RESUMEN
PI3K is one of the most frequently mutated genes in cancers and has been the target of numerous anticancer therapies. With the additional development of therapeutics that mobilize the immune system, such as Abs with effector functions, bispecific Abs, and checkpoint inhibitors, many small molecule inhibitors that target PI3K are being combined with these immunomodulatory treatments. However, the PI3K pathway is also essential for lymphocyte function, and the presence of the PI3K inhibitor may render the immunomodulatory therapeutic ineffective in these combinatorial treatments. Therefore, therapeutics with enhanced activity, such as afucosylated Abs, which promote signaling and function, may be ideal in these types of treatments to offset the negative effect of PI3K inhibitors on immune cell function. Indeed, we show that afucosylated Abs can counterbalance these inhibitory effects on FcγRIIIa-driven signaling in human NK cells to produce signals similar to cells treated only with fucosylated Ab. Furthermore, NK cell activation, degranulation, chemokine/cytokine production, and Ab-dependent cellular cytotoxicity were similar between inhibitor-treated, afucosylated Ab-stimulated NK cells and cells activated only with its fucosylated counterpart. To our knowledge, these studies also identified a previously undefined role for phospho-S6 in human NK cells. In this study, a kinetic delay in PI3K-driven phosphorylation of S6 was observed to control transcription of the temporally regulated production of IFN-γ and TNF-α but not MIP-1α, MIP-1ß, and RANTES. Together, these studies demonstrate the importance of the PI3K pathway for S6 phosphorylation in human NK cells and the need to combine PI3K inhibitors with therapeutic molecules that enhance immunomodulatory function for anticancer therapies.
Asunto(s)
Antineoplásicos/farmacología , Células Asesinas Naturales/inmunología , Neoplasias/tratamiento farmacológico , Fosfatidilinositol 3-Quinasas/metabolismo , Inhibidores de las Quinasa Fosfoinosítidos-3/farmacología , Receptores de IgG/metabolismo , Proteínas Quinasas S6 Ribosómicas/metabolismo , Anticuerpos/química , Anticuerpos/metabolismo , Citotoxicidad Celular Dependiente de Anticuerpos , Células Cultivadas , Citocinas/metabolismo , Fucosa/química , Humanos , Inmunomodulación , Activación de Linfocitos , Fosforilación , Transducción de SeñalRESUMEN
The PI3K pathway is commonly activated in cancer. Only a few studies have attempted to explore the spectrum of phosphorylation signaling downstream of the PI3K cascade. Such insight, however, is imperative to understand the mechanisms responsible for oncogenic phenotypes. By applying MS-based phosphoproteomics, we mapped 2509 phosphorylation sites on 1096 proteins, and quantified their responses to activation or inhibition of PIK3CA using isogenic knock-in derivatives and a series of targeted inhibitors. We uncovered phosphorylation changes in a wide variety of proteins involved in cell growth and proliferation, many of which have not been previously associated with PI3K signaling. A significant update of the posttranslational modification database PHOSIDA (http://www.phosida.com) allows efficient use of the data. All MS data have been deposited in the ProteomeXchange with identifier PXD003899 (http://proteomecentral.proteomexchange.org/dataset/PXD003899).
Asunto(s)
Transformación Celular Neoplásica/genética , Células Epiteliales/metabolismo , Regulación Neoplásica de la Expresión Génica , Proteínas de Neoplasias/genética , Fosfatidilinositol 3-Quinasas/genética , Fosfoproteínas/genética , Procesamiento Proteico-Postraduccional , Antineoplásicos/farmacología , Línea Celular , Transformación Celular Neoplásica/metabolismo , Transformación Celular Neoplásica/patología , Fosfatidilinositol 3-Quinasa Clase I , Colon/citología , Colon/efectos de los fármacos , Colon/metabolismo , Bases de Datos Genéticas , Células Epiteliales/citología , Células Epiteliales/efectos de los fármacos , Humanos , Internet , Mutación , Proteínas de Neoplasias/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Fosfoproteínas/metabolismo , Fosforilación , Inhibidores de Proteínas Quinasas/farmacología , Proteómica/métodos , Transducción de Señal , Programas InformáticosRESUMEN
A series of suitable five-membered heterocyclic alternatives to thiophenes within a thienobenzoxepin class of PI3-kinase (PI3K) inhibitors was discovered. Specific thiazolobenzoxepin 8-substitution was identified that increased selectivity over PI3Kß. PI3Kß-sparing compound 27 (PI3Kß Ki,app/PI3Kα Ki,app=57) demonstrated dose-dependent knockdown of pAKT, pPRAS40 and pS6RP in vivo as well as differential effects in an in vitro proliferation cell line screen compared to pan PI3K inhibitor GDC-0941. A new structure-based hypothesis for reducing inhibition of the PI3K ß isoform while maintaining activity against α, δ and γ isoforms is presented.
