title: Hepatitis B virus protein up-regulated HLJ1 expression via the transcription factor YY1 in human hepatocarcinoma cells.
abstract: The hepatitis B virus (HBV) protein plays a major role in hepatocellular carcinoma (HCC) development. However, its contribution to tumor invasion and metastasis has not been established so far. HLJ1 was recently cloned and classified as a member of the heat shock protein 40 family (Hsp40/DnaJ) which is abundantly expressed in HBV-related tumors, might be involved in tumor progression. In this study, the role of HBV in activation of HLJ1 was investigated. In HepG2 cells with transit or stable expression of HBV, HLJ1 expression was activated by HBV. The activity assay of HLJ1 promoter revealed that HBV up-regulated HLJ1 expression through the transcription factor YY1 sites within the HLJ1 promoter. YY1 expression was significantly up-regulated by HBV in a concentration-dependent manner. Knockdown of YY1 expression could partially reduce the HBV-induced HLJ1 activation which indicated that YY1 would be involved in HBV-induced HLJ1 expression. In conclusion, our data showed that HBV could promote HLJ1 expression by up-regulating the transcription factor YY1, and this provided a new insight of the mechanism of HBV induction in tumor metastasis.
authors.affiliation: Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Second Affiliated Hospital, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Xuefei
authors.initials: X
authors.lastname: Cai
authors.forename: Ke
authors.initials: K
authors.lastname: Chen
authors.forename: Zengchan
authors.initials: Z
authors.lastname: Wang
authors.forename: Liying
authors.initials: L
authors.lastname: Wang
authors.forename: Min
authors.initials: M
authors.lastname: Ren
authors.forename: Ailong
authors.initials: A
authors.lastname: Huang
authors.forename: Hua
authors.initials: H
authors.lastname: Tang
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D050956:HSP40 Heat-Shock Proteins / Q000378:metabolism*; D056945:Hep G2 Cells; D006515:Hepatitis B virus / Q000378:metabolism*; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D015854:Up-Regulation; D050986:YY1 Transcription Factor / Q000378:metabolism*
chemical_list: C494650:DNAJB4 protein, human; D050956:HSP40 Heat-Shock Proteins; D050986:YY1 Transcription Factor; C494698:YY1 protein, human