Objective·To analyze the expression changes of adhesion G protein-coupled receptor F1(ADGRF1)in the occurrence and development of pancreatic ductal adenocarcinoma(PDAC),and explore the impact of ADGRF1 on the proliferation of PDAC cells and the potential molecular mechanisms that promote PDAC progression.Methods·The expression of ADGRF1 at mRNA level was analyzed based on the Gene Expression Omnibus(GEO)database and The Cancer Genome Atlas(TCGA)database,respectively.The expression of ADGRF1 in normal pancreatic ductal epithelial cells(hTERT-HPNE)and various PDAC tumor cells was detected by using real-time fluorescence quantitative PCR(qPCR)and Western blotting.Immunohistochemical staining(IHC)was used to detect the differential expression of ADGRF1 in cancer tissues and adjacent tissues of PDAC patients.After knocking down ADGRF1 with small interfering RNA(siRNA)transfection,the changes in the proliferation ability of PDAC AsPC-1 and SW1990 cells were detected through CCK8 assay and plate cloning experiment.Stable overexpression of ADGRF1 was constructed in PDAC Patu8988 cell line,and the proliferation changes induced by overexpression of ADGRF1 were evaluated through CCK8 assay.RNA sequencing(RNA-seq),gene set enrichment analysis(GSEA),and immune infiltration analysis were utilized to predict signaling pathways associated with ADGRF1-mediated promotion of PDAC cancer progression.Results·Analysis of the TCGA database and GEO database revealed higher expression of ADGRF1 mRNA in PDAC tissues compared to normal pancreatic tissues(all P=0.000).qPCR and Western blotting results demonstrated up-regulation of ADGRF1 mRNA and protein levels in various PDAC cells compared to hTERT-HPNE cells(all P<0.05).IHC results confirmed higher ADGRF1 expression in PDAC cancer tissues compared to adjacent tissues.Furthermore,downregulation of ADGRF1 inhibited the proliferation of PDAC AsPC-1 and SW1990 cell lines,while overexpression of ADGRF1 promoted the proliferation of Patu8988 cells(all P<0.05).RNA-seq,GSEA enrichment analysis,and immune infiltration analysis revealed that ADGRF1 expression was related to signaling pathways such as interferon-α(IFN-α),tumor necrosis factor-α(TNF-α),and nuclear factor κB(NF-κB).Conclusion·ADGRF1 is highly expressed in PDAC cells and tissues,and promotes the proliferation of PDAC cells via immune-related signaling pathways.

Objective·To establish a mouse model with dormant cancer and no obvious metastasis by combining the preimmune strategy with the mVenus-p27K-cell G0 phase indicator system,the DTR-HSV/TK suicide gene system,and the Luc2-tdTomato tracer system.Methods·The KPC1199 mouse pancreatic cancer cell line was transfected with the mVenus-p27K-cell G0 phase indicator system,the DTR-HSV/TK suicide gene system,and the Luc2-tdTomato tracer system to construct a stable expression cell line,KPC1199-PDL.After being cultured in the serum-free condition,KPC1199-PDL cells were sorted into mVenus(+)cells and mVenus(-)cells by flow cytometry,and the expression of G0 phase-related genes was verified by real-time fluorescence quantitative PCR(qPCR).Sensitivity of KPC1199-PDL cells to diphtheria toxin(DTX)and ganciclovir(GCV)was evaluated by CCK-8 assay.A transsplenic portal vein-hepatic metastasis model was constructed in wild-type C57BL/6 mice to validate the function of KPC1199-PDL cells in vivo by immunofluorescence technology.The KPC1199-PDL cells were injected subcutaneously into C57BL/6 mice,followed by in situ injection of DTX and GCV to ablate subcutaneous tumors 5 d later,to obtain preimmunized mice.The transsplenic portal vein-hepatic metastasis models were constructed in these mice.Bioluminescence imaging was used to evaluate subcutaneous tumor ablation and hepatic metastasis in the mice,and immunofluorescence assay was used to detect the distribution and dormant state of tumor cells in the livers of preimmunize mice.Results·The three tool systems were stably expressed in KPC1199-PDL cells,and their proliferative ability was not affected.In the serum starving condition,some KPC1199-PDL cells expressed the mVenus protein,indicating entry into the G0 phase;the mVenus(+)cells sorted out by flow cytometry exhibited significantly higher expression of G0 phase-related genes(all P<0.05)and significantly lower expression of the proliferation-related gene compared with mVenus(-)cells(P<0.05).The CCK-8 assay demonstrated high sensitivity of KPC1199-PDL cells to DTX and GCV.In vivo experiments confirmed that KPC1199-PDL cells could be effectively traced through tdTomato protein expression,and could indicate entry into the G0 phase through mVenus protein expression.Following subcutaneous tumor implantation and drug ablation,preimmunized mice were successfully obtained.In the subsequent transsplenic portal vein-hepatic metastasis model,no metastatic signals were observed in the liver by bioluminescence imaging,but single or small clusters of G0 phase tumor cells expressing both mVenus and tdTomato,not expressing the proliferation marker Ki67,were detected in liver tissue sections by immunofluorescence analysis.Conclusions·A recognizable and traceable dormant cancer model is constructed with the combination of the preimmune mouse model of pancreatic cancer,the mVeneus-p27K-indicator system,the DTR-HSV/TK suicide gene system,and the Luc2-tdTomato tracer system.