95例胃癌组织,通过免疫组化检测PD-L1和TAFs的表达。结果显示,实验组PD-L1 mRNA和蛋白表达量均显著高于对照组。胃癌中PD-L1的表达与大量淋巴细胞浸润、弥漫性/混合性组织学和瘤内TAFs有关。综上所述,TAFs通过提高PD-L1的表达促进胃癌细胞株的生长。Previous studies have focused on the changes of tumour cells in immune escape, and less is known about the effect of the tumour microenvironment (TME) on immune escape. Tumour-associated fibroblasts (TAFs) cells are an important part of the TME and have special physiological and biochemical characteristics, but the specific mechanism has not been clarified. In order to investigate the effect of TAFs on the expression of PD-L1 in gastric cancer cells, gastric cancer cell lines MNK45, SGC7901 were non-contact coculturing with TAFs 1, 3 and 7 d via transwell. PD-L1 mRNA and protein expression were detected using qRT-PCR and FCM. Then, 95 cases of gastric cancer tissues were selected and PD-L1 and TAFs expressions were determined by immunohistochemical examination. The results showed that the mRNA and protein expression of PD-L1 in the experiment group were significantly higher than that in the control group. PD-L1 expression was associated with massive lymphocyte infiltration, diffuse/mixed histology and intratumoral TAFs in gastric cancers. In conclusion, TAFs promoted the growth of gastric cancer cell lines by increasing the PD-L1 expression.
