Downregulation of Bcl-2 and activation of caspase-8 in the UVB-induced apoptosis of a cultured human melanoma cell line.
OBJECTIVE
This study was performed to determine the effect of UV radiation on the activation of apoptosis regulatory proteins using cultured human melanoma cells.


METHODS
G361 lightly pigmented melanoma cells were irradiated with increasing doses of UVB and analyzed for an apoptotic mechanism using a cell viability test, TEM, FACS, and western blotting analysis.


RESULTS
TEM and FACS showed apoptotic features of cell death after UVB irradiation. Western blotting disclosed downregulation of Bcl-2 and the activation of caspase-9. Caspase-8, a downstream molecule of Fas/FasL interaction, was also activated. The activation of downstream molecules of both caspase-8 and caspase-9 was also demonstrated.


CONCLUSIONS
Our data showed that the regulation of the Bcl-2 family and caspase-8 may work together to activate a caspase-3 mediated apoptotic pathway following UVB irradiation of cultured human melanoma cells.
Park
K H
KH
Graduate School of Biotechnology, Korea University, Seoul, Korea.
Choi
H O
HO
Jang
D D
DD
Park
Y I
YI
Park
K C
KC
D017209:Apoptosis / Q000528:radiation effects*; D015153:Blotting, Western; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases / Q000378:metabolism*; D016009:Chi-Square Distribution; D015536:Down-Regulation; D004789:Enzyme Activation / Q000528:radiation effects; D005434:Flow Cytometry; D006801:Humans; D008545:Melanoma / Q000378:metabolism / Q000473:pathology*; D008854:Microscopy, Electron; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D014466:Ultraviolet Rays / Q000009:adverse effects*
D019253:Proto-Oncogene Proteins c-bcl-2; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases