RESUMEN
Increased expression and nuclear translocation of ß-CATENIN is frequently observed in breast cancer, and it correlates with poor prognosis. Current treatment strategies targeting ß-CATENIN are not as efficient as desired. Therefore, detailed understanding of ß-CATENIN regulation is crucial. Bone morphogenetic proteins (BMP) and Wingless/Integrated (WNT) pathway crosstalk is well-studied for many cancer types including colorectal cancer, whereas it is still poorly understood for breast cancer. Analysis of breast cancer patient data revealed that BMP2 and BMP6 were significantly downregulated in tumors. Since mutation frequency in genes enhancing ß-CATENIN protein stability is relatively low in breast cancer, we aimed to investigate whether decreased BMP ligand expression could contribute to a high protein level of ß-CATENIN in breast cancer cells. We demonstrated that downstream of BMP stimulation, SMAD4 is required to reduce ß-CATENIN protein stability through the phosphorylation in MCF7 and T47D cells. Consequently, BMP stimulation reduces ß-CATENIN levels and prevents its nuclear translocation and target gene expression in MCF7 cells. Conversely, BMP stimulation has no effect on ß-CATENIN phosphorylation or stability in MDA-MB-231 and MDA-MB-468 cells. Likewise, SMAD4 modulation does not alter the response of those cells, indicating that SMAD4 alone is insufficient for BMP-induced ß-CATENIN phosphorylation. While our data suggest that considering BMP activity may serve as a prognostic marker for understanding ß-CATENIN accumulation risk, further investigation is needed to elucidate the differential responsiveness of breast cancer cell lines.
Asunto(s)
Proteínas Morfogenéticas Óseas , Neoplasias de la Mama , Estabilidad Proteica , beta Catenina , Femenino , Humanos , beta Catenina/metabolismo , Proteína Morfogenética Ósea 2/metabolismo , Proteínas Morfogenéticas Óseas/metabolismo , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Neoplasias de la Mama/genética , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica , Células MCF-7 , Fosforilación , Proteína Smad4/metabolismo , Proteína Smad4/genéticaRESUMEN
The large isoform of the transmembrane protein angiomotin (AMOT130) controls cell proliferation and migration of many cell types. AMOT130 associates to the actin cytoskeleton and regulates tight-junction maintenance and signaling often via endosomal uptake of polarity proteins at tight junctions. AMOT130 is highly polarized and present only at the apical side of polarized cells. Here we show that bone morphogenetic protein (BMP) growth factor signaling and AMOT function are interlinked in apical-basal polarized cells. BMP6 controls AMOT internalization and endosomal trafficking in epithelial cells. AMOT130 interacts with the BMP receptor BMPR2 and facilitates SMAD activation and target gene expression. We further demonstrate that this effect of AMOT on BMP-SMAD signaling is dependent on endocytosis and specific to the apical side of polarized epithelial and endothelial cells. Knockdown of AMOT reduces SMAD signaling only from the apical side of polarized cells, while basolateral BMP-SMAD signaling is unaffected. This allows for the first time interference with BMP signaling in a polarized manner and identifies AMOT130 as a novel BMP signaling regulator.
