Abstract | PURPOSE: EXPERIMENTAL DESIGN:
Small interfering RNA and chemical CK2 inhibitors were used to reduce CK2 activity. Control and CK2 activity-reduced cells were cultured with 6-TG and assessed by flow cytometry to measure apoptosis and cell cycle profiles. Additionally, confocal microscopy was used to assess localization of CK2 catalytic units following 6-TG treatment. RESULTS: Transfection of small interfering RNA against the CK2 alpha and/or alpha' catalytic subunits results in marked apoptosis of HeLa cells following treatment with 6-TG. Chemical inhibitors of CK2 also induce apoptosis following 6-TG treatment. Apoptosis induced by 6-TG is similarly observed in both mismatch repair-proficient and -deficient HCT116 and HeLa cells. Concomitant treatment with a pan- caspase inhibitor or transfection of apoptosis repressor with caspase recruitment domain markedly suppresses the apoptotic response to DNA damage by 6-TG in the CK2-reduced cells, indicating caspase regulation by CK2. CK2 alpha relocalizes to the endoplasmic reticulum after 6-TG treatment. Additionally, transfection of Cdc2 with a mutation at Ser(39) to Ala, which is the CK2 phosphorylation site, partially inhibits cell cycle progression in G(1) to G(2) phase following 6-TG treatment. CONCLUSION: CK2 is essential for apoptosis inhibition following DNA damage induced by 6-TG, controlling caspase activity.
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Authors | Kazuhiko Yamane, Timothy J Kinsella |
Journal | Clinical cancer research : an official journal of the American Association for Cancer Research
(Clin Cancer Res)
Vol. 11
Issue 6
Pg. 2355-63
(Mar 15 2005)
ISSN: 1078-0432 [Print] United States |
PMID | 15788687
(Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, U.S. Gov't, P.H.S.)
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Chemical References |
- Enzyme Inhibitors
- RNA, Small Interfering
- Casein Kinase II
- Caspases
- Thioguanine
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Topics |
- Apoptosis
(drug effects, physiology)
- Casein Kinase II
(genetics, pharmacology)
- Caspases
(drug effects, metabolism)
- Cell Cycle
(drug effects, physiology)
- DNA Damage
(drug effects)
- DNA Repair
- Endoplasmic Reticulum
(metabolism)
- Enzyme Inhibitors
(pharmacology)
- HeLa Cells
(enzymology)
- Humans
- RNA, Small Interfering
(pharmacology)
- Thioguanine
(pharmacology)
- Transfection
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