Publications (21) View all
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Article: Current review of small molecule Ret kinase inhibitors.
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ABSTRACT: Aberrant Ret kinase activity has been implicated in multiple carcinomas and disorders. Many strategies have been implemented to identify Ret kinase inhibitors. This review details current efforts to discover novel small molecule Ret kinase inhibitors. Furthermore, we compile a comprehensive list of Ret kinase inhibitors and describe clinical results of advanced assets with Ret inhibitory activity.Mini Reviews in Medicinal Chemistry 02/2010; 10(2):138-46. · 2.53 Impact Factor -
Article: The development of a high-content screening binding assay for the smoothened receptor.
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ABSTRACT: In this study, the development of an image-based high-content screening (HCS) binding assay for the seven-transmembrane (7TM) receptor Smoothened (Smo) is described. Using BacMam-based gene delivery of Smo, BODIPY-cyclopamine as a fluorescent probe, and a confocal imaging system, a robust 384-well assay that could be used for high-throughput compound profiling activities was developed. The statistically robust HCS binding assay was developed through optimization of multiple parameters, including cell transduction conditions, Smo expression levels, the image analysis algorithm, and staining procedures. Evaluation of structurally diverse compounds, including functional Smo activators, inhibitors, and related analogs, demonstrated good compound potency correlations between high-content imaging binding, membrane fluorescence polarization binding, and gene reporter assays. Statistical analysis of data from a screening test set of compounds at a single 10-µM concentration suggested that the high-content imaging Smo binding assay is amenable for use in hit identification. The 384-well HCS assay was rapidly developed and met statistical assay performance targets, thus demonstrating its utility as a fluorescent whole-cell binding assay suitable for compound screening and profiling.Journal of Biomolecular Screening 05/2012; 17(7):900-11. · 2.05 Impact Factor -
Article: Estrogen-related receptor-α is a metabolic regulator of effector T-cell activation and differentiation.
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ABSTRACT: Stimulation of resting CD4(+) T lymphocytes leads to rapid proliferation and differentiation into effector (Teff) or inducible regulatory (Treg) subsets with specific functions to promote or suppress immunity. Importantly, Teff and Treg use distinct metabolic programs to support subset specification, survival, and function. Here, we describe that the orphan nuclear receptor estrogen-related receptor-α (ERRα) regulates metabolic pathways critical for Teff. Resting CD4(+) T cells expressed low levels of ERRα protein that increased on activation. ERRα deficiency reduced activated T-cell numbers in vivo and cytokine production in vitro but did not seem to modulate immunity through inhibition of activating signals or viability. Rather, ERRα broadly affected metabolic gene expression and glucose metabolism essential for Teff. In particular, up-regulation of Glut1 protein, glucose uptake, and mitochondrial processes were suppressed in activated ERRα(-/-) T cells and T cells treated with two chemically independent ERRα inhibitors or by shRNAi. Acute ERRα inhibition also blocked T-cell growth and proliferation. This defect appeared as a result of inadequate glucose metabolism, because provision of lipids, but not increased glucose uptake or pyruvate, rescued ATP levels and cell division. Additionally, we have shown that Treg requires lipid oxidation, whereas Teff uses glucose metabolism, and lipid addition selectively restored Treg--but not Teff--generation after acute ERRα inhibition. Furthermore, in vivo inhibition of ERRα reduced T-cell proliferation and Teff generation in both immunization and experimental autoimmune encephalomyelitis models. Thus, ERRα is a selective transcriptional regulator of Teff metabolism that may provide a metabolic means to modulate immunity.Proceedings of the National Academy of Sciences 11/2011; 108(45):18348-53. · 9.68 Impact Factor -
Article: The metabolic regulator ERRα, a downstream target of HER2/IGF-1R, as a therapeutic target in breast cancer.
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ABSTRACT: A genomic signature designed to assess the activity of the estrogen-related receptor alpha (ERRα) was used to profile more than 800 breast tumors, revealing a shorter disease-free survival in patients with tumors exhibiting elevated receptor activity. Importantly, this signature also predicted the ability of an ERRα antagonist, XCT790, to inhibit proliferation in cellular models of breast cancer. Using a chemical genomic approach, it was determined that activation of the Her2/IGF-1R signaling pathways and subsequent C-MYC stabilization upregulate the expression of peroxisome proliferator-activated receptor gamma coactivator-1 beta (PGC-1β), an obligate cofactor for ERRα activity. PGC-1β knockdown in breast cancer cells impaired ERRα signaling and reduced cell proliferation, implicating a functional role for PGC-1β/ERRα in the pathogenesis of breast cancers.Cancer cell 10/2011; 20(4):500-10. · 25.29 Impact Factor -
Article: Ligand-dependent regulation of the activity of the orphan nuclear receptor, small heterodimer partner (SHP), in the repression of bile acid biosynthetic CYP7A1 and CYP8B1 genes.
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ABSTRACT: Small heterodimer partner (SHP) plays important roles in diverse biological processes by directly interacting with transcription factors and inhibiting their activities. SHP has been designated an orphan nuclear receptor, but whether its activity can be modulated by ligands has been a long-standing question. Recently, retinoid-related molecules, including 4-[3-(1-adamantyl)-4-hydroxyphenyl]-3-chlorocinnamic acid (3Cl-AHPC), were shown to bind to SHP and enhance apoptosis. We have examined whether 3Cl-AHPC acts as an agonist and increases SHP activity in the repression of bile acid biosynthetic CYP7A1 and CYP8B1 genes and delineated the underlying mechanisms. Contrary to this expectation, micromolar concentrations of 3Cl-AHPC increased CYP7A1 expression but indirectly via p38 kinase signaling. Nanomolar concentrations, however, repressed CYP7A1 expression and decreased bile acid levels in HepG2 cells, and little repression was observed when SHP was down-regulated by small hairpin RNA. Mechanistic studies revealed that 3Cl-AHPC bound to SHP, increased the interaction of SHP with liver receptor homologue (LRH)-1, a hepatic activator for CYP7A1 and CYP8B1 genes, and with repressive cofactors, Brahma, mammalian Sin3a, and histone deacetylase-1, and, subsequently, increased the occupancy of SHP and these cofactors at the promoters. Mutation of Leu-100, predicted to contact 3Cl-AHPC within the SHP ligand binding pocket by molecular modeling, severely impaired the increased interaction with LRH-1, and repression of LRH-1 activity mediated by 3Cl-AHPC. 3Cl-AHPC repressed SHP metabolic target genes in a gene-specific manner in human primary hepatocytes and HepG2 cells. These data suggest that SHP may act as a ligand-regulated receptor in metabolic pathways. Modulation of SHP activity by synthetic ligands may be a useful therapeutic strategy.Molecular Endocrinology 05/2011; 25(7):1159-69. · 4.54 Impact Factor