Asunto(s)
Benzoxepinas/química , Inhibidores Enzimáticos/química , Inhibidores de las Quinasa Fosfoinosítidos-3 , Tiazoles/química , Benzoxepinas/síntesis química , Benzoxepinas/farmacología , Sitios de Unión , Proliferación Celular/efectos de los fármacos , Evaluación Preclínica de Medicamentos , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Humanos , Células MCF-7 , Simulación del Acoplamiento Molecular , Fosfatidilinositol 3-Quinasa/metabolismo , Isoformas de Proteínas/antagonistas & inhibidores , Isoformas de Proteínas/metabolismo , Estructura Terciaria de Proteína , Proteínas Proto-Oncogénicas c-akt/metabolismo , Relación Estructura-ActividadRESUMEN
In fruit fly research, chromosomal deletions are indispensable tools for mapping mutations, characterizing alleles and identifying interacting loci. Most widely used deletions were generated by irradiation or chemical mutagenesis. These methods are labor-intensive, generate random breakpoints and result in unwanted secondary mutations that can confound phenotypic analyses. Most of the existing deletions are large, have molecularly undefined endpoints and are maintained in genetically complex stocks. Furthermore, the existence of haplolethal or haplosterile loci makes the recovery of deletions of certain regions exceedingly difficult by traditional methods, resulting in gaps in coverage. Here we describe two methods that address these problems by providing for the systematic isolation of targeted deletions in the D. melanogaster genome. The first strategy used a P element-based technique to generate deletions that closely flank haploinsufficient genes and minimize undeleted regions. This deletion set has increased overall genomic coverage by 5-7%. The second strategy used FLP recombinase and the large array of FRT-bearing insertions described in the accompanying paper to generate 519 isogenic deletions with molecularly defined endpoints. This second deletion collection provides 56% genome coverage so far. The latter methodology enables the generation of small custom deletions with predictable endpoints throughout the genome and should make their isolation a simple and routine task.
Asunto(s)
Elementos Transponibles de ADN , Drosophila melanogaster/genética , Eliminación de Secuencia , Animales , Genoma , Mutagénesis InsercionalRESUMEN
BACKGROUND: Breast (BCa) and prostate (PCa) cancer are two of the most common but survivable cancers. One important component of survivorship that is impacted by treatment long term is diminished quality of life (QoL). Supervised exercise improves QoL and subsequent outcomes but is not accessible for all survivors. Additionally, many factors influence QoL including physical activity (PA), cardiorespiratory fitness (CRF), physical function, and fatigue. However, the COVID-19 pandemic has highlighted the need to increase access to exercise beyond supervised exercise facilities. Home-based exercise may provide a feasible alternative for cancer survivors especially for those living in rural communities. OBJECTIVES: The primary aim is to investigate the effects of home-based exercise training (Pre-training vs. Post-training) on QoL in BCa/PCa. A secondary aim is to investigate PA, CRF, physical function, and fatigue and potential moderators (age, cancer-type, intervention duration and type). Home-based exercise trials (randomized crossover or quasi-experimental design) with adults (aged 18 years and over) breast or prostate cancer survivors (not currently undergoing chemotherapy or radiation treatment) were eligible for inclusion. DATA SOURCES: Electronic databases were searched (inception-December 2022) for studies which included adult BCa or PCa survivors (not currently on chemotherapy/radiation), at least measured QoL, and undergoing unsupervised, home-based exercise training. APPRAISAL AND SYNTHESIS METHODS: Initially, 819 studies were identified, from which 17 studies (20 effects) involving 692 participants