alvocidib and Ovarian-Neoplasms

CDK12 is a cyclin-dependent kinase that plays critical roles in DNA replication, transcription, mRNA splicing, and DNA damage repair. CDK12 genomic changes, including mutation, amplification, deletion, and fusion, lead to various cancers, such as colorectal cancer, gastric cancer, and ovarian cancer. An increasing number of CDK12 inhibitors have been reported since CDK12 was identified as a biomarker and cancer therapeutic target. A major challenge lies in that CDK12 and CDK13 share highly similar sequences, which leads to great difficulties in the development of highly selective CDK12 inhibitors. In recent years, great efforts were made in developing selective CDK12 blockers. Techniques including PROTAC and molecular glue degraders were also applied to facilitate their development. Also, the drug combination strategy of CDK12 small molecule inhibitors were studied. This review discusses the latest studies on CDK12 inhibitors and analyzes their structure-activity relationships, shedding light on their further development.

Topics: Cyclin-Dependent Kinases; DNA Repair; Drug Discovery; Female; Humans; Mutation; Ovarian Neoplasms

Based upon promising preclinical and phase 1 trial results, combined flavopiridol and cisplatin therapy was evaluated in patients with ovarian and primary peritoneal cancers.. A two cohort phase 2 trial of cisplatin (60 mg/m2 IV) immediately followed by flavopiridol (100 mg/m2 IV, 24 h infusion; 21 day cycles) was undertaken in patients with recurrent platin-sensitive or platin-resistant disease (progression>vs. ≤6 months following prior platin-based therapy). Measurable disease (RECIST)--or evaluable disease plus CA125>2X post-treatment nadir--and ECOG performance≤2 were required.. Forty-five patients were enrolled between December 23, 2004 and February 25, 2010: 40 platin-resistant (Group 1), and 5 platin-sensitive (Group 2). In Group 1, the median number of treatment cycles was 3 (range 2-12). Only 10% of patients incurred grade 4 toxicities, but grade 3 toxicities were common (65%): neutropenia (17.5%); nausea (12.5%); vomiting, fatigue, thrombosis, anemia (10% each). Seven patients (17.5%) achieved a confirmed response (1 CR, 6 PR; median duration 118 days); ten additional patients (25%) attained maintained stable disease. Median time to progression was 4.3 months; overall survival was 16.1 months. Pilot translational studies assessed ascites flavopiridol level; surrogate marker studies were uninformative. In Group 2, although 4 of 5 patients responded (2 confirmed PRs with median time to progression, 10.8 months and median overall survival 20.6 months) the cohort was closed due to poor accrual.. The assessed flavopiridol and cisplatin regimen displayed clinical activity in platin resistant and sensitive ovarian/primary peritoneal cancers, meriting further study.

Topics: Adolescent; Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Cell Survival; Cisplatin; Cohort Studies; Disease-Free Survival; Drug Resistance, Neoplasm; Female; Flavonoids; Humans; Middle Aged; Ovarian Neoplasms; Peritoneal Neoplasms; Piperidines; Young Adult

The purpose is to investigate the effects of the sequential combination treatment of Taxol and flavopiridol on human ovarian carcinoma in vitro and in vivo.. Cell viabilities were determined using the cell counting kit and by flow cytometry. RT-PCR, TUNEL, and immunoblotting assays were used to detect cellular apoptotic activities following treatments. Tumor growth and microvessel density (MVD) detection of mice bearing SKOV3 cells were studied.. Taxol or flavopiridol alone was cytotoxic against SKOV3 cells in vitro with a viability rate of 38.2 ± 1.3 % for 1 µmol/L Taxol and 44.3 ± 5.9 % for 300 nM flavopiridol. Sequential combination treatment with Taxol and flavopiridol resulted in a viability rate of 9.1 ± 0.8 %. The apoptotic rate of SKOV3 cells was 15.7 ± 1.7, 9.4 ± 0.4 and 51.1 ± 2.5 % for Taxol, flavopiridol, and combination of Taxol and flavopiridol, respectively. Significant synergisms were observed in SKOV3 cells in vitro, following the sequential combination of Taxol for 24 h followed by flavopiridol for 24 h, which resulted in the most substantial cell death and the highest apoptotic rate. All treatments showed significant suppression of tumor growth at the end point of the in vivo study. All treatments significantly reduce the value of MVD.. Sequential combination treatment with Taxol and flavopiridol exerted synergistic cytotoxic activities against SKOV3 cells in vitro and significantly suppress the tumor growth of mice bearing SKOV3 cells. It should be further explored as a potential clinically useful regimen against ovarian cancer.

