RESUMEN
Androgen receptor (AR) and its ligand androgens are important for development and physiology of various tissues. AR and its ligands also play critical role in the development of various diseases, making it a valuable therapeutic target. AR ligands, both agonists and antagonists, are being widely used to treat pathological conditions, including prostate cancer and hypogonadism. Despite AR being studied widely over the last five decades, the last decade has seen striking advances in the knowledge on AR and discoveries that have the potential to translate to the clinic. This review provides an overview of the advances in AR biology, AR molecular mechanisms of action, and next generation molecules that are currently in development. Several of the areas described in the review are just unraveling and the next decade will bring more clarity on these developments that will put AR at the forefront of both basic biology and drug development.
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Ovarian cancer is the most lethal gynecological malignancy, with a 5-year survival rate of approximately 50%. The dismal prognosis is due in part to metastatic disease and acquired drug resistance to conventional chemotherapies such as taxanes. Colchicine binding site inhibitors (CBSIs) are attractive alternatives to taxanes because they could potentially achieve oral bioavailability and overcome drug resistance associated with the prolonged use of taxanes. VERU-111 is one of the most advanced CBSIs that is orally available, potent, well-tolerated, and has shown good efficacy in several preclinical solid tumor models. Here, we demonstrate for the first time the in vitro potency of VERU-111 as well as its efficacy at inhibiting tumor growth and metastasis in an orthotopic ovarian cancer mouse model. VERU-111 has nanomolar potency against ovarian cancer cell lines and strongly inhibits colony formation, proliferation, invasion, and migration. VERU-111 disrupts microtubule formation to induce mitotic catastrophe and, ultimately, apoptosis in a concentration-dependent manner. The efficacy of VERU-111 was comparable with standard chemotherapy paclitaxel, the current first-line treatment for ovarian cancer, with no observed synergy with combination paclitaxel + VERU-111 treatment. In vivo, VERU-111 markedly suppressed ovarian tumor growth and completely suppressed distant organ metastasis. Together, these results support VERU-111 for its potential as a novel therapy for ovarian cancer, particularly for late-stage metastatic disease. Significance Statement VERU-111 is an investigational new drug and has comparable efficacy as paclitaxel in suppressing tumor cell proliferation, colony formation, and migration in ovarian cancer models in vitro and has potent in vivo anti-tumor and anti-metastatic activity in an orthotopic ovarian cancer mouse model. VERU-111 has low systemic toxicity and, unlike paclitaxel, is orally bioavailable and is not a substrate for the major drug efflux transporters, making it a promising and attractive alternative to taxane-based therapy.
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BACKGROUND: Improving survival for patients diagnosed with metastatic disease and overcoming chemoresistance remain significant clinical challenges in treating breast cancer. Triple-negative breast cancer (TNBC) is an aggressive subtype characterized by a lack of therapeutically targetable receptors (ER/PR/HER2). TNBC therapy includes a combination of cytotoxic chemotherapies, including microtubule-targeting agents (MTAs) like paclitaxel (taxane class) or eribulin (vinca class); however, there are currently no FDA-approved MTAs that bind to the colchicine-binding site. Approximately 70 % of patients who initially respond to paclitaxel will develop taxane resistance (TxR). We previously reported that an orally bioavailable colchicine-binding site inhibitor (CBSI), VERU-111, inhibits TNBC tumor growth and treats pre-established metastatic disease. To further improve the potency and metabolic stability of VERU-111, we created next-generation derivatives of its scaffold, including 60c. RESULTS: 60c shows improved in vitro potency compared to VERU-111 for taxane-sensitive and TxR TNBC models, and suppress TxR primary tumor growth without gross toxicity. 60c also suppressed the expansion of axillary lymph node metastases existing prior to treatment. Comparative analysis of excised organs for metastasis between 60c and VERU-111 suggested that 60c has unique anti-metastatic tropism. 60c completely suppressed metastases to the spleen and was more potent to reduce metastatic burden in the leg bones and kidney. In contrast, VERU-111 preferentially inhibited liver metastases and lung metastasis repression was similar. Together, these results position 60c as an additional promising CBSI for TNBC therapy, particularly for patients with TxR disease.
