RESUMEN
The BRAFV600E mutation occurs in more than 50% of cutaneous melanomas, and results in the constitutive activation of the mitogen-activated protein kinases (MAPK) pathway. MAP kinase-interacting serine/threonine-protein kinase 1 and 2 (MNK1/2) are downstream effectors of the activated MAPK pathway, and important molecular targets in invasive and metastatic cancer. Despite the well-known role of MNK1 in regulating mRNA translation, little is known concerning the impact of its aberrant activation on gene transcription. Here, we show that changes in the activity, or abundance, of MNK1 result in changes in the expression of pro-oncogenic and pro-invasive genes. Among the MNK1-upregulated genes, we identify Angiopoietin-like 4 (ANGPTL4), which in turn promotes an invasive phenotype via its ability to induce the expression of matrix metalloproteinases (MMPs). Using a pharmacologic inhibitor of MNK1/2, SEL201, we demonstrate that BRAFV600E-mutated cutaneous melanoma cells are reliant on MNK1/2 for invasion and lung metastasis.
Asunto(s)
Proteína 4 Similar a la Angiopoyetina/genética , Péptidos y Proteínas de Señalización Intracelular/genética , Neoplasias Pulmonares/genética , Melanoma/tratamiento farmacológico , Proteínas Serina-Treonina Quinasas/genética , Proteínas Proto-Oncogénicas B-raf/genética , Neoplasias Cutáneas/tratamiento farmacológico , Animales , Línea Celular Tumoral , Progresión de la Enfermedad , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Técnicas de Inactivación de Genes , Xenoinjertos , Humanos , Péptidos y Proteínas de Señalización Intracelular/antagonistas & inhibidores , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/secundario , Melanoma/genética , Melanoma/patología , Ratones , Mutación/genética , Invasividad Neoplásica/genética , Invasividad Neoplásica/patología , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Transducción de Señal/efectos de los fármacos , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/patología , Transcriptoma/genética , Melanoma Cutáneo MalignoRESUMEN
The mechanisms by which breast cancers progress from relatively indolent ductal carcinoma in situ (DCIS) to invasive ductal carcinoma (IDC) are not well understood. However, this process is critical to the acquisition of metastatic potential. MAPK-interacting serine/threonine-protein kinase 1 (MNK1) signaling can promote cell invasion. NODAL, a morphogen essential for embryogenic patterning, is often reexpressed in breast cancer. Here we describe a MNK1/NODAL signaling axis that promotes DCIS progression to IDC. We generated MNK1 knockout (KO) or constitutively active MNK1 (caMNK1)-expressing human MCF-10A-derived DCIS cell lines, which were orthotopically injected into the mammary glands of mice. Loss of MNK1 repressed NODAL expression, inhibited DCIS to IDC conversion, and decreased tumor relapse and metastasis. Conversely, caMNK1 induced NODAL expression and promoted IDC. The MNK1/NODAL axis promoted cancer stem cell properties and invasion in vitro. The MNK1/2 inhibitor SEL201 blocked DCIS progression to invasive disease in vivo. In clinical samples, IDC and DCIS with microinvasion expressed higher levels of phospho-MNK1 and NODAL versus low-grade (invasion-free) DCIS. Cumulatively, our data support further development of MNK1 inhibitors as therapeutics for preventing invasive disease. SIGNIFICANCE: These findings provide new mechanistic insight into progression of ductal carcinoma and support clinical application of MNK1 inhibitors to delay progression of indolent ductal carcinoma in situ to invasive ductal carcinoma.
Asunto(s)
Carcinoma de Mama in situ/patología , Neoplasias de la Mama/patología , Carcinoma Ductal de Mama/patología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteína Nodal/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal , Animales , Carcinoma de Mama in situ/metabolismo , Neoplasias de la Mama/metabolismo , Sistemas CRISPR-Cas , Carcinoma Ductal de Mama/metabolismo , Línea Celular Tumoral , Proliferación Celular , Progresión de la Enfermedad , Femenino , Xenoinjertos , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Ratones , Ratones Desnudos , Proteínas Serina-Treonina Quinasas/genéticaRESUMEN
Peroxisomes are a critical rheostat of reactive oxygen species (ROS), yet their role in drug sensitivity and resistance remains unexplored. Gene expression analysis of clinical lymphoma samples suggests that peroxisomes are involved in mediating drug resistance to the histone deacetylase inhibitor (HDACi) Vorinostat (Vor), which promotes ROS-mediated apoptosis. Vor augments peroxisome numbers in cultured lymphoma cells, concomitant with increased levels of peroxisomal proteins PEX3, PEX11B, and PMP70. Genetic inhibition of peroxisomes, using PEX3 knockdown, reveals that peroxisomes protect lymphoma cells against Vor-mediated cell death. Conversely, Vor-resistant cells were tolerant to elevated ROS levels and possess upregulated levels of (1) catalase, a peroxisomal antioxidant, and (2) plasmalogens, ether glycerophospholipids that represent peroxisome function and serve as antioxidants. Catalase knockdown induces apoptosis in Vor-resistant cells and potentiates ROS-mediated apoptosis in Vor-sensitive cells. These findings highlight the role of peroxisomes in resistance to therapeutic intervention in cancer, and provide a novel modality to circumvent drug resistance.
