Further evidence of hepatic transdifferentiation in hepatoid adenocarcinomas of the stomach: quantitative analysis of mRNA for albumin and hepatocyte nuclear factor-4alpha.
OBJECTIVE
To assess the production of a liver-specific protein, albumin, and of a master transcriptional factor, hepatocyte nuclear factor (HNF)-4alpha, in hepatoid adenocarcinoma tissue.


METHODS
Standard and quantitative RT-PCR, using five cases of hepatoid and three cases of non-hepatoid gastric adenocarcinoma.


RESULTS
Hepatoid adenocarcinomas expressed similarly large amounts of albumin mRNA as those expressed in hepatocellular carcinoma and normal liver tissues. The observed amounts were several hundred times more than those in non-hepatoid adenocarcinoma and normal stomach tissues. HNF-4alpha mRNA was expressed in all stomach samples examined, and the levels of expression did not quantitatively differ between hepatoid and non-hepatoid adenocarcinomas of the stomach.


CONCLUSIONS
These results provide further support of a relationship between hepatic transdifferentiation in hepatoid adenocarcinomas and albumin mRNA expression. Furthermore, transdifferentiation to the hepatocytic phenotype in hepatoid adenocarcinoma tissue was not directly associated with HNF-4alpha expression, thus suggesting that transdifferentiation proceeds by a complicated mechanism.
Yano
Tomoyuki
T
Department of Molecular Pathology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Kishimoto
Takashi
T
Tomaru
Utano
U
Kawarada
You
Y
Kato
Hiroyuki
H
Yoshiki
Takashi
T
Ishikura
Hiroshi
H
D000230:Adenocarcinoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D000418:Albumins / Q000235:genetics* / Q000378:metabolism; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002471:Cell Transformation, Neoplastic; D004268:DNA-Binding Proteins; D015972:Gene Expression Regulation, Neoplastic; D051557:Hepatocyte Nuclear Factor 4; D006801:Humans; D010750:Phosphoproteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis*; D012334:RNA, Neoplasm / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
D000418:Albumins; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; C496592:HNF4A protein, human; D051557:Hepatocyte Nuclear Factor 4; C403128:MLX protein, human; D010750:Phosphoproteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D014157:Transcription Factors