Topics: Animals; Antineoplastic Agents; Apoptosis; Carcinoma, Ovarian Epithelial; Cell Line, Tumor; Drug Synergism; Female; Flavonoids; Humans; In Situ Nick-End Labeling; Mice; Neoplasms, Glandular and Epithelial; Ovarian Neoplasms; Paclitaxel; Piperidines; Xenograft Model Antitumor Assays

Induction of cell apoptosis and regulation of cell cycle are very attractive for treatments of tumors including ovarian carcinoma. Flavopiridol is a potent small molecular cyclin-dependent kinase(cdk) inhibitor, but its antitumor efficacy is not satisfied yet. Caspase-3 play a major role in the transduction of apoptotic signals and the execution of apoptosis in mammalian cells. We have successfully constructed the recombinant adenovirues AdHTVP2G5-rev-casp3 containing autocatalytic caspase-3 (rev-caspase-3) driven by amplified hTERT promoter system (TSTA-hTERTp). In this study, we applied it with flavopiridol to investigate their antitumor effect on ovarian cancer in vitro and in vivo.. Cell viabilities were determined using Cell Counting Kit 8 and flow cytometry. RT-PCR and immunoblotting assays were used to detect cellular apoptotic activities. Tumor growth and survival of mice bearing tumors were studied.. Flavopiridol or AdHTVP2G5-rev-casp3 at low dosage alone was mildly cytotoxic in vitro with a viability rate of 86.5 ± 4.7% for 300 nM flavopiridol and 88.9 ± 5.4% for AdHTVP2G5-rev-casp3 (MOI 20). By contrast, significant synergism of their sequential combination was observed, and the treatment of AdHTVP2G5-rev-casp3 (MOI 20) infection for 72 h, followed by flavopiridol (300 nM) for 48 h, can result in the most synergistic cell death, with cell survival rate and apoptotic rate of 11.6% and 69.7%, respectively. The sequential combination showed synergistic tumor suppression rate of 77.8%, which was significantly higher than that of AdHTVP2G5-rev-casp3 (33.6%) or flavopiridol (40.1%) alone. The mean survival of mice treated with the combination was 286 ± 8 d, which was synergistically longer than that of mice treated with AdHTVP2G5-rev-casp3 (141 ± 14d), flavopiridol (134 ± 10 d) or controls (106 ± 11 d) (P < 0.01).. The sequential combination of rev-caspase-3 and flavopiridol result in significant synergistic cell killing effects, significant tumor growth suppression and extended survival of mice bearing OVCAR3 cells. The combination should be further explored as a potential clinically useful regimen against ovarian cancer.

Topics: Animals; Antineoplastic Agents; Apoptosis; Caspase 3; Cell Survival; Combined Modality Therapy; Female; Flavonoids; Genetic Therapy; Humans; Injections, Intraperitoneal; Mice, Nude; Ovarian Neoplasms; Piperidines; Telomerase; Tumor Burden; Xenograft Model Antitumor Assays

Failure of platinum chemotherapy is an unresolved issue in ovarian cancer. Targeted therapy has been added to the treatment options in solid cancers. Alvocidib is a cyclin dependent kinase inhibitor.. This study evaluated the effects of alvocidib together with carboplatin on ovarian cancer cells (BG-1 and Skov-3) in vitro applying proliferation assays, cell cycle distribution analyses, apoptosis induction assays, and drug accumulation assay.. Proliferation of both cell lines was inhibited by carboplatin and alvocidib. The interaction index revealed drug synergism at distinct drug concentrations. Cell cycle distribution was altered. Alvocidib induced apoptosis in Skov-3 cells, and necrosis in BG-1 cells. Rhodamine accumulation was increased by alvocidib or both compounds together.. These data provide evidence for antiproliferative effects of alvocidib on human ovarian cancer cells in vitro associated with changes in cell cycle distribution, the induction of apoptosis, and modulation of intracellular drug accumulation. Alvocidib and carboplatin showed some cooperative activity.

Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Carboplatin; Cell Division; Cell Line, Tumor; Drug Synergism; Female; Flavonoids; Humans; Ovarian Neoplasms; Piperidines

Rohitukine, a chromane alkaloid, is a precursor of flavopiridol, a promising anti-cancer compound. Currently in Phase III clinical trials, flavopiridol is a potent inhibitor of several cyclin-dependent kinases (CDKs). Rohitukine was first reported from Amoora rohituka (0.083% dry weight) followed by that in Dysoxylum binectariferum (0.9% dry weight), both belonging to the family Meliaceae. Here, we report incredibly high yields of rohitukine (7% dry weight) in trees of D. binectariferum from the Western Ghats, India. Crude extracts of the tree were found to be highly effective against ovarian and breast cancer lines tested.

Topics: Antineoplastic Agents, Phytogenic; Breast Neoplasms; Cell Line, Tumor; Female; Flavonoids; Humans; India; Limonins; Meliaceae; Neoplasms; Ovarian Neoplasms; Phytotherapy; Piperidines; Plant Bark; Plant Extracts; Plant Stems; Protein Kinase Inhibitors; Trees

to investigate the antitumor effects on ovarian cancer using recombinant adenoviruses expressing autocatalytic caspase-3 driven by amplified human telomerase reverse transcriptase promoter (AdHTVP2G5-rev-casp3) combined with flavopiridol.. following the treatment with AdHTVP2G5-rev-casp3 combined with flavopiridol, cell survival rate was measured by cell counting kit 8; cell apoptotic rate and cell cycle distribution were detected by flow cytometry. Western blot was performed to observe the expression of p17, the active subunit of caspase-3, and p85, the cleavage segment of substrate of caspase-3, in AO cells. The mice survival rates were measured for abdominally metastatic tumor models and the volume of tumor nodules were determined for subcutaneous tumor models following the treatments of AdHTVP2G5-rev-casp3 combined with flavopiridol. HE staining was used to detect the histopathological changes of various organs, and the serum level of alanine transaminase (ALT) and aspartate aminotransferase (AST) were measured to monitor liver damages following the intraperitoneal administration of AdHTVP2G5-rev-casp3 and flavopiridol.. there was no significant cell-killing effects or apoptosis in AO cells following treatments with AdHTVP2G5-rev-casp3 or flavopiridol at low dosage alone (apoptotic rate all < 11%), whereas significant synergism of their sequential combination was observed in AO cells. This sequential treatment of AdHTVP2G5-rev-casp3 [multiplicity of infection (MOI) was 20] infection for 72 hours, followed by flavopiridol (300 nmol/L) for 48 hours, could result in the most substantial cell death, and AO cells survival rate and apoptotic rate were 73.5% and 11.6%, respectively. Following treatments with AdHTVP2G5-rev-casp3 at low doses (MOI = 10), there was a significant increase in cell number with S-phase content (62.5%), which resulted in the most marked apoptosis induced by sequential treatments with flavopiridol. The sequential combination could induce significantly higher levels of p17 and p85 expression than that when their applications alone. Combined AdHTVP2G5-rev-casp3 and flavopiridol treatment prolonged mouse survival [mean survival time of (286 ± 6) days] and suppressed tumor growth significantly (tumor growth suppression rate of 81%), when compared with treatment using either alone. The levels of serum ALT and AST were not significantly elevated and no obvious lesions were found in any organs in treatments with AdHTVP2G5-rev-casp3 of low doses combined with flavopiridol.. AdHTVP2G5-rev-casp3 at low doses results in a significant increase in cell number with S-phase content, which significantly enhanced the sensitivity of cells to flavopiridol. Treatments of autocatalytic caspase-3 combined at low doses with flavopiridol result in significant synergistic antitumor effects, significant tumor growth suppression and prolonged survival of mice. When compared with normal dose flavopiridol alone, the combination could resulted in minimal liver toxicity.