were extracted. Effect sizes were calculated as standardized mean differences (SMD). Data were pooled using a 3-level model with restricted maximum likelihood estimation. Pooled SMD was used to assess the magnitude of effect, where <0.2, 0.2, 0.5, and 0.8 was defined as trivial, small, moderate, and large respectively. RESULTS: Home-based exercise resulted in small improvements in QoL (SMD = 0.30, 95% CI 0.01, 0.60, p = 0.042), PA (SMD = 0.49, 95% CI 0.26, 0.75, p<0.001) and CRF (SMD = 0.45, 95% CI -0.01, 0.91, p = 0.056). Physical function (SMD = 0.00, 95% CI -0.21, 0.21, p = 1.000) and fatigue (SMD = -0.61, 95%CI -1.53, 0.32, p = 0.198) did not change. CONCLUSIONS: Home-based exercise results in small improves QoL in BCa/PCa survivors, independent of cancer type, intervention duration and type, or age. Home-based exercise also improves PA and CRF enhancing survivorship. Therefore, home-based exercise is an efficacious alternative option to improve QoL for BCa and PCa survivors especially for those who live in rural communities or lack access to exercise facilities.
Asunto(s)
Neoplasias de la Mama , Supervivientes de Cáncer , Fatiga , Aptitud Física , Neoplasias de la Próstata , Autocuidado , Adolescente , Adulto , Humanos , Masculino , Ejercicio Físico/fisiología , Fatiga/etiología , Fatiga/fisiopatología , Fatiga/terapia , Neoplasias de la Próstata/complicaciones , Neoplasias de la Próstata/fisiopatología , Neoplasias de la Próstata/terapia , Calidad de Vida , Neoplasias de la Mama/complicaciones , Neoplasias de la Mama/fisiopatología , Neoplasias de la Mama/terapia , Femenino , Aptitud Física/fisiología , Capacidad Cardiovascular/fisiología , Estado Funcional , Autocuidado/métodosRESUMEN
People with spinal cord injury (SCI) face unique challenges during the COVID-19 pandemic, including greater risk of poor COVID-19-related outcomes, increased social isolation, and restricted access to important services. Furthermore, COVID-19 related restrictions have decreased already low levels of physical activity (PA) in this population. Therefore, the purpose of this commentary is to: 1) address the impact of COVID-19 on PA and sedentary behavior (SB) in people with SCI; 2) provide potential SB reduction strategies to guide future research; and 3) provide recommendations to increase PA and reduce SB on behalf of the American College of Sports Medicine Exercise is Medicine (ACSM-EIM) and Healthy Living for Pandemic Event Protection (HL-PIVOT) using a social-ecological model targeting the individual-, social environment-, physical environment-, and policy-level determinants of behavior in people with SCI.
Asunto(s)
COVID-19 , Personas con Discapacidad , Traumatismos de la Médula Espinal , Ejercicio Físico , Humanos , Pandemias , SARS-CoV-2 , Conducta Sedentaria , Traumatismos de la Médula Espinal/complicacionesRESUMEN
Small molecule inhibitors that target the phosphatidylinositol 3-kinase (PI3K) signaling pathway have received significant interest for the treatment of cancers. The class I isoform PI3Kα is most commonly associated with solid tumors via gene amplification or activating mutations. However, inhibitors demonstrating both PI3K isoform and mutant specificity have remained elusive. Herein, we describe the optimization and characterization of a series of benzoxazepin-oxazolidinone ATP-competitive inhibitors of PI3Kα which also induce the selective degradation of the mutant p110α protein, the catalytic subunit of PI3Kα. Structure-based design informed isoform-specific interactions within the binding site, leading to potent inhibitors with greater than 300-fold selectivity over the other Class I PI3K isoforms. Further optimization of pharmacokinetic properties led to excellent in vivo exposure and efficacy and the identification of clinical candidate GDC-0077 (inavolisib, 32), which is now under evaluation in a Phase III clinical trial as a treatment for patients with PIK3CA-mutant breast cancer.
