المؤلفون: Bardees M. Foda, Richard R. Neubig

المصدر: International Journal of Molecular Sciences, Vol 24, Iss 18, p 13785 (2023)

مصطلحات موضوعية: melanoma, resistance, immune checkpoint, BRAF, RhoGTPase, Biology (General), QH301-705.5, Chemistry, QD1-999

الوصف: Cutaneous melanoma is the deadliest skin cancer. Most have Ras-MAPK pathway (BRAFV600E or NRAS) mutations and highly effective targeted therapies exist; however, they and immune therapies are limited by resistance, in part driven by small GTPase (Rho and Rac) activation. To facilitate preclinical studies of combination therapies to provide durable responses, we describe the first mouse melanoma lines resistant to BRAF inhibitors. Treatment of mouse lines, YUMM1.7 and YUMMER, with vemurafenib (Vem), the BRAFV600E-selective inhibitor, resulted in high-level resistance (IC50 shifts 20–30-fold). Resistant cells showed enhanced activation of Rho and the downstream transcriptional coactivator, myocardin-related transcription factor (MRTF). Resistant cells exhibited increased stress fibers, nuclear translocation of MRTF-A, and an increased MRTF-A gene signature. Pharmacological inhibition of the Rho/MRTF pathway using CCG-257081 reduced viability of resistant lines and enhanced sensitivity to Vem. Remarkably, co-treatment of parental lines with Vem and CCG-257081 eliminated resistant colony development. Resistant cells grew more slowly in vitro, but they developed highly aggressive tumors with a shortened survival of tumor-bearing mice. Increased expression of immune checkpoint inhibitor proteins (ICIs) in resistant lines may contribute to aggressive in vivo behavior. Here, we introduce the first drug-resistant mouse melanoma models for assessing combinations of targeted and immune therapies.

وصف الملف: electronic resource

العلاقة: https://www.mdpi.com/1422-0067/24/18/13785Test; https://doaj.org/toc/1661-6596Test; https://doaj.org/toc/1422-0067Test

الوصول الحر: https://doaj.org/article/3e514b6d55644bd7a5522b3d1d868d16Test

المؤلفون: Kendell M. Pawelec, Megan Varnum, Jack R. Harkema, Bruce Auerbach, Scott D. Larsen, Richard R. Neubig

المصدر: Pharmacology Research & Perspectives, Vol 10, Iss 6, Pp n/a-n/a (2022)

مصطلحات موضوعية: drug‐induced lung fibrosis, MRTF/SRF inhibitor, nintedanib, prevention model, Therapeutics. Pharmacology, RM1-950

الوصف: Abstract Bleomycin‐induced lung fibrosis is a debilitating disease, linked to high morbidity and mortality in chemotherapy patients. The MRTF/SRF transcription pathway has been proposed as a potential therapeutic target, as it is critical for myofibroblast differentiation, a hallmark of fibrosis. In human lung fibroblasts, the MRTF/SRF pathway inhibitor, CCG‐257081, effectively decreased mRNA levels of downstream genes: smooth muscle actin and connective tissue growth factor, with IC50s of 4 and 15 μM, respectively. The ability of CCG‐257081 to prevent inflammation and fibrosis, measured via pulmonary collagen content and histopathology, was tested in a murine model of bleomycin‐induced lung fibrosis. Animals were given intraperitoneal bleomycin for 4 weeks and concurrently dosed with CCG‐257081 (0, 10, 30, and 100 mg/kg PO), a clinical anti‐fibrotic (nintedanib) or the clinical standard of care (prednisolone). Mice treated with 100 mg/kg CCG‐257081 gained weight vs. vehicle‐treated control mice, while those receiving nintedanib and prednisolone lost significant weight. Hydroxyproline content and histological findings in tissue of animals on 100 mg/kg CCG‐257081 were not significantly different from naive tissue, indicating successful prevention. Measures of tissue fibrosis were comparable between CCG‐257081 and nintedanib, but only the MRTF/SRF inhibitor decreased plasminogen activator inhibitor‐1 (PAI‐1), a marker linked to fibrosis, in bronchoalveolar lavage fluid. In contrast, prednisolone led to marked increases in lung fibrosis by all metrics. This study demonstrates the potential use of MRTF/SRF inhibitors to prevent bleomycin‐induced lung fibrosis in a clinically relevant model of the disease.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2052-1707Test

