mk-1775 and Disease-Models--Animal

Patients with advanced biliary tract cancer (BTC) have a poor prognosis, and novel treatments are needed. Gemcitabine, the standard of care for BTC, induces DNA damage; however, the ability of cancer cells to repair DNA dampens its effects. To improve the efficacy of gemcitabine, we combined it with MK1775, a Wee1 inhibitor that prevents activation of the G2/M checkpoint. BTC cell lines were treated with gemcitabine only or in combination with MK1775 to determine the therapeutic potential of BTC. Gemcitabine inhibited the growth and induced the apoptosis of four BTC cell lines to a greater extent when added with MK1775 than when added alone. The effects of the combination treatment were observed in both p53 wild-type and p53 mutant cell lines and were unaffected by knockdown of wild-type p53. The combination treatment increased the percentage of apoptotic cells and decreased the percentage of cells synthesizing DNA, suggesting that it caused DNA-damaged cells to accumulate and possibly die in S phase. It did not induce apoptosis when cells were arrested in mitosis using nocodazole. In a xenograft mouse model, gemcitabine plus MK1775 (but not either alone) inhibited the growth of tumors generated from inoculated BTC cells. Our results show that MK1775 highly enhances gemcitabine cytotoxicity in BTC regardless of p53 status. We suggest that the combination treatment elicits a DNA damage response and consequent apoptosis. Our preclinical study provides a basis for future clinical trials of gemcitabine plus MK1775 in patients with BTC.

Topics: Animals; Apoptosis; Biliary Tract Neoplasms; Disease Models, Animal; Gemcitabine; Humans; Mice; Tumor Suppressor Protein p53

Despite advances in surgery, chemotherapy, and radiation, there are limited treatment options for advanced head and neck squamous cell carcinoma (HNSCC) and survival remains very poor. Therefore, effective therapies are desperately needed. Recently, selective exploitation of DNA damage and replication stress responses has become a novel approach for cancer treatment. Wee1 kinase and Rad51 recombinase are two proteins involved in regulating replication stress and homologous recombination repair in cancer cells. In this study, we investigated the combined effect of Rad51 inhibitor (B02) and Wee1 inhibitor (AZD1775)

Topics: Animals; Apoptosis; Cell Cycle; Cell Cycle Proteins; Cell Line, Tumor; Cell Survival; Cells, Cultured; Computational Biology; Disease Models, Animal; DNA Damage; DNA Repair; Dose-Response Relationship, Drug; Drug Synergism; Gene Expression Profiling; Homologous Recombination; Humans; Mice; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidinones; Rad51 Recombinase; Radiation-Sensitizing Agents; Squamous Cell Carcinoma of Head and Neck; Xenograft Model Antitumor Assays

WEE1 plays an important role in the regulation of cell cycle G2/M checkpoints and DNA damage response (DDR). Inhibition of WEE1 can increase the instability of the genome and have anti-tumor effects in some solid tumors. However, it has certain limitations for multiple cancer cells from different lineages. Therefore, we consider the use of synthetic lethal interactions to enhance the therapeutic effect. Our experiments proved that WEE1 inhibitor (WEE1i) can activate the ataxia telangiectasia and RAD3-related (ATR) pathway and that blockage of ATR dramatically sensitized the WEE1i-induced cell death. The tumor-selective synthetic lethality between bioavailable WEE1 and ATR inhibitors led to tumor remission in vivo. Mechanistically, the combination promoted the accumulation of cytosolic double-strand DNA, which subsequently activated the stimulator of the interferon gene (STING) pathway and induced the production of type I interferon and CD8+ T cells, thereby inducing anti-tumor immunity. Furthermore, our study found that immune checkpoint programmed death-ligand 1 is upregulated by the combination therapy, and blocking PD-L1 further enhances the effect of the combination therapy. In summary, as an immunomodulator, the combination of WEE1i with ATR inhibitor (ATRi) and immune checkpoint blockers provides a potential new approach for cancer treatment.

