|
Accession number;02A0357264
|
| Title;Suppression of Postmitochondrial Signaling and Delayed Response to UV-induced Nuclear Apoptosis in HeLa Cells. |
| Author;
SASAI K
(Hiroshima Univ., Hiroshima)
YAJIMA H
(Hiroshima Univ., Hiroshima)
SUZUKI F
(Hiroshima Univ., Hiroshima)
|
Journal Title;Jpn J Cancer Res
|
Journal Code:F0633A
|
ISSN:0910-5050
|
|
VOL.93;NO.3;PAGE.275-283(2002)
|
| Figure&Table&Reference;FIG.4, REF.36 |
| Pub. Country;Japan |
| Language;English |
| Abstract;Activation of postmitochondrial pathways by UV irradiation was examined using mouse lymphoma 3SB and human leukemic Jurkat cells and two human carcinoma cell lines (HeLa and MCF-7). Exposure of 3SB and Jurkat cells resulted in large amounts of cytochrome c and apoptosis-inducing factor (AIF) being released into the cytosol, and a clear laddering pattern of DNA fragments was observed within 3 h of incubation after irradiation. Simultaneously, activation of caspase-9 and its downstream caspases was detected. HeLa and MCF-7 cells also showed extensive release of mitochondrial factors and caspase-9 activation at 4 to 6 h after exposure, but apoptotic nuclear changes appeared much later. Compared with 3SB and Jurkat cells, these carcinoma cell lines exhibited reduced activation of caspase-9-like proteolytic activity by UV radiation, and levels of caspase-3-like activity in HeLa cells were extremely low, similar to those in caspase-3-deficient MCF-7 cells. These results suggest that the delayed response to UV-induced nuclear apoptosis in HeLa cells is due to a reduced activation of the caspase cascade downstream of cytochrome c release and suppression of caspase-3 activity. (author abst.) |
|
|
|
Related Articles;
|
|
