title: MiR-19a, miR-122 and miR-223 are differentially regulated by hepatitis B virus X protein and involve in cell proliferation in hepatoma cells.
abstract: Hepatitis B virus (HBV) X protein (HBx) is a type of oncogenic protein involved in the progression of hepatocellular carcinoma (HCC) via interacting with host genes. Dysregulation of microRNAs (miRNAs) has been observed in HCC. This study aimed to investigate the role of HBx protein in the regulation of miR-19a, miR-122 and miR-223, and examine if these miRNAs involve in progression of malignant hepatocytes.
  
  
  
  Quantitative real time PCR (qRT-PCR) was used to measure the expression of miR-19a, miR-122 and miR-223 in patient samples and in HepG2 cells transfected with HBx or 1.3 fold HBV genome and also in HepG2.2.15 cells, which stably produces HBV. Their target mRNAs and proteins-PTEN, cyclin G1 and c-myc were measured by qRT-PCR and western blot, respectively. The effect of miR-19a, miR-122 and miR-223, and their respective target genes, on cell proliferation was analyzed using 5-ethynyl-2-deoxyuridine incorporation and MTT assay.
  
  
  
  MiR-19a showed an up-regulation in HBV-positive HCC patients compared to healthy controls and HBV-negative HCC patients, while miR-122 and miR-223 showed a down-regulation compared to healthy controls, and miR-122 in HBV-positive HCC patients was also down-regulated when compared to HBV-negative HCC patients. MiR-19a was found to be up-regulated in HepG2 cells transfected with HBx or 1.3 fold HBV genome, but down-regulated in HepG2.2.15 cells. MiR-122 and miR-223 were down-regulated in HBx or 1.3 fold HBV transfected HepG2 cells as well as in HepG2.2.15 cell. Their target mRNAs and corresponding proteins-PTEN was down-regulated, while cyclin G1 and c-myc were found to be up-regulated. Modulated expression of miR-19a, miR-122 and miR-223 enhanced cell proliferation of HBx-transfected HepG2 cells, and rescue experiment further showed that their target genes-PTEN, cyclin G1and c-myc involved in cell proliferation of HBx-transfected HepG2 cells.
  
  
  
  The expression of miR-19a, miR-122 and miR-223 were differentially regulated by HBx protein, the differential expression of miR-19a, miR-122 and miR-223 plays an important role in cell proliferation of HCC. This study provides new insight into understanding how HBx protein interacts with miRNAs and subsequently regulates host function.
authors.affiliation: Department of Oncology, The Fifth Affiliated Hospital of Guangzhou Medical University, No.621, Gangwan Road, Huangpu District, Guangzhou, 510700, China. guifangyu1023@gmail.com.
authors.forename: Guifang
authors.initials: G
authors.lastname: Yu
authors.affiliation: Department of Oncology, The Fifth Affiliated Hospital of Guangzhou Medical University, No.621, Gangwan Road, Huangpu District, Guangzhou, 510700, China.
authors.forename: Xuezhu
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Oncology, The Fifth Affiliated Hospital of Guangzhou Medical University, No.621, Gangwan Road, Huangpu District, Guangzhou, 510700, China.
authors.forename: Shudi
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Oncology, The Fifth Affiliated Hospital of Guangzhou Medical University, No.621, Gangwan Road, Huangpu District, Guangzhou, 510700, China.
authors.forename: Weipeng
authors.initials: W
authors.lastname: Ye
authors.affiliation: Department of Oncology, The Fifth Affiliated Hospital of Guangzhou Medical University, No.621, Gangwan Road, Huangpu District, Guangzhou, 510700, China.
authors.forename: Kailian
authors.initials: K
authors.lastname: Hou
authors.affiliation: Department of Oncology, The Fifth Affiliated Hospital of Guangzhou Medical University, No.621, Gangwan Road, Huangpu District, Guangzhou, 510700, China.
authors.forename: Min
authors.initials: M
authors.lastname: Liang
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000473:pathology* / Q000821:virology; D016022:Case-Control Studies; D049109:Cell Proliferation / Q000235:genetics; D056766:Cyclin G1 / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D056945:Hep G2 Cells; D006515:Hepatitis B virus / Q000502:physiology; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics* / Q000473:pathology* / Q000821:virology; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D051059:PTEN Phosphohydrolase / Q000378:metabolism; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism*; D014162:Transfection; D054334:Viral Regulatory and Accessory Proteins
chemical_list: D056766:Cyclin G1; D035683:MicroRNAs; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D015534:Trans-Activators; D054334:Viral Regulatory and Accessory Proteins; C057628:hepatitis B virus X protein; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human
keywords: Cyclin G1; HepG2; Hepatitis B virus X protein; Hepatocellular carcinoma; PTEN; c-myc; microRNAs