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Browsing by Author "Angus, Steven P."
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Item Brigatinib causes tumor shrinkage in both NF2-deficient meningioma and schwannoma through inhibition of multiple tyrosine kinases but not ALK(PLOS, 2021-07-15) Chang, Long-Sheng; Oblinger, Janet L.; Smith, Abbi E.; Ferrer, Marc; Angus, Steven P.; Hawley, Eric; Petrilli, Alejandra M.; Beauchamp, Roberta L.; Riecken, Lars Björn; Erdin, Serkan; Poi, Ming; Huang, Jie; Bessler, Waylan K.; Zhang, Xiaohu; Guha, Rajarshi; Thomas, Craig; Burns, Sarah S.; Gilbert, Thomas S.K.; Jiang, Li; Li, Xiaohong; Lu, Qingbo; Yuan, Jin; He, Yongzheng; Dixon, Shelley A.H.; Masters, Andrea; Jones, David R.; Yates, Charles W.; Haggarty, Stephen J.; La Rosa, Salvatore; Welling, D. Bradley; Stemmer-Rachamimov, Anat O.; Plotkin, Scott R.; Gusella, James F.; Guinney, Justin; Morrison, Helen; Ramesh, Vijaya; Fernandez-Valle, Cristina; Johnson, Gary L.; Blakeley, Jaishri O.; Clapp, D. Wade; Pediatrics, School of MedicineNeurofibromatosis Type 2 (NF2) is an autosomal dominant genetic syndrome caused by mutations in the NF2 tumor suppressor gene resulting in multiple schwannomas and meningiomas. There are no FDA approved therapies for these tumors and their relentless progression results in high rates of morbidity and mortality. Through a combination of high throughput screens, preclinical in vivo modeling, and evaluation of the kinome en masse, we identified actionable drug targets and efficacious experimental therapeutics for the treatment of NF2 related schwannomas and meningiomas. These efforts identified brigatinib (ALUNBRIG®), an FDA-approved inhibitor of multiple tyrosine kinases including ALK, to be a potent inhibitor of tumor growth in established NF2 deficient xenograft meningiomas and a genetically engineered murine model of spontaneous NF2 schwannomas. Surprisingly, neither meningioma nor schwannoma cells express ALK. Instead, we demonstrate that brigatinib inhibited multiple tyrosine kinases, including EphA2, Fer and focal adhesion kinase 1 (FAK1). These data demonstrate the power of the de novo unbiased approach for drug discovery and represents a major step forward in the advancement of therapeutics for the treatment of NF2 related malignancies.Item Cabozantinib for neurofibromatosis type 1-related plexiform neurofibromas: a phase 2 trial(Springer Nature, 2021-01) Fisher, Michael J.; Shih, Chie-Schin; Rhodes, Steven D.; Armstrong, Amy E.; Wolters, Pamela L.; Dombi, Eva; Zhang, Chi; Angus, Steven P.; Johnson, Gary L.; Packer, Roger J.; Allen, Jeffrey C.; Ullrich, Nicole J.; Goldman, Stewart; Gutmann, David H.; Plotkin, Scott R.; Rosser, Tena; Robertson, Kent A.; Widemann, Brigitte C.; Smith, Abbi E.; Bessler, Waylan K.; He, Yongzheng; Park, Su-Jung; Mund, Julie A.; Jiang, Li; Bijangi-Vishehsaraei, Khadijeh; Robinson, Coretta Thomas; Cutter, Gary R.; Korf, Bruce R.; Blakeley, Jaishri O.; Clapp, D. Wade; Pediatrics, School of MedicineNeurofibromatosis type 1 (NF1) plexiform neurofibromas (PNs) are progressive, multicellular neoplasms that cause morbidity and may transform to sarcoma. Treatment of Nf1fl/fl;Postn-Cre mice with cabozantinib, an inhibitor of multiple tyrosine kinases, caused a reduction in PN size and number and differential modulation of kinases in cell lineages that drive PN growth. Based on these findings, the Neurofibromatosis Clinical Trials Consortium conducted a phase II, open-label, nonrandomized Simon two-stage study to assess the safety, efficacy and biologic activity of cabozantinib in patients ≥16 years of age with NF1 and progressive or symptomatic, inoperable PN ( NCT02101736 ). The trial met its primary outcome, defined as ≥25% of patients achieving a partial response (PR, defined as ≥20% reduction in target lesion volume as assessed by magnetic resonance imaging (MRI)) after 12 cycles of therapy. Secondary outcomes included adverse events (AEs), patient-reported outcomes (PROs) assessing pain and quality of life (QOL), pharmacokinetics (PK) and the levels of circulating endothelial cells and cytokines. Eight of 19 evaluable (42%) trial participants achieved a PR. The median change in tumor volume was 15.2% (range, +2.2% to -36.9%), and no patients had disease progression while on treatment. Nine patients required dose reduction or discontinuation of therapy due to AEs; common AEs included gastrointestinal toxicity, hypothyroidism, fatigue and palmar plantar erythrodysesthesia. A total of 11 grade 3 AEs occurred in eight patients. Patients with PR had a significant reduction in tumor pain intensity and pain interference in daily life but no change in global QOL scores. These data indicate that cabozantinib is active in NF1-associated PN, resulting in tumor volume