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Colchicina , Neoplasias de la Mama Triple Negativas , Ensayos Antitumor por Modelo de Xenoinjerto , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias de la Mama Triple Negativas/patología , Neoplasias de la Mama Triple Negativas/metabolismo , Humanos , Femenino , Animales , Colchicina/farmacología , Línea Celular Tumoral , Sitios de Unión , Moduladores de Tubulina/farmacología , Antineoplásicos/farmacología , Proliferación Celular/efectos de los fármacos , Piridinas/farmacología , Ratones Desnudos , Ratones , Carga Tumoral/efectos de los fármacosRESUMEN
Triple-negative breast cancer (TNBC) is an aggressive subtype with no targeted therapeutics. The luminal androgen receptor (LAR) subtype constitutes 15% of TNBC and is enriched for androgen receptor (AR) and AR target genes. Here, we show that a cohort of TNBC not only expresses AR at a much higher rate (â¼80%) but also expresses AR splice variants (AR-SVs) (â¼20%), further subclassifying LAR-TNBC. Higher AR and AR-SV expression and corresponding aggressive phenotypes are observed predominantly in specimens obtained from African American women. LAR TNBC specimens are enriched for interferon, Janus kinase (JAK)-signal activator and transducer (STAT), and androgen signaling pathways, which are exclusive to AR-expressing epithelial cancer cells. AR- and AR-SV-expressing TNBC cell proliferation and xenograft and patient-tumor explant growth are inhibited by AR N-terminal domain-binding selective AR degrader or by a JAK inhibitor. Biochemical analysis suggests that STAT1 is an AR coactivator. Collectively, our work identifies pharmacologically targetable TNBC subtypes and identifies growth-promoting interaction between AR and JAK-STAT signaling.
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Neoplasias de la Mama Triple Negativas , Humanos , Femenino , Neoplasias de la Mama Triple Negativas/metabolismo , Receptores Androgénicos/genética , Receptores Androgénicos/metabolismo , Transducción de Señal/genética , Proliferación Celular/genética , Regulación Neoplásica de la Expresión GénicaRESUMEN
Glioblastoma (GBM) is an aggressive brain cancer with a poor prognosis. While surgical resection is the primary treatment, adjuvant temozolomide (TMZ) chemotherapy and radiotherapy only provide slight improvement in disease course and outcome. Unfortunately, most treated patients experience recurrence of highly aggressive, therapy-resistant tumours and eventually succumb to the disease. To increase chemosensitivity and overcome therapy resistance, we have modified the chemical structure of the PFI-3 bromodomain inhibitor of the BRG1 and BRM catalytic subunits of the SWI/SNF chromatin remodelling complex. Our modifications resulted in compounds that sensitized GBM to the DNA alkylating agent TMZ and the radiomimetic bleomycin. We screened these chemical analogues using a cell death ELISA with GBM cell lines and a cellular thermal shift assay using epitope tagged BRG1 or BRM bromodomains expressed in GBM cells. An active analogue, IV-129, was then identified and further modified, resulting in new generation of bromodomain inhibitors with distinct properties. IV-255 and IV-275 had higher bioactivity than IV-129, with IV-255 selectively binding to the bromodomain of BRG1 and not BRM, while IV-275 bound well to both BRG1 and BRM bromodomains. In contrast, IV-191 did not bind to either bromodomain or alter GBM chemosensitivity. Importantly, both IV-255 and IV-275 markedly increased the extent of DNA damage induced by TMZ and bleomycin as determined by nuclear γH2AX staining. Our results demonstrate that these next-generation inhibitors selectively bind to the bromodomains of catalytic subunits of the SWI/SNF complex and sensitize GBM to the anticancer effects of TMZ and bleomycin. This approach holds promise for improving the treatment of GBM.