Asunto(s)
Neoplasias de la Mama , Fosfatidilinositol 3-Quinasas , Humanos , Femenino , Inhibidores de las Quinasa Fosfoinosítidos-3/farmacología , Inhibidores de las Quinasa Fosfoinosítidos-3/uso terapéutico , Fosfatidilinositol 3-Quinasas/metabolismo , Fosfatidilinositol 3-Quinasa Clase I/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Línea Celular Tumoral , MutaciónRESUMEN
PIK3CA is one of the most frequently mutated oncogenes; the p110a protein it encodes plays a central role in tumor cell proliferation. Small-molecule inhibitors targeting the PI3K p110a catalytic subunit have entered clinical trials, with early-phase GDC-0077 studies showing antitumor activity and a manageable safety profile in patients with PIK3CA-mutant breast cancer. However, preclinical studies have shown that PI3K pathway inhibition releases negative feedback and activates receptor tyrosine kinase signaling, reengaging the pathway and attenuating drug activity. Here we discover that GDC-0077 and taselisib more potently inhibit mutant PI3K pathway signaling and cell viability through unique HER2-dependent mutant p110a degradation. Both are more effective than other PI3K inhibitors at maintaining prolonged pathway suppression. This study establishes a new strategy for identifying inhibitors that specifically target mutant tumors by selective degradation of the mutant oncoprotein and provide a strong rationale for pursuing PI3Kα degraders in patients with HER2-positive breast cancer. SIGNIFICANCE: The PI3K inhibitors GDC-0077 and taselisib have a unique mechanism of action; both inhibitors lead to degradation of mutant p110a protein. The inhibitors that have the ability to trigger specific degradation of mutant p110a without significant change in wild-type p110a protein may result in improved therapeutic index in PIK3CA-mutant tumors.See related commentary by Vanhaesebroeck et al., p. 20.This article is highlighted in the In This Issue feature, p. 1.
Asunto(s)
Antineoplásicos , Neoplasias de la Mama , Fosfatidilinositol 3-Quinasa Clase I , Imidazoles , Oxazepinas , Inhibidores de las Quinasa Fosfoinosítidos-3 , Receptor ErbB-2 , Femenino , Humanos , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Línea Celular Tumoral/efectos de los fármacos , Fosfatidilinositol 3-Quinasa Clase I/genética , Imidazoles/farmacología , Imidazoles/uso terapéutico , Oxazepinas/farmacología , Oxazepinas/uso terapéutico , Inhibidores de las Quinasa Fosfoinosítidos-3/farmacología , Inhibidores de las Quinasa Fosfoinosítidos-3/uso terapéutico , Receptor ErbB-2/genéticaRESUMEN
The phosphatidylinositol 3-kinase (PI3K) pathway is a major determinant of cell cycling and proliferation. Its deregulation, by activation or transforming mutations of the p110alpha subunit, is associated with the development of many cancers. 2-(1H-Indazol-4-yl)-6-(4-methanesulfonyl-piperazin-1-ylmethyl)-4-morpholin-4-yl-thieno[3,2-d]pyrimidine (GDC-0941) is a novel small molecule inhibitor of PI3K currently being evaluated in the clinic as an anticancer agent. The objectives of these studies were to characterize the relationships between GDC-0941 plasma concentrations and tumor reduction in MCF7.1 breast cancer xenografts and to evaluate the association between the tumor pharmacodynamic biomarker [phosphorylated (p) Akt and phosphorylated proline-rich Akt substrate of 40 kDa (pPRAS40)] responses and antitumor efficacy. MCF7.1 tumor-bearing mice were treated for up to 3 weeks with GDC-0941 at various doses (12.5-200 mg/kg) and dosing schedules (daily to weekly). An indirect response model fitted to tumor growth data indicated that the GDC-0941 plasma concentration required for tumor stasis was approximately 0.3 muM. The relationship between GDC-0941 plasma concentrations and inhibition of pAkt and pPRAS40 in tumor was also investigated after a single oral dose of 12.5, 50, or 150 mg/kg. An indirect response model was fitted to the inhibition of Akt and PRAS40 phosphorylation data and provided IC(50) estimates of 0.36 and 0.29 muM for pAkt and pPRAS40, respectively. The relationship between pAkt inhibition and tumor volume was further explored using an integrated pharmacokinetic biomarker tumor growth model, which showed that a pAkt inhibition of at least 30% was required to achieve stasis after GDC-0941 treatment of the MCF7.1 xenograft.
