Experimental and Molecular Therapeutics最新文献

{"title":"Abstract 1348: Targeted degradation of PARP14 Using a heterobifunctional small molecule","authors":"T. Wigle, Yue Ren, J. Molina, Daniel J. Blackwell, L. Schenkel, K. Swinger, Anne Cheug, R. Abo, E. Minissale, A. Lu, C. Majer, W. Church, B. W. Dorsey, M. Niepel, N. R. Perl, K. Kuplast-Barr, K. McEachern, M. Vasbinder, H. Keilhack, K. Kuntz","doi":"10.1158/1538-7445.AM2021-1348","DOIUrl":"https://doi.org/10.1158/1538-7445.AM2021-1348","url":null,"abstract":"PARP14 is an interferon-stimulated gene that is overexpressed in multiple tumor types and has been shown to promote the pro-tumor M2 polarization of macrophages and support Th2/Th17 signaling in models of allergic airway disease. PARP14 is a large 203 kDa protein that possesses a catalytic domain responsible for the transfer of mono-ADP-ribose to its substrates, three macrodomains that bind mono-ADP-ribose, a WWE domain that serves as a binding module for poly-ADP-ribose, and an RNA recognition motif. We have previously shown that the potent and reversible enzymatic inhibitor, RBN012759 (IC50 1,000-fold selective over polyPARPs), links PARP14 catalytic inhibition with suppression of the antitumor immune response in human primary macrophages and human kidney cancer explants. While this catalytic inhibitor of PARP14 was able to suppress IL-4-driven pro-tumor gene expression in macrophages, it is unknown what roles the non-enzymatic biomolecular recognition motifs play in the biological function of PARP14. To further understand this, we describe a heterobifunctional small molecule, RBN012811, based on a catalytic inhibitor of PARP14 that binds in the enzyme9s NAD+-binding site and recruits the E3 ligase cereblon to ubiquitinate PARP14 and selectively target it for degradation. RBN012811 has a IC50 of 0.01 μM against PARP14 in a biophysical assay and is at least 200-fold selective over all other PARPs. In KYSE-270 cancer cells, RBN012811 has a half-maximal degradation concentration (DC50) of 0.005 μM and it does not cause degradation of other PARP enzymes. In human primary macrophages PARP14 degradation by RBN012811 led to a dose-dependent decrease of IL-10 release induced by IL-4 stimulation. Our data demonstrates that RBN012811 is a useful tool to enable further exploration of the role of PARP14 in inflammation and cancer. Citation Format: Tim Wigle, Yue Ren, Jennifer Molina, Danielle Blackwell, Laurie Schenkel, Kerren Swinger, Anne Cheug, Ryan Abo, Elena Minissale, Alvin Lu, Christina Majer, William Church, Bryan Dorsey, Mario Niepel, Nicholas Perl, Kristy Kuplast-Barr, Kristen McEachern, Melissa Vasbinder, Heike Keilhack, Kevin Kuntz. Targeted degradation of PARP14 Using a heterobifunctional small molecule [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1348.","PeriodicalId":12258,"journal":{"name":"Experimental and Molecular Therapeutics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85431296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract LB097: MET inhibitor enhances efficacies of gemcitabine and olaparib in pancreatic cancer cells","authors":"Mei-Kuang Chen, Yuan Gao, Dihua Yu, M. Hung","doi":"10.1158/1538-7445.AM2021-LB097","DOIUrl":"https://doi.org/10.1158/1538-7445.AM2021-LB097","url":null,"abstract":"Gemcitabine is one of the current first-line chemotherapy agents in pancreatic cancer treatment. However, the response rate of pancreatic cancer patients to gemcitabine treatment is lower than 20%. Among the potential targeted therapies for pancreatic cancer patients, PARP inhibitor (Olaparib) has been approved by the U.S. Food and Drug Administration for maintenance treatment of metastatic pancreatic adenocarcinoma patients with germline BRCA-mutation. Taking advantages of the high oxidative stress in most pancreatic cancer cells, therapeutic agents that enhance the burden of oxidative DNA damages in these cancer cells can be introduced in novel treatment strategies. Because c-MET overexpression positively correlates with poor prognosis in pancreatic cancer, and our previous