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PloS One 2014Dinaciclib is a potent CDK1, 2, 5 and 9 inhibitor being developed for the treatment of cancer. Additional understanding of antitumor mechanisms and identification of...
Dinaciclib is a potent CDK1, 2, 5 and 9 inhibitor being developed for the treatment of cancer. Additional understanding of antitumor mechanisms and identification of predictive biomarkers are important for its clinical development. Here we demonstrate that while dinaciclib can effectively block cell cycle progression, in vitro and in vivo studies, coupled with mouse and human pharmacokinetics, support a model whereby induction of apoptosis is a main mechanism of dinaciclib's antitumor effect and relevant to the clinical duration of exposure. This was further underscored by kinetics of dinaciclib-induced downregulation of the antiapoptotic BCL2 family member MCL1 and correlation of sensitivity with the MCL1-to-BCL-xL mRNA ratio or MCL1 amplification in solid tumor models in vitro and in vivo. This MCL1-dependent apoptotic mechanism was additionally supported by synergy with the BCL2, BCL-xL and BCL-w inhibitor navitoclax (ABT-263). These results provide the rationale for investigating MCL1 and BCL-xL as predictive biomarkers for dinaciclib antitumor response and testing combinations with BCL2 family member inhibitors.
Topics: Aniline Compounds; Animals; Antineoplastic Agents; Apoptosis; Bridged Bicyclo Compounds, Heterocyclic; Cell Cycle Checkpoints; Cell Line, Tumor; Cyclic N-Oxides; Disease Models, Animal; Diterpenes; Drug Resistance, Neoplasm; Drug Synergism; Epoxy Compounds; Female; Gene Dosage; Humans; Indolizines; Male; Mice; Myeloid Cell Leukemia Sequence 1 Protein; Neoplasms; Phenanthrenes; Pyridinium Compounds; RNA, Messenger; Sulfonamides; Xenograft Model Antitumor Assays; bcl-X Protein
PubMed: 25289887
DOI: 10.1371/journal.pone.0108371 -
Molecular Cancer Therapeutics Feb 2016PARP1/2 are required for single-strand break repair, and their inhibition causes DNA replication fork collapse and double-strand break (DSB) formation. These DSBs are...
PARP1/2 are required for single-strand break repair, and their inhibition causes DNA replication fork collapse and double-strand break (DSB) formation. These DSBs are primarily repaired via homologous recombination (HR), a high-fidelity repair pathway. Should HR be deficient, DSBs may be repaired via error-prone nonhomologous end-joining mechanisms, or may persist, ultimately resulting in cell death. The combined disruption of PARP and HR activities thus produces synthetic lethality. Multiple myeloma cells are characterized by chromosomal instability and pervasive DNA damage, implicating aberrant DNA repair. Cyclin-dependent kinases (CDK), upstream modulators of HR, are dysregulated in multiple myeloma. Here, we show that a CDK inhibitor, dinaciclib, impairs HR repair and sensitizes multiple myeloma cells to the PARP1/2 inhibitor ABT-888. Dinaciclib abolishes ABT-888-induced BRCA1 and RAD51 foci and potentiates DNA damage, indicated by increased γH2AX foci. Dinaciclib treatment reduces expression of HR repair genes, including Rad51, and blocks BRCA1 phosphorylation, a modification required for HR repair, thus inhibiting HR repair of chromosome DSBs. Cotreatment with dinaciclib and ABT-888 in vitro resulted in synthetic lethality of multiple myeloma cells, but not normal CD19(+) B cells, and slowed growth of multiple myeloma xenografts in SCID mice almost two-fold. These findings support combining dinaciclib with PARP inhibitors for multiple myeloma therapy. Mol Cancer Ther; 15(2); 241-50. ©2015 AACR.
Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Bridged Bicyclo Compounds, Heterocyclic; Cell Line, Tumor; Cell Survival; Cyclic N-Oxides; Cyclin-Dependent Kinases; Drug Synergism; Gene Expression Regulation, Neoplastic; Homologous Recombination; Humans; Indolizines; Mice; Mice, SCID; Multiple Myeloma; Poly(ADP-ribose) Polymerase Inhibitors; Pyridinium Compounds; Xenograft Model Antitumor Assays
PubMed: 26719576
DOI: 10.1158/1535-7163.MCT-15-0660 -
Frontiers in Cell and Developmental... 2015Hematologic malignancies represent the fourth most frequently diagnosed cancer in economically developed countries. In hematologic malignancies normal hematopoiesis is... (Review)
Review
Hematologic malignancies represent the fourth most frequently diagnosed cancer in economically developed countries. In hematologic malignancies normal hematopoiesis is interrupted by uncontrolled growth of a genetically altered stem or progenitor cell (HSPC) that maintains its ability of self-renewal. Cyclin-dependent kinases (CDKs) not only regulate the mammalian cell cycle, but also influence other vital cellular processes, such as stem cell renewal, differentiation, transcription, epigenetic regulation, apoptosis, and DNA repair. Chromosomal translocations, amplification, overexpression and altered CDK activities have been described in different types of human cancer, which have made them attractive targets for pharmacological inhibition. Mouse models deficient for one or more CDKs have significantly contributed to our current understanding of the physiological functions of CDKs, as well as their roles in human cancer. The present review focuses on selected cell cycle kinases with recent emerging key functions in hematopoiesis and in hematopoietic malignancies, such as CDK6 and its role in MLL-rearranged leukemia and acute lymphocytic leukemia, CDK1 and its regulator WEE-1 in acute myeloid leukemia (AML), and cyclin C/CDK8/CDK19 complexes in T-cell acute lymphocytic leukemia. The knowledge gained from gene knockout experiments in mice of these kinases is also summarized. An overview of compounds targeting these kinases, which are currently in clinical development in various solid tumors and hematopoietic malignances, is presented. These include the CDK4/CDK6 inhibitors (palbociclib, LEE011, LY2835219), pan-CDK inhibitors that target CDK1 (dinaciclib, flavopiridol, AT7519, TG02, P276-00, terampeprocol and RGB 286638) as well as the WEE-1 kinase inhibitor, MK-1775. The advantage of combination therapy of cell cycle inhibitors with conventional chemotherapeutic agents used in the treatment of AML, such as cytarabine, is discussed.
PubMed: 25914884
DOI: 10.3389/fcell.2015.00016 -
Oncogene Mar 2023Targeting cyclin-dependent kinases (CDKs) has recently emerged as a promising therapeutic approach against cancer. However, the anticancer mechanisms of different CDK...
Targeting cyclin-dependent kinases (CDKs) has recently emerged as a promising therapeutic approach against cancer. However, the anticancer mechanisms of different CDK inhibitors (CDKIs) are not well understood. Our recent study revealed that selective CDK4/6 inhibitors sensitize colorectal cancer (CRC) cells to therapy-induced apoptosis by inducing Death Receptor 5 (DR5) via the p53 family member p73. In this study, we investigated if this pathway is involved in anticancer effects of different CDKIs. We found that less-selective CDKIs, including flavopiridol, roscovitine, dinaciclib, and SNS-032, induced DR5 via p73-mediated transcriptional activation. The induction of DR5 by these CDKIs was mediated by dephosphorylation of p73 at Threonine 86 and p73 nuclear translocation. Knockdown of a common target of these CDKIs, including CDK1, 2, or 9, recapitulated p73-mediated DR5 induction. CDKIs strongly synergized with 5-fluorouracil (5-FU), the most commonly used CRC chemotherapy agent, in vitro and in vivo to promote growth suppression and apoptosis, which required DR5 and p73. Together, these findings indicate p73-mediated DR5 induction as a potential tumor suppressive mechanism and a critical target engaged by different CDKIs in potentiating therapy-induced apoptosis in CRC cells. These findings help better understand the anticancer mechanisms of CDKIs and may help facilitate their clinical development and applications in CRC.
Topics: Humans; Cyclin-Dependent Kinases; Cell Line, Tumor; Colonic Neoplasms; Antineoplastic Agents; Apoptosis; Fluorouracil
PubMed: 36721000
DOI: 10.1038/s41388-023-02598-6 -
Cell Death & Disease Jun 2022Constitutive activation of cyclin-dependent kinases (CDKs) or arginine auxotrophy are hallmarks of Glioblastoma multiforme (GBM). The latter metabolic defect renders...
