Bcl-2 overexpression protects human keratinocyte cells from Ukrain-induced apoptosis but not from G2/M arrest.

Drugs Exp Clin Res. 2000;26(5-6):149-56. Bcl-2 overexpression protects human keratinocyte cells from Ukrain-induced apoptosis but not from G2/M arrest. Roublevskaia IN, Haake AR, Polevoda BV. Department of Dermatology, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA. Exposure of ME180 and A431 carcinoma cells to Ukrain (NSC-631570), results in cell cycle arrest at the G2/M phase. Ukrain selectively inhibits growth of ME180 and A431 carcinoma cells at a concentration range from 3.5 microM to 7.0 microM and induces apoptosis. In contrast, normal human keratinocytes showed no difference in the kinetics of progression through the cell cycle in response to this compound. We found that at a concentration of 7.0 microM of this drug [url=http://en.wikipedia.org/wiki/Bcl-2_protein]Bcl-2 protein[/url] overexpression protected HaCaT cell line keratinocytes against apoptosis induced by Ukrain but did not prevent [url=http://clincancerres.aacrjournals.org/cgi/content/full/8/11/3311]G2/M arrest[/url]. Following exposure of normal keratinocytes to Ukrain, we detected an increase in [url=http://en.wikipedia.org/wiki/Bcl-2_protein]Bcl-2 protein[/url] levels and a significant change in protein modification as suggested by observation of its different isoform with shifted electrophoretic mobility. Bcl-2 protein expression and its isoform distribution did not change substantially in ME180 and A431 carcinoma cells. We also suggest that drug-induced mitotic arrest and apoptosis represent dual Ukrain action on cell cycle progression machinery and Bcl-2-involved program cell death in the cell.