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Glioblastoma , Humanos , Glioblastoma/tratamiento farmacológico , Glioblastoma/genética , Dominios Proteicos , Temozolomida/farmacología , Muerte Celular , Bleomicina/farmacología , Daño del ADNRESUMEN
Polymerization of tubulin dimers to form microtubules is one of the key events in cell proliferation. The inhibition of this event has long been recognized as a potential treatment option for various types of cancer. Compound 1e was previously developed by our team as a potent inhibitor of tubulin polymerization that binds to the colchicine site. To further improve the potency and therapeutic properties of compound 1e, we hypothesized based on the X-ray crystal structure that modification of the pyrimidine dihydroquinoxalinone scaffold with additional hetero-atom (N, O, and S) substituents could allow the resulting new compounds to bind more tightly to the colchicine site and display greater efficacy in cancer therapy. We therefore synthesized a series of new pyrimidine dihydroquinoxalinone derivatives, compounds 10, 12b-c, 12e, 12h, and 12j-l, and evaluated their cytotoxicity and relative ability to inhibit proliferation, resulting in the discovery of new tubulin-polymerization inhibitors. Among these, the most potent new inhibitor was compound 12k, which exhibited high cytotoxic activity in vitro, a longer half-life than the parental compound in liver microsomes (IC50 = 0.2 nM, t 1/2 = >300 min), and significant potency against a wide range of cancer cell lines including those from melanoma and breast, pancreatic, and prostate cancers. High-resolution X-ray crystal structures of the best compounds in this scaffold series, 12e, 12j, and 12k, confirmed their direct binding to the colchicine site of tubulin and revealed their detailed molecular interactions. Further evaluation of 12k in vivo using a highly taxane-resistant prostate cancer xenograft model, PC-3/TxR, demonstrated the strong tumor growth inhibition at the low dose of 2.5 mg/kg (i.v., twice per week). Collectively, these results strongly support further preclinical evaluations of 12k as a potential candidate for development.
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A major challenge for new drug discovery in the area of androgen receptor (AR) antagonists lies in predicting the druggable properties that will enable small molecules to retain their potency and stability during further studies in vitro and in vivo. Indole (compound 8) is a first-in-class AR antagonist with very high potency (IC50 = 0.085 µM) but is metabolically unstable. During the metabolic studies described herein, we synthesized new small molecules that exhibit significantly improved stability while retaining potent antagonistic activity for an AR. This structure-activity relationship (SAR) study of more than 50 compounds classified with three classes (Class I, II, and III) and discovered two compounds (32c and 35i) that are potent AR antagonists (e.g., IC50 = 0.021 µM, T1/2 = 120 min for compound 35i). The new antagonists exhibited improved in vivo pharmacokinetics (PK) with high efficacy antiandrogen activity in Hershberger and antiandrogen Enz-Res tumor xenograft models that overexpress AR (LNCaP-AR).
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Antagonistas de Receptores Androgénicos , Neoplasias de la Próstata , Masculino , Humanos , Antagonistas de Receptores Androgénicos/farmacología , Antagonistas de Receptores Androgénicos/uso terapéutico , Receptores Androgénicos/metabolismo , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/patología , Antagonistas de Andrógenos , Nitrilos/farmacología , Línea Celular Tumoral , Proliferación CelularRESUMEN
Extensive preclinical studies have shown that colchicine-binding site inhibitors (CBSIs) are promising drug candidates for cancer therapy. Although numerous CBSIs were generated and evaluated, but so far the FDA has not approved any of them due to undesired adverse events or insufficient efficacies. We previously reported two very potent CBSIs, the dihydroquinoxalinone compounds 5 m and 5t. In this study, we further optimized the structures of compounds 5 m and 5t and integrated them to generate a new analog, SB226. X-ray crystal structure studies and a tubulin polymerization assay confirmed that SB226 is a CBSI that could disrupt the microtubule dynamics and interfere with microtubule assembly. Biophysical measurements using surface plasmon resonance (SPR) spectroscopy verified the high binding affinity of SB226 to tubulin dimers. The in vitro studies showed that SB226 possessed sub-nanomolar anti-proliferative activities with an average IC50 of 0.76 nM against a panel of cancer cell lines, some of which are paclitaxel-resistant, including melanoma, breast cancer and prostate cancer cells. SB226 inhibited the colony formation and migration of Taxol-resistant A375/TxR cells, and induced their G2/M phase arrest and apoptosis. Our subsequent in vivo studies confirmed that 4 mg/kg SB226 strongly inhibited the tumor growth of A375/TxR melanoma xenografts in mice and induced necrosis, anti-angiogenesis, and apoptosis in tumors. Moreover, SB226 treatment significantly inhibited spontaneous axillary lymph node, lung, and liver metastases originating from subcutaneous tumors in mice without any obvious toxicity to the animals' major organs, demonstrating the therapeutic potential of SB226 as a novel anticancer agent for cancer therapy.