Constitutive activation of cyclin-dependent kinases (CDKs) or arginine auxotrophy are hallmarks of Glioblastoma multiforme (GBM). The latter metabolic defect renders tumor cells vulnerable to arginine-depleting substances, such as arginine deiminase from Streptococcus pyogenes (SpyADI). Previously, we confirmed the susceptibility of patient-derived GBM cells towards SpyADI as well as CDK inhibitors (CDKis). To improve therapeutic effects, we here applied a combined approach based on SpyADI and CDKis (dinaciclib, abemaciclib). Three arginine-auxotrophic patient-derived GBM lines with different molecular characteristics were cultured in 2D and 3D and effects of this combined SpyADI/CDKi approach were analyzed in-depth. All CDKi/SpyADI combinations yielded synergistic antitumoral effects, especially when given sequentially (SEQ), i.e., CDKi in first-line and most pronounced in the 3D models. SEQ application demonstrated impaired cell proliferation, invasiveness, and viability. Mitochondrial impairment was demonstrated by increasing mitochondrial membrane potential and decreasing oxygen consumption rate and extracellular acidification rate after SpyADI/abemaciclib monotherapy or its combination regimens. The combined treatment even induced autophagy in target cells (abemaciclib/SpyADI > dinaciclib/SpyADI). By contrast, the unfolded protein response and p53/p21 induced senescence played a minor role. Transmission electron microscopy confirmed damaged mitochondria and endoplasmic reticulum together with increased vacuolization under CDKi mono- and combination therapy. SEQ-abemaciclib/SpyADI treatment suppressed the DSB repair system via NHEJ and HR, whereas SEQ-dinaciclib/SpyADI treatment increased γ-H2AX accumulation and induced Rad51/Ku80. The latter combination also activated the stress sensor GADD45 and β-catenin antagonist AXIN2 and induced expression changes of genes involved in cellular/cytoskeletal integrity. This study highlights the strong antitumoral potential of a combined arginine deprivation and CDK inhibition approach via complex effects on mitochondrial dysfunction, invasiveness as well as DNA-damage response. This provides a good starting point for further in vitro and in vivo proof-of-concept studies to move forward with this strategy.
Topics: Arginine; Autophagy; Cell Line, Tumor; Cyclin-Dependent Kinases; Glioblastoma; Humans
PubMed: 35717443
DOI: 10.1038/s41419-022-05006-1 -
Scientific Reports Mar 2021Medulloblastoma (MB) is the most common aggressive paediatric brain tumour and, despite the recent progress in the treatments of MB patients, there is still an urgent...
Medulloblastoma (MB) is the most common aggressive paediatric brain tumour and, despite the recent progress in the treatments of MB patients, there is still an urgent need of complementary or alternative therapeutic options for MB infants. Cyclin Dependent Kinase inhibitors (CDKi) are at the front-line of novel targeted treatments for multiple cancers and the CDK4/6 specific inhibitor palbociclib has been pre-clinically identified as an effective option for MB cells. Herein, we identified the pan-CDKi dinaciclib as a promising alternative to palbociclib for the suppression of MB cells proliferation. We present evidence supporting dinaciclib's ability to inhibit MB cells in vitro proliferation at considerably lower doses than palbociclib. Sequencing data and pathway analysis suggested that dinaciclib is a potent cell death inducer in MB cells. We found that dinaciclib-triggered apoptosis is triggered by CDK9 inhibition and the resultant reduction in RNA pol II phosphorylation, which leads to the downregulation of the oncogenic marker MYC, and the anti-apoptotic protein MCL-1. Specifically, we demonstrated that MCL-1 is a key apoptotic mediator for MB cells and co-treatment of dinaciclib with BH3 mimetics boosts the therapeutic efficacy of dinaciclib. Together, these findings highlight the potential of multi-CDK inhibition by dinaciclib as an alternative option to CDK4/6 specific inhibition, frequently associated with drug resistance in patients.
Topics: Cell Proliferation; Cyclic N-Oxides; Cyclin-Dependent Kinases; Drug Screening Assays, Antitumor; Humans; Indolizines; Medulloblastoma; Neoplasm Proteins; Protein Kinase Inhibitors; Pyridinium Compounds
PubMed: 33686114
DOI: 10.1038/s41598-021-84082-3 -
Cancer Medicine Aug 2019This study aimed to identify and evaluate the mechanism by which apoptosis and cell cycle arrest were induced by dinaciclib in lymphoma Raji cells.