الوصول الحر: https://doaj.org/article/44200ee4fb6143fda9eddfcf3ba10f31Test

المؤلفون: Sean A. Misek, Bardees M. Foda, Thomas S. Dexheimer, Maisah Akram, Susan E. Conrad, Jens C. Schmidt, Richard R. Neubig, Kathleen A. Gallo

المصدر: Frontiers in Oncology, Vol 12 (2022)

مصطلحات موضوعية: BRAF, resistance, mitosis, inhibitor, pharmacology, compound screen, Neoplasms. Tumors. Oncology. Including cancer and carcinogens, RC254-282

الوصف: Single agent and combination therapy with BRAFV600E/K and MEK inhibitors have remarkable efficacy against melanoma tumors with activating BRAF mutations, but in most cases BRAF inhibitor (BRAFi) resistance eventually develops. One resistance mechanism is reactivation of the ERK pathway. However, only about half of BRAFi resistance is due to ERK reactivation. The purpose of this study is to uncover pharmacological vulnerabilities of BRAFi-resistant melanoma cells, with the goal of identifying new therapeutic options for patients whose tumors have developed resistance to BRAFi/MEKi therapy. We screened a well-annotated compound library against a panel of isogenic pairs of parental and BRAFi-resistant melanoma cell lines to identify classes of compounds that selectively target BRAFi-resistant cells over their BRAFi-sensitive counterparts. Two distinct patterns of increased sensitivity to classes of pharmacological inhibitors emerged. In two cell line pairs, BRAFi resistance conferred increased sensitivity to compounds that share the property of cell cycle arrest at M-phase, including inhibitors of aurora kinase (AURK), polo-like kinase (PLK), tubulin, and kinesin. Live cell microscopy, used to track mitosis in real time, revealed that parental but not BRAFi-resistant melanoma cells were able to exit from compound-induced mitotic arrest through mitotic slippage, thus escaping death. Consistent with the key role of Cyclin B1 levels in regulating mitosis at the spindle checkpoint in arrested cells, we found lower Cyclin B1 levels in parental compared with BRAFi-resistant melanoma cells, suggesting that inability to down-regulate Cyclin B1 expression levels may explain the increased vulnerability of resistant cells to mitotic inhibitors. Another BRAFi-resistant cell line showed increased sensitivity to Chk1/2 inhibitors, which was associated with an accumulation of DNA damage, resulting in mitotic failure. This study demonstrates that BRAFi-resistance, in at least a subset of melanoma cells, confers vulnerability to pharmacological disruption of mitosis and suggests a targeted synthetic lethal approach for overcoming resistance to BRAF/MEK-directed therapies.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fonc.2022.766794/fullTest; https://doaj.org/toc/2234-943XTest

الوصول الحر: https://doaj.org/article/13e3b3bcb52f4731ab7a41e5e5dd7d41Test

المؤلفون: Philip McMillan, Thomas Dexhiemer, Richard R. Neubig, Bruce D. Uhal

المصدر: Frontiers in Immunology, Vol 12 (2021)

مصطلحات موضوعية: COVID-19, autoimmunity, lung, solubleACE-2, macrophage, Immunologic diseases. Allergy, RC581-607

الوصف: The COVID-19 pandemic caused by the coronavirus SARS-COV-2 has cost many lives worldwide. In dealing with affected patients, the physician is faced with a very unusual pattern of organ damage that is not easily explained on the basis of prior knowledge of viral-induced pathogenesis. It is established that the main receptor for viral entry into tissues is the protein angiotensin-converting enzyme-2 [“ACE-2”, (1)]. In a recent publication (2), a theory of autoimmunity against ACE-2, and/or against the ACE-2/SARS-COV-2 spike protein complex or degradation products thereof, was proposed as a possible explanation for the unusual pattern of organ damage seen in COVID-19. In the light of more recent information, this manuscript expands on the earlier proposed theory and offers additional, testable hypotheses that could explain both the pattern and timeline of organ dysfunction most often observed in COVID-19.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fimmu.2021.582166/fullTest; https://doaj.org/toc/1664-3224Test

الوصول الحر: https://doaj.org/article/36872b29194d449ea2933a9d488713ffTest

المؤلفون: Vanessa Benham, Blair Bullard, Thomas S. Dexheimer, Matthew P. Bernard, Richard R. Neubig, Karen T. Liby, Jamie J. Bernard

المصدر: Scientific Reports, Vol 9, Iss 1, Pp 1-12 (2019)

