The novel cyclin-dependent kinase inhibitor flavopiridol downregulates Bcl-2 and induces growth arrest and apoptosis in chronic B-cell leukemia lines Journal Article


Authors: K├Ânig, A.; Schwartz, G. K.; Mohammad, R. M.; Al-Katib, A.; Gabrilove, J. L.
Article Title: The novel cyclin-dependent kinase inhibitor flavopiridol downregulates Bcl-2 and induces growth arrest and apoptosis in chronic B-cell leukemia lines
Abstract: Flavopiridol is a novel, potent inhibitor of cyclin-dependent kinases (CDK). This synthetic flavone has been reported to exhibit antitumor activity in murine and human tumor cell lines in vitro and in vivo and is currently undergoing clinical phase I evaluation. In the present study, 1 Epstein-Barr virus (EBV)-transformed B-prolymphocytic cell line (JVM-2), 1 EBV- transformed B-CLL cell line (183CLL), and 1 non-EBV transformed B-CLL cell line (WSU-CLL) were used as targets. Treatment of the cells with flavopiridol (100 nmol/L to 400 nmol/L) led to a marked dose- and time-dependent inhibition of cell growth and survival as determined using trypan blue exclusion. Morphologic analysis showed characteristic apoptotic changes such as chromatin condensation and fragmentation, membrane blebbing, and formation of apoptotic bodies. Furthermore, quantitative assessment of apoptosis- associated DNA strand breaks by in situ TdT labeling showed that a significant number of flavopiridol-treated cells underwent apoptosis. These cellular effects were associated with a significant decrease in bcl-2 expression as observed by Northern and Western blotting. The results showed that flavopiridol downregulates bcl-2 mRNA and bcl-2 protein expression within 24 hours. Genistein and quercetin, two flavonoids that do not inhibit CDKs, did not affect bcl-2 expression. These data suggest an additional mechanism of action of this new flavone which might be useful as an agent in the treatment of chronic lymphoid malignancies.
Keywords: human cell; cell survival; apoptosis; enzyme inhibition; down-regulation; antineoplastic activity; tumor cells, cultured; enzyme inhibitor; quercetin; enzyme inhibitors; rna, messenger; cell transformation; immunoblotting; down regulation; flavonoid; flavonoids; flavopiridol; piperidines; cyclin-dependent kinases; proto-oncogene proteins c-bcl-2; growth disorder; cell labeling; northern blotting; genistein; chronic leukemia; dna strand; leukemia, b-cell; humans; human; priority journal; article
Journal Title: Blood
Volume: 90
Issue: 11
ISSN: 0006-4971
Publisher: American Society of Hematology  
Date Published: 1997-12-01
Start Page: 4307
End Page: 4312
Language: English
PUBMED: 9373241
PROVIDER: scopus
DOI/URL:
Notes: Article -- Export Date: 17 March 2017 -- Source: Scopus