OBJECTIVE
This study aimed to identify and evaluate the mechanism by which apoptosis and cell cycle arrest were induced by dinaciclib in lymphoma Raji cells.
METHODS
The colony formation assay was used to detect cell proliferation of Raji cells. Cell cycle arrest and cell apoptosis were determined by flow cytometry and TUNEL assays, respectively. Protein expression related to the Raji cell state was evaluated by Western blot. The Raji/Dinaciclib drug-resistant cell line was established, where the regulating functions of CDK1-involved pathway were verified. In addition, the effect of dinaciclib in vivo was examined in orthotopically implanted tumors in nude mice.
RESULTS
Cell apoptosis was induced, and DNA synthesis ability was decreased in a time-dependent manner in dinaciclib-treated lymphoma Raji cells. Furthermore, the cell cycle was found to be blocked in the G2/M Phase. Further study indicated that CDK1-involved pathway played a key regulatory role in this process. It was revealed by cell transfection that the expression of cell cycle proteins was downregulated after treatment with dinaciclib through a CDK1-involved pathway, which eventually led to apoptosis. Knockdown of CDK1 restored the sensitivity of the Raji/Dinaciclib cells to dinaciclib. Xenograft model of nude mice showed that dinaciclib treatment in vivo could effectively inhibit tumor growth, consistent with the experiment results mentioned before.
CONCLUSION
In this study, we clarified the mechanisms through which dinaciclib induces Raji cell apoptosis and blocks the cell cycle through a CDK1-involved pathway, which supported that dinaciclib had potential values in the treatment of lymphoma.
Topics: Animals; Antineoplastic Agents; Bridged Bicyclo Compounds, Heterocyclic; CDC2 Protein Kinase; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cyclic N-Oxides; Down-Regulation; Drug Resistance, Neoplasm; Female; Humans; Indolizines; Lymphoma; Mice; Mice, Nude; Pyridinium Compounds; Signal Transduction; Xenograft Model Antitumor Assays
PubMed: 31207099
DOI: 10.1002/cam4.2324 -
Cell Cycle (Georgetown, Tex.) May 2022Clear cell renal cell carcinoma (CC-RCC) remains one of the most deadly forms of kidney cancer despite recent advancements in targeted therapeutics, including tyrosine...
Clear cell renal cell carcinoma (CC-RCC) remains one of the most deadly forms of kidney cancer despite recent advancements in targeted therapeutics, including tyrosine kinase and immune checkpoint inhibitors. Unfortunately, these therapies have not been able to show better than a 16% complete response rate. In this study we evaluated a cyclin-dependent kinase inhibitor, Dinaciclib, as a potential new targeted therapeutic for CC-RCC. , Dinaciclib showed anti-proliferative and pro-apoptotic effects on CC-RCC cell lines in Cell Titer Glo, Crystal Violet, FACS-based cell cycle analysis, and TUNEL assays. Additionally, these responses were accompanied by a reduction in phospho-Rb and pro-survival MCL-1 cell signaling responses, as well as the induction of caspase 3 and PARP cleavage. , Dinaciclib efficiently inhibited primary tumor growth in an orthotopic, patient-derived xenograft-based CC-RCC mouse model. Importantly, Dinaciclib targeted both CD105 cancer stem cells (CSCs) and CD105 non-CSCs . Moreover, normal cell lines, as well as a CC-RCC cell line with re-expressed von-Hippel Lindau () tumor suppressor gene, were protected from Dinaciclib-induced cytotoxicity when not actively dividing, indicating an effective therapeutic window due to synthetic lethality of Dinaciclib treatment with loss. Thus, Dinaciclib represents a novel potential therapeutic for CC-RCC.
Topics: Animals; Carcinoma, Renal Cell; Cell Line, Tumor; Cyclic N-Oxides; Cyclin-Dependent Kinase Inhibitor Proteins; Cyclin-Dependent Kinases; Female; Humans; Indolizines; Kidney Neoplasms; Male; Mice; Protein Kinase Inhibitors; Pyridinium Compounds; Synthetic Lethal Mutations; Von Hippel-Lindau Tumor Suppressor Protein
PubMed: 35240916
DOI: 10.1080/15384101.2022.2041783 -
Molecules (Basel, Switzerland) Oct 2020The hormonal luminal-A is the most pre-dominant sub type of breast cancer (BC), and it is associated with a high level of cyclin D1 in Saudi patients. Tamoxifen is the...