studies show that oxidative stress induced-nuclear c-MET phosphorylates PARP1 to reduce oxidative DNA damages, we focused on developing novel treatment strategies by combining c-MET inhibitors (crizotinib and tivantinib) with either gemcitabine or olaparib. In this study, we found that gemcitabine induced nuclear accumulation of c-MET, and that tivantinib reduced c-MET mediated PARP1 phosphorylation in both BxPC-3 and L3.6pl pancreatic cancer cell lines. We also found that combination of tivantinib with either gemcitabine or Olaparib induced more DNA damages than the single agent treatments. Further, we demonstrated the synergistic effects of c-MET inhibitors combined with gemcitabine or Olaparib in pancreatic cancer cell lines, suggesting that combining c-MET inhibitor with PARP inhibitor or gemcitabine is a novel and rational therapeutic strategy for pancreatic cancer treatment. Citation Format: Meikuang Chen, Yuan Gao, Dihua Yu, Mien-Chie Hung. MET inhibitor enhances efficacies of gemcitabine and olaparib in pancreatic cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB097.","PeriodicalId":12258,"journal":{"name":"Experimental and Molecular Therapeutics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85537497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract LB123: A high value pharmacological platform dedicated to the real time study of stimulatory immune checkpoint signaling pathways","authors":"A. Maurin, C. Franchet, S. Schann, X. Leroy","doi":"10.1158/1538-7445.AM2021-LB123","DOIUrl":"https://doi.org/10.1158/1538-7445.AM2021-LB123","url":null,"abstract":"Immune checkpoint (ICP) co-receptors play a key role in the fine modulation of the immune response. While inhibitory ICP co-receptors are mainly characterized in cancer by the exhaustion of the immune response, stimulatory ICP co-receptors are clearly involved in an anarchic activation of the immune system leading to autoimmune diseases. But in another hand, this subtype of co-receptor shows a great asset in cancer therapy by increasing anti-tumoral response. All together, these co-receptors show a great interest for the development of innovative therapies in immunology or immuno-oncology. Nowadays, treatments targeting these co-receptors are currently tested in clinical trials or approved for use in man, especially antibodies targeting both inhibitory and stimulatory ICP. Small molecule-based strategy is tested in early drug discovery and in early clinical trials. In order to screen and assess the potency and efficiency of these therapies, robust and reliable cell-based assays are urgently needed. At Domain Therapeutics, using our powerful proprietary BRET technology: bioSens-AllTM, we successfully develop and validate a cell-based assay platform to assess immune checkpoint pharmacology. The activation or blockade of the signaling of checkpoint co-receptors are monitored in real time and in living cells. BRET assays dedicated to stimulatory ICPs: 4-1BB/4-1BB Ligand and OX-40/OX-40 Ligand were designed. BRET assay development is inspired by the natural recruitment and proximity of specific cytoplasmic partners very close to their co-receptors in an activated pathway. Indeed, the first assay design is based on the co-receptor fused with rGFP and its cytoplasmic partner fused with a rLucII. In the second assay design, the co-receptor is no longer fused, but is co-transfected with a membrane anchor fused with the rGFP and co-transfected with the cytoplasmic partner fused with rLucII. So, in an activated system (soluble ligand, antibody or in co-culture system) a modulation of BRET can be observed. For ICP assays dedicated to 4-1BB, BRET signal is triggered using soluble ligand, agonist antibody, or co-culture where TRAF1 is the biosensor fused with rLucII. Further validation was obtained for OX-40/OX-40 Ligand. Those BRET assays complement once previously developed for inhibitory ICPs axis: PD-1/PD-Ligand 1 or PD-Ligand 2 and CTLA-4/CD80-CD86. The ICP Platform set up here shows a good accuracy and robustness and represents a strong and