Asunto(s)
Biomarcadores/metabolismo , Neoplasias de la Mama/patología , División Celular/efectos de los fármacos , Indazoles/farmacología , Inhibidores de las Quinasa Fosfoinosítidos-3 , Inhibidores de Proteínas Quinasas/farmacología , Sulfonamidas/farmacología , Animales , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Indazoles/farmacocinética , Ratones , Ratones Desnudos , Fosforilación , Inhibidores de Proteínas Quinasas/farmacocinética , Sulfonamidas/farmacocinéticaRESUMEN
Mutations that inactivate the retinoblastoma (Rb) pathway are common in human tumors. Such mutations promote tumor growth by deregulating the G1 cell cycle checkpoint. However, uncontrolled cell cycle progression can also produce new liabilities for cell survival. To uncover such liabilities in Rb mutant cells, we performed a clonal screen in the Drosophila eye to identify second-site mutations that eliminate Rbf(-) cells, but allow Rbf(+) cells to survive. Here we report the identification of a mutation in a novel highly conserved peptidyl prolyl isomerase (PPIase) that selectively eliminates Rbf(-) cells from the Drosophila eye.
Asunto(s)
Drosophila melanogaster/embriología , Ojo/embriología , Isomerasa de Peptidilprolil/genética , Proteína de Retinoblastoma/genética , Secuencia de Aminoácidos , Animales , Drosophila melanogaster/enzimología , Drosophila melanogaster/genética , Ojo/enzimología , Datos de Secuencia Molecular , MutaciónRESUMEN
Letrozole is a commonly used treatment option for metastatic hormone receptor-positive (HR+) breast cancer, but many patients ultimately relapse. Due to the importance of phosphoinositide-3 kinase (PI3K) in breast cancer, PI3K inhibitors such as taselisib are attractive for combination with endocrine therapies such as letrozole. Taselisib was evaluated as a single agent and in combination with letrozole in a breast cancer cell line engineered to express aromatase. The combination of taselisib and letrozole decreased cellular viability and increased apoptosis relative to either single agent. Signaling cross-talk between the PI3K and ER pathways was associated with efficacy for the combination. In a secreted factor screen, multiple soluble factors, including members of the epidermal and fibroblast growth factor families, rendered breast cancer cells non-responsive to letrozole. It was discovered that many of these factors signal through the PI3K pathway and cells remained sensitive to taselisib in the presence of the soluble factors. We also found that letrozole resistant lines have elevated PI3K pathway signaling due to an increased level of p110α, but are still sensitive to taselisib. These data provide rationale for clinical evaluation of PI3K inhibitors to overcome resistance to endocrine therapies in ER+ breast cancer.
RESUMEN
Inhibition of phosphoinositide 3-kinase (PI3K) signaling is an appealing approach to treat brain tumors, especially glioblastoma multiforme (GBM). We previously disclosed our successful approach to prospectively design potent and blood-brain barrier (BBB) penetrating PI3K inhibitors. The previously disclosed molecules were ultimately deemed not suitable for clinical development due to projected poor metabolic stability in humans. We, therefore, extended our studies to identify a BBB penetrating inhibitor of PI3K that was also projected to be metabolically stable in human. These efforts required identification of a distinct scaffold for PI3K inhibitors relative to our previous efforts and ultimately resulted in the identification of GDC-0084 (16). The discovery and preclinical characterization of this molecule are described within.
RESUMEN
Inhibitors of the class I phosphoinositide 3-kinase (PI3K) isoform PI3Kα have received substantial attention for their potential use in cancer therapy. Despite the particular attraction of targeting PI3Kα, achieving selectivity for the inhibition of this isoform has proved challenging. Herein we report the discovery of inhibitors of PI3Kα that have selectivity over the other class I isoforms and all other kinases tested. In GDC-0032 (3, taselisib), we previously minimized inhibition of PI3Kß relative to the other class I insoforms. Subsequently, we extended our efforts to identify PI3Kα-specific inhibitors using PI3Kα crystal structures to inform the design of benzoxazepin inhibitors with selectivity for PI3Kα through interactions with a nonconserved residue. Several molecules selective for PI3Kα relative to the other class I isoforms, as well as other kinases, were identified. Optimization of properties related to drug metabolism then culminated in the identification of the clinical candidate GDC-0326 (4).