reduction and pain improvement.Item FOXA1 and adaptive response determinants to HER2 targeted therapy in TBCRC 036(Springer Nature, 2021-05-12) Angus, Steven P.; Stuhlmiller, Timothy J.; Mehta, Gaurav; Bevill, Samantha M.; Goulet, Daniel R.; Olivares-Quintero, J. Felix; East, Michael P.; Tanioka, Maki; Zawistowski, Jon S.; Singh, Darshan; Sciaky, Noah; Chen, Xin; He, Xiaping; Rashid, Naim U.; Chollet-Hinton, Lynn; Fan, Cheng; Soloway, Matthew G.; Spears, Patricia A.; Jefferys, Stuart; Parker, Joel S.; Gallagher, Kristalyn K.; Forero-Torres, Andres; Krop, Ian E.; Thompson, Alastair M.; Murthy, Rashmi; Gatza, Michael L.; Perou, Charles M.; Earp, H. Shelton; Carey, Lisa A.; Johnson, Gary L.; Pediatrics, School of MedicineInhibition of the HER2/ERBB2 receptor is a keystone to treating HER2-positive malignancies, particularly breast cancer, but a significant fraction of HER2-positive (HER2+) breast cancers recur or fail to respond. Anti-HER2 monoclonal antibodies, like trastuzumab or pertuzumab, and ATP active site inhibitors like lapatinib, commonly lack durability because of adaptive changes in the tumor leading to resistance. HER2+ cell line responses to inhibition with lapatinib were analyzed by RNAseq and ChIPseq to characterize transcriptional and epigenetic changes. Motif analysis of lapatinib-responsive genomic regions implicated the pioneer transcription factor FOXA1 as a mediator of adaptive responses. Lapatinib in combination with FOXA1 depletion led to dysregulation of enhancers, impaired adaptive upregulation of HER3, and decreased proliferation. HER2-directed therapy using clinically relevant drugs (trastuzumab with or without lapatinib or pertuzumab) in a 7-day clinical trial designed to examine early pharmacodynamic response to antibody-based anti-HER2 therapy showed reduced FOXA1 expression was coincident with decreased HER2 and HER3 levels, decreased proliferation gene signatures, and increased immune gene signatures. This highlights the importance of the immune response to anti-HER2 antibodies and suggests that inhibiting FOXA1-mediated adaptive responses in combination with HER2 targeting is a potential therapeutic strategy.Item High-content image-based analysis and proteomic profiling identifies Tau phosphorylation inhibitors in a human iPSC-derived glutamatergic neuronal model of tauopathy(Springer Nature, 2021-08-23) Cheng, Chialin; Reis, Surya A.; Adams, Emily T.; Fass, Daniel M.; Angus, Steven P.; Stuhlmiller, Timothy J.; Richardson, Jared; Olafson, Hailey; Wang, Eric T.; Patnaik, Debasis; Beauchamp, Roberta L.; Feldman, Danielle A.; Silva, M. Catarina; Sur, Mriganka; Johnson, Gary L.; Ramesh, Vijaya; Miller, Bruce L.; Temple, Sally; Kosik, Kenneth S.; Dickerson, Bradford C.; Haggarty, Stephen J.; Pediatrics, School of MedicineMutations in MAPT (microtubule-associated protein tau) cause frontotemporal dementia (FTD). MAPT mutations are associated with abnormal tau phosphorylation levels and accumulation of misfolded tau protein that can propagate between neurons ultimately leading to cell death (tauopathy). Recently, a p.A152T tau variant was identified as a risk factor for FTD, Alzheimer's disease, and synucleinopathies. Here we used induced pluripotent stem cells (iPSC) from a patient carrying this p.A152T variant to create a robust, functional cellular assay system for probing pathophysiological tau accumulation and phosphorylation. Using stably transduced iPSC-derived neural progenitor cells engineered to enable inducible expression of the pro-neural transcription factor Neurogenin 2 (Ngn2), we generated disease-relevant, cortical-like glutamatergic neurons in a scalable, high-throughput screening compatible format. Utilizing automated confocal microscopy, and an advanced image-processing pipeline optimized for analysis of morphologically complex human neuronal cultures, we report quantitative, subcellular localization-specific effects of multiple kinase inhibitors on tau, including ones under clinical investigation not previously reported to affect tau phosphorylation. These results demonstrate the potential for using patient iPSC-derived ex vivo models of tauopathy as genetically accurate, disease-relevant systems to probe tau biochemistry and support the discovery of novel therapeutics for tauopathies.Item A molecular basis for neurofibroma-associated skeletal manifestations in NF1(Elsevier, 2020-11) Ma, Yun; Gross, Andrea; Dombi, Eva; Pemov, Alex; Choi, Kwangmin; Chaney, Katherine; Rhodes, Steven D.; Angus, Steven P.; Sciaky, Noah; Clapp, D. Wade; Ratner, Nancy; Widemann, Brigitte C.; Rios, Jonathan J.; Elefteriou, Florent; Pediatrics, School of MedicinePurpose: Plexiform neurofibromas (pNF) develop in children with neurofibromatosis type 1 (NF1) and can be associated with several skeletal