Topics: Animals; Ataxia Telangiectasia Mutated Proteins; B7-H1 Antigen; CD8-Positive T-Lymphocytes; Cell Cycle Proteins; Cell Death; Cell Line, Tumor; Colorectal Neoplasms; Disease Models, Animal; DNA; DNA Damage; DNA, Neoplasm; Drug Synergism; Female; G2 Phase Cell Cycle Checkpoints; Genomic Instability; Humans; Immunity; Immunotherapy; Indoles; Interferon Type I; M Phase Cell Cycle Checkpoints; Membrane Proteins; Mice; Mice, Inbred C57BL; Molecular Targeted Therapy; Morpholines; Ovarian Neoplasms; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Pyrimidinones; Sulfonamides; Tumor Microenvironment; Tumor Stem Cell Assay; Up-Regulation

When Zika virus emerged as a public health emergency there were no drugs or vaccines approved for its prevention or treatment. We used a high-throughput screen for Zika virus protease inhibitors to identify several inhibitors of Zika virus infection. We expressed the NS2B-NS3 Zika virus protease and conducted a biochemical screen for small-molecule inhibitors. A quantitative structure-activity relationship model was employed to virtually screen ∼138,000 compounds, which increased the identification of active compounds, while decreasing screening time and resources. Candidate inhibitors were validated in several viral infection assays. Small molecules with favorable clinical profiles, especially the five-lipoxygenase-activating protein inhibitor, MK-591, inhibited the Zika virus protease and infection in neural stem cells. Members of the tetracycline family of antibiotics were more potent inhibitors of Zika virus infection than the protease, suggesting they may have multiple mechanisms of action. The most potent tetracycline, methacycline, reduced the amount of Zika virus present in the brain and the severity of Zika virus-induced motor deficits in an immunocompetent mouse model. As Food and Drug Administration-approved drugs, the tetracyclines could be quickly translated to the clinic. The compounds identified through our screening paradigm have the potential to be used as prophylactics for patients traveling to endemic regions or for the treatment of the neurological complications of Zika virus infection.

Topics: Animals; Antiviral Agents; Artificial Intelligence; Chlorocebus aethiops; Disease Models, Animal; Drug Evaluation, Preclinical; High-Throughput Screening Assays; Immunocompetence; Inhibitory Concentration 50; Methacycline; Mice, Inbred C57BL; Protease Inhibitors; Quantitative Structure-Activity Relationship; Small Molecule Libraries; Vero Cells; Zika Virus; Zika Virus Infection

As standard treatments for cancer, DNA-damaging chemotherapeutic agents and irradiation therapy improve survival in patients with various cancers. Wee1, a kinase associated with the cell cycle, causes G2/M cell cycle arrest to allow repair of injured DNA in cancer cells, and a Wee1 inhibitor has been confirmed to lead to apoptosis in cancer cells. Recently, there has been renewed interest in exploring the immune environment which plays a significant role in tumour suppression. A Wee1 inhibitor combined with radiotherapy has been tested in lung, pancreatic, and prostate cancer and melanoma in vivo or in vitro. There is still no research evaluating the immunoregulatory effects of AZD1775 plus high-dose irradiation (IR) in vivo. T cell killing and CD8+ T cell depletion assays demonstrated that the combination of AZD1775 and IR delayed tumour growth in breast cancer mouse models. Additionally, combination treatment also suppressed the expression of PD-L1, a co-inhibitor, through the STAT3-IRF1 axis. The importance and originality of this study are that it explores the internal and external mechanisms of AZD1775 combined with a single high dose of IR and provides a rationale for applying the combination therapy described above in a clinical trial.

Topics: Animals; Breast Neoplasms; CD8-Positive T-Lymphocytes; Cell Cycle Proteins; Cell Line, Tumor; Combined Modality Therapy; Dendritic Cells; Disease Models, Animal; Enzyme Inhibitors; Female; Humans; Mice; Mice, Inbred BALB C; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidinones; Radiation, Ionizing