Asunto(s)
Antineoplásicos/farmacología , Benzoxepinas/farmacología , Diseño de Fármacos , Imidazoles/farmacología , Oxazepinas/farmacología , Inhibidores de las Quinasa Fosfoinosítidos-3 , Inhibidores de Proteínas Quinasas/farmacología , Animales , Antineoplásicos/química , Antineoplásicos/metabolismo , Benzoxepinas/química , Benzoxepinas/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Fosfatidilinositol 3-Quinasa Clase I , Perros , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Imidazoles/química , Imidazoles/metabolismo , Isoenzimas/antagonistas & inhibidores , Isoenzimas/metabolismo , Macaca fascicularis , Ratones , Microsomas Hepáticos/química , Microsomas Hepáticos/metabolismo , Modelos Moleculares , Estructura Molecular , Oxazepinas/química , Oxazepinas/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/metabolismo , Ratas , Ratas Sprague-Dawley , Relación Estructura-ActividadRESUMEN
Phosphoinositide-3 kinase (PI3K) signaling pathway alterations occur broadly in cancer and PI3K is a promising therapeutic target. Here, we investigated acquired resistance to GDC-0941, a PI3K inhibitor in clinical trials. Colorectal cancer (CRC) cells made to be resistant to GDC-0941 were discovered to secrete amphiregulin, which resulted in increased EGFR/MAPK signaling. Moreover, prolonged PI3K pathway inhibition in cultured cells over a period of months led to a secondary loss of PTEN in 40% of the CRC lines with acquired resistance to PI3K inhibition. In the absence of PI3K inhibitor, these PTEN-null PI3K inhibitor-resistant clones had elevated PI3K pathway signaling and decreased sensitivity to MAPK pathway inhibitors. Importantly, PTEN loss was not able to induce resistance to PI3K inhibitors in the absence of amphiregulin, indicating a multimodal mechanism of acquired resistance. The combination of PI3K and MAPK pathway inhibitors overcame acquired resistance in vitro and in vivo.
RESUMEN
Dysfunctional signaling through the phosphoinositide 3-kinase (PI3K)/AKT/mTOR pathway leads to uncontrolled tumor proliferation. In the course of the discovery of novel benzoxepin PI3K inhibitors, we observed a strong dependency of in vivo antitumor activity on the free-drug exposure. By lowering the intrinsic clearance, we derived a set of imidazobenzoxazepin compounds that showed improved unbound drug exposure and effectively suppressed growth of tumors in a mouse xenograft model at low drug dose levels. One of these compounds, GDC-0032 (11l), was progressed to clinical trials and is currently under phase I evaluation as a potential treatment for human malignancies.
Asunto(s)
Antineoplásicos/síntesis química , Imidazoles/síntesis química , Oxazepinas/síntesis química , Inhibidores de las Quinasa Fosfoinosítidos-3 , Animales , Antineoplásicos/farmacocinética , Antineoplásicos/farmacología , Línea Celular Tumoral , Ensayos de Selección de Medicamentos Antitumorales , Femenino , Hepatocitos/metabolismo , Humanos , Imidazoles/farmacocinética , Imidazoles/farmacología , Técnicas In Vitro , Isoenzimas/antagonistas & inhibidores , Ratones , Ratones Desnudos , Microsomas Hepáticos/metabolismo , Trasplante de Neoplasias , Oxazepinas/farmacocinética , Oxazepinas/farmacología , Relación Estructura-Actividad , Trasplante HeterólogoRESUMEN
The human epidermal growth factor receptor (HER) family of tyrosine kinases is deregulated in multiple cancers either through amplification, overexpression, or mutation. ERBB3/HER3, the only member with an impaired kinase domain, although amplified or overexpressed in some cancers, has not been reported to carry oncogenic mutations. Here, we report the identification of ERBB3 somatic mutations in ~11% of colon and gastric cancers. We found that the ERBB3 mutants transformed colonic and breast epithelial cells in a ligand-independent manner. However, the mutant ERBB3 oncogenic activity was dependent on kinase-active ERBB2. Furthermore, we found that anti-ERBB antibodies and small molecule inhibitors effectively blocked mutant ERBB3-mediated oncogenic signaling and disease progression in vivo.