مصطلحات موضوعية: Medicine, Science

الوصف: Abstract Obesity is associated with ~40% of cancer diagnoses but there are currently no effective preventive strategies, illustrating a need for chemoprevention. We previously demonstrated that fibroblast growth factor 2 (FGF2) from adipose tissue stimulates malignant transformation, as measured by growth in soft agar, the gold-standard in vitro transformation assay. Because the soft agar assay is unsuitable for high throughput screens (HTS), we developed a novel method using 3D growth in ultra-low attachment conditions as an alternative to growth in agar to discover compounds that inhibit transformation. Treating non-tumorigenic, skin epithelial JB6 P+ cells with FGF2 stimulates growth in ultra-low attachment conditions analogous to growth in the soft agar. This transformation HTS identified picropodophyllin, an insulin growth factor 1 receptor (IGF1R) inhibitor, and fluvastatin, an HMG-CoA reductase inhibitor, as potential chemopreventive agents. These compounds were validated for efficacy using two non-tumorigenic cell lines in soft agar. Another IGF1R inhibitor and other statins were also tested and several were able to inhibit growth in soft agar. This novel 3D HTS platform is fast, robust and has the potential to identify agents for obesity-associated cancer prevention.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2045-2322Test

الوصول الحر: https://doaj.org/article/ed4f3360f28b4854a3d1704bfd5877ccTest

المؤلفون: Aristides D. Tagalakis, Shivam Madaan, Scott D. Larsen, Richard R. Neubig, Peng T. Khaw, Ian Rodrigues, Saurabh Goyal, Kin Sheng Lim, Cynthia Yu-Wai-Man

المصدر: Journal of Nanobiotechnology, Vol 16, Iss 1, Pp 1-11 (2018)

مصطلحات موضوعية: Nanocarrier, Sustained release, Inhibitor, Glaucoma, Fibrosis, Biotechnology, TP248.13-248.65, Medical technology, R855-855.5

الوصف: Abstract Background Sustained drug delivery is a large unmet clinical need in glaucoma. Here, we incorporated a Myocardin-Related Transcription Factor/Serum Response Factor inhibitor, CCG-222740, into slow release large unilamellar vesicles derived from the liposomes DOTMA (1,2-di-O-octadecenyl-3-trimethylammonium propane) and DOPC (1,2-dioleoyl-sn-glycero-3-phosphocholine), and tested their effects in vitro and in vivo. Results The vesicles were spherical particles of around 130 nm and were strongly cationic. A large amount of inhibitor could be incorporated into the vesicles. We showed that the nanocarrier CCG-222740 formulation gradually released the inhibitor over 14 days using high performance liquid chromatography. Nanocarrier CCG-222740 significantly decreased ACTA2 gene expression and was not cytotoxic in human conjunctival fibroblasts. In vivo, nanocarrier CCG-222740 doubled the bleb survival from 11.0 ± 0.6 days to 22.0 ± 1.3 days (p = 0.001), decreased conjunctival scarring and did not have any local or systemic adverse effects in a rabbit model of glaucoma filtration surgery. Conclusions Our study demonstrates proof-of-concept that a nanocarrier-based formulation efficiently achieves a sustained release of a Myocardin-Related Transcription Factor/Serum Response Factor inhibitor and prevents conjunctival fibrosis in an established rabbit model of glaucoma filtration surgery.

وصف الملف: electronic resource

العلاقة: http://link.springer.com/article/10.1186/s12951-018-0425-3Test; https://doaj.org/toc/1477-3155Test

الوصول الحر: https://doaj.org/article/01cbae81bc8b41f7bd5ccf2d64ab173fTest

المؤلفون: Huijie Feng, Suad Khalil, Richard R. Neubig, Christos Sidiropoulos

المصدر: Neurobiology of Disease, Vol 116, Iss , Pp 131-141 (2018)

مصطلحات موضوعية: GNAO1, cAMP, Neurotransmitter, Movement disorder, Epilepsy, Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571

