DNA hypomethylation of proliferating cell nuclear antigen gene in human hepatocellular carcinoma is not due to cell proliferation.
Proliferating cell nuclear antigen (PCNA) gene expresses preferentially in proliferative cells or tissues. The levels of PCNA mRNA are very low in livers of adult mammals. Expression of PCNA gene in hepatocellular carcinoma tissues was, however, elevated; and 5'-CCGG-3' sequences of the gene in neoplastic tissue were less methylated. Such DNA hypomethylation was concluded, on the basis of two observations, not to be due to the cell proliferation in hepatoma tissues. First, while the expression of PCNA was increased during serum-stimulation of quiescent Hep G2 cells, the DNA methylation pattern of PCNA gene remained unchanged. Second, in rat liver regeneration, the PCNA mRNA level rose and declined, but the DNA methylation status of PCNA gene was unaltered. Therefore, the DNA hypomethylation of the PCNA gene found in hepatocellular carcinoma was not due to cell proliferation, but a possible consequence of cell transformation.
Liu
Y W
YW
Institute of Life Science, National Tsing-Hua University, Hsin-Chu, Taiwan.
Chang
K J
KJ
Liu
Y C
YC
D000818:Animals; D000951:Antigens, Neoplasm / Q000097:blood / Q000235:genetics*; D015152:Blotting, Northern; D015139:Blotting, Southern; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000276:immunology / Q000473:pathology; D002455:Cell Division; D015342:DNA Probes; D004273:DNA, Neoplasm / Q000737:chemistry* / Q000302:isolation & purification; D006801:Humans; D008099:Liver / Q000378:metabolism; D008113:Liver Neoplasms / Q000235:genetics* / Q000276:immunology / Q000473:pathology; D008297:Male; D008745:Methylation; D009687:Nuclear Proteins / Q000097:blood / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length; D018809:Proliferating Cell Nuclear Antigen; D012333:RNA, Messenger / Q000032:analysis / Q000302:isolation & purification; D051381:Rats; D017208:Rats, Wistar; D014407:Tumor Cells, Cultured
D000951:Antigens, Neoplasm; D015342:DNA Probes; D004273:DNA, Neoplasm; D009687:Nuclear Proteins; D018809:Proliferating Cell Nuclear Antigen; D012333:RNA, Messenger