comorbidities. Preclinical mouse studies revealed Nf1 deficiency in osteoprogenitor cells disrupts, in a MEK-dependent manner, pyrophosphate (PPi) homeostasis and skeletal mineralization. The etiology of NF-associated skeletal manifestations remains unknown. Methods: We used mouse models of NF1 neurofibromas to assess bone mineralization of skeletal structures adjacent to tumors. Expression of genes involved in pyrophosphate homeostasis was assessed in mouse and human NF tumors and Schwann cell cultures. We used dual-energy X-ray absorptiometry (DXA) to assess tumor-associated changes in bone mineral density (BMD) in an individual with NF1 following treatment with the MEK inhibitor selumetinib. Results: We detected increased nonmineralized bone surfaces adjacent to tumors in mouse models of NF1 neurofibromas. Expression of Enpp1, a PPi-generating ectophosphatase, and ANKH, a PPi transporter, was increased in mouse and human neurofibroma-derived tissues and Schwann cells, respectively. In one patient, tumor-associated reductions in BMD were partially rescued following therapy with selumetinib. Conclusion: Results indicate that NF-associated skeletal pathologies in NF1 are associated with dysregulated pyrophosphate homeostasis in adjacent NF tumors and suggest that treatment of NFs with MEK inhibitors may improve skeletal manifestations of the disease.Item A proteasome-resistant fragment of NIK mediates oncogenic NF-κB signaling in schwannomas(Oxford University Press, 2019-02-15) Gehlhausen, Jeffrey R.; Hawley, Eric; Wahle, Benjamin Mark; He, Yongzheng; Edwards, Donna; Rhodes, Steven D.; Lajiness, Jacquelyn D.; Staser, Karl; Chen, Shi; Yang, Xianlin; Yuan, Jin; Li, Xiaohong; Jiang, Li; Smith, Abbi; Bessler, Waylan; Sandusky, George; Stemmer-Rachamimov, Anat; Stuhlmiller, Timothy J.; Angus, Steven P.; Johnson, Gary L.; Nalepa, Grzegorz; Yates, Charles W.; Clapp, D. Wade; Park, Su-Jung; Pediatrics, School of MedicineSchwannomas are common, highly morbid and medically untreatable tumors that can arise in patients with germ line as well as somatic mutations in neurofibromatosis type 2 (NF2). These mutations most commonly result in the loss of function of the NF2-encoded protein, Merlin. Little is known about how Merlin functions endogenously as a tumor suppressor and how its loss leads to oncogenic transformation in Schwann cells (SCs). Here, we identify nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)-inducing kinase (NIK) as a potential drug target driving NF-κB signaling and Merlin-deficient schwannoma genesis. Using a genomic approach to profile aberrant tumor signaling pathways, we describe multiple upregulated NF-κB signaling elements in human and murine schwannomas, leading us to identify a caspase-cleaved, proteasome-resistant NIK kinase domain fragment that amplifies pathogenic NF-κB signaling. Lentiviral-mediated transduction of this NIK fragment into normal SCs promotes proliferation, survival, and adhesion while inducing schwannoma formation in a novel in vivo orthotopic transplant model. Furthermore, we describe an NF-κB-potentiated hepatocyte growth factor (HGF) to MET proto-oncogene receptor tyrosine kinase (c-Met) autocrine feed-forward loop promoting SC proliferation. These innovative studies identify a novel signaling axis underlying schwannoma formation, revealing new and potentially druggable schwannoma vulnerabilities with future therapeutic potential.Item SOX4 and SMARCA4 cooperatively regulate PI3k signaling through transcriptional activation of TGFBR2(Springer Nature, 2021-04-09) Mehta, Gaurav A.; Angus, Steven P.; Khella, Christen A.; Tong, Kevin; Khanna, Pooja; Dixon, Shelley A.H.; Verzi, Michael P.; Johnson, Gary L.; Gatza, Michael L.; Pediatrics, School of MedicineDysregulation of PI3K/Akt signaling is a dominant feature in basal-like or triple-negative breast cancers (TNBC). However, the mechanisms regulating this pathway are largely unknown in this subset of aggressive tumors. Here we demonstrate that the transcription factor SOX4 is a key regulator of PI3K signaling in TNBC. Genomic and proteomic analyses coupled with mechanistic studies identified TGFBR2 as a direct transcriptional target of SOX4 and demonstrated that TGFBR2 is required to mediate SOX4-dependent PI3K signaling. We further report that SOX4 and the SWI/SNF ATPase SMARCA4, which are uniformly overexpressed in basal-like tumors, form a previously unreported complex that is required to maintain an open chromatin conformation at the TGFBR2 regulatory regions in order to mediate TGFBR2 expression and PI3K signaling. Collectively, our findings delineate the mechanism by which SOX4 and SMARCA4 cooperatively regulate PI3K/Akt signaling and suggest that this complex may play an essential role in TNBC genesis and/or progression.