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Antineoplásicos , Melanoma , Moduladores de Tubulina , Animales , Humanos , Masculino , Ratones , Antineoplásicos/química , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Sitios de Unión , Línea Celular Tumoral , Proliferación Celular , Colchicina/farmacología , Melanoma/tratamiento farmacológico , Paclitaxel/farmacología , Paclitaxel/uso terapéutico , Polimerizacion/efectos de los fármacos , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/química , Moduladores de Tubulina/farmacología , Moduladores de Tubulina/uso terapéuticoRESUMEN
Androgen receptor (AR) and its splice variants (AR-SVs) promote prostate cancer (PCa) growth by orchestrating transcriptional reprogramming. Mechanisms by which the low complexity and intrinsically disordered primary transactivation domain (AF-1) of AR and AR-SVs regulate transcriptional programming in PCa remains poorly defined. Using omics, live and fixed fluorescent microscopy of cells, and purified AF-1 and AR-V7 recombinant proteins we show here that AF-1 and the AR-V7 splice variant form molecular condensates by liquid-liquid phase separation (LLPS) that exhibit disorder characteristics such as rapid intracellular mobility, coactivator interaction, and euchromatin induction. The LLPS and other disorder characteristics were reversed by a class of small-molecule-selective AR-irreversible covalent antagonists (SARICA) represented herein by UT-143 that covalently and selectively bind to C406 and C327 in the AF-1 region. Interfering with LLPS formation with UT-143 or mutagenesis resulted in chromatin condensation and dissociation of AR-V7 interactome, all culminating in a transcriptionally incompetent complex. Biochemical studies suggest that C327 and C406 in the AF-1 region are critical for condensate formation, AR-V7 function, and UT-143's irreversible AR inhibition. Therapeutically, UT-143 possesses drug-like pharmacokinetics and metabolism properties and inhibits PCa cell proliferation and tumor growth. Our work provides critical information suggesting that clinically important AR-V7 forms transcriptionally competent molecular condensates and covalently engaging C327 and C406 in AF-1, dissolves the condensates, and inhibits its function. The work also identifies a library of AF-1-binding AR and AR-SV-selective covalent inhibitors for the treatment of PCa.
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Neoplasias de la Próstata Resistentes a la Castración , Neoplasias de la Próstata , Masculino , Humanos , Receptores Androgénicos/metabolismo , Cisteína , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/metabolismo , Antagonistas de Receptores Androgénicos/farmacología , Neoplasias de la Próstata Resistentes a la Castración/patología , Línea Celular Tumoral , Isoformas de Proteínas/metabolismoRESUMEN
HER2+ breast cancer accounts for 15% of all breast cancer cases. Current frontline therapy for HER2+ metastatic breast cancer relies on targeted antibodies, trastuzumab and pertuzumab, combined with microtubule inhibitors in the taxane class (paclitaxel or docetaxel). It is well known that the clinical efficacy of taxanes is limited by the development of chemoresistance and hematological and neurotoxicities. The colchicine-binding site inhibitors (CBSIs) are a class of promising alternative agents to taxane therapy. Sabizabulin (formerly known as VERU-111) is a potent CBSI that overcomes P-gp-mediated taxane resistance, is orally bioavailable, and inhibits tumor growth and distant metastasis in triple negative breast cancer (TNBC). Herein, we demonstrate the efficacy of sabizabulin in HER2+ breast cancer. In vitro, sabizabulin inhibits the proliferation of HER2+ breast cancer cell lines with low nanomolar IC50 values, inhibits clonogenicity, and induces apoptosis in a concentration-dependent manner. In vivo, sabizabulin inhibits breast tumor growth in the BT474 (ER+/PR+/HER2+) xenograft model and a HER2+ (ER-/PR-) metastatic patient-derived xenograft (PDX) model, HCI-12. We demonstrate that sabizabulin is a promising alternative agent to target tubulin in HER2+ breast cancer with similar anti-metastatic efficacy to paclitaxel, but with the advantage of oral bioavailability and lower toxicity than taxanes.