Asunto(s)
Apoptosis/efectos de los fármacos , Citoprotección/efectos de los fármacos , Inhibidores de Histona Desacetilasas/farmacología , Linfoma/patología , Peroxisomas/metabolismo , Catalasa/metabolismo , Línea Celular Tumoral , Técnicas de Silenciamiento del Gen , Silenciador del Gen/efectos de los fármacos , Humanos , Peróxido de Hidrógeno/metabolismo , Ácidos Hidroxámicos/farmacología , Lipoproteínas/metabolismo , Proteínas de la Membrana/metabolismo , Modelos Biológicos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Especies Reactivas de Oxígeno/metabolismo , VorinostatAsunto(s)
Resistencia a Antineoplásicos/genética , Perfilación de la Expresión Génica/métodos , Inhibidores de Histona Desacetilasas/farmacología , Inhibidores de Proteasoma/farmacología , Animales , Antineoplásicos/farmacología , Compuestos de Boro/farmacología , Bortezomib/farmacología , Glicina/análogos & derivados , Glicina/farmacología , Humanos , Ácidos Hidroxámicos/farmacología , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/metabolismo , Masculino , Ratones SCID , Pronóstico , Células U937 , Vorinostat , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Perturbation in the transcriptional control of genes driving differentiation is an established paradigm whereby oncogenic fusion proteins promote leukemia. From a retinoic acid (RA)-sensitive acute promyelocytic leukemia (APL) cell line, we derived an RA-resistant clone characterized by a block in transcription initiation, despite maintaining wild-type PML/RARA expression. We uncovered an aberrant interaction among PML/RARA, nucleophosmin (NPM), and topoisomerase II beta (TOP2B). Surprisingly, RA stimulation in these cells results in enhanced chromatin association of the nucleosome remodeler BRG1. Inhibition of NPM or TOP2B abrogated BRG1 recruitment. Furthermore, NPM inhibition and targeting BRG1 restored differentiation when combined with RA. Here, we demonstrate a role for NPM and BRG1 in obstructing RA differentiation and implicate chromatin remodeling in mediating therapeutic resistance in malignancies. NPM mutations are the most common genetic change in patients with acute leukemia (AML); therefore, our model may be applicable to other more common leukemias driven by NPM.
Asunto(s)
ADN Helicasas/metabolismo , Proteínas Nucleares/metabolismo , Factores de Transcripción/metabolismo , Activación Transcripcional/efectos de los fármacos , Tretinoina/toxicidad , Proteína beta Potenciadora de Unión a CCAAT/genética , Proteína beta Potenciadora de Unión a CCAAT/metabolismo , Diferenciación Celular/efectos de los fármacos , Línea Celular Tumoral , Ensamble y Desensamble de Cromatina/efectos de los fármacos , Inmunoprecipitación de Cromatina , ADN Helicasas/antagonistas & inhibidores , ADN Helicasas/genética , ADN-Topoisomerasas de Tipo II/metabolismo , Proteínas de Unión al ADN/metabolismo , Resistencia a Antineoplásicos/efectos de los fármacos , Humanos , Leucemia Promielocítica Aguda/metabolismo , Leucemia Promielocítica Aguda/patología , Proteínas Nucleares/antagonistas & inhibidores , Proteínas Nucleares/genética , Nucleofosmina , Proteínas de Unión a Poli-ADP-Ribosa , Regiones Promotoras Genéticas , Proteína de la Leucemia Promielocítica/genética , Proteína de la Leucemia Promielocítica/metabolismo , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptor alfa de Ácido Retinoico/genética , Receptor alfa de Ácido Retinoico/metabolismo , Factores de Transcripción/antagonistas & inhibidores , Factores de Transcripción/genéticaRESUMEN
If looking for a mnemonic to remember the relevant facts about acute promyelocytic leukemia (APL), one just has to remember that APL is a disease of A's. It is acute and it is highly sensitive to treatment with anthracyclines, all-trans-retinoic acid (RA) and arsenic trioxide (ATO). The presence of fusions involving the retinoic acid receptor alpha (RARA) is without question the central player driving APL and dictating the response of this disease to these therapeutic agents. However, beyond this knowledge, the molecular mechanisms that contribute to the complicated pathogenesis and the response to treatment of APL are not completely defined. As more is understood about this hematological malignancy, there are more opportunities to refine and improve treatment based on this knowledge. In this review article, we discuss the response of APL to these "A" therapies.
