Biological Effect Of Senescent Interstitial Fibroblast On Human Colon Cancer LoVo Cells

Objective:We had established interstitial fibroblast senescence model to simulate tumor associated fibroblast in tumor microenvironment.In this experiment we will observe the effect of senescentinterstitial fibroblast on epithelial mesenchymal transition(EMT), subcutaneous tumorigenesis and other biological effects in LoVo cells.Methods:A co-culture system of senescent interstitial fibroblast(LV-GALC)/normal interstitial fibroblast(LV-NC)and LoVo cells is established(Group A: LoVo cells and LV-GALC,Group B: LoVo cells and LV-NC).The expressions of EMT-related indicators in LoVo cells were detected by Western Blot.LV-GALC/LV-NC were mixed with LoVo cells,then subcutaneously inoculated into the nude mice to establish the mouse subcutaneous tumor model and the subcutaneous tumorigenicity were observed.The expressions of cancer stem cell(CSC)related genes in LoVo cells were detected by Flow Cytometry.Cell signaling pathway analysis for transcriptome were used to select differentially expressed genes or proteins and then detected the proteins in tumor tissues by Western Blot.Results:The results of Western Blot showed that the expression of E-cadherin was down-regulated,but there was no significant difference.The expression of Vimentin was up-regulated,significantly increased at 48 h and 72 h,the difference was statistically significant(p<0.05).Both the tumor volume and tumor weight in group A were greater than the group B(p<0.05).Group A and group B were both positive expression of CD44 and hadno significant difference,while CD24, CD133 were no significant expression. Transcriptome analysis had revealed activator of transcription 3(ATF3) and other related gene expression inrelation to the endoplasmic reticulum protein processing signal pathway significantly increased in colon cancer cells ingroup A. The expression of ATF3 in the tumor tissue of group A was significantly higher than group B(p<0.05).Conclusions:The senescent interstitial fibroblast might induce the expression of ATF3 in LoVo cellsby secreting cytokines and other related regulatory factors.And then accelerate EMT progressand and enhance the ability of tumorigenicity in human colon cancer LoVo cells.