As treatment options for patients with incurable metastatic castration-resistant prostate cancer (mCRPC) are considerably limited, novel effective therapeutic options are needed. Checkpoint kinase 1 (CHK1) is a highly conserved protein kinase implicated in the DNA damage response (DDR) pathway that prevents the accumulation of DNA damage and controls regular genome duplication. CHK1 has been associated with prostate cancer (PCa) induction, progression, and lethality; hence, CHK1 inhibitors SCH900776 (also known as MK-8776) and the more effective SCH900776 analog MU380 may have clinical applications in the therapy of PCa. Synergistic induction of DNA damage with CHK1 inhibition represents a promising therapeutic approach that has been tested in many types of malignancies, but not in chemoresistant mCRPC. Here, we report that such therapeutic approach may be exploited using the synergistic action of the antimetabolite gemcitabine (GEM) and CHK1 inhibitors SCH900776 and MU380 in docetaxel-resistant (DR) mCRPC. Given the results, both CHK1 inhibitors significantly potentiated the sensitivity to GEM in a panel of chemo-naïve and matched DR PCa cell lines under 2D conditions. MU380 exhibited a stronger synergistic effect with GEM than clinical candidate SCH900776. MU380 alone or in combination with GEM significantly reduced spheroid size and increased apoptosis in all patient-derived xenograft 3D cultures, with a higher impact in DR models. Combined treatment induced premature mitosis from G1 phase resulting in the mitotic catastrophe as a prestage of apoptosis. Finally, treatment by MU380 alone, or in combination with GEM, significantly inhibited tumor growth of both PC339-DOC and PC346C-DOC xenograft models in mice. Taken together, our data suggest that metabolically robust and selective CHK1 inhibitor MU380 can bypass docetaxel resistance and improve the effectiveness of GEM in DR mCRPC models. This approach might allow for dose reduction of GEM and thereby minimize undesired toxicity and may represent a therapeutic option for patients with incurable DR mCRPC.

• MeSH
• buněčná smrt účinky léků   MeSH
• checkpoint kinasa 1 antagonisté a inhibitory   metabolismus   MeSH
• chemorezistence účinky léků   MeSH
• deoxycytidin analogy a deriváty   farmakologie   MeSH
• docetaxel farmakologie   MeSH
• lidé MeSH
• mitóza * účinky léků   MeSH
• myši SCID MeSH
• nádorové buněčné linie MeSH
• nádory prostaty patologie   MeSH
• piperidiny chemie   farmakologie   MeSH
• proliferace buněk účinky léků   MeSH
• pyrazoly chemie   farmakologie   MeSH
• pyrimidiny chemie   farmakologie   MeSH
• S fáze účinky léků   MeSH
• xenogenní modely - testy protinádorové aktivity MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• checkpoint kinasa 1 antagonisté a inhibitory   MeSH
• karcinom z renálních buněk * diagnóza   epidemiologie   terapie   MeSH
• lidé MeSH
• rizikové faktory MeSH
• terciární prevence MeSH
• TOR serin-threoninkinasy antagonisté a inhibitory   MeSH
• vaskulární endoteliální růstové faktory antagonisté a inhibitory   MeSH
• von Hippelova-Lindauova nemoc MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH

Progress in cancer therapy changed the outcome of many patients and moved therapy from chemotherapy agents to targeted drugs. Targeted drugs already changed the clinical practice in treatment of leukemias, such as imatinib (BCR/ABL inhibitor) in chronic myeloid leukemia (CML) and acute lymphoblastic leukemia (ALL), ibrutinib (Bruton's tyrosine kinase inhibitor) in chronic lymphocytic leukemia (CLL), venetoclax (BCL2 inhibitor) in CLL and acute myeloid leukemia (AML) or midostaurin (FLT3 inhibitor) in AML. In this review, we focused on DNA damage response (DDR) inhibition, specifically on inhibition of ATR-CHK1 pathway. Cancer cells harbor often defects in different DDR pathways, which render them vulnerable to DDR inhibition. Some DDR inhibitors showed interesting single-agent activity even in the absence of cytotoxic drug especially in cancers with underlying defects in DDR or DNA replication. Almost no mutations were found in ATR and CHEK1 genes in leukemia patients. Together with the fact that ATR-CHK1 pathway is essential for cell development and survival of leukemia cells, it represents a promising therapeutic target for treatment of leukemia. ATR-CHK1 inhibition showed excellent results in preclinical testing in acute and chronic leukemias. However, results in clinical trials are so far insufficient. Therefore, the ongoing and future clinical trials will decide on the success of ATR/CHK1 inhibitors in clinical practice of leukemia treatment.