reliable technology for drug discovery dedicated to ICPs. Our spatio-temporal cell-based functional assays can support broad drug programs, including: High Throughput Functional Screening, Lead Optimization and Bioanalytical QC lot Release. Citation Format: Alice GENTIL DIT MAURIN, Christel FRANCHET, Stephan SCHANN, Xavier LEROY. A high value pharmacological platform dedicated to the real time study of stimulatory immune checkpoint signaling pathways [abstract]. In: Proceedings of the American Association for Cancer R","PeriodicalId":12258,"journal":{"name":"Experimental and Molecular Therapeutics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84066234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract 1400: SWI/SNF chromatin remodeling complex regulation of YAP-dependent enhancers drives therapeutic resistance in triple-negative breast cancer","authors":"Yihao Li, Xintao Qiu, Hui Liu, Xiaoqing Wang, Renee C. Geck, Alok K. Tewari, Kin-hoe Chow, P. Cejas, Quang-De Nguyen, Henry W. Long, Shirley X. Liu, A. Toker, Myles A. Brown","doi":"10.1158/1538-7445.AM2021-1400","DOIUrl":"https://doi.org/10.1158/1538-7445.AM2021-1400","url":null,"abstract":"","PeriodicalId":12258,"journal":{"name":"Experimental and Molecular Therapeutics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84593215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract 1218: Targeting B-RAF and checkpoint inhibitor resistant melanoma with RSK inhibitor PMD-026 in pre-clinical models","authors":"J. Ramos, Stephanie J Si, T. Fujii, Brien K. Haun, Won Seok Yang, Aarthi Jayanthan, S. Dunn","doi":"10.1158/1538-7445.AM2021-1218","DOIUrl":"https://doi.org/10.1158/1538-7445.AM2021-1218","url":null,"abstract":"","PeriodicalId":12258,"journal":{"name":"Experimental and Molecular Therapeutics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78021316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract 962: Small-molecule NSC58874 releases and activates p73 via induction of mutant p53 degradation in cancer cells","authors":"Shengliang Zhang, W. El-Deiry","doi":"10.1158/1538-7445.AM2021-962","DOIUrl":"https://doi.org/10.1158/1538-7445.AM2021-962","url":null,"abstract":"The tumor suppressor p53 is the most frequently mutated gene in cancer. Mutant p53 is a challenge to target in cancer therapy due to its many mutations and the fact that it is an inactivated transcription factor. p73 is a member of the p53 family but very rarely mutated in cancer cells. Therefore, activation of p73 is one of the promising strategies to restore the p53 pathway signaling in cancer therapy. Our laboratory has reported that p73 can be activated by small molecules to restore p53 pathway signaling via induction of p73 expression or interruption of p73 interaction with mutant p53. In the present study, we explored a strategy for releasing p73 from a mutant p53 inhibitory complex by induction of mutant p53 degradation using small molecule NSC59984. We previously reported that NSC59984 induces mutant p53 degradation and restores p53 pathway signaling through p73 in p53-mutant cancer cells. To address the mechanism of whether p73 is released from a mutant p53 inhibitory complex to transcriptionally regulate p53 targets, we performed p53-RE-luc reporter assays and Chromatin Immunoprecipitation (ChIP)-PCR in cancer cells with overexpression of p73. We found NSC59984 enhances p73-mediated signaling based on p53 target (such as p21 and noxa) induction at the protein level and p53-RE-luc reporter assay. Further ChIP-PCR analysis showed that NSC59984 treatment increases p73-binding to the p21 and Noxa promoters. These results taken together suggest that NSC59984 enhances p73 transcriptional activity to restore the p53 pathway signaling. It is also well known that p73 activity is regulated through a complex mechanism such as post-translational modifications and protein-protein interactions. We found that NSC59984 can stimulate the ERK2 signaling pathway. The MEK1 inhibitor U0126 partially blocked p73 binding to the p21 and Noxa promoters and their gene expression in