Modulation Of EMT Transition And Clinicopathologic Significance In Colon Cancer Cells By Nanog-miR-200caxis

Background:Colon carcinoma is the third leading cause of deaths from cancer,which represents a major therapeutic challenge.EMT(epithelial-mesenchymal transition)exists widely in mechanism of the majorities of malignant tumor,such as breast,colon and prostate cancers.Nanog is a important transcription factor which is related with the regulation of self-renewal and stemness of colon cancer stem cells.The miRNAs also contribute to preserving stemness of embryonic stem cells and human CSCs and play a key role in regulating EMT plasticity.The present study is to investigate the primary relationship between Nanog and miR-200 c expression in colon cancer,the further mechanism how Nanog transcriptionally regulates miR-200 c expression is needed.Methodology:In the clinical samples,we collected forty-nine colorectal carcinoma patients and their peri-cancerous mucosa.The quantitative real-time RT-PCR was used to detect the miR-200 c and miR-141 expression levels,to analysis the changes of miR-200c/141,to analysis the correlation with the pathological features and the cumulative survival of patients one-year after surgical treatment(P>0.05)through analysing the combined quantitative expression of miR-200c/141.In the cell levels,the relative expression level of Nanog in human colon cancer HT-29,HCT116,SW480 and LS174 T cells have been quantitated by the real-time quantitative PCR.SW480 and LS174 T cells were transfected with the lentivirus particles expressing Nanog.The stable transfected cells were selected with puromycin.Real-time quantitative PCR and/or Western blot experiments were used to detect Nanog and miR-200 c expression.Conclusions/Significance:In the clinical samples,comparing with their peri-cancerous mucosa,the miR-200 c and miR-141 levels in colorectal carcinoma samples were significantly reduced.There was a relationship between miR-141 expression levels and the tumor size and the lymph node(s)metastasis of colorectal carcinoma patients(P<0.05).At the same time,The miR-141 expression levels in these cancerous tissues of colorectal carcinoma patients who had not lymph node(s)metastasis were significantly higher than those who had lymph node(s)metastasis.Meanwhile,the miR-141 expression levels in the cancerous tissues of colorectal carcinoma patients who were at clinical early stages were significantly higher than that who were at clinical late stages.There was significant relationship between combined miR-200c/141 expression levels and the tumor size.But,the miR-200 c and miR-141 expression levels were not related to the cumulative survival of patients one-year after surgical treatment(P>0.05).In these colon cancer cells,our Real-time quantitative PCRs data indicated that there was a relative high expression of Nanog m RNA in HT-29 and HCT116 cells and a relative low expression of Nanog mRNA in SW480 and LS174 T cells.There was a significant increased Nanog expression of both transcriptional and protein levels in Nanog enforced expressed SW480 and LS174 T cells compared with those control cells.Quantitation of miR-200 c in Nanog enforced expressed SW480 and LS174 T cells was also significantly lower than the control cells(P<0.05).Conclusions:In the clinical samples,the reduced miR-200c/141 expression levels in colorectal carcinoma were related to the tumor size,lymph node(s)metastasis and clinical stages of colorectal carcinoma patients.In these colon cancer cells,over-expression of Nanog in SW480 and LS174 T cells led to the reduction of miR-200 c expression,which is closely related to the epithelial-mesenchymal transition(EMT).This result indicated the negative correlation between Nanog and miR-200 c expression level.The specific regulatory mechanism between Nanog and miR-200 c is yet to be study in further.