ABSTRACT
In recent years, p53 was identified to regulate the expression of many miRNAs and was also regulated by miRNAs. In this paper, we found that miR-138 showed a pronounced increase after p53 activation in human non-small cell lung cancer (NSCLC) cells, which is mediated by p53 binding sites in the promoter region of its host gene, but this did not happen with rat and mouse cells. More interestingly, we found that p53 could be also regulated by miR-138 in mouse and rat cells, but not in the human NSCLC cells. Our results suggest the existence of species-specific differences of the regulations of miRNA against its targets and the regulations of miRNA itself by other proteins.
Subject(s)
Gene Expression Regulation , MicroRNAs/metabolism , Tumor Suppressor Protein p53/metabolism , Animals , Cell Line , Humans , Mice , RatsABSTRACT
UNLABELLED: We report a new biomarker of hepatocarcinoma, vasorin (VASN), screened by a subtractive EMSA-SELEX strategy from AFP negative serum of hepatocellular carcinoma (HCC) patients with extrahepatic metastases. VASN was verified to be highly expressed in sera of 100 cases of HCC patients compared with 97 cases of normal persons and 129 cases of hepatitis patients. Further validation by Q-PCR,IFA and Western blot showed higher expression of VASN at mRNA and protein levels in HCC cell lines and HCC tissues than in normal controls. RNA interference and forced overexpression assays verified that VASN promotes cell proliferation and migration and inhibits apoptosis. Down-regulation of microRNA miR145 and miR146a is an important mechanism leading to high expression of VASN. CONCLUSION: As a membrane protein and/or as free protein, VASN may be an effective target for biological treatment of liver cancer and is a potential biomarker for HCC diagnosis. Small molecular nucleotides targeting VASN are promising biological therapies to HCC.