Suppressive Role Of MYCT1 And The Regulation Of C/EBP ? On MYCT1 Expression In Hepatocellular Carcinoma

Objective: Hepatocellular carcinoma(HCC)is one of the most common malignant tumors of gastrointestinal tumors.Due to its rapid onset,high degree of malignancy and multiple metastasis,it has maintained relatively high morbidity and mortality in China,even the world.Pathogenic factors of hepatocellular carcinoma are mixed and molecular mechanism of its development is still not clear.Therefore,there is still a lack of effective targeted treatment.Myc target 1(MYCT1)gene,also known as MTLC,was first discovered in laryngeal carcinoma and associated with the development of multiple tumors,which played different roles in different tumors.CCAAT/enhancer binding protein ?(C/EBP?)is a transcription factor with a CAAT enhancer binding domain.It plays an important role in the regulation of inflammation,cell proliferation,cell differentiation and involves in tumor progression.In this study,we used relevant molecular biotechnology to detect the Suppressive role of MYCT1 and the regulation of C/EBP? on MYCT1 expression in hepatocellular carcinoma Methods: Thirty pairs of fresh HCC cancer and para-cancer tissues were obtained for quantitative real-time polymerase chain reaction(qRT-PCR)to detect the mRNA expression level of MYCT1 in HCC.Another thirty pairs of HCC tissue sections were acquired for IHC to detect the protein expression level of MYCT1 in HCC.Statistical analysis was performed on clinical pathological features.We transfected over expression vectors and small interfering RNAs to SMMC7721 cells and performed related cell function assays to detect MYCT1 function in SMMC7721 cells.The expression of MYCT1 gene by C/EBP? regulation was detected by Real-time qPCR and Western Blot.The potential binding sites of C/EBP? and MYCT1 were predicted by bioinformatics prediction and the binding sites were identified by Dual-luciferase reporter assay system and chromatin immunoprecipitation(CHIP).Results: 1.Real-time qPCR,IHC and related clinicopathological features analysis showed that MYCT1 expression was down-regulated in HCC tissues(P<0.05)and its mRNA expression was associated with age and HBV infection(P<0.05).2.Related cell function assays showed that MYCT1 significantly inhibited HCC cells proliferation,invasion and migration in vitro(P<0.05),but not apoptosis.3.Bioinformatics prediction results showed that MYCT1 was a potential target gene of C/EBP?.Real-time qPCR and Western Blot results showed that knockdown of C/EBP? could increase the expression of MYCT1 gene(P<0.05).4.Dual-luciferase reporter assay system and CHIP results showed that C/EBP? did not directly target the MYCT1 promoter region.Conclusions: 1.MYCT1 gene plays a tumor suppressor role in HCC and its mRNA expression level is negatively correlated with age and HBV infection.2.MYCT1 significantly inhibits HCC cell proliferation,invasion and migration in vitro,but not apoptosis.3.C/EBP? participates in MYCT1 gene expression in an indirect manner rather than directly targeting binding.