UCN-01 in ovary cancer cells: effective as a single agent and in combination with cis-diamminedichloroplatinum(II)independent of p53 status.
Our goal was to determine the cytotoxicity of 7-OH-hydroxystaurosporine (UCN-01) as a single agent and in combination with cis-diamminedichloroplatinum(II) (CDDP) in a panel of ovarian carcinoma cells. We sought to examine the role of p53 gene function and alterations in cell cycle progression or other mechanisms of action of UCN-01 including perturbation of the apoptosis pathway mediated by NF-kappaB and Bcl-2/Bax. Cytotoxicity was determined from dose-response curves established by the Alamar blue vital dye indicator assay. Restoration of wild-type p53 in a p53 null cell line, SKOV 3, was achieved by transfection of a p53 expression vector. Cell cycle distribution was measured by fluorescence-activated cell sorting analysis of ethidium bromide-stained nuclei. Apoptosis was measured by quantitative fluorescence microscopy. NF-kappaB DNA binding activity was measured by electrophoretic mobility shift assay. Bcl-2 and Bax levels were determined by Western immunoblotting. UCN-01 was effective as a cytotoxic agent alone and in combination with CDDP in all cell lines studied, regardless of p53 status. The degree of sensitization to CDDP conferred by UCN-01, however, was found to correlate with p53 gene status. p53 wild-type cells seem to be more sensitive to the cytotoxic effects of the combination of UCN-01 + CDDP than the p53 mutant cells. This was confirmed in cells in which p53 wild-type function was restored by transfection of p53 cDNA, but these cells are also significantly more sensitive to CDDP alone. The effects of UCN-01 on cell cycle progression also appear to be p53 dependent but may not be the primary mechanism of action. The rate of apoptosis is increased 4-fold in UCN-01 + CDDP-treated cells compared to either agent alone. UCN-01 does not effect NF-kappaB DNA binding activity or Bcl-2 and Bax levels. UCN-01 enhances CDDP cytotoxicity and apoptosis in ovary cancer cells. This occurs regardless of p53 status, but wild-type p53 seems to increase the degree of sensitization.
Husain
A
A
Division of Gynecologic Oncology, Department of Surgery, Division of Solid Tumors, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
Yan
X J
XJ
Rosales
N
N
Aghajanian
C
C
Schwartz
G K
GK
Spriggs
D R
DR
D000470:Alkaloids / Q000633:toxicity*; D000970:Antineoplastic Agents / Q000633:toxicity*; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D002453:Cell Cycle / Q000187:drug effects / Q000235:genetics; D002470:Cell Survival / Q000187:drug effects; D002945:Cisplatin / Q000633:toxicity*; D004357:Drug Synergism; D005260:Female; D016158:Genes, p53; D006801:Humans; D016296:Mutagenesis; D010051:Ovarian Neoplasms / Q000235:genetics / Q000473:pathology*; D011994:Recombinant Proteins / Q000378:metabolism; D019311:Staurosporine / Q000031:analogs & derivatives; D013997:Time Factors; D014162:Transfection; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
D000470:Alkaloids; D000970:Antineoplastic Agents; D011994:Recombinant Proteins; D016159:Tumor Suppressor Protein p53; C054852:7-hydroxystaurosporine; D019311:Staurosporine; D002945:Cisplatin