201. Gossypol exerts its cytotoxic effect on HL-60 leukemic cell line via decreasing activity of protein phosphatase 2A and interacting with human telomerase reverse transcriptase activity.
- Author
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Sahin F, Avci CB, Gunduz C, Sezgin C, Simsir IY, and Saydam G
- Subjects
- Apoptosis genetics, Cell Line, Tumor, Cell Survival drug effects, HL-60 Cells, Humans, Leukemia, Promyelocytic, Acute enzymology, Okadaic Acid pharmacology, Protein Phosphatase 2 metabolism, Gossypol pharmacology, Leukemia, Promyelocytic, Acute drug therapy, Protein Phosphatase 2 antagonists & inhibitors, Telomerase metabolism
- Abstract
In this study, we aimed to investigate the potential relationship between gossypol-induced cytotoxicity of human promyelocytic leukemia cell line (HL-60) leukemic cells and intracellular serine/threonine protein phosphatase (PP) dynamics and human telomerase reverse transcriptase (hTERT) activity. Gossypol was found to be cytotoxic in HL-60 cells with the IC(50) dose of 4.5 microM. The combination of gossypol and okadaic acid in IC(50) doses revealed the increased cytotoxicity in a time-dependent manner. Treatment of cells with gossypol has shown significant decrease in PP2A activity. The expression of the PP2A catalytic subunit was downregulated in gossypol-treated cells with 24 hours' intervals. hTERT mRNA levels were gradually decreased. In conclusion, during gossypol-induced cytotoxicity, intracellular activity and expression of PP2A was decreased as well as the activity of hTERT. The variation of hTERT activity in gossypol-treated HL-60 cells may be the potential reason for the phosphatase interaction during the gossypol treatment of leukemic cells resulting in cellular cytotoxicity.
- Published
- 2010
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