Topics: Adenoviridae; Animals; Apoptosis; Caspase 3; Cell Cycle; Cell Line, Tumor; Cyclin-Dependent Kinases; Drug Synergism; Female; Flavonoids; Flow Cytometry; Gene Transfer Techniques; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Transplantation; Ovarian Neoplasms; Piperidines; Promoter Regions, Genetic; Survival Rate; Telomerase; Treatment Outcome; Xenograft Model Antitumor Assays

To investigate the antitumor effect of flavopiridol in ovarian cancer.. After the treatment with flavopiridol of AO cells, cell apoptotic rate and cell cycle distribution were detected by flow cytometer and the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labelling (TUNEL). Real time PCR was used to detect the expression of cyclin D and active caspase-3 in AO cells. Subcutaneous tumor models and abdominally spread tumor models of human ovarian carcinoma using AO cells in BALB/c nude mice were established. The mouse survival rates were measured for abdominally spread tumor models and the volume of tumor nodules was determined for subcutaneous tumor models following the treatments of flavopiridol. TUNEL was used to detect cell apoptosis, and immunohistochemistry was used to measure microvessel density (MVD) in tumor tissues.. AO cells showed apoptotic rates of 4.1%, 10.7% and 7.6% following the treatments with flavopiridol at 150, 300 and 500 nmol/L respectively, accompanied by an increase in G(1) progression and a decrease in S phase progression. The level of active caspase-3 increased (2.55 vs 2.49) and the level of cyclin D expression decreased significantly (0.25 vs 0.69, P < 0.05) after treatments with flavopiridol. Flavopiridol prolonged mouse survival [mean survival time of (141 +/- 14) days] and suppressed tumor growth significantly (tumor growth suppression rate of 40%), when compared with treatment using phosphate-buffered saline [(106 +/- 11) days, P < 0.05]. Apoptosis was detected in tumor tissues treated with flavopiridol. MVD of tumor tissue was 12 +/- 5 following flavopiridol treatment, significantly higher than that of 35 +/- 10 treated with phosphate-buffered saline (P < 0.05).. Flavopiridol results in significant suppression of ovarian carcinoma cell growth and prolongs survival of mice.

Topics: Animals; Antineoplastic Agents; Apoptosis; Caspase 3; Cell Cycle; Cell Line, Tumor; Cyclin D; Cyclin-Dependent Kinases; Cyclins; Dose-Response Relationship, Drug; Female; Flavonoids; Flow Cytometry; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Ovarian Neoplasms; Piperidines; Survival Analysis; Xenograft Model Antitumor Assays

Germ cell tumours (GCTs) are highly sensitive to cisplatin-based chemotherapy. The inability to arrest the cell cycle at the G1/S-check-point due to a lack of retinoblastoma gene product RB has been suggested as one potential explanation for this feature. Flavopiridol (FP), an inhibitor of cyclin dependent kinases, causes cell cycle arrest or apoptosis depending on the relation of the transcription factor E2F1 and RB.. The effect of FP was evaluated in GCT-derived cell lines NT2, 2102 EP and NCCIT in comparison to cell lines derived from ovarian cancer (SKOV), breast cancer (MCF7), and cervical cancer (HeLa) using the MTT-assay. Cell cycle progression and induction of apoptosis were assessed by flow cytometry and immunoblot analysis of PARP-cleavage.. FP did not affect cell cycle progression and proliferation of GCT cell lines at sublethal doses. At higher concentrations, cell death occurred independent of cell cycle progression. The IC50 was approximately fivefold lower for the three GCT cell lines (60/60/70 nM) than for the other tumour cell lines tested (350/280/300 nM). Lethal doses in vitro were markedly lower than plasma concentrations of FP achieved in clinical studies. In vitro sensitivity to FP did not correlate with that to cisplatin. The cell lines NTera2 and NCCIT showed comparable responses to FP despite differing in their IC50 to cisplatin by factor 4. Flow cytometry and immunoblot for PARP indicated apoptotic cell death induced by FP. Synergism between either cisplatin or paclitaxel and FP was not observed. However, at low concentrations, cytotoxicity of FP and cisplatin appeared to be additive.. These prelinical investigations suggest a significant antitumour activity of FP in GCT. GCT derived cell lines were far more responsive to FP than cell lines derived from other solid tumours. In contrast to other models, FP did not induce cell cycle arrest in the GCT-derived cell lines tested, possibly due to the known lack of RB-expression in GCTs. However, apoptosis was induced unrelated to cell cycle progression already at low concentrations. No cross resistance between FP and cisplatin was observed. A clinical trial evaluating the activity of FP in patients with cisplatin-refractory GCTs appears to be warranted.