Targeting poly ADP-ribose polymerase (PARP) has been recently identified as a promising option against gastric cancer (GC). However, PARP inhibitors alone achieve limited efficacy. Combination strategies, especially with homologous recombination (HR) impairment, are of great hope to optimize PARP inhibitor's efficacy and expand target populations but remains largely unknown. Herein, we investigated whether a WEE1/ Polo-like kinase 1 (PLK1) dual inhibitor AZD1775 reported to impair HR augmented anticancer activity of a PARP inhibitor olaparib and its underlying mechanisms.. GC cell lines and in vivo xenografts were employed to determine antitumor activity of PARP inhibitor combined with WEE1/PLK1 dual inhibitor AZD1775. Western blot, genetic knockdown by siRNA, flow cytometry, Immunohistochemistry were performed to explore the underlying mechanisms.. AZD1775 dually targeting WEE1/PLK1 enhanced effects of olaparib on growth inhibition and apoptotic induction in GC cells. Mechanistic investigations elucidate that WEE1/PLK1 blockade downregulated several HR-related proteins and caused an accumulation in γH2AX. As confirmed in both GC cell lines and mice bearing GC xenografts, these effects were enhanced by AZD1775-olaparib combination compared to olaparib alone, suggesting that disrupting HR-mediated DNA damage repairs (DDR) by WEE1/PLK1 blockade might be responsible for improved GC cells' response to PARP inhibitors. Given the DNA damage checkpoint as a primary target of WEE1 inhibition, our data also demonstrate that AZD1775 abrogated olaparib-activated DNA damage checkpoint through CDC2 de-phosphorylation, followed by mitotic progression with unrepaired DNA damage (marked by increased pHH3-stained and γH2AX-stained cells, respectively).. PARP inhibitor olaparib combined with WEE1/PLK1 dual inhibitor AZD1775 elicited potentiated anticancer activity through disrupting DDR signaling and the DNA damage checkpoint. It sheds light on the combination strategy of WEE1/PLK1 dual inhibitors with PARP inhibitors in the treatment of GC, even in HR-proficient patients.

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Disease Models, Animal; DNA Damage; DNA Repair; Drug Synergism; Female; Humans; Mice; Nuclear Proteins; Phthalazines; Piperazines; Polo-Like Kinase 1; Poly(ADP-ribose) Polymerase Inhibitors; Protein Serine-Threonine Kinases; Protein-Tyrosine Kinases; Proto-Oncogene Proteins; Pyrazoles; Pyrimidines; Pyrimidinones; Stomach Neoplasms; Xenograft Model Antitumor Assays

Poor prognosis in triple-negative breast cancer (TNBC) is due to an aggressive phenotype and lack of biomarker-driven targeted therapies. Overexpression of cyclin E and phosphorylated-CDK2 are correlated with poor survival in patients with TNBC, and the absence of CDK2 desensitizes cells to inhibition of Wee1 kinase, a key cell-cycle regulator. We hypothesize that cyclin E expression can predict response to therapies, which include the Wee1 kinase inhibitor, AZD1775.. Mono- and combination therapies with AZD1775 were evaluated in TNBC cell lines and multiple patient-derived xenograft (PDX) models with different cyclin E expression profiles. The mechanism(s) of cyclin E-mediated replicative stress were investigated following cyclin E induction or CRISPR/Cas9 knockout by a number of assays in multiple cell lines.. Cyclin E overexpression (i) is enriched in TNBCs with high recurrence rates, (ii) sensitizes TNBC cell lines and PDX models to AZD1775, (iii) leads to CDK2-dependent activation of DNA replication stress pathways, and (iv) increases Wee1 kinase activity. Moreover, treatment of cells with either CDK2 inhibitors or carboplatin leads to transient transcriptional induction of cyclin E (in cyclin E-low tumors) and result in DNA replicative stress. Such drug-mediated cyclin E induction in TNBC cells and PDX models sensitizes them to AZD1775 in a sequential treatment combination strategy.

Topics: Animals; Apoptosis; Bridged Bicyclo Compounds, Heterocyclic; Cell Cycle Proteins; Cell Line, Tumor; Cyclic N-Oxides; Cyclin E; Disease Models, Animal; DNA Repair; DNA Replication; Drug Resistance, Neoplasm; Gene Expression; Humans; Indolizines; Mice; Mice, Knockout; Models, Biological; Nuclear Proteins; Prognosis; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Pyrazoles; Pyridinium Compounds; Pyrimidinones; Stress, Physiological; Triple Negative Breast Neoplasms; Xenograft Model Antitumor Assays

Protein kinase inhibitors (PKIs) are currently tested in clinical studies (phase I-III) as an alternative strategy against (recurrent) ovarian cancer. Besides their anti-tumour efficacy, several PKIs have also shown radiosensitizing effects when combined with external beam radiation. Based on these results we asked if the addition of PKIs offers a therapeutic opportunity to improve radioimmunotherapy (RIT) against ovarian cancer. Five PKIs (alisertib, MK1775, MK2206, saracatinib, temsirolimus) were chosen for cytotoxicity screenings based on their current clinical trials in the treatment of ovarian cancer and their influence on cell cycle regulation and DNA damage repair pathways. We combined selected PKIs with. PKIs cytotoxicity was determined via cell colony-forming assays. Biomarker of DNA double-strand breaks (DSBs, γH2A.X) was analysed by western blot and fluorescence microscopy. Flow cytometric measurements were performed to evaluate levels of apoptosis based on mono- or combination treatments. The best combination was used for in vivo combination therapy studies in nude mice with SKOV3ip and IGROV1 human ovarian cancer xenografts. Bonferroni correction was used to determine statistical significance for multiple comparisons.. The highest cytotoxicity against both cell lines was observed for MK1775 and alisertib. Combinations including. Our results warrant further evaluation of combination of MK1775 and radioimmunotherapy.

