Effect Of RNA-binding Protein HuR On Expression Of CREPT Protein In Colorectal Cancer

CREPT?Cell-cycle-related and expression-elevated protein in tumor?,a newly discovered human tumor-associated protein that enhances cell proliferation during tumorigenesis,was demonstrated highly expressed in most of tumors.However,it remains unclear how CREPT itself up-regulated expression in colorectal cancers.Human antigen R?HuR?is an RNA-binding protein,which binds to the AU-rich element?ARE?in the3?-untranslated region?3?-UTR?of certain mRNA,and stabilizes mRNA and regulates its translation.In this study,we further analyzed the co-regulation effect of microRNA383and HuR on CREPT expression on the basis of clarifying the regulation of HuR on CREPT expression,and laid a theoretical foundation for the molecular mechanism of colorectal cancer.In this study,we used Western Blot experiment to study the regulation of HuR on the expression of CREPT protein.HuR can positively regulate the expression of CREPT.We also observed that HuR knockdown could down-regulate the expression of CREPT in colon cancer cells.Western Blot and RT-PCR experiments showed that HuR overexpression up-regulated the expression of CREPT at the mRNA level and protein level.The direct interaction between HuR and CREPT was found by RNA-IP assay.Further detection of luciferase reporter assay showed that HuR directly targeted the3?-UTR of CREPT.On this basis,we further studied the co-regulation of CREPT by HuR and miR-383.In addition,by CCK-8 assay,colony formation assay,we systematically studied the effects of HuR on the proliferation,cell migration,colony formation of HCT116?/?cell line.By flow cytometry,the effect of HuR on cell cycle was further explored.These results showed that after targeting CREPT,HuR promoted HCT116?/?growth and proliferation,and promoted rapid cell cycle into G₂/M phase,while inhibiting apoptosis.Finally,we demonstrated that HuR overexpression in colon cancer cells promoted the growth of cells.Our results revealed that the low expression of CREPT in colorectal cancers is attributed to the increased level of HuR.The regulation mechanism of RNA binding protein HuR on CREPT mRNA was systematically explored,revealing that CREPT plays an important role in the occurrence and development of colorectal cancer.The comprehensive study of HuR and microRNA on CREPT protein provided a basis for new targeted drug discovery.