The Cyclin-Dependent Kinase Inhibitor Seliciclib (R-roscovitine; CYC202) Decreases the Expression of Mitotic Control Genes and Prevents Entry into Mitosis

Cancer Research UK Centre for Cancer Therapeutics, The Institute of Cancer Research, Haddow Laboratories, Sutton, Surrey, UK.
Cell cycle (Georgetown, Tex.) (Impact Factor: 4.57). 01/2008; 6(24):3114-31. DOI: 10.4161/cc.6.24.5142
Source: PubMed


The cyclin-dependent kinase (CDK) inhibitor seliciclib (R-roscovitine, CYC202) shows promising antitumor activity in preclinical models and is currently undergoing phase II clinical trials. Inhibition of the CDKs by seliciclib could contribute to cell cycle arrest and apoptosis seen with the drug. However, it is common for drugs to exert multiple effects on gene expression and biochemical pathways. To further our understanding of the molecular pharmacology of seliciclib, we employed cDNA microarrays to determine changes in gene expression profiles induced by the drug in HT29 human colon cancer cells. Concentrations of seliciclib were used that inhibited RB phosphorylation and cell proliferation. An increase in the mRNA expression for CJUN and EGR1 was confirmed by Western blotting, consistent with activation of the ERK1/2 MAPK pathway by seliciclib. Transcripts of key genes required for the progression through mitosis showed markedly reduced expression, including Aurora-A/B (AURK-A/B), Polo-like kinase (PLK), cyclin B2 (CCNB2), WEE1 and CDC25C. Reduced expression of these mitotic genes was also seen at the protein level. siRNA-mediated depletion of Aurora-A protein led to an arrest of cells in the G(2)/M phase, consistent with the effects of seliciclib treatment. Inhibition of mitotic entry following seliciclib treatment was indicated by a reduction of histone H3 phosphorylation, which is catalyzed by Aurora-B, and by decreased expression of mitotic markers, including phospho-protein phosphatase 1 alpha. The results indicate a potential mechanism through which seliciclib prevents entry into mitosis. Gene expression profiling has generated hypotheses that led to an increase in our knowledge of the cellular effects of seliciclib and could provide potential pharmacodynamic or response biomarkers for use in animal models and clinical trials.

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    • "As NU6140 inhibits the activity of CDK2 by competitive binding to the ATP site [11] [12] and we found NU6140 did not rapidly downregulate CDK2 expression, CDK2 activity but not the expression level is important for cells to proceed from the G2 to M phase of the cell cycle. Another broad-spectrum CDK inhibitor (roscovitine) has also been shown to decrease the expression of mitotic control genes and prevent the entry of HT29 human colon cancer cells into mitosis [51]. Targeting TF expression in cancer cells is a promising and attractive method for finding new treatment options. "
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    ABSTRACT: As cyclin-dependent kinases (CDKs) regulate cell cycle progression and RNA transcription, CDKs are attractive targets for creating cancer cell treatments. In this study we investigated the effects of the small molecular agent NU6140 (inhibits CDK2 and cyclin A interaction) on human embryonic stem (hES) cells and embryonal carcinoma-derived (hEC) cells via the expression of transcription factors responsible for pluripotency. A multiparameter flow cytometric method was used to follow changes in the expression of NANOG, OCT4, and SOX2 together in single cells. Both hES and hEC cells responded to NU6140 treatment by induced apoptosis and a decreased expression of NANOG, OCT4, and SOX2 in surviving cells. A higher sensitivity to NU6140 application in hES than hEC cells was detected. NU6140 treatment arrested hES and hEC cells in the G2 phase and inhibited entry into the M phase as evidenced by no significant increase in histone 3 phosphorylation.When embryoid bodies (EBs) formed from NU6104 treated hES cells were compared to EBs from untreated hES cells differences in ectodermal, endodermal, and mesodermal lineages were found. The results of this study highlight the importance of CDK2 activity in maintaining pluripotency of hES and hEC cells and in differentiation of hES cells.
    International Journal of Cell Biology 11/2014; 2014. DOI:10.1155/2014/280638
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    • "Study by Buchanan et al [79] on murine adenocarcinoma mammary cells provided new clues regarding the mechanism involved in the modulation of mammary tumor cell growth and survival induced by glypican-3. Gene expression profiling has generated hypotheses that led to an increase in our knowledge of the cellular effects of seliciclib (cdk inhibitor) and could provide potential pharmacodynamic or response biomarkers for use in animal models and clinical trials [80]. Another Cdk inhibitor SU9516 is over expressed in HCT116 cells by the knockout of the p21WAF1/CIP1 gene which suppresses thymidylate synthase and enhances chemosensitivity to 5-Flurouracil [81]. "
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    Cell Division 01/2010; 5(1):4. DOI:10.1186/1747-1028-5-4 · 3.53 Impact Factor
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    • "They have been used to inhibit growth of several types of tumor cells in numerous preclinical studies, both in vitro and in vivo (Drees et al., 1997; Schwartz et al., 1997; Arguello et al., 1998; Erickson et al., 1998; Chien et al., 1999; Shapiro et al., 1999; Tirado et al., 2005). Several Cdk inhibitors (Flavopiridol, UCN-01, Roscovitine, AT7519) have advanced to human clinical trials for evaluation as treatment for a broad range of solid tumors and hematological malignancies such as chronic lymphocytic leukemia (CLL) (Senderowicz, 1999; Senderowicz and Sausville, 2000; Whittaker et al., 2007; Wyatt et al., 2008). "
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