The Yoshida AH-130 rat ascites hepatoma is a model system for studying the
mechanisms involved in the protein hypercatabolism associated with cancer c
achexia. The present study was aimed at investigating if the calpain-3 gene
expression in skeletal muscle was affected by tumor growth. The results pr
esented clearly show that calpain-3 gene expression is considerably reduced
in experimental cancer cachexia, while there is a reciprocal change in the
expression of the ubiquitin-dependent proteolytic system and in the ubiqui
tous m-calpain. The results, observed during cancer cachexia, suggest a pot
ential counterregulatory role of calpain-3 in muscle proteolysis. (C) 2000
Elsevier Science B.V. All rights reserved.