Topics: Animals; Antineoplastic Agents, Immunological; Apoptosis; Cell Line, Tumor; Cell Survival; Disease Models, Animal; DNA Breaks, Double-Stranded; Female; Humans; Immunoconjugates; Lutetium; Mice; Neural Cell Adhesion Molecule L1; Protein Kinase Inhibitors; Pyrazoles; Pyrimidines; Pyrimidinones; Radioimmunotherapy; Radioisotopes; Xenograft Model Antitumor Assays

Research into the biology of soft tissue sarcomas has uncovered very few effective treatment strategies that improve upon the current standard of care which usually involves surgery, radiation, and chemotherapy. Many patients with large (>5 cm), high-grade sarcomas develop recurrence, and at that point have limited treatment options available. One challenge is the heterogeneity of genetic drivers of sarcomas, and many of these are not validated targets. Even when such genes are tractable targets, the rarity of each subtype of sarcoma makes advances in research slow. Here we describe the development of a synergistic combination treatment strategy that may be applicable in both soft tissue sarcomas as well as sarcomas of bone that takes advantage of targeting the cell cycle. We show that Rb-positive cell lines treated with the CDK4/6 inhibitor palbociclib reversibly arrest in the G

Topics: Animals; Cell Cycle Checkpoints; Cell Cycle Proteins; Cell Line, Tumor; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Disease Models, Animal; Drug Resistance, Neoplasm; Gene Knockdown Techniques; Humans; Male; Mice; Nuclear Proteins; Piperazines; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Pyrazoles; Pyridines; Pyrimidines; Pyrimidinones; Retinoblastoma Protein; Sarcoma; Xenograft Model Antitumor Assays

Although PARP inhibitors target

Topics: Animals; Antineoplastic Agents; BRCA1 Protein; BRCA2 Protein; Cell Cycle; Cell Cycle Proteins; Cell Line, Tumor; Disease Models, Animal; DNA Mutational Analysis; Drug Resistance, Neoplasm; Female; Gene Knockdown Techniques; Humans; Mice; Mutation; Nuclear Proteins; Poly(ADP-ribose) Polymerase Inhibitors; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Pyrimidinones; Selection, Genetic; Xenograft Model Antitumor Assays

Wee1 regulates key DNA damage checkpoints, and in this study, the efficacy of the Wee1 inhibitor MK-1775 was evaluated in glioblastoma multiforme (GBM) xenograft models alone and in combination with radiation and/or temozolomide.. In vitro MK-1775 efficacy alone and in combination with temozolomide, and the impact on DNA damage, was analyzed by Western blotting and γH2AX foci formation. In vivo efficacy was evaluated in orthotopic and heterotopic xenografts. Drug distribution was assessed by conventional mass spectrometry (MS) and matrix-assisted laser desorption/ionization (MALDI)-MS imaging.. GBM22 (IC50 = 68 nmol/L) was significantly more sensitive to MK-1775 compared with five other GBM xenograft lines, including GBM6 (IC50 >300 nmol/L), and this was associated with a significant difference in pan-nuclear γH2AX staining between treated GBM22 (81% cells positive) and GBM6 (20% cells positive) cells. However, there was no sensitizing effect of MK-1775 when combined with temozolomide in vitro. In an orthotopic GBM22 model, MK-1775 was ineffective when combined with temozolomide, whereas in a flank model of GBM22, MK-1775 exhibited both single-agent and combinatorial activity with temozolomide. Consistent with limited drug delivery into orthotopic tumors, the normal brain to whole blood ratio following a single MK-1775 dose was 5%, and MALDI-MS imaging demonstrated heterogeneous and markedly lower MK-1775 distribution in orthotopic as compared with heterotopic GBM22 tumors.. Limited distribution to brain tumors may limit the efficacy of MK-1775 in GBM.

