The underlying cause of low response rates to existing immunotherapies is that tumor cells dominate tumor immune escape through surface antigen deficiency and inducing tumor immunosuppressive microenvironment (TIME). Here, we proposed an in situ tumor cell engineering strategy to disrupt tumor immune escape at the root by restoring tumor cell MHC-I/tumor-specific antigen complex (MHC-I/TSA) expression to promote T-cell recognition and by silencing tumor cell CD55 to increase the ICOSL⁺ B-cell proportion and reverse the TIME. A doxorubicin (DOX) and dual-gene plasmid (MAC pDNA, encoding both MHC-I/ASMTNMELM and CD55-shRNA) coloaded drug delivery system (LCPN@ACD) with tumor targeting and charge/size dual-conversion properties was prepared. LCPN@ACD-induced ICD promoted DC maturation and enhanced T-cell activation and infiltration. LCPN@ACD enabled effective expression of MHC-I/TSA on tumor cells, increasing the ability of tumor cell recognition and killing. LCPN@ACD downregulated tumor cell CD55 expression, increased the proportion of ICOSL⁺ B cells and CTLs, and reversed the TIME, thus greatly improving the efficacy of αPD-1 and CAR-T therapies. The application of this in situ tumor cell engineering strategy eliminated the source of tumor immune escape, providing new ideas for solving the challenges of clinical immunotherapy.

Purpose To investigate the expression of SNRPA in gastric cancer and its effect on the proliferation,migration and invasion of gastric cancer cells.Methods The expression of SNRPA in gastric cancer tissues was ana-lyzed using The Cancer Genome Atlas(TCGA)database.The level of SNRPA was detected by immunohistochemistry(EnVision method),and its relationship with clinicopathological parameters was analyzed.Western blot was used to detect the expression of SNRPA in 15 cases of fresh gastric cancer and paracancerous tissues.The expression of SNRPA in MGC-803 and GES-1 cells was detected by immunofluorescence staining.The effects of SNRPA expression on the proliferation,migration and invasion of gastric cancer cell lines were determined by RNA interference technology and cell function assays,and the expression levels of Cyclin D1 protein and EMT-related proteins(E-cadherin,N-cadher-in)were detected by Western blot.Results The expression level of SNRPA in gastric cancer tissues was significantly higher than that in normal gastric mucosal tissues(P＜0.05),with an area under the curve(AUC)of 0.902 for diag-nostic accuracy.The Kaplan-Meier survival curves showed that the survival time of the group with high expression of SNRPA was shorter.SNRPA expression correlated with tumor size,Ki67,infiltration depth,and p53 status(P＜0.05).Compared with the corresponding control group,SNRPA silencing inhibited the proliferation,migration and in-vasion ability of gastric cancer cells,accompanied by decreased Cyclin D1 and N-cadherin expression and increased E-cadherin expression(P＜0.05).Conclusion SNRPA expression is upregulated in gastric cancer tissues and cell lines,promoting the proliferation,migration,and invasion of gastric cancer cells,and may be a potential molecular marker for gastric cancer.

Purpose To investigate the expression of SNRPA in gastric cancer and its effect on the proliferation,migration and invasion of gastric cancer cells.Methods The expression of SNRPA in gastric cancer tissues was ana-lyzed using The Cancer Genome Atlas(TCGA)database.The level of SNRPA was detected by immunohistochemistry(EnVision method),and its relationship with clinicopathological parameters was analyzed.Western blot was used to detect the expression of SNRPA in 15 cases of fresh gastric cancer and paracancerous tissues.The expression of SNRPA in MGC-803 and GES-1 cells was detected by immunofluorescence staining.The effects of SNRPA expression on the proliferation,migration and invasion of gastric cancer cell lines were determined by RNA interference technology and cell function assays,and the expression levels of Cyclin D1 protein and EMT-related proteins(E-cadherin,N-cadher-in)were detected by Western blot.Results The expression level of SNRPA in gastric cancer tissues was significantly higher than that in normal gastric mucosal tissues(P＜0.05),with an area under the curve(AUC)of 0.902 for diag-nostic accuracy.The Kaplan-Meier survival curves showed that the survival time of the group with high expression of SNRPA was shorter.SNRPA expression correlated with tumor size,Ki67,infiltration depth,and p53 status(P＜0.05).Compared with the corresponding control group,SNRPA silencing inhibited the proliferation,migration and in-vasion ability of gastric cancer cells,accompanied by decreased Cyclin D1 and N-cadherin expression and increased E-cadherin expression(P＜0.05).Conclusion SNRPA expression is upregulated in gastric cancer tissues and cell lines,promoting the proliferation,migration,and invasion of gastric cancer cells,and may be a potential molecular marker for gastric cancer.