RESUMEN
Triple-negative breast cancer (TNBC) is a highly aggressive type of breast cancer. Unlike other subtypes of breast cancer, TNBC lacks hormone and growth factor receptor targets. Colchicine-binding site inhibitors (CBSI) targeting tubulin have been recognized as attractive agents for cancer therapy, but there are no CBSI drugs currently FDA approved. CH-2-77 has been reported to have potent antiproliferative activity against a panel of cancer cells in vitro and efficacious antitumor effects on melanoma xenografts, yet, its anticancer activity specifically against TNBC is unknown. Herein, we demonstrate that CH-2-77 inhibits the proliferation of both paclitaxel-sensitive and paclitaxel-resistant TNBC cells with an average IC50 of 3 nmol/L. CH-2-77 also efficiently disrupts the microtubule assembly, inhibits the migration and invasion of TNBC cells, and induces G2-M cell-cycle arrest. The increased number of apoptotic cells and the pattern of expression of apoptosis-related proteins in treated MDA-MB-231 cells suggest that CH-2-77 induces cell apoptosis through the intrinsic apoptotic pathway. In vivo, CH-2-77 shows acceptable overall pharmacokinetics and strongly suppresses the growth of orthotopic MDA-MB-231 xenografts without gross cumulative toxicities when administered 5 times a week. The in vivo efficacy of CH-2-77 (20 mg/kg) is comparable with that of CA4P (28 mg/kg), a CBSI that went through clinical trials. Importantly, CH-2-77 prevents lung metastasis originating from the mammary fat pad in a dose-dependent manner. Our data demonstrate that CH-2-77 is a promising new generation of tubulin inhibitors that inhibit the growth and metastasis of TNBC, and it is worthy of further development as an anticancer agent.
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Neoplasias de la Mama Triple Negativas , Apoptosis , Sitios de Unión , Línea Celular Tumoral , Proliferación Celular , Colchicina/farmacología , Colchicina/uso terapéutico , Humanos , Paclitaxel/farmacología , Neoplasias de la Mama Triple Negativas/patología , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/farmacología , Moduladores de Tubulina/uso terapéuticoRESUMEN
Tubulin is an important cancer drug target. Compounds that bind at the colchicine site in tubulin have attracted significant interest as they are generally less affected by multidrug resistance than other potential drugs. Modeling is useful in understanding the interactions between tubulin and colchicine binding site inhibitors (CBSIs), but because the colchicine binding site contains two flexible loops whose conformations are highly ligand-dependent, modeling has its limitations. X-ray crystallography provides experimental pictures of tubulin-ligand interactions at this challenging colchicine site. Since 2004, when the first X-ray structure of tubulin in complex with N-deacetyl-N-(2-mercaptoacetyl)-colchicine (DAMA-colchicine) was published, many X-ray crystal structures have been reported for tubulin complexes involving the colchicine binding site. In this review, we summarize the crystal structures of tubulin in complexes with various CBSIs, aiming to facilitate the discovery of new generations of tubulin inhibitors.
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Colchicina , Tubulina (Proteína) , Sitios de Unión , Colchicina/química , Colchicina/metabolismo , Colchicina/farmacología , Cristalografía por Rayos X , Ligandos , Tubulina (Proteína)/química , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/química , Moduladores de Tubulina/metabolismo , Moduladores de Tubulina/farmacologíaRESUMEN
Glioblastoma (GBM) is the most aggressive and treatment-refractory malignant adult brain cancer. After standard of care therapy, the overall median survival for GBM is only â¼6 months with a 5-year survival <10%. Although some patients initially respond to the DNA alkylating agent temozolomide (TMZ), unfortunately most patients become resistant to therapy and brain tumors eventually recur. We previously found that knockout of BRG1 or treatment with PFI-3, a small molecule inhibitor of the BRG1 bromodomain, enhances sensitivity of GBM cells to temozolomide in vitro and in vivo GBM animal models. Those results demonstrated that the BRG1 catalytic subunit of the SWI/SNF chromatin remodeling complex appears to play a critical role in regulating TMZ-sensitivity. In the present study we designed and synthesized Structurally Related Analogs of PFI-3 (SRAPs) and tested their bioactivity in vitro. Among of the SRAPs, 9f and 11d show better efficacy than PFI-3 in sensitizing GBM cells to the antiproliferative and cell death inducing effects of temozolomide in vitro, as well as enhancing the inhibitor effect of temozolomide on the growth of subcutaneous GBM tumors.