Topics: Antineoplastic Agents; Apoptosis; Breast Neoplasms; Carcinoma, Embryonal; Cell Cycle; Cell Line, Tumor; Cisplatin; Dose-Response Relationship, Drug; Drug Synergism; Female; Flavonoids; Humans; Inhibitory Concentration 50; Ovarian Neoplasms; Paclitaxel; Piperidines; Uterine Cervical Neoplasms

Recently we reported that inhibition of cyclin-dependent kinases (cdks) by flavopiridol enhanced the radiation response of murine ovarian carcinoma cells in culture. The purpose of this investigation was to extend these studies to in vivo tumor models and test whether flavopiridol increases the therapeutic ratio of radiotherapy.. Three transplantable syngeneic mouse tumors were used: mammary carcinoma (MCa-29), ovarian carcinoma (OCa-I), and a lymphoma (Ly-TH). Tumor treatment endpoints included growth delay, cure, and spontaneous lung metastases (OCa-I tumor). The normal tissue endpoint was survival of jejunal crypt cells quantified microscopically. A range of flavopiridol doses from 0.625 to 5.0 mg/kg were given systemically once or twice daily over 5, 10, or 20 days. Combined therapy flavopiridol treatments were initiated either several days before or shortly after the start of single dose or daily fractionated radiotherapy.. The major findings of this study are that all three tumors treated with flavopiridol alone responded by tumor growth delay. Two of the tumors (MCa-29 and Ly-TH) responded in a schedule-dependent manner with larger radiation enhancement factors when flavopiridol treatment was started a few hours after irradiation (radioenhancement factors [EF] Ly-TH = 2.04, EF MCa-29 = 1.50 for single dose irradiation). When combined with fractionated irradiation (2.6 Gy daily for 10 or 20 days), flavopiridol enhanced the response of the MCa-29 tumor by a factor of 1.25-1.46. A fractional radiation dose of 6 Gy in combination with flavopiridol produced a 62.5% cure rate compared with 25% tumor cure for radiation alone. A novel finding of this study was the demonstration of antimetastatic activity of flavopiridol in addition to its effect on the local primary tumor. Both the incidence and absolute number of lung metastasis were reduced when flavopiridol followed surgical removal of the large (10 mm) primary leg tumor. The normal jejunum treated with flavopiridol and radiation responded in a schedule independent manner and the degree of radioenhancement (EF, 1.05-1.06) was much less than for any of the tumors studied.. Therapeutic gain was achieved when flavopiridol treatment was initiated either before or after the start of radiotherapy. Flavopiridol shows promising clinical potential administered alone or in combination with other cytotoxic agents, including both chemotherapy and radiotherapy.

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Cyclin-Dependent Kinases; Dose Fractionation, Radiation; Drug Screening Assays, Antitumor; Enzyme Inhibitors; Female; Flavonoids; Jejunum; Lung Neoplasms; Mice; Mice, Inbred C3H; Ovarian Neoplasms; Piperidines; Radiation-Sensitizing Agents

1H-Pyrazolo[3,4-b]pyridine 3 (SQ-67563) has been shown to be a potent, selective inhibitor of CDK1/CDK2 in vitro. In cells 3 acts as a cytotoxic agent with the ability to block cell cycle progression and/or induce apoptosis. The solid state structure of 3 bound to CDK2 shows 3 resides coincident with the ATP purine binding site and forms important H-bonding interactions with Leu83 on the protein backbone.

Topics: Antineoplastic Agents; Biological Assay; CDC2 Protein Kinase; CDC2-CDC28 Kinases; Cell Cycle; Cyclin-Dependent Kinase 2; Cyclin-Dependent Kinases; Enzyme Inhibitors; Female; Humans; Hydrogen Bonding; Models, Molecular; Molecular Conformation; Ovarian Neoplasms; Protein Serine-Threonine Kinases; Pyrazoles; Pyridines; Structure-Activity Relationship; Tumor Cells, Cultured

