Elevated procaspase levels in human melanoma.
In this study procaspase expression levels were investigated by Western blotting in a panel of established melanoma cell lines, transformed melanocytic cell lines and normal primary melanocytes. Upstream caspases such as procaspase-8 that contain a death effector domain were found to be overexpressed in transformed melanocytes and melanoma cell lines compared with melanocytes. Heterogeneous levels of procaspase-8 were seen in melanoma cells, including one cell line that completely lacked procaspase-8 expression. Procaspase-10 is generally overexpressed in transformed melanocytes and melanoma cell lines. Expression of the downstream procaspases-3 and -7 was increased in melanoma cells compared with normal melanocytes. Procaspases containing caspase recruitment domains such as procaspase-2 were expressed at similar levels in nearly all the cell lines investigated. Reduced levels of procaspase-1 compared with normal melanocytes were detected in transformed melanocytes and melanoma cell lines. These data indicate that procaspase levels in general increase during the malignant transformation of melanocytic cells.
Fink
D
D
Department of Clinical Pharmacology, Section of Experimental Oncology/Molecular Pharmacology, University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
Schlagbauer-Wadl
H
H
Selzer
E
E
Lucas
T
T
Wolff
K
K
Pehamberger
H
H
Eichler
H G
HG
Jansen
B
B
D015153:Blotting, Western; D020169:Caspases / Q000737:chemistry / Q000378:metabolism*; D002461:Cell Line, Transformed; D002471:Cell Transformation, Neoplastic / Q000378:metabolism; D002478:Cells, Cultured; D004790:Enzyme Induction; D004792:Enzyme Precursors / Q000737:chemistry / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008544:Melanocytes / Q000166:cytology / Q000201:enzymology; D008545:Melanoma / Q000201:enzymology* / Q000473:pathology; D008970:Molecular Weight; D014407:Tumor Cells, Cultured
D004792:Enzyme Precursors; D020169:Caspases