Study On The Mechanism Of PDCD11 Regulating N-Cadherin To Promote EMT,Invasion And Metastasis Of Colon Cancer

Objective:The incidence rate and mortality of colorectal cancer(CRC)rank second and third in all tumors,respectively.The difficulty of early diagnosis and the difficulty of tackling tumor metastasis are the important reasons for the high incidence rate and mortality of CRC.Therefore,there is an urgent need to explore a reliable molecular marker for early diagnosis of colon cancer to apply to early screening of colon cancer,and to deeply explore the mechanism of promoting invasion and metastasis of this molecular marker in colon cancer,providing a new theoretical basis for the diagnosis and treatment of colon cancer in the future.This study aims to reveal the cancer promoting effect of PDCD11 in colon cancer and the correlation between its upregulation and tumor prognosis and survival through bioinformatics and related cell experiments.At the same time,the potential mechanism pathway of PDCD11regulating downstream mechanism molecules was screened through 4D non labeled quantitative proteomics technology,and the specific molecular mechanism of PDCD11promoting tumor invasion and metastasis was elaborated in detail.Methods:The difference of PDCD11 expression in colon cancer and pan-cancer was analyzed by bioinformatics,and the correlation between its high expression in colon cancer and tumor survival and prognosis was analyzed.ROC curve was used to analyze the predictive efficiency of PDCD11 in predicting the incidence and survival of colon cancer one year after onset.At the same time,the correlation between the expression of PDCD11 and several common immune checkpoints of colon cancer was analyzed,and whether its expression affected the efficacy of several immunosuppressants was predicted.The correlation between PDCD11 expression and immune cell infiltration was analyzed by TCGA database data.Through MTT test,clone formation test and scratch test,it was proved that the up-regulated expression of PDCD11 could promote the proliferation and migration of colon cancer cells.The expression changes of classical tumor pathway molecules after PDCD11knockout were screened by Western Blot experiment,and the molecules in line with the expected trend were verified by celigo cell count,MTT and Transwell functional recovery verification,locking the downstream mechanism molecule as N-cadherin.4D Label-free proteomics technique was used to screen the changes of all protein expression levels in colon cancer cells after PDCD11 knockout,and enrich significant change pathways to find the potential mechanism of PDCD11 regulation of N-cadherin.Results:The results of bioinformatics analysis showed that the expression of PDCD11 was up-regulated in both paired and unpaired samples of colon cancer(p<0.001).In pan-cancer,the expression of PDCD11 was down-regulated in KICH(chromophobe cell carcinoma of the kidney),but not significantly different in THCA(thyroid carcinoma),but increased in other tumors.OS curve showed that the high expression of PDCD11 led to the decrease of overall survival time(OS)of colon cancer.The results of ROC curve showed that the predictive ability of variable PDCD11 was higher in predicting the outcome of Tumor and Normal(AUC=0.917),but in predicting the outcome of one year after the occurrence of the disease,the predictive ability of variable PDCD11 was general(AUC=0.541).The results of immune checkpoint correlation analysis showed that the expression of PDCD11 was positively correlated with CTLA4 and PDCD1 in colon cancer,p<0.05.There was no significant correlation with CD274.The results of MTT test,clone formation test and scratch test showed that the proliferation and migration ability of colon cancer RKO cells were significantly inhibited after PDCD11 knockdown.The results of immunocytic infiltration analysis showed that the expression of PDCD11 was positively correlated with neutrophils,dendritic cells,CD8~+T cells,CD4~+T cells and macrophages(p<0.05),but not with B cells(p>0.05).The results of Western Blot showed that after PDCD11 gene knockout,the expression of Twist,c-Myc,P-AKT,Fibronectin,Snail,Slug,Vimentin,P-β-Catenin,P-P38,MMP-9,P38,P-m TOR,P-ERK1/2,MMP-2 and N-Cadherin were significantly down-regulated,which was consistent with the expected trend.The results of celigo cell proliferation function recovery test showed that the trend of slow proliferation after overexpression of each gene had different degrees,and the trend of slow proliferation after overexpression of N-Cadherin was the most obvious.The results of MTT and Transwell functional recovery test showed that the overexpression of N-Cadherin gene could significantly restore the proliferation function and invasion and metastasis function of the target gene knockout group.The results of 4D Label-free proteomic enrichment analysis showed that after the low expression of PDCD11,the signal pathways of p53,JAK-STAT and VEGF were changed.Conclusion:(1)PDCD11 is highly expressed in colon cancer and pan-cancer,and is related to the survival and prognosis of colon cancer.(2)PDCD11 can promote the proliferation,invasion and metastasis of colon cancer cells,and is related to the immune cell infiltration of colon cancer.(3)PDCD11 promotes the occurrence of EMT in colon cancer,and affects cell viability,invasion and metastasis by regulating the expression of N-cadherin.(4)PDCD11 may regulate N-cadherin through p53,JAK-STAT and VEGF signal pathways.