• MeSH
• akutní nemoc MeSH
• ATM protein antagonisté a inhibitory   metabolismus   MeSH
• checkpoint kinasa 1 antagonisté a inhibitory   metabolismus   MeSH
• chronická nemoc MeSH
• cílená molekulární terapie MeSH
• leukemie farmakoterapie   genetika   metabolismus   patologie   MeSH
• lidé MeSH
• poškození DNA MeSH
• randomizované kontrolované studie jako téma MeSH
• signální transdukce účinky léků   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

p53-mutated tumors often exhibit increased resistance to standard chemotherapy and enhanced metastatic potential. Here we demonstrate that inhibition of dihydroorotate dehydrogenase (DHODH), a key enzyme of the de novo pyrimidine synthesis pathway, effectively decreases proliferation of cancer cells via induction of replication and ribosomal stress in a p53- and checkpoint kinase 1 (Chk1)-dependent manner. Mechanistically, a block in replication and ribosomal biogenesis result in p53 activation paralleled by accumulation of replication forks that activate the ataxia telangiectasia and Rad3-related kinase/Chk1 pathway, both of which lead to cell cycle arrest. Since in the absence of functional p53 the cell cycle arrest fully depends on Chk1, combined DHODH/Chk1 inhibition in p53-dysfunctional cancer cells induces aberrant cell cycle re-entry and erroneous mitosis, resulting in massive cell death. Combined DHODH/Chk1 inhibition effectively suppresses p53-mutated tumors and their metastasis, and therefore presents a promising therapeutic strategy for p53-mutated cancers.

• MeSH
• checkpoint kinasa 1 antagonisté a inhibitory   genetika   metabolismus   MeSH
• fenylmočovinové sloučeniny farmakologie   MeSH
• geny erbB-2 MeSH
• HCT116 buňky MeSH
• inhibitory proteinkinas farmakologie   MeSH
• kontrolní body buněčného cyklu * účinky léků   MeSH
• leflunomid farmakologie   MeSH
• lidé MeSH
• MFC-7 buňky MeSH
• myši inbrední BALB C MeSH
• myši inbrední NOD MeSH
• myši SCID MeSH
• myši transgenní MeSH
• nádorový supresorový protein p53 nedostatek   genetika   MeSH
• nádory prsu farmakoterapie   genetika   metabolismus   patologie   MeSH
• oxidoreduktasy působící na CH-CH vazby antagonisté a inhibitory   genetika   metabolismus   MeSH
• proliferace buněk * účinky léků   MeSH
• protokoly protinádorové kombinované chemoterapie farmakologie   MeSH
• pyraziny farmakologie   MeSH
• pyrimidiny biosyntéza   MeSH
• regulace genové exprese u nádorů MeSH
• ribozomy genetika   metabolismus   MeSH
• signální transdukce MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The project consists of preclinical development of novel small-molecule selective inhibitor of CHK1 kinase (OH209EN1) with expected effective antitumour activity based on the concept of synthetic lethality. This revolutionary concept in targeted anticancer therapy is based on simultaneous elimination of two or more complementary pathways essential for the cell, which results in lethal effect. This mechanism of action, already validated in the clinic, can be selectively applied to cancer cells while taking advantage of the mutations (e. g., in TP53 or ATM genes) acquired during the development of malignancy. In the pilot test, our unique inhibitor OH209EN1 demonstrated significantly better activity than the structurally related compound SCH900776, which is already profiled in clinical trials. Our newly developed organic synthesis is envisioned to afford gram quantities of OH209EN1 that are necessary for thorough testing of the compound. Efficacy of OH209EN1 will be assessed in solid tumours and leukaemias where targeted inhibition of CHK1 will provide the synthetic lethal response.

