Mutations in the C-terminus of the X protein of hepatitis B virus regulate Wnt-5a expression in hepatoma Huh7 cells: cDNA microarray and proteomic analyses.
BACKGROUND
The hepatitis B virus x gene (HBx) is a promiscuous transactivator implicated in the development of hepatocellular carcinoma (HCC). The present study was designed to investigate the molecular events regulated by HBx.


METHODS
Genomic and proteomic expression profiling was performed in Huh7 HCC cells transfected with HBx mutants with a C-terminal deletion. The gene and protein expression of wingless-type murine-mammary-tumour virus (MMTV) integration site family, member 5A (Wnt-5a) was validated by analyses of reverse transcription-polymerase chain reaction (RT-PCR), real-time RT-PCR, western blot and immunohistochemistry.


RESULTS
Differentially expressed genes and proteins were found in the transfected Huh7 HCC cells; most of them were involved in transcriptional regulation, although others including oncogenes or tumor suppressor genes, and molecules involved in cell junctions, signal transduction pathways, metabolism or the immune response were also observed. The expression of the Wnt-5a gene was elevated >10-fold in Huh7 cells transfected with the HBx3'-30 amino acid deletion mutant. However, the expression was downregulated by the transfection with the HBx3'-40 amino acid deletion mutant. The changes in Wnt-5a expression were also observed in human HCC tissues, compared with corresponding non-cancerous liver tissues. A negative correlation was found between the expression of Wnt-5a and HBx COOH mutations in HCC tissues.


CONCLUSIONS
HBx mutants may participate in the development and progression of HCC, at least in part through the Wnt-5a pathway.
Liu
Xiaohong
X
Department of Pathology, Changhai Hospital, Second Military Medical University, 174 Changhai Road, Shanghai 200433, People's Republic of China.
Wang
Li
L
Zhang
Shuhui
S
Lin
Jing
J
Zhang
Shunmin
S
Feitelson
Mark A
MA
Gao
Hengjun
H
Zhu
Minghua
M
D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000378:metabolism / Q000821:virology*; D045744:Cell Line, Tumor; D015180:Electrophoresis, Gel, Two-Dimensional; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000821:virology*; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D040901:Proteomics; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015534:Trans-Activators / Q000235:genetics*; D014162:Transfection; D054334:Viral Regulatory and Accessory Proteins; D051153:Wnt Proteins / Q000096:biosynthesis*; D000071818:Wnt-5a Protein
D011518:Proto-Oncogene Proteins; D015534:Trans-Activators; D054334:Viral Regulatory and Accessory Proteins; C085389:WNT5A protein, human; D051153:Wnt Proteins; D000071818:Wnt-5a Protein; C057628:hepatitis B virus X protein