Impaired binding properties of thyroxine-binding globulin in hepatocellular carcinoma and chronic liver disease.
To determine the factors underlying the apparent reduction in binding ability of thyroxine-binding globulin in hepatocellular carcinoma, hormone-binding characteristics were further examined in patients with this disease and in control subjects. No differences in affinity constants with respect to triodothyronine or serum thyroxine-binding globulin from hepatocellular carcinoma, cirrhotic and normal subjects were found. The affinity for thyroxine was significantly reduced in hepatocellular carcinoma (0.41 +/- 0.13 x 10(10) mol-1) and cirrhotic (0.65 +/- 0.1 x 10(10) mol-1) patients compared with normal subjects (0.94 +/- 0.7 x 10(10) mol-1). Investigations carried out on liver tissue obtained from patients with hepatocellular carcinoma and chronic liver disease showed that thyroxine-binding globulin within tumor tissue was elevated and bound less exogenous tracer hormone compared with that obtained from nontumor tissue. Tumor-derived thyroxine-binding globulin with altered binding properties is, at least partly, responsible for the abnormal behavior of the serum protein in patients with hepatocellular carcinoma.
Hutchinson
W L
WL
Institute of Liver Studies, King's College Hospital, Denmark Hill, London, United Kingdom.
White
Y S
YS
Fagan
E A
EA
Johnson
P J
PJ
Williams
R
R
D000328:Adult; D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D002908:Chronic Disease; D003600:Cytosol / Q000378:metabolism; D006801:Humans; D008107:Liver Diseases / Q000378:metabolism*; D008113:Liver Neoplasms / Q000378:metabolism*; D008875:Middle Aged; D013974:Thyroxine / Q000378:metabolism; D013975:Thyroxine-Binding Proteins / Q000378:metabolism*
D013975:Thyroxine-Binding Proteins; D013974:Thyroxine