Navržený projekt představuje preklinický vývoj nového nízkomolekulárního selektivního inhibitoru kinázy CHK1 (OH209EN1), u kterého se předpokládá silná protinádorová aktivita, založená na mechanismu syntetické letality. Jedná se o přelomový koncept cíleného působení protinádorových léčiv, kdy simultánním vyřazením dvou či více vzájemně komplementárních a pro buňku esenciálních biologických drah dojde k jejímu letálnímu poškození. Tento mechanismus účinku, o jehož funkčnosti již existují silné klinické důkazy, lze selektivně omezit pouze na nádorové buňky, využije-li se mutací získaných v důsledku maligní transformace (např. v genech TP53, ATM). V pilotních testech vykázal náš unikátní inhibitor OH209EN1 podstatně lepší účinnost než strukturně příbuzná sloučenina SCH900776, která je nyní klinicky testována. Námi nově vyvinutá organická syntéza by měla umožnit přípravu OH209EN1 v gramových množstvích, potřebných pro důkladné testování této sloučeniny. Účinky OH209EN1 budou analyzovány u solidních tumorů a leukémií, kde předpokládáme, že cílená inhibice CHK1 navodí syntetickou letali...

• MeSH
• checkpoint kinasa 1 antagonisté a inhibitory   MeSH
• chronická lymfatická leukemie farmakoterapie   MeSH
• cytostatické látky terapeutické užití   MeSH
• geny p53 MeSH
• nádorové supresorové proteiny terapeutické užití   MeSH
• nádory endometria farmakoterapie   MeSH
• nádory prsu farmakoterapie   MeSH
• nádory vaječníků farmakoterapie   MeSH
• poškození DNA MeSH
• preklinické hodnocení léčiv MeSH
• umělé letální mutace MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• onkologie
• molekulární biologie, molekulární medicína
• farmacie a farmakologie
• NLK Publikační typ
• závěrečné zprávy o řešení grantu AZV MZ ČR

Introduction of small-molecule inhibitors of B-cell receptor signaling and BCL2 protein significantly improves therapeutic options in chronic lymphocytic leukemia. However, some patients suffer from adverse effects mandating treatment discontinuation, and cases with TP53 defects more frequently experience early progression of the disease. Development of alternative therapeutic approaches is, therefore, of critical importance. Here we report details of the anti-chronic lymphocytic leukemia single-agent activity of MU380, our recently identified potent, selective, and metabolically robust inhibitor of checkpoint kinase 1. We also describe a newly developed enantioselective synthesis of MU380, which allows preparation of gram quantities of the substance. Checkpoint kinase 1 is a master regulator of replication operating primarily in intra-S and G2/M cell cycle checkpoints. Initially tested in leukemia and lymphoma cell lines, MU380 significantly potentiated efficacy of gemcitabine, a clinically used inducer of replication stress. Moreover, MU380 manifested substantial single-agent activity in both TP53-wild type and TP53-mutated leukemia and lymphoma cell lines. In chronic lymphocytic leukemia-derived cell lines MEC-1, MEC-2 (both TP53-mut), and OSU-CLL (TP53-wt) the inhibitor impaired cell cycle progression and induced apoptosis. In primary clinical samples, MU380 used as a single-agent noticeably reduced the viability of unstimulated chronic lymphocytic leukemia cells as well as those induced to proliferate by anti-CD40/IL-4 stimuli. In both cases, effects were comparable in samples harboring p53 pathway dysfunction (TP53 mutations or ATM mutations) and TP53-wt/ATM-wt cells. Lastly, MU380 also exhibited significant in vivo activity in a xenotransplant mouse model (immunodeficient strain NOD-scid IL2Rγnull ) where it efficiently suppressed growth of subcutaneous tumors generated from MEC-1 cells.

