Metallothionein concentration in the liver of patients with Wilson's disease, primary biliary cirrhosis, and liver metastasis of colorectal cancer

Abstract

In patients with primary biliary cirrhosis and Wilson's disease liver copper concentrations become elevated during the evolution of the disorder. The accumulated copper is thought to be detoxified by metallothionein, a protein which binds copper and zinc. In liver metastasis of colorectal cancer, copper and zinc concentrations are usually decreased compared to normal liver tissue, but little is known about the concomitant metallothionein levels. In the present study metallothionein concentrations were determined in archival liver samples from patients with primary biliary cirrhosis and Wilson's disease, and in both normal and malignancy-containing liver samples from patients with metastasis from a colorectal adenocarcinoma. Twenty-seven control liver samples contained 3.98±1.55 mg metallothionein/g protein. From the 21 liver samples of patients with primary library cirrhosis, which had a mean metallothionein concentration of 6.06±5.03 mg/g protein, 6 were above the highest control level. Liver metallothionein concentrations for the 8 patients with Wilson's disease were significantly elevated (10.98±6.93 mg/g protein, p<0.005 vs. controls and p<0.05 vs. primary biliary cirrhosis). In the 11 liver metastases from colorectal adenocarcinomas metallothionein concentrations (1.17±0.90 mg/g protein) were significantly (p<0.005) lower than surrounding normal liver tissue (4.25±1.75 mg/g protein). We conclude that in primary biliary cirrhosis and Wilson's disease increased liver metallothionein concentrations may detoxify the accumulated copper. Furthermore, liver metastasis of colorectal cancer contains less metallothionein than the surrounding normal liver tissue.