الوصف: Mutations in the GNAO1 gene cause a complex constellation of neurological disorders including epilepsy, developmental delay, and movement disorders. GNAO1 encodes Gαo, the α subunit of Go, a member of the Gi/o family of heterotrimeric G protein signal transducers. Go is the most abundant membrane protein in the mammalian central nervous system and plays major roles in synaptic neurotransmission and neurodevelopment. GNAO1 mutations were first reported in early infantile epileptic encephalopathy 17 (EIEE17) but are also associated with a more common syndrome termed neurodevelopmental disorder with involuntary movements (NEDIM). Here we review a mechanistic model in which loss-of-function (LOF) GNAO1 alleles cause epilepsy and gain-of-function (GOF) alleles are primarily associated with movement disorders. We also develop a signaling framework related to cyclic AMP (cAMP), synaptic vesicle release, and neural development and discuss gene mutations perturbing those mechanisms in a range of genetic movement disorders. Finally, we analyze clinical reports of patients carrying GNAO1 mutations with respect to their symptom onset and discuss pharmacological/surgical treatments in the context of our mechanistic model.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S0969996118301438Test; https://doaj.org/toc/1095-953XTest

الوصول الحر: https://doaj.org/article/313152d83c4f4bb5a7fc7941e59abcf5Test

المؤلفون: Kathryn M. Appleton, Charuta C. Palsuledesai, Sean A. Misek, Maja Blake, Joseph Zagorski, Kathleen A. Gallo, Thomas S. Dexheimer, Richard R. Neubig

المصدر: Cancers, Vol 13, Iss 9, p 2012 (2021)

مصطلحات موضوعية: Rho GTPase, MEK inhibitor, resistance, Neoplasms. Tumors. Oncology. Including cancer and carcinogens, RC254-282

الوصف: The Ras/MEK/ERK pathway has been the primary focus of targeted therapies in melanoma; it is aberrantly activated in almost 80% of human cutaneous melanomas (≈50% BRAFV600 mutations and ≈30% NRAS mutations). While drugs targeting the MAPK pathway have yielded success in BRAFV600 mutant melanoma patients, such therapies have been ineffective in patients with NRAS mutant melanomas in part due to their cytostatic effects and primary resistance. Here, we demonstrate that increased Rho/MRTF-pathway activation correlates with high intrinsic resistance to the MEK inhibitor, trametinib, in a panel of NRAS mutant melanoma cell lines. A combination of trametinib with the Rho/MRTF-pathway inhibitor, CCG-222740, synergistically reduced cell viability in NRAS mutant melanoma cell lines in vitro. Furthermore, the combination of CCG-222740 with trametinib induced apoptosis and reduced clonogenicity in SK-Mel-147 cells, which are highly resistant to trametinib. These findings suggest a role of the Rho/MRTF-pathway in intrinsic trametinib resistance in a subset of NRAS mutant melanoma cell lines and highlight the therapeutic potential of concurrently targeting the Rho/MRTF-pathway and MEK in NRAS mutant melanomas.

وصف الملف: electronic resource

العلاقة: https://www.mdpi.com/2072-6694/13/9/2012Test; https://doaj.org/toc/2072-6694Test

الوصول الحر: https://doaj.org/article/55e2041ccfe9498c8e7bf323839fa719Test

المؤلفون: Cynthia Yu-Wai-Man, Bradley Spencer-Dene, Richard M. H. Lee, Kim Hutchings, Erika M. Lisabeth, Richard Treisman, Maryse Bailly, Scott D. Larsen, Richard R. Neubig, Peng T. Khaw

المصدر: Scientific Reports, Vol 7, Iss 1, Pp 1-13 (2017)

مصطلحات موضوعية: Medicine, Science

الوصف: Abstract The myocardin-related transcription factor/serum response factor (MRTF/SRF) pathway represents a promising therapeutic target to prevent fibrosis. We have tested the effects of new pharmacological inhibitors of MRTF/SRF signalling in a preclinical model of fibrosis. CCG-222740, a novel MRTF/SRF inhibitor, markedly decreased SRF reporter gene activity and showed a greater inhibitory effect on MRTF/SRF target genes than the previously described MRTF-A inhibitor CCG-203971. CCG-222740 was also five times more potent, with an IC50 of 5 μM, in a fibroblast-mediated collagen contraction assay, was less cytotoxic, and a more potent inhibitor of alpha-smooth muscle actin protein expression than CCG-203971. Local delivery of CCG-222740 and CCG-203971 in a validated and clinically relevant rabbit model of scar tissue formation after glaucoma filtration surgery increased the long-term success of the surgery by 67% (P

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2045-2322Test

الوصول الحر: https://doaj.org/article/d0d09e6ee5ac462a80dbec12fafe4e2cTest

المؤلفون: Brent Martin, Dylan Kahl, Erika M. Lisabeth, Richard R. Neubig, Sarah Haynes, Scott D. Larsen

المصدر: Proceedings for Annual Meeting of The Japanese Pharmacological Society. 2018, :SY84-4