CNNM4 Promotes The Biological Behavior Of Pancreatic Cancer And Its Clinical Significance

ObjectivePancreatic adenocarcinoma(PAAD)is one of the most difficult malignancies to treat.The mortality rate is close to the morbidity rate,posing a serious threat to human health.Cyclin and CBS domain divalent metal cation transport mediator 4(CNNM4)is a divalent cation transport protein with an efflux role for Mg2+.Numerous studies have confirmed the involvement of Mg2+ transporters in the progression of CNNM4 in a variety of malignancies,such as colorectal,bile duct,prostate,and gastric cancers.In PAAD,CNNM4 was highly expressed and associated with shorter survival in patients,suggesting that differential CNNM4 expression may be closely associated with PAAD progression.Therefore,this study will investigate the correlation between CNNM4 expression in PAAD and clinicopathological factors and prognosis,as well as its effect on the biological function of pancreatic cancer cells and preliminary exploration of its mechanism of action.Methods1.The intersection of the GEO dataset GSE16515 DEGs with magnesium ion transport proteins was plotted using a Venn diagram.Data from TCGA and GEO database PAAD-related datasets(GSE16515,GSE15471)were used to verify the difference in CNNM4 mRNA expression in PAAD patients versus normal pancreatic tissue and to analyze prognosis.The signaling pathways that CNNM4 may be involved in regulating were analyzed by GO/KEGG and GSEA.The correlation of CNNM4 gene expression profile with the degree of immune cell infiltration in PAAD patients was analyzed using the TIMER online database and R language to predict the effect of immunotherapy.Statistical analysis was performed using SPSS 26.0 and R4.2.3.2.As PC-1,MIAPa Ca-2,PANC-1,PATU-8988 T,Bx PC-3 and HPDE6-C7 cells were cultured in vitro,and the expression of CNNM4 mRNA in the above six cell lines was detected by q RT-PCR.Bx PC-3 cells with high CNNM4 mRNA expression levels were selected to construct CNNM4 lentivirus interference models,and the effect of CNNM4 interference was verified by q RT-PCR.The effect of CNNM4 on the proliferation of pancreatic cancer cells was investigated by CCK-8 and clone formation assays.Results1.According to the results of the TCGA and GEO database analysis,the expression of CNNM4 was significantly different in various tumors,including pancreatic cancer.The gene expression was higher in PAAD tumor tissue than in normal pancreatic tissue(P < 0.001).The correlation between CNNM4 expression levels and clinical characteristics was analyzed.The results showed that expressed CNNM4 was significantly correlated with the T-stage of pancreatic cancer(P < 0.01)and possibly with the pathological grade,but not with the N-stage,M-stage,age,gender,ethnicity,primary treatment outcome,tumor location,history of chronic pancreatitis,and history of diabetes.The results of the GO/KEGG enrichment analysis showed that CNNM4 interacting genes were involved in various biological processes,such as digestion and absorption,cation transport,and chemical signaling.The enrichment analysis suggested that the CNNM4 differential expression phenotype was significantly enriched in multiple tumorigenic pathways(TP63 signaling pathway,P53 signaling pathway,TGF-β signaling pathway)and was associated with metabolic reprogramming of pancreatic cancer.In PAAD tissues,CNNM4 expression levels were positively correlated with the abundance of Th2,NK CD56 bright,and Tcm cells and negatively correlated with the abundance of p DC,TFH,Tgd,and NK cells(P < 0.05).2.The expression levels of CNNM4 mRNA in pancreatic cancer cells,namely BxPC-3,PANC-1,PATU-8988 T,and As PC-1,were higher than those in human immortalized normal pancreatic epithelial cells,HPDE6-C7 cells,and the expression levels of MIAPa Ca-2 were lower than those in HPDE6-C7 in that order.The results of the CCK-8 and clone formation assays showed that down-regulation of CNNM4 promoted the proliferation and clone formation rate of pancreatic cancer cells.Similarly,the results of the Transwell migration and invasion assays showed that down-regulation of CNNM4 promoted the migration and invasion of pancreatic cancer cells.Furthermore,the results of the scratch assay showed that down-regulation of CNNM4 ncreased the ability of pancreatic cancer cells to migrate and move.ConclusionCNNM4 plays a role as an oncogene suppressor in the progression of pancreatic cancer by participating in the regulation of various tumor signaling pathways,such as TP65,P53,and TGF-β.Additionally,it may trigger the reprogramming of energy metabolism in pancreatic cancer through the regulation of Mg2+ transport in cells,leading to abnormal proliferation of tumor cells and promoting the development and progression of pancreatic cancer.