Apoptosis in human hepatocellular carcinoma and in liver cell dysplasia is correlated with p53 protein immunoreactivity.
OBJECTIVE
To investigate the prevalence of apoptosis in human hepatocellular carcinomas (HCC) of different types and grades and in liver cell dysplasia, and to test whether the apoptotic rate is correlated with the p53 protein status.


METHODS
37 HCC and 66 six liver samples with liver cell dysplasia were analysed for apoptosis using in situ DNA end labelling (ISEL), and for p53 protein expression by immunohistochemistry. In HCCs, proliferative activity was quantitatively assessed using proliferating cell nuclear antigen labelling.


RESULTS
The apoptotic index in HCC as based on ISEL ranged from 0.1 to 13.5 per 1000 cells analysed and was not related to type or grade. No nuclear staining was observed in multinuclear tumour cells. There was a significant correlation between the apoptotic rate and both the proliferative activity and p53 protein reactivity. In liver samples containing p53 protein positive liver cell dysplasia cells, there was a significantly higher apoptotic rate of these cells.


CONCLUSIONS
Apoptosis is detectable in HCC, and is not related to type and grade. There is a highly significant positive correlation between the apoptotic rate in HCC and both the proliferative activity and p53 protein expression. A similar phenomenon occurs for putative cancer precursors. The findings support the role of p53 in regulating apoptosis in preneoplastic and neoplastic liver lesions.
Zhao
M
M
Institute of Pathology of the University, Berne, Switzerland.
Zimmermann
A
A
D017209:Apoptosis / Q000502:physiology*; D006528:Carcinoma, Hepatocellular / Q000378:metabolism / Q000473:pathology*; D002455:Cell Division / Q000502:physiology; D006801:Humans; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization; D008113:Liver Neoplasms / Q000378:metabolism / Q000473:pathology*; D009363:Neoplasm Proteins / Q000378:metabolism*; D011230:Precancerous Conditions / Q000378:metabolism / Q000473:pathology*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
D009363:Neoplasm Proteins; D016159:Tumor Suppressor Protein p53