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Antineoplásicos Alquilantes/farmacología , Compuestos de Azabiciclo/farmacología , ADN Helicasas/antagonistas & inhibidores , Glioblastoma/tratamiento farmacológico , Proteínas Nucleares/antagonistas & inhibidores , Piridinas/farmacología , Temozolomida/farmacología , Factores de Transcripción/antagonistas & inhibidores , Animales , Antineoplásicos Alquilantes/química , Compuestos de Azabiciclo/química , Muerte Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , ADN Helicasas/metabolismo , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Femenino , Glioblastoma/metabolismo , Glioblastoma/patología , Humanos , Ratones , Ratones Congénicos , Ratones Endogámicos NOD , Estructura Molecular , Neoplasias Experimentales/tratamiento farmacológico , Neoplasias Experimentales/metabolismo , Neoplasias Experimentales/patología , Proteínas Nucleares/metabolismo , Piridinas/química , Relación Estructura-Actividad , Temozolomida/química , Factores de Transcripción/metabolismoRESUMEN
COVID-19, an acute viral pneumonia, has emerged as a devastating pandemic. Drug repurposing allows researchers to find different indications of FDA-approved or investigational drugs. In this current study, a sequence of pharmacophore and molecular modeling-based screening against COVID-19 Mpro (PDB: 6LU7) suggested a subset of drugs, from the Drug Bank database, which may have antiviral activity. A total of 44 out of 8823 of the most promising virtual hits from the Drug Bank were subjected to molecular dynamics simulation experiments to explore the strength of their interactions with the SARS-CoV-2 Mpro active site. MD findings point toward three drugs (DB04020, DB12411, and DB11779) with very low relative free energies for SARS-CoV-2 Mpro with interactions at His41 and Met49. MD simulations identified an additional interaction with Glu166, which enhanced the binding affinity significantly. Therefore, Glu166 could be an interesting target for structure-based drug design. Quantitative structural-activity relationship analysis was performed on the 44 most promising hits from molecular docking-based virtual screening. Partial least square regression accurately predicted the values of independent drug candidates' binding energy with impressively high accuracy. Finally, the EC50 and CC50 of 10 drug candidates were measured against SARS-CoV-2 in cell culture. Nilotinib and bemcentinib had EC50 values of 2.6 and 1.1 µM, respectively. In summary, the results of our computer-aided drug design provide a roadmap for rational drug design of Mpro inhibitors and the discovery of certified medications as COVID-19 antiviral therapeutics.
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COVID-19 , Inhibidores de Proteasas , Antivirales/farmacología , Proteasas 3C de Coronavirus , Reposicionamiento de Medicamentos , Humanos , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Pirimidinas , SARS-CoV-2RESUMEN
Glioblastoma (GBM) is a deadly and incurable brain cancer with limited therapeutic options. PFI-3 is a small-molecule bromodomain (BRD) inhibitor of the BRM/BRG1 subunits of the SWI/SNF chromatin remodeling complex. The objective of this study is to determine the efficacy of PFI-3 as a potential GBM therapy. We report that PFI-3 binds to these BRDs when expressed in GBM cells. PFI-3 markedly enhanced the antiproliferative and cell death-inducing effects of temozolomide (TMZ) in TMZ-sensitive GBM cells as well as overcame the chemoresistance of highly TMZ-resistant GBM cells. PFI-3 also altered gene expression in GBM and enhanced the basal and interferon-induced expression of a subset of interferon-responsive genes. Besides the effects of PFI-3 on GBM cells in vitro, we found that PFI-3 markedly potentiated the anticancer effect of TMZ in an intracranial GBM animal model, resulting in a marked increase in survival of animals bearing GBM tumors. Taken together, we identified the BRG1 and BRM subunits of SWI/SNF as novel targets in GBM and revealed the therapeutic potential of applying small molecule inhibitors of SWI/SNF to improve the clinical outcome in GBM using standard-of-care chemotherapy.