Asunto(s)
Antraciclinas/uso terapéutico , Antibióticos Antineoplásicos/uso terapéutico , Arsenicales/uso terapéutico , Células Precursoras de Granulocitos/efectos de los fármacos , Leucemia Promielocítica Aguda/tratamiento farmacológico , Óxidos/uso terapéutico , Tretinoina/uso terapéutico , Antraciclinas/farmacología , Antibióticos Antineoplásicos/farmacología , Trióxido de Arsénico , Arsenicales/farmacología , Diferenciación Celular/efectos de los fármacos , Línea Celular Tumoral , Resistencia a Antineoplásicos , Regulación Leucémica de la Expresión Génica , Humanos , Terapia Molecular Dirigida , Proteínas de Neoplasias/efectos de los fármacos , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/fisiología , Proteínas de Fusión Oncogénica/efectos de los fármacos , Proteínas de Fusión Oncogénica/genética , Proteínas de Fusión Oncogénica/fisiología , Óxidos/farmacología , Inhibidores de Topoisomerasa II/farmacología , Inhibidores de Topoisomerasa II/uso terapéutico , Transcripción Genética/genética , Tretinoina/farmacologíaRESUMEN
Darinaparsin (Dar; ZIO-101; S-dimethylarsino-glutathione) is a promising novel organic arsenical currently undergoing clinical studies in various malignancies. Dar consists of dimethylarsenic conjugated to glutathione (GSH). Dar induces more intracellular arsenic accumulation and more cell death than the FDA-approved arsenic trioxide (ATO) in vitro, but exhibits less systemic toxicity. Here, we propose a mechanism for Dar import that might explain these characteristics. Structural analysis of Dar suggests a putative breakdown product: dimethylarsino-cysteine (DMAC). We show that DMAC is very similar to Dar in terms of intracellular accumulation of arsenic, cell cycle arrest, and cell death. We found that inhibition of γ-glutamyl-transpeptidase (γ-GT) protects human acute promyelocytic leukemia cells (NB4) from Dar, but not from DMAC, suggesting a role for γ-GT in the processing of Dar. Overall, our data support a model where Dar, a GSH S-conjugate, is processed at the cell surface by γ-GT, leading to formation of DMAC, which is imported via xCT, xAG, or potentially other cystine/cysteine importing systems. Further, we propose that Dar induces its own import via increased xCT expression. These mechanisms may explain the enhanced toxicity of Dar toward cancer cells compared with ATO.
Asunto(s)
Antineoplásicos/metabolismo , Arsenicales/metabolismo , Glutatión/análogos & derivados , Sistema de Transporte de Aminoácidos y+/metabolismo , Antineoplásicos/farmacología , Trióxido de Arsénico , Arsenicales/farmacología , Transporte Biológico , Línea Celular Tumoral , Cisteína/análogos & derivados , Cisteína/metabolismo , Glutatión/metabolismo , Glutatión/farmacología , Humanos , Óxidos/farmacología , Compuestos de Sulfhidrilo/metabolismo , gamma-Glutamiltransferasa/metabolismoRESUMEN
Post-translational modifications, such as acetylation and ubiquitination, can greatly expand the functionality of a particular protein. The promyelocytic leukemia (PML) protein is a functionally promiscuous protein with proposed roles in many cellular processes. Its cellular headquarters are the macromolecular structures termed PML nuclear bodies. Post-translational modification of PML is emerging as a defining feature of this protein that regulates its physiological consequences. This review will highlight the expansion of our knowledge about the post-translational modifications of PML.
Asunto(s)
Proteínas Nucleares/fisiología , Procesamiento Proteico-Postraduccional , Factores de Transcripción/fisiología , Proteínas Supresoras de Tumor/fisiología , Humanos , Proteínas Nucleares/metabolismo , Fosforilación , Proteína de la Leucemia Promielocítica , Receptores de Ácido Retinoico/metabolismo , Receptor alfa de Ácido Retinoico , Proteínas Modificadoras Pequeñas Relacionadas con Ubiquitina/metabolismo , Factores de Transcripción/metabolismo , Proteínas Supresoras de Tumor/metabolismoRESUMEN
The ability of retinoids to inhibit breast cancer cell growth correlates with estrogen receptor (ER) alpha status, as shown by the antiproliferative effects of retinoids in ERalpha-positive breast cancer cells and their use as chemopreventive agents in premenopausal women. The discovery of ERbeta, also present in breast cancer cells, has added a new level of complexity to this malignancy. To determine the retinoid response in ERbeta-expressing breast cancer cells, we used retroviral transduction of ERbeta in ER-negative MDA-MB-231 cells. Western blot and immunofluorescence confirmed expression and nuclear localization of ERbeta, whereas functionality was shown using an estrogen response element-containing reporter. A significant retinoic acid (RA)-mediated growth inhibition was observed in the transduced ERbeta-positive cells as shown by proliferation assays. Addition of estradiol, tamoxifen, or ICI 182,780 had no effect on cell growth and did not alter RA sensitivity. We observed that retinoids altered ERbeta-mediated transcriptional activity from an estrogen response element, which was confirmed by decreased expression of the pS2 gene, and from an activator protein response element. Conversely, the expression of ERbeta altered RA receptor (RAR) beta expression, resulting in greater induction of RARbeta gene expression on RA treatment, without altered expression of RARalpha. Our data provide evidence of transcriptional crosstalk between ERbeta and RAR in ERbeta-positive breast cancer cells that are growth inhibited by RA.