Topics: Animals; Blood-Brain Barrier; Cell Cycle Proteins; Dacarbazine; Disease Models, Animal; DNA Damage; Glioblastoma; Humans; Mice; Nuclear Proteins; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Pyrimidinones; Temozolomide; Tumor Burden; Xenograft Model Antitumor Assays

Although the majority of patients with HPV(+) oropharyngeal cancers have a favorable prognosis, there are some patients with tumors that are resistant to aggressive chemoradiotherapy with unusual patterns of locoregional and systemic recurrences. Therefore, more effective therapies are needed. In this study, we investigated the chemosensitizing efficacy of the selective Wee-1 kinase inhibitor, AZD-1775, in HPV(+) head and neck squamous cell carcinoma (HNSCC).. Clonogenic survival assays and an orthotopic mouse model of HPV(+) oral cancer were used to examine the in vitro and in vivo sensitivity of HPV(+) HNSCC cell lines to AZD-1775 in combination with cisplatin, respectively. Cell-cycle analysis, DNA damage (γH2AX), homologous recombination (HR), and apoptosis were examined to dissect molecular mechanisms.. We found that AZD-1775 displays single-agent activity and enhances the response of HPV(+) HNSCC cells to cisplatin both in vitro and in vivo. The sensitivity of the HPV(+) HNSCC cells to AZD-1775 alone or in combination with cisplatin was associated with G2 checkpoint abrogation, persistent DNA damage, and apoptosis induction. This finding of AZD-1775 increasing the sensitivity of HPV(+) HNSCC cells to cisplatin through apoptosis was not seen previously in the HPV(-) HNSCC cancer cells and is accompanied by a decreased expression of the antiapoptotic proteins, MCl-1and XIAP, which appear to be cleaved following AZD-1775 treatment.. AZD-1775 selectively sensitizes HPV(+) HNSCC cells and orthotopic oral xenografts to cisplatin through apoptosis and support the clinical investigation of AZD-1775 in combination with cisplatin particularly in patients with advanced and recurrent metastatic HPV(+) HNSCC tumors.

Topics: Animals; Antineoplastic Agents; Apoptosis; Carcinoma, Squamous Cell; Caspases; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Cisplatin; Disease Models, Animal; Drug Resistance, Neoplasm; Drug Synergism; G2 Phase Cell Cycle Checkpoints; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Genes, p53; Head and Neck Neoplasms; Humans; Inhibitory Concentration 50; Male; Mice; Myeloid Cell Leukemia Sequence 1 Protein; Nuclear Proteins; Papillomavirus Infections; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Pyrimidinones; Squamous Cell Carcinoma of Head and Neck; Tumor Burden; X-Linked Inhibitor of Apoptosis Protein; Xenograft Model Antitumor Assays

Inhibition of the DNA damage checkpoint kinase WEE1 potentiates genotoxic chemotherapies by abrogating cell-cycle arrest and proper DNA repair. However, WEE1 is also essential for unperturbed cell division in the absence of extrinsic insult. Here, we investigate the anticancer potential of a WEE1 inhibitor, independent of chemotherapy, and explore a possible cellular context underlying sensitivity to WEE1 inhibition. We show that MK-1775, a potent and selective ATP-competitive inhibitor of WEE1, is cytotoxic across a broad panel of tumor cell lines and induces DNA double-strand breaks. MK-1775-induced DNA damage occurs without added chemotherapy or radiation in S-phase cells and relies on active DNA replication. At tolerated doses, MK-1775 treatment leads to xenograft tumor growth inhibition or regression. To begin addressing potential response markers for MK-1775 monotherapy, we focused on PKMYT1, a kinase functionally related to WEE1. Knockdown of PKMYT1 lowers the EC(50) of MK-1775 by five-fold but has no effect on the cell-based response to other cytotoxic drugs. In addition, knockdown of PKMYT1 increases markers of DNA damage, γH2AX and pCHK1(S345), induced by MK-1775. In a post hoc analysis of 305 cell lines treated with MK-1775, we found that expression of PKMYT1 was below average in 73% of the 33 most sensitive cell lines. Our findings provide rationale for WEE1 inhibition as a potent anticancer therapy independent of a genotoxic partner and suggest that low PKMYT1 expression could serve as an enrichment biomarker for MK-1775 sensitivity.

Topics: Animals; Antineoplastic Agents; Cell Cycle; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Disease Models, Animal; DNA Damage; Drug Evaluation, Preclinical; Drug Resistance, Neoplasm; Female; Gene Knockdown Techniques; Humans; Membrane Proteins; Mice; Neoplasms; Nuclear Proteins; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Pyrimidinones; Tumor Burden; Xenograft Model Antitumor Assays