• MeSH
• apoptóza MeSH
• buněčný cyklus MeSH
• checkpoint kinasa 1 antagonisté a inhibitory   MeSH
• chemorezistence účinky léků   MeSH
• chronická lymfatická leukemie farmakoterapie   genetika   patologie   MeSH
• deoxycytidin analogy a deriváty   farmakologie   MeSH
• inhibitory proteinkinas farmakologie   MeSH
• lidé MeSH
• mutace * MeSH
• myši inbrední NOD MeSH
• myši SCID MeSH
• myši MeSH
• nádorové biomarkery genetika   MeSH
• nádorové buňky kultivované MeSH
• nádorový supresorový protein p53 genetika   MeSH
• piperidiny farmakologie   MeSH
• proliferace buněk MeSH
• protinádorové antimetabolity farmakologie   MeSH
• pyrazoly farmakologie   MeSH
• pyrimidiny farmakologie   MeSH
• regulace genové exprese u nádorů účinky léků   MeSH
• synergismus léků * MeSH
• xenogenní modely - testy protinádorové aktivity MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The Wee1 inhibitor MK1775 (AZD1775) is currently being tested in clinical trials for cancer treatment. Here, we show that the p53 target and CDK inhibitor p21 protects against MK1775-induced DNA damage during S-phase. Cancer and normal cells deficient for p21 (HCT116 p21-/-, RPE p21-/-, and U2OS transfected with p21 siRNA) showed higher induction of the DNA damage marker γH2AX in S-phase in response to MK1775 compared to the respective parental cells. Furthermore, upon MK1775 treatment the levels of phospho-DNA PKcs S2056 and phospho-RPA S4/S8 were higher in the p21 deficient cells, consistent with increased DNA breakage. Cell cycle analysis revealed that these effects were due to an S-phase function of p21, but MK1775-induced S-phase CDK activity was not altered as measured by CDK-dependent phosphorylations. In the p21 deficient cancer cells MK1775-induced cell death was also increased. Moreover, p21 deficiency sensitized to combined treatment of MK1775 and the CHK1-inhibitor AZD6772, and to the combination of MK1775 with ionizing radiation. These results show that p21 protects cancer cells against Wee1 inhibition and suggest that S-phase functions of p21 contribute to mediate such protection. As p21 can be epigenetically downregulated in human cancer, we propose that p21 levels may be considered during future applications of Wee1 inhibitors.

• MeSH
• checkpoint kinasa 1 antagonisté a inhibitory   MeSH
• cyklin-dependentní kinasy antagonisté a inhibitory   metabolismus   MeSH
• fosforylace účinky léků   MeSH
• HCT116 buňky MeSH
• inhibitor p21 cyklin-dependentní kinasy genetika   metabolismus   MeSH
• kontrolní body fáze S buněčného cyklu účinky léků   MeSH
• lidé MeSH
• malá interferující RNA genetika   MeSH
• nádory farmakoterapie   metabolismus   MeSH
• poškození DNA účinky léků   genetika   MeSH
• proteiny buněčného cyklu antagonisté a inhibitory   MeSH
• protinádorové látky farmakologie   terapeutické užití   MeSH
• pyrazoly farmakologie   terapeutické užití   MeSH
• pyrimidinony farmakologie   terapeutické užití   MeSH
• transfekce MeSH
• tyrosinkinasy antagonisté a inhibitory   MeSH
• viabilita buněk účinky léků   genetika   účinky záření   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Although Chk1 kinase inhibitors are currently under clinical investigation as effective cancer cell sensitizers to the cytotoxic effects of numerous chemotherapeutics, there is still a considerable uncertainty regarding their role in modulation of anticancer potential of platinum-based drugs. Here we newly demonstrate the ability of one of the most specific Chk1 inhibitors, SCH900776 (MK-8776), to enhance human colon cancer cell sensitivity to the cytotoxic effects of platinum(II) cisplatin and platinum(IV)- LA-12 complexes. The combined treatment with SCH900776 and cisplatin or LA-12 results in apparent increase in G1/S phase-related apoptosis, stimulation of mitotic slippage, and senescence of HCT116 cells. We further show that the cancer cell response to the drug combinations is significantly affected by the p21, p53, and PTEN status. In contrast to their wt counterparts, the p53- or p21-deficient cells treated with SCH900776 and cisplatin or LA-12 enter mitosis and become polyploid, and the senescence phenotype is strongly suppressed. While the cell death induced by SCH900776 and cisplatin or LA-12 is significantly delayed in the absence of p53, the anticancer action of the drug combinations is significantly accelerated in p21-deficient cells, which is associated with stimulation of apoptosis beyond G2/M cell cycle phase. We also show that cooperative killing action of the drug combinations in HCT116 cells is facilitated in the absence of PTEN. Our results indicate that SCH900776 may act as an important modulator of cytotoxic response triggered by platinum-based drugs in colon cancer cells.

