TMEM205 Induces TAM/M2 Polarization To Promote Cisplatin Resistance In Gastric Cancer

Objective:To study the molecular mechanism of transmembrane protein 205(TMEM205)attenuating the sensitivity of gastric cancer(GC)to cisplatin(DDP)by regulating the polarization of tumor-associated macrophages(TAMs),providing a new therapeutic target for clinical DDP resistance.Materials and Methods:1.The sensitivity of SGC-7901 cells and SGC-7901/DDP cells to DDP were detected by MTT assay.2.The stemness of SGC-7901 cells and SGC-7901/DDP cells were detected by Western Blot and Immunofluorescence assays.3.Established the Co-culture system of SGC-7901 cells,SGC-7901/DDP cells and THP-1 cells,then the effects of GC cells on TAM/M2 polarization were detected by Western Blot,Immunofluorescence and Flow cytometry assays.4.The expression of TMEM205 in GC and the relationship between TMEM205 and clinicopathological parameters were detected by The Human Protein Atlas,CCLE,Ualcan and TIMER databases.5.The expression of TMEM205 in GES-1 cells,SGC-7901 cells and SGC-7901/DDP cells were detected by Western Blot assay.6.The effects of TMEM205 on the proliferation and stemness of SGC-7901/DDP cells were detected by MTT,Ed U,Clone formation,Western Blot and Immunofluorescence assays.7.The effects of TMEM205 on SGC-7901/DDP cells migration and angiogenesis of GC were detected by Cell scratch,Transwell,Microtubule formation and Western Blot assays.8.The effect of TMEM205 on the epithelial-mesenchymal transition(EMT)of SGC-7901/DDP cells was detected by Western Blot and Immunofluorescence assays.9.Established the Co-culture system of SGC-7901/DDP cells and THP-1 cells,the effect of TMEM205 on TAM/M2 polarization was detected by Western Blot,Immunofluorescence and Flow cytometry assays.10.The effects of TMEM205 on the expression of Wnt/β-catenin signaling pathway-related proteins in SGC-7901/DDP cells were detected by Western Blot and Immunofluorescence assays.Results:1.The results of Western Blot and Immunofluorescence assays showed that compared with SGC-7901 cells,the expression of stemness-related markers were up-regulated in SGC-7901/DDP cells(P<0.05 or P<0.01).2.The results of Western Blot,Immunofluorescence and Flow cytometry assays showed that compared with SGC-7901 cells,SGC-7901/DDP cells induced the expression of M2 macrophage(TAM/M2)markers(P<0.05 or P<0.01).3.Bioinformatics analysis databases results showed that TMEM205 was overexpressed in various tumor tissues including GC and had correlations with clinicopathological parameters of GC(P<0.05 or P<0.01).4.The results of MTT,Ed U,Clone formation,Western Blot and Immunofluorescence assays showed that silencing TMEM205 inhibited the proliferation of SGC-7901/DDP cells,and down-regulated the expression of stemness-related markers in SGC-7901/DDP cells(P<0.05 or P<0.01).5.The results of Cell scratch,Transwell,Western Blot and Microtubule formation assays showed that silencing TMEM205 inhibited the migration of SGC-7901/DDP cells,the formation of tube lumen of HUVECs,and down-regulated the expression levels of VEGF,MMP2and MMP9 in SGC-7901/DDP cells(P<0.05 or P<0.01);the results of Western Blot and Immunofluorescence assays showed that silencing TMEM205 up-regulated the expression of epithelial markers,down-regulated the expression of mesenchymal markers,then inhibited the EMT process of SGC-7901/DDP cells(P<0.05 or P<0.01).6.The results of Western Blot,Immunofluorescence and Flow cytometry assays showed that silencing TMEM205 in SGC-7901/DDP cells in the Co-culture system,which resulted that the expression of CD206 was down-regulated and the expression of CD86 and i NOS were up-regulated in THP-1 cells,the number of CD206~+/CD68~+cells were decreased and the number of CD86~+/CD68~+cells were increased in THP-1 cells(P<0.05 or P<0.01).7.The results of Western Blot and Immunofluorescence assays showed that silencing TMEM205 inhibited the expression of Wnt/β-catenin signaling pathway-related proteins in SGC-7901/DDP cells(P<0.05 or P<0.01).Conclusions:TMEM205 promoted the proliferation,stemness,migration,angiogenesis and EMT process of SGC-7901/DDP cells by activating the Wnt/β-catenin signaling pathway.In addition,TMEM205 further promoted the malignant evolution of SGC-7901/DDP cells by inducing TAM/M2 polarization.