小鼠GSDME对肿瘤进展的抑制作用及其机制

The inhibitory effect of GSDME on tumor progression and its underlying mechanisms in mice

目的 探究GSDME对小鼠肿瘤进展的影响及机制。方法 利用蛋白质免疫印迹检测蛋白表达;利用野生型和GSDME敲除小鼠构建肿瘤模型并监测肿瘤进展;利用CRISPR-Cas9技术敲除MC38细胞的GSDME并构建肿瘤模型。利用体外诱导骨髓细胞分化成为巨噬细胞和树突状细胞,并分别进行尾静脉回输观察肿瘤生长;利用多通道流式细胞技术检测肿瘤中免疫细胞的浸润、CD8^(+)T细胞的功能分子、肿瘤相关巨噬细胞和树突状细胞的Cleaved Caspase-3及表型分子。结果 GSDME敲除促进肿瘤进展,减少肿瘤内CD8^(+)T细胞数量,减少IFN-γ和Perforin在CD8^(+)T细胞的表达。GSDME主要表达在巨噬和树突状细胞,分别回输GSDME敲除的巨噬和树突状细胞不显著影响肿瘤进展。GSDME敲除小鼠肿瘤内Cleaved Caspase-3阳性巨噬和树突状细胞减少,且Cleaved Caspase-3阳性巨噬细胞表达更多iNOS和MHCII,Cleaved Caspase-3阳性树突状细胞表达更多CD80和CD86。结论 GSDME增加具有促进CD8^(+)T细胞功能的Cleaved Caspase-3阳性巨噬和树突状细胞,进而抑制肿瘤进展。

This study aims to explore the role of mouse GSDME in tumor progression and its mechanisms.Wide type and GSDME knockout mice were used to establish tumor models and the tumor growth was monitored;CRISPR-Cas9 was employed to knockout GSDME in MC38 cells.Bone marrow-derived macrophage and dendritic cells were culture in vitro and adoptively transferred into tumor-bearing mice,respectively.Western blotting was conducted to detect protein expression in cells;flow cytometry was used to analysis the immune cell number,CD8~+T cell function,and Cleaved Caspase-3 expression in TAM and TADC cells.According to the above experiments,we found that GSDME deficiency promoted tumor progression in mice.GSDME knockout reduced the number of CD8~+T cells and decreased IFN-γ and Perforin in CD8~+T cells in tumors.GSDME was mainly expressed in macrophages and dendritic cells,and adoptive transferring GSDME deficient macrophages or dendritic cells did not affect tumor progression.However,GSDME deficient mice reduced the ratio of Cleaved Caspase-3 positive macrophages and dendritic cells in tumors,and Cleaved Caspase-3 positive macrophages expressed more iNOS and MHCII,while Cleaved Caspase-3 positive dendritic cells expressed more CD80 and CD86.In general,GSDME increases Cleaved Caspase-3 positive macrophages and dendritic cells that promote CD8~+T cell function,thereby inhibiting tumor progression.