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Neoplasias del Colon/genética , Mutación , Receptor ErbB-3/genética , Neoplasias Gástricas/genética , Sitios de Unión , Proliferación Celular , Supervivencia Celular/genética , Transformación Celular Neoplásica/genética , Técnicas de Silenciamiento del Gen , Humanos , Modelos Moleculares , Estructura Terciaria de Proteína , Receptor ErbB-3/metabolismo , Receptor ErbB-3/fisiologíaRESUMEN
The PTEN/PI3K pathway is commonly mutated in cancer and therefore represents an attractive target for therapeutic intervention. To investigate the primary phenotypes mediated by increased pathway signaling in a clean, patient-relevant context, an activating PIK3CA mutation (H1047R) was knocked-in to an endogenous allele of the MCF10A non-tumorigenic human breast epithelial cell line. Introduction of an endogenously mutated PIK3CA allele resulted in a marked epithelial-mesenchymal transition (EMT) and invasive phenotype, compared to isogenic wild-type cells. The invasive phenotype was linked to enhanced PIP(3) production via a S6K-IRS positive feedback mechanism. Moreover, potent and selective inhibitors of PI3K were highly effective in reversing this phenotype, which is optimally revealed in 3-dimensional cell culture. In contrast, inhibition of Akt or mTOR exacerbated the invasive phenotype. Our results suggest that invasion is a core phenotype mediated by increased PTEN/PI3K pathway activity and that therapeutic agents targeting different nodes of the PI3K pathway may have dramatic differences in their ability to reverse or promote cancer metastasis.
Asunto(s)
Fenotipo , Fosfatidilinositol 3-Quinasas/metabolismo , Transducción de Señal , Línea Celular Tumoral , Movimiento Celular/genética , Supervivencia Celular/genética , Fosfatidilinositol 3-Quinasa Clase I , Análisis por Conglomerados , Activación Enzimática/genética , Transición Epitelial-Mesenquimal/genética , Perfilación de la Expresión Génica , Silenciador del Gen , Humanos , Indazoles/farmacología , Mutación , Neoplasias/genética , Neoplasias/metabolismo , Fosfatidilinositol 3-Quinasas/genética , Inhibidores de las Quinasa Fosfoinosítidos-3 , Dominios y Motivos de Interacción de Proteínas/genética , Interferencia de ARN , Transducción de Señal/efectos de los fármacos , Sulfonamidas/farmacologíaRESUMEN
Inhibition of phosphoinositide 3-kinase (PI3K) signaling through PI3Kα has received significant attention for its potential in cancer therapy. While the PI3K pathway is a well-established and widely pursued target for the treatment of many cancer types due to the high frequency of abnormal PI3K signaling, glioblastoma multiforme (GBM) is particularly relevant because the pathway is implicated in more than 80% of GBM cases. Herein, we report the identification of PI3K inhibitors designed to cross the blood-brain barrier (BBB) to engage their target where GBM tumors reside. We leveraged our historical experience with PI3K inhibitors to identify correlations between physicochemical properties and transporter efflux as well as metabolic stability to focus the selection of molecules for further study.