cells treated with NSC59984, and this correlated with the rescue of mutant p53 stabilization. These results suggest that p73 is released from mutant p53 inhibitory complex and further stimulated through ERK2 signaling, as a mechanism of tumor suppression in tumors with mutant p53. Citation Format: Shengliang Zhang, Wafik S. El-Deiry. Small-molecule NSC58874 releases and activates p73 via induction of mutant p53 degradation in cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 962.","PeriodicalId":12258,"journal":{"name":"Experimental and Molecular Therapeutics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78119502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract 1283: Discovery of selective and potent BRD4 protein degraders using Plexium's DELPhe platform","authors":"G. Parker, J. A. Toth, G. Leriche, S. Bailey, K. Chng, S. Fish, A. Jamborcic, E. Daniele, E. Green, M. Hocker, A. Kallel, P. A. Thompson, Steven D. Brown, Kandaswamy Vijayan","doi":"10.1158/1538-7445.AM2021-1283","DOIUrl":"https://doi.org/10.1158/1538-7445.AM2021-1283","url":null,"abstract":"","PeriodicalId":12258,"journal":{"name":"Experimental and Molecular Therapeutics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78122247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract 1266: Discovery and preclinical evaluation of a novel covalent inhibitor of FABP5 for cancer therapy","authors":"D. Chikkanna, L. Satyam, Sunil Kumar Pnaigrahi, V. Khairnar, M. Pothuganti, L. Kaza, N. R. Kalidindi, V. Nataraj, A. K. Gatta, N. Krishnamurthy, S. Patil, DS Samiulla, K. Aithal, V. Ahuja, N. K. Tiwari, KB Charamannna, Pravin Pise, T. Anthony, K. Nellore, S. Giri, S. Chelur, S. Samajdar, M. Ramachandra","doi":"10.1158/1538-7445.AM2021-1266","DOIUrl":"https://doi.org/10.1158/1538-7445.AM2021-1266","url":null,"abstract":"","PeriodicalId":12258,"journal":{"name":"Experimental and Molecular Therapeutics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73293396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract LB113: Regulation of PARP-1 expression in mammary tumor cell lines after treatment with olaparib","authors":"M. Moschetta-Pinheiro, Jucimara Colombo, Murilo de Souza Tuckumantel, Gabriela Karam Rebolho, D. A. P. Zuccari","doi":"10.1158/1538-7445.AM2021-LB113","DOIUrl":"https://doi.org/10.1158/1538-7445.AM2021-LB113","url":null,"abstract":"Introduction: Breast cancer is the most common tumor type among women and has a high mortality rate, which is associated with late detection of the disease and treatment failure due to the acquisition of resistance to protocol treatments. It is known that a variety of antitumor drugs are capable of inducing chemoresistance by activating DNA repair pathways. Among these, the PARPs are involved in the recognition and repair of simple-strand breaks. As a consequence, new drugs such as PARP inhibitors (olaparib), are being investigated as potential therapeutic targets in cancer, as an alternative to evade the resistance of tumor cells to chemotherapeutic agents, such as those in the class of platinum salts. In this context, the aim of this study was to evaluate the PARP expression after olaparib tratament with in mammary tumor cell lines. Materials and Methods: Mammary tumor cell lines MDA-MB-468 and CF41 was cultured in DMEM high glucose culture medium, at 37°C in 5% CO2. Cell viability was measured by MTT assay after treatment with different concentrations of carboplatin. Once stablished the concentration of 10µM for carboplatin and 10µM of olaparib, the protein and gene expression of PARP-1 were detected by immunofluorescence and real time PCR, respectively. Results: There was a significantly decrease of cell viability after treatment with different concentrations of carboplatin in 24 hours. Both PARP-1 protein and gene expression significantly decreased after treatment with carboplatin and olaparib. In some cases, the treatment action was potentiated when performed in combination. Conclusion: Our results suggest the efficacy of olaparib in controlling the mechanism of DNA repair activated