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Systemic sclerosis (SSc; scleroderma) is a chronic fibrotic disease involving TGF-ß1. Low serum vitamin D (vit D) correlates with the degree of fibrosis and expression of TGF-ß1. This study was designed to determine whether the noncalcemic vit D analog, 17,20S(OH)2pD, suppresses fibrosis and mediators of the TGF-ß1 pathway in the bleomycin (BLM) model of fibrosis. Fibrosis was induced into the skin of female C57BL/6 mice by repeated injections of BLM (50 µg/100 µL) subcutaneously. Mice received daily oral gavage with either vehicle (propylene glycol) or 17,20S(OH)2pD using 5, 15, or 30 µg/kg for 21 days. The injected skin was biopsied; analyzed histologically; examined for total collagen by Sircol; and examined for mRNA expression of MMP-13, BMP-7, MCP-1, Gli1, and Gli2 by TR-PCR. Spleen was analyzed for lymphocytes using flow cytometry. Serum was analyzed for cytokines using a multiplexed ELISA. Results showed that all three doses of 17,20S(OH)2pD suppressed net total collagen production, dermal thickness, and total collagen content in the BLM fibrosis model. 17,20S(OH)2pD also increased MMP-13 expression, decreased MCP-1 and Gli-2 expression in vivo, and suppressed serum levels of IL-13, TNF-α, IL-6, IL-10, IL-17, and IL-12p70. In summary, 17,20S(OH)2pD modulates the mediators of fibrosis in vivo and suppresses total collagen production and dermal thickness. This antifibrotic property of 17,20S(OH)2pD offers new therapeutic approaches for fibrotic disorders.
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Bleomicina/toxicidad , Colecalciferol/análogos & derivados , Modelos Animales de Enfermedad , Fibrosis/tratamiento farmacológico , Esclerodermia Sistémica/complicaciones , Enfermedades de la Piel/tratamiento farmacológico , Animales , Antibióticos Antineoplásicos/toxicidad , Colecalciferol/farmacología , Citocinas/metabolismo , Femenino , Fibrosis/etiología , Fibrosis/patología , Ratones , Ratones Endogámicos C57BL , Esclerodermia Sistémica/inducido químicamente , Esclerodermia Sistémica/patología , Enfermedades de la Piel/etiología , Enfermedades de la Piel/patologíaRESUMEN
We previously reported a potent tubulin inhibitor CH-2-77. In this study, we optimized the structure of CH-2-77 by blocking metabolically labile sites and synthesized a series of CH-2-77 analogues. Two compounds, 40a and 60c, preserved the potency while improving the metabolic stability over CH-2-77 by 3- to 4-fold (46.8 and 29.4 vs 10.8 min in human microsomes). We determined the high-resolution X-ray crystal structures of 40a (resolution 2.3 Å) and 60c (resolution 2.6 Å) in complex with tubulin and confirmed their direct binding at the colchicine-binding site. In vitro, 60c maintained its mode of action by inhibiting tubulin polymerization and was effective against P-glycoprotein-mediated multiple drug resistance and taxol resistance. In vivo, 60c exhibited a strong inhibitory effect on tumor growth and metastasis in a taxol-resistant A375/TxR xenograft model without obvious toxicity. Collectively, this work showed that 60c is a promising lead compound for further development as a potential anticancer agent.