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Barrera Hematoencefálica/metabolismo , Diseño de Fármacos , Inhibidores Enzimáticos/metabolismo , Inhibidores Enzimáticos/farmacología , Inhibidores de las Quinasa Fosfoinosítidos-3 , Animales , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Perros , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacocinética , Femenino , Humanos , Enlace de Hidrógeno , Células de Riñón Canino Madin Darby , Ratones , Permeabilidad , Propiedades de SuperficieRESUMEN
PURPOSE: Glioblastoma (GBM), the most common primary brain tumor in adults, presents a high frequency of alteration in the PI3K pathway. Our objectives were to identify a dual PI3K/mTOR inhibitor optimized to cross the blood-brain barrier (BBB) and characterize its brain penetration, pathway modulation in the brain and efficacy in orthotopic xenograft models of GBM. EXPERIMENTAL DESIGN: Physicochemical properties of PI3K inhibitors were optimized using in silico tools, leading to the identification of GNE-317. This compound was tested in cells overexpressing P-glycoprotein (P-gp) or breast cancer resistance protein (BCRP). Following administration to mice, GNE-317 plasma and brain concentrations were determined, and phosphorylated biomarkers (pAkt, p4EBP1, and pS6) were measured to assess PI3K pathway suppression in the brain. GNE-317 efficacy was evaluated in the U87, GS2, and GBM10 orthotopic models of GBM. RESULTS: GNE-317 was identified as having physicochemical properties predictive of low efflux by P-gp and BCRP. Studies in transfected MDCK cells showed that GNE-317 was not a substrate of either transporter. GNE-317 markedly inhibited the PI3K pathway in mouse brain, causing 40% to 90% suppression of the pAkt and pS6 signals up to 6-hour postdose. GNE-317 was efficacious in the U87, GS2, and GBM10 orthotopic models, achieving tumor growth inhibition of 90% and 50%, and survival benefit, respectively. CONCLUSIONS: These results indicated that specific optimization of PI3K inhibitors to cross the BBB led to potent suppression of the PI3K pathway in healthy brain. The efficacy of GNE-317 in 3 intracranial models of GBM suggested that this compound could be effective in the treatment of GBM.
Asunto(s)
Antineoplásicos/farmacocinética , Barrera Hematoencefálica/metabolismo , Neoplasias Encefálicas/tratamiento farmacológico , Glioblastoma/tratamiento farmacológico , Inhibidores de las Quinasa Fosfoinosítidos-3 , Inhibidores de Proteínas Quinasas/farmacocinética , Pirimidinas/farmacocinética , Tiofenos/farmacocinética , Animales , Antineoplásicos/farmacología , Neoplasias Encefálicas/enzimología , Neoplasias Encefálicas/patología , Permeabilidad Capilar , Línea Celular , Permeabilidad de la Membrana Celular , Perros , Femenino , Glioblastoma/enzimología , Glioblastoma/patología , Humanos , Ratones , Terapia Molecular Dirigida , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Pirimidinas/farmacología , Tiofenos/farmacología , Carga Tumoral/efectos de los fármacos , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Alterations of the phosphoinositide-3 kinase (PI3K)/Akt signaling pathway occur broadly in cancer via multiple mechanisms including mutation of the PIK3CA gene, loss or mutation of phosphatase and tensin homolog (PTEN), and deregulation of mammalian target of rapamycin (mTOR) complexes. The dysregulation of this pathway has been implicated in tumor initiation, cell growth and survival, invasion and angiogenesis, thus, PI3K and mTOR are promising therapeutic targets for cancer. We discovered GDC-0980, a selective, potent, orally bioavailable inhibitor of Class I PI3 kinase and mTOR kinase (TORC1/2) with excellent pharmacokinetic and pharmaceutical properties. GDC-0980 potently inhibits signal transduction downstream of both PI3K and mTOR, as measured by pharmacodynamic (PD) biomarkers, thereby acting upon two key pathway nodes to produce the strongest attainable inhibition of signaling in the pathway. Correspondingly, GDC-0980 was potent across a broad panel of cancer cell lines, with the greatest potency in breast, prostate, and lung cancers and less activity in melanoma and pancreatic cancers, consistent with KRAS and BRAF acting as resistance markers. Treatment of cancer cell lines with GDC-0980 resulted in G1 cell-cycle arrest, and in contrast to mTOR inhibitors, GDC-0980 induced apoptosis in certain cancer cell lines, including those with direct pathway activation via PI3K and PTEN. Low doses of GDC-0980 potently inhibited tumor growth in xenograft models including those with activated PI3K, loss of LKB1 or PTEN, and elicited an exposure-related decrease in PD biomarkers. These preclinical data show that GDC-0980 is a potent and effective dual PI3K/mTOR inhibitor with promise for the clinic.