Flavopiridol, a cyclin-dependent kinase (cdk) inhibitor, can cause cell cycle arrest, induce apoptosis in cancer cells, and inhibit tumor cell growth in vivo. The present study investigated the in vitro radiosensitizing effect of flavopiridol and the underlying molecular mechanisms in a murine ovarian cancer cell line, OCA-I. Flavopiridol inhibited cell growth in a dose-dependent manner and enhanced cell radiosensitivity assessed by the clonogenic cell survival assay. A flavopiridol dose of 300 nM, given for 1 day, enhanced radiosensitivity by a factor of 2.1. Clonogenic cell survival after split-dose radiation showed that flavopiridol inhibited repair from radiation damage. In addition, flavopiridol treatment (300 nM, 1 day) resulted in decreased levels of Ku70 and Ku86 proteins that play a role in DNA repair processes, suggesting that DNA repair processes may have been disrupted by this agent. Flow cytometry analysis showed that flavopiridol (300 nM, 1 day) accumulated the cells in G(1) and G(2) phases, with a significant reduction in the S phase component. This cell cycle redistribution is likely another mechanism underlying flavopiridol-induced cell radiosensitivity. Flavopiridol down-regulated cyclin D1 and cyclin E protein levels and also inhibited phosphorylation of retinoblastoma protein, which is inconsistent with the observed cell cycle arrest. Among the cdks tested, cdk-9, the catalytic subunit of positive transcription elongation factor b, was significantly down-regulated by flavopiridol, suggesting that flavopiridol may modulate cellular transcription processes. Furthermore, flavopiridol on its own induced apoptosis in the OCA-I cells, whereas in combination with radiation, exerted no additional increase in apoptosis. Taken together, our data show that flavopiridol strongly augmented the response of ovarian carcinoma cells to radiation and that the underlying mechanisms included inhibition of sublethal DNA damage repair and cell cycle redistribution. At the molecular level, transcriptional regulation by flavopiridol may have been involved.

Topics: Animals; Antigens, Nuclear; Antineoplastic Agents; Apoptosis; Caspase 3; Caspases; Cell Cycle; Cyclin D1; Cyclin E; Cyclin-Dependent Kinases; DNA Helicases; DNA Repair; DNA-Binding Proteins; Drug Screening Assays, Antitumor; Enzyme Activation; Enzyme Inhibitors; Female; Flavonoids; Gamma Rays; Ku Autoantigen; Mice; Neoplasm Proteins; Ovarian Neoplasms; Piperidines; Radiation Tolerance; Radiation-Sensitizing Agents

Flavopiridol, the first inhibitor of cyclin-dependent kinases to enter clinical trials, has shown promising antineoplastic activity and is currently undergoing Phase II testing. Little is known about mechanisms of resistance to this agent. In the present study, we have characterized an ovarian carcinoma cell line [OV202 high passage (hp)] that spontaneously developed drug resistance upon prolonged passage in tissue culture. Standard cytogenetic analysis and spectral karyotyping revealed that OV202 hp and the parental low passage line OV202 shared several marker chromosomes, confirming the relatedness of these cell lines. Immunoblotting demonstrated that OV202 and OV202 hp contained similar levels of a variety of polypeptides involved in cell cycle regulation, including cyclin-dependent kinases 2 and 4; cyclins A, D1, and E; and proliferating cell nuclear antigen. Despite these similarities, OV202 hp was resistant to flavopiridol and cisplatin, with increases of 5- and 3-fold, respectively, in the mean drug concentrations required to inhibit colony formation by 90%. In contrast, OV202 hp and OV202 displayed indistinguishable sensitivities to oxaliplatin, paclitaxel, topotecan, 1,3-bis(2-chloroethyl)-1-nitrosourea, etoposide, doxorubicin, vincristine, and 5-fluorouracil, suggesting that the spontaneously acquired resistance was not attributable to altered P-glycoprotein levels or a general failure to engage the cell death machinery. After incubation with cisplatin, whole cell platinum and platinum-DNA adducts measured using mass spectrometry were lower in OV202 hp cells than OV202 cells. Similarly, after flavopiridol exposure, whole cell flavopiridol concentrations measured by a newly developed high performance liquid chromatography assay were lower in OV202 hp cells. These data are consistent with the hypothesis that acquisition of spontaneous resistance to flavopiridol and cisplatin in OV202 hp cells is due, at least in part, to reduced accumulation of the respective drugs. These observations not only provide the first characterization of a flavopiridol-resistant cell line but also raise the possibility that alterations in drug accumulation might be important in determining sensitivity to this agent.

Topics: Antineoplastic Agents; Carmustine; Chromosome Aberrations; Chromosome Mapping; Cisplatin; DNA Adducts; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Female; Flavonoids; Humans; Karyotyping; Organoplatinum Compounds; Ovarian Neoplasms; Oxaliplatin; Piperidines; Tumor Cells, Cultured