The hormonal luminal-A is the most pre-dominant sub type of breast cancer (BC), and it is associated with a high level of cyclin D1 in Saudi patients. Tamoxifen is the golden therapy for hormonal BC, but resistance of cancer cells to tamoxifen contributes to the recurrence of BC due to many reasons, including high levels of AIB1 and cyclin D1. Overcoming drug resistance could be achieved by exploring alternative targetable therapeutic pathways and new drugs or combinations. The objective of this study was to determine the differentially enriched pathways in 12 samples of Saudi women diagnosed with luminal-A using the PamChip peptide microarray-based kinase activity profiling, and to compare the activity of HAA and dinaciclib with tamoxifen in singles and combinations in the MCF7 luminal-A cell line. Our results of network and pathway analysis of the 12 samples highlighted the importance of VEGFR and CDKs in promoting luminal-A breast cancer. The activation of VEGF signaling via VEGFR-2 leads to activation of PI3K/AKT kinases and an increase of cell survival, and leads to activation of Hsp90, which induces the phosphorylation of FAK1, resulting in cytoskeleton remodeling. PLC-gamma 1 is also activated, leading to FAK-2 and PKC activation. Notably, the G/S cell cycle phases and phosphorylation processes contribute to the top seven tumorigenesis processes in the 12 samples. Further, the MTT combination of HAA and dinaciclib showed the best combination index (CI), was more clonogenic against MCF7 cells compared to the other combinations, and it also showed the best selectivity index (SI) in normal MRC5 cells. Interestingly, HAA and dinaciclib showed a synergistic apoptotic and G cell cycle effect in MCF7 cells, which was supported by their synergistic CDK2, cyclin D1, and PCNA inhibition activities. Additionally, the combination showed VEGFR-2 and Hsp90 inhibition activities in MCF7 cells. The results show the significance of targeting VEGFR-2 and cyclin D1 in Saudi luminal-A breast cancer patients, and the effect of combining HAA and dinaciclib on those targets in the MCF7 model. It also warrants further preclinical and in vivo investigations for the combination of HAA and dinaciclib as a possible future second-line treatment for luminal-A breast cancers.
Topics: Adult; Aged; Breast Neoplasms; Cell Cycle; Cell Line; Cyclic N-Oxides; Cyclin D1; Cyclin-Dependent Kinase 2; Focal Adhesion Kinase 1; Focal Adhesion Kinase 2; HSP90 Heat-Shock Proteins; Humans; Indolizines; MCF-7 Cells; Middle Aged; Phospholipase C gamma; Pyridinium Compounds; Vascular Endothelial Growth Factor Receptor-2
PubMed: 33050377
DOI: 10.3390/molecules25204606 -
Blood Cancer Journal Jul 2016The treatment of multiple myeloma (MM) is rapidly evolving. In the United States, four drugs (panobinostat, ixazomib, daratumumab and elotuzumab) were approved for the... (Review)
Review
The treatment of multiple myeloma (MM) is rapidly evolving. In the United States, four drugs (panobinostat, ixazomib, daratumumab and elotuzumab) were approved for the treatment of MM in 2015. As a result of improved diagnosis and therapy, there has been a dramatic improvement in the outcome of MM in the last decade, probably more than any other malignancy. Numerous agents continue to be studied in preclinical models and in clinical trials, with many demonstrating clinical efficacy that appears promising enough to have a trajectory for regulatory approval. The purpose of this article is to summarize the current data and provide perspective on new investigational agents with promising single-agent activity in MM. The agents reviewed include Isatuximab, an anti-CD38 monoclonal antibody; marizomib, a new proteasome inhibitor; oprozomib, an oral proteasome inhibitor; filanesib (ARRY-520), a kinesin spindle protein inhibitor; dinaciclib, a cyclin-dependent kinase inhibitor; venetoclax (ABT-199), a selective BCL-2 inhibitor; and LGH-447, pan PIM kinase inhibitor.
Topics: Antibodies, Monoclonal; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Clinical Trials as Topic; Drugs, Investigational; Humans; Molecular Targeted Therapy; Multiple Myeloma; Treatment Outcome
PubMed: 27471867
DOI: 10.1038/bcj.2016.53