• MeSH
• apoptóza účinky léků   MeSH
• buněčný cyklus účinky léků   genetika   MeSH
• checkpoint kinasa 1 antagonisté a inhibitory   genetika   metabolismus   MeSH
• cisplatina farmakologie   MeSH
• genový knockout MeSH
• inhibitor p21 cyklin-dependentní kinasy genetika   metabolismus   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• nádorový supresorový protein p53 genetika   metabolismus   MeSH
• nádory tračníku farmakoterapie   genetika   metabolismus   patologie   MeSH
• poškození DNA účinky léků   MeSH
• protinádorové látky farmakologie   MeSH
• pyrazoly farmakologie   MeSH
• pyrimidiny farmakologie   MeSH
• sloučeniny platiny farmakologie   MeSH
• stárnutí buněk účinky léků   MeSH
• viabilita buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Checkpoint-mediated dependency of tumor cells can be deployed to selectively kill them without substantial toxicity to normal cells. Specifically, loss of CHK1, a serine threonine kinase involved in the surveillance of the G2-M checkpoint in the presence of replication stress inflicted by DNA-damaging drugs, has been reported to dramatically influence the viability of tumor cells. CHK1's pivotal role in maintaining genomic stability offers attractive opportunity for increasing the selectivity, effectivity, and reduced toxicity of chemotherapy. Some recently identified CHK1 inhibitors entered clinical trials in combination with DNA antimetabolites. Herein, we report synthesis and profiling of MU380, a nontrivial analogue of clinically profiled compound SCH900776 possessing the highly unusual N-trifluoromethylpyrazole motif, which was envisioned not to undergo metabolic oxidative dealkylation and thereby provide greater robustness to the compound. MU380 is a selective and potent inhibitor of CHK1 which sensitizes a variety of tumor cell lines to hydroxyurea or gemcitabine up to 10 times. MU380 shows extended inhibitory effects in cells, and unlike SCH900776, does not undergo in vivo N-dealkylation to the significantly less selective metabolite. Compared with SCH900776, MU380 in combination with GEM causes higher accumulation of DNA damage in tumor cells and subsequent enhanced cell death, and is more efficacious in the A2780 xenograft mouse model. Overall, MU380 represents a novel state-of-the-art CHK1 inhibitor with high potency, selectivity, and improved metabolic robustness to oxidative N-dealkylation. Mol Cancer Ther; 16(9); 1831-42. ©2017 AACR.

• MeSH
• apoptóza účinky léků   MeSH
• biologické markery MeSH
• buněčný cyklus účinky léků   MeSH
• checkpoint kinasa 1 antagonisté a inhibitory   MeSH
• chemorezistence účinky léků   MeSH
• dealkylace účinky léků   MeSH
• inhibitory proteinkinas chemická syntéza   farmakologie   MeSH
• kontrolní body buněčného cyklu účinky léků   MeSH
• lidé MeSH
• metylace MeSH
• modely nemocí na zvířatech MeSH
• molekulární struktura MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• protinádorové látky chemická syntéza   farmakologie   MeSH
• pyrazoly farmakologie   MeSH
• pyrimidiny farmakologie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• xenogenní modely - testy protinádorové aktivity MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

• Klíčová slova
• prexasertib,
• MeSH
• checkpoint kinasa 1 * antagonisté a inhibitory   MeSH
• dítě MeSH
• dospělí MeSH
• klinické zkoušky, fáze II jako téma MeSH
• lidé MeSH
• malobuněčný karcinom plic farmakoterapie   MeSH
• nádory farmakoterapie   klasifikace   MeSH
• protokoly protinádorové kombinované chemoterapie MeSH
• pyraziny * aplikace a dávkování   škodlivé účinky   terapeutické užití   MeSH
• pyrazoly * aplikace a dávkování   škodlivé účinky   terapeutické užití   MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• Publikační typ
• zprávy MeSH