METALLOTHIONEIN AND APOPTOSIS IN PRIMARY HUMAN HEPATOCELLULAR-CARCINOMA AND METASTATIC ADENOCARCINOMA

Aims: Differences in expression of metallothionein (MT) have been repo rted in various human tumours. MT is mainly expressed in proliferating epithelial tumour cells but in human hepatocellular carcinoma (HCC) t here is only a minimal expression of MT, Since MT is a zinc binding pr otein and certain inducers of MT including zinc play a role in apoptos is, studies were undertaken to compare the expression of MT and the pr esence of apoptotic cells (APPC) in both primary HCC and metastatic ad enocarcinoma. Methods and results: Histological sections of 13 cases o f primary HCC and eight cases of metastatic adenocarcinoma were obtain ed from archival samples. They were stained for MT using a polyclonal antibody which crossreacts readily with human MT and for APPC by the T UNEL technique. Normal human liver had consistent MT staining with no detectable APPC, The primary HCC showed moderate MT staining with a sm all number of APPC while metastatic adenocarcinoma showed no MT staini ng with a large number of APPC. Conclusions: These results suggest a r elationship between absence of MT and appearance of APPC in human live r tumours, especially in metastatic adenocarcinomas.