Analysis of gene expression profile induced by hepatocyte nuclear factor 4alpha in hepatoma cells using an oligonucleotide microarray.
Hepatocyte nuclear factor 4alpha (HNF-4alpha), a liver-specific transcription factor, plays a significant role in many liver-specific functions, including lipid, glucose, drug, and ammonia metabolism, and also in embryonal liver development. However, its functions and regulation are not yet clearly understood. In this study, we constructed an adenovirus vector carrying rat HNF-4alpha cDNA and transfected the adenovirus to human hepatoma cells, HuH-7, to enforce expression of the exogenous HNF-4alpha gene. We analyzed HNF-4alpha-induced genes using cDNA microarray technology, which included over 9000 genes. As a result, 62 genes showed a greater than 2.0-fold change in expression level after the viral transfection. Fifty-six genes were consistently induced by HNF-4alpha overexpression, and six genes were repressed. To assess HNF-4alpha function, we attempted to classify the genes, which had been classified by their encoding protein functions in a previous report. We could classify 45 genes. The rest of the HNF-4alpha-sensitive genes were unclassified (4 genes) or not identified (13 genes). Among the classified genes, almost half of the induced genes (26 of 40) were related to metabolism genes and particularly to lipid metabolism-related genes. This cDNA microarray analysis showed that HNF-4alpha is one of the central liver metabolism regulators.
Naiki
Takafumi
T
First Department of Internal Medicine and the Department of Neurology and Psychiatry, Gifu University School of Medicine, Gifu, Japan.
Nagaki
Masahito
M
Shidoji
Yoshihiro
Y
Kojima
Hisanori
H
Imose
Motoaki
M
Kato
Tomohiro
T
Ohishi
Nobuko
N
Yagi
Kunio
K
Moriwaki
Hisataka
H
D000256:Adenoviridae / Q000378:metabolism; D000818:Animals; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D015152:Blotting, Northern; D015153:Blotting, Western; D019556:COS Cells; D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins; D015536:Down-Regulation; D005786:Gene Expression Regulation; D018014:Gene Transfer Techniques; D051557:Hepatocyte Nuclear Factor 4; D022781:Hepatocytes / Q000378:metabolism*; D006801:Humans; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism; D008858:Microscopy, Phase-Contrast; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D010750:Phosphoproteins / Q000378:metabolism*; D051381:Rats; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D015854:Up-Regulation; D001616:beta-Galactosidase / Q000378:metabolism
D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C496592:HNF4A protein, human; D051557:Hepatocyte Nuclear Factor 4; C403128:MLX protein, human; D010750:Phosphoproteins; D014157:Transcription Factors; D001616:beta-Galactosidase