by PARPs in human and canine breast cancer cells. Citation Format: Marina Gobbe Moschetta-Pinheiro, Jucimara Colombo, Murilo de Souza Tuckumantel, Gabriela Karam Rebolho, Debora Aparecida Zuccari. Regulation of PARP-1 expression in mammary tumor cell lines after treatment with olaparib [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB113.","PeriodicalId":12258,"journal":{"name":"Experimental and Molecular Therapeutics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73308703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract 1370: ADME and toxicology profiles of first-in-class DRD2/ClpP-targeted imipridone ONC201","authors":"S. Morrow, R. Tarapore, A. Guo, Magdalena Nej, Yunlan Fang, Gina Theerman, Leah Lake, M. Stogniew, V. Prabhu, J. Allen","doi":"10.1158/1538-7445.AM2021-1370","DOIUrl":"https://doi.org/10.1158/1538-7445.AM2021-1370","url":null,"abstract":"Imipridone ONC201 is a first-in-class DRD2 antagonist and ClpP agonist that is well tolerated and induces durable tumor regressions in H3 K27M-mutant glioma patients with once weekly dosing. We evaluated the toxicology, absorption, distribution, metabolism and excretion of ONC201 in animals. Repeat-dose 28-day studies with weekly oral ONC201 in rats and dogs revealed NOAELs (75 and 60 mg/kg, respectively) that represent higher dose levels compared to the 625 mg clinical dose. Genotoxicity (AMES, in vitro and in vivo micronucleus assays) assays demonstrated that ONC201 is not mutagenic at exposures above the RP2D and 2µM average Cmax in patients. The 3T3 neural red uptake assay showed ONC201 is not a phototoxin (photo-irritant factor 1.1). In embryofetal development studies, ONC201 did not lead to maternal effects in rats or rabbits and caused fetal malformations in 3/61 rabbit fetuses with daily dosing (from gestation day 7-17 or 19) at 62.5 and 25 mg/kg, respectively. A quantitative whole-body autoradiography study conducted in rats with one dose of [14C]-ONC201 showed rapidly tissue distribution peaking at 1h in most tissues and exhibiting a plasma terminal half-life of 5.6h. The endocrine, metabolic/excretory, ocular and GI tract tissues contained the highest distribution of [14C]ONC201. [14C]-ONC201 was distributed evenly across CNS substructures, including the midline region. Consistent with the uniform distribution, ONC201 displayed high permeability (23-31×10-6 cm/s, 7-700 μM) and was not a substrate of efflux transporters in Caco-2 cells (efflux ratio 0.46-0.79). ONC201 exerted inhibitory potential on MDR1- and BCRP-mediated transport at 200μM. Clinical trials with ONC201 restrict use of concomitant medications that induce or inhibit CYP enzymes, but several supportive medications can affect these enzymes. In vitro studies revealed that ONC201 is not an inducer of 7 major human CYP enzymes but does inhibit and is a substrate of CYP 2B6, 2C8, 2C9, 2C19, 2D6 and 3A4 (IC50 20-90µM). Analysis of dexamethasone, a known inducer of CYP3A4, did not show a correlation between baseline dose level and ONC201 plasma concentrations in H3 K27M-mutant glioma patients (n=22). Metabolic profiling in human hepatocytes revealed only one metabolite, ONC207, that was >10% in abundance. ONC207 did not achieve an IC50 in cancer cell viability and DRD2 antagonism assays. Assaying by LC-MS/MS of plasma samples obtained from ONC201-treated H3 K27M-mutant glioma patients (n=20) confirmed the presence of ONC207 as the major metabolite. A mass balance study conducted in rats with one dose of [14C]-ONC201 showed that the main route of excretion was biliary (61.18%) via the feces (69.78%), with urine (24.99%) also contributing to overall recovery. Together, these data inform the administration of ONC201 to advanced cancer patients who often require a range of comedications and comorbidities. Citation Format: Sara Morrow, Rohinton Tarapore, Ailan Guo, Magdalena Nej, Yun","PeriodicalId":12258,"journal":{"name":"Experimental and Molecular Therapeutics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80429063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}