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Antineoplásicos/uso terapéutico , Neoplasias/tratamiento farmacológico , Piridinas/uso terapéutico , Moduladores de Tubulina/uso terapéutico , Tubulina (Proteína)/metabolismo , Animales , Antineoplásicos/síntesis química , Antineoplásicos/metabolismo , Antineoplásicos/farmacocinética , Sitios de Unión , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Diseño de Fármacos , Ensayos de Selección de Medicamentos Antitumorales , Estabilidad de Medicamentos , Femenino , Puntos de Control de la Fase G2 del Ciclo Celular/efectos de los fármacos , Humanos , Masculino , Ratones Endogámicos NOD , Ratones SCID , Microsomas Hepáticos/metabolismo , Estructura Molecular , Metástasis de la Neoplasia/prevención & control , Piridinas/síntesis química , Piridinas/metabolismo , Piridinas/farmacocinética , Relación Estructura-Actividad , Tubulina (Proteína)/química , Moduladores de Tubulina/síntesis química , Moduladores de Tubulina/metabolismo , Moduladores de Tubulina/farmacocinética , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
The survivin (BIRC5) expression is very low in normal differentiated adult tissues, but it is one of the most widely upregulated genes in tumor cells. The overexpression of survivin in many cancer types has been positively correlated with resistance to chemotherapy, tumor metastasis, and poor patient survival. Survivin is considered to be a cancer specific biomarker and serves as a potential cancer drug target. In this report, we describe the design and syntheses of a series of novel selective survivin inhibitors based on the hydroxyquinoline scaffold from our previously reported lead compound MX-106. The best compound identified in this study is compound 12b. In vitro, 12b inhibited cancer cell proliferation with an average IC50 value of 1.4 µM, using a panel of melanoma, breast, and ovarian cancer cell lines. The metabolic stability of 12b improved over MX-106 by 1.7-fold (88 vs 51 min in human microsomes). Western blot analyses demonstrated that treatments with 12b selectively decreased survivin protein levels, but negligibly affected other closely related members in the IAP family proteins, and strongly induced cancer cell apoptosis. In vivo, compound 12b effectively inhibited melanoma tumor growth when tested using a human A375 melanoma xenograft model. Further evaluation using an aggressive, orthotopic ovarian cancer mouse model showed that 12b was highly efficacious in suppressing both primary tumor growth in ovaries and tumor metastasis to multiple peritoneal organs. Collectively, results in this study strongly suggest that the hydroxyquinoline scaffold, represented by 12b and our earlier lead compound MX-106, has abilities to selectively target survivin and is promising for further preclinical development.
Asunto(s)
Hidroxiquinolinas/química , Survivin/antagonistas & inhibidores , Animales , Proliferación Celular , Humanos , Ratones , Modelos Moleculares , Relación Estructura-Actividad , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Small molecules that interact with the colchicine binding site in tubulin have demonstrated therapeutic efficacy in treating cancers. We report the design, syntheses, and antitumor efficacies of new analogues of pyridopyrimidine and hydroquinoxalinone compounds with improved drug-like characteristics. Eight analogues, 5j, 5k, 5l, 5m, 5n, 5r, 5t, and 5u, showed significant improvement in metabolic stability and demonstrated strong antiproliferative potency in a panel of human cancer cell lines, including melanoma, lung cancer, and breast cancer. We report crystal structures of tubulin in complex with five representative compounds, 5j, 5k, 5l, 5m, and 5t, providing direct confirmation for their binding to the colchicine site in tubulin. A quantitative structure-activity relationship analysis of the synthesized analogues showed strong ability to predict potency. In vivo, 5m (4 mg/kg) and 5t (5 mg/kg) significantly inhibited tumor growth as well as melanoma spontaneous metastasis into the lung and liver against a highly paclitaxel-resistant A375/TxR xenograft model.
Asunto(s)
Antineoplásicos/farmacología , Quinoxalinas/farmacología , Moduladores de Tubulina/farmacología , Animales , Antineoplásicos/síntesis química , Antineoplásicos/química , Apoptosis/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Cristalografía por Rayos X , Diseño de Fármacos , Resistencia a Antineoplásicos , Femenino , Humanos , Masculino , Ratones , Relación Estructura-Actividad Cuantitativa , Quinoxalinas/química , Moduladores de Tubulina/química , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
A series of propanamide derivatives were designed, synthesized, and pharmacologically characterized as selective androgen receptor degraders (SARDs) and pan-antagonists that exert a broad-scope androgen receptor (AR) antagonism. Incorporating different basic heteromonocyclic B-ring structural elements in the common A-ring-linkage-B-ring nonsteroidal antiandrogen general pharmacophore contributed to a novel scaffold of small molecules with SARD and pan-antagonist activities even compared to our recently published AF-1 binding SARDs such as UT-69 (11), UT-155 (12), and UT-34 (13). Compound 26f exhibited inhibitory and degradation effects in vitro in a wide array of wtAR, point mutant, and truncation mutant-driven prostate cancers (PCs). Further, 26f inhibited tumor cell growth in a xenograft model composed of enzalutamide-resistant (EnzR) LNCaP cells. These results demonstrate an advancement toward the development of novel SARDs and pan-antagonists with efficacy against EnzR prostate cancers.