Asunto(s)
Proteínas Morfogenéticas Óseas/metabolismo , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Proteínas de Microfilamentos/metabolismo , Proteínas Smad/metabolismo , Angiomotinas , Proteína Morfogenética Ósea 6/metabolismo , Línea Celular , Membrana Celular/metabolismo , Polaridad Celular/fisiología , Endosomas/metabolismo , Células Endoteliales/metabolismo , Células Epiteliales/metabolismo , Células HEK293 , Humanos , Células MCF-7 , Proteínas de la Membrana/metabolismo , Fosfoproteínas/metabolismo , Fosforilación , Transducción de Señal/fisiología , Uniones Estrechas/metabolismoRESUMEN
Objective: Acute myeloid leukemia (AML) is a complex disease affected by both genetic and epigenetic factors. Histone methylation and demethylation are types of epigenetic modification in chromatin remodeling and gene expression. Abnormal expression of histone demethylases is indicated in many types of cancer including AML. Although many commercial drugs are available to treat AML, an absolute cure has not been discovered yet. However, inhibition of demethylases could be a potential cure for AML. Methylstat is a chemical agent that inhibits the Jumonji C domain-containing demethylases. Materials and Methods: The cytotoxic and apoptotic effects of methylstat and doxorubicin on HL-60 cells were detected by MTT cell viability assay, double staining of treated cells with annexin-V/propidium iodide, and caspase-3 activity assay. Mitochondrial activity was analyzed using JC-1 dye. The expression levels of the BCL2 and BCL2L1 anti-apoptotic genes in HL-60 cells were determined using real-time polymerase chain reaction (PCR). Lastly, the cytostatic effect was determined by cell cycle analysis. Results: In our research, cytotoxic, cytostatic, and apoptotic effects of methylstat on human HL-60 cells were investigated. Cytotoxic and cytostatic analyses revealed that methylstat decreased cell proliferation in a dose-dependent cytotoxic manner and arrested HL-60 cells in the G2/M and S phases. Methylstat also induced apoptosis through the loss of mitochondrial membrane potential and increases in caspase-3 enzyme activity. The expression levels of BCL2 and BCL2L1 were also decreased according to real-time PCR results. Finally, the combination of methylstat with doxorubicin resulted in synergistic cytotoxic effects on HL-60 cells. Conclusion: Taken together, these results demonstrate that methylstat may be a powerful candidate as a drug component of AML treatment protocols.
Asunto(s)
Antineoplásicos/farmacología , Histona Demetilasas con Dominio de Jumonji/antagonistas & inhibidores , Leucemia Mieloide Aguda/enzimología , Dominios y Motivos de Interacción de Proteínas/efectos de los fármacos , Antineoplásicos/uso terapéutico , Apoptosis/efectos de los fármacos , Biomarcadores de Tumor , Caspasa 3/metabolismo , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Relación Dosis-Respuesta a Droga , Regulación Neoplásica de la Expresión Génica , Histonas/metabolismo , Humanos , Histona Demetilasas con Dominio de Jumonji/química , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/genética , Metaloproteinasas de la Matriz/metabolismo , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Metilación , Terapia Molecular Dirigida/efectos adversos , Terapia Molecular Dirigida/métodosRESUMEN
Cartilaginous tissue requires structural and metabolic support after traumatic or chronic injuries because of its limited capacity for regeneration. However, current techniques for cartilage regeneration are either invasive or ineffective for long-term repair. Developing alternative approaches to regenerate cartilage tissue is needed. Therefore, versatile scaffolds formed by biomaterials are promising tools for cartilage regeneration. Bioactive scaffolds further enhance the utility in a broad range of applications including the treatment of major cartilage defects. This chapter provides an overview of cartilage tissue, tissue defects, and the methods used for regeneration, with emphasis on peptide scaffold materials that can be used to supplement or replace current medical treatment options.
Asunto(s)
Materiales Biocompatibles/química , Cartílago/fisiopatología , Péptidos/química , Regeneración , Animales , Cartílago/lesiones , Humanos , Medicina Regenerativa/métodos , Ingeniería de Tejidos/métodos , Andamios del Tejido/químicaRESUMEN
Burn injuries are one of the most common types of trauma worldwide, and their unique physiology requires the development of specialized therapeutic materials for their treatment. Here, we report the use of synthetic, functional and biodegradable peptide nanofiber gels for the improved healing of burn wounds to alleviate the progressive loss of tissue function at the post-burn wound site. These bioactive nanofiber gels form scaffolds that recapitulate the structure and function of the native extracellular matrix through signaling peptide epitopes, which can trigger angiogenesis through their affinity to basic growth factors. In this study, the angiogenesis-promoting properties of the bioactive scaffolds were utilized for the treatment of a thermal burn model. Following the excision of necrotic tissue, bioactive gels and control solutions were applied topically onto the wound area. The wound healing process was evaluated at 7, 14 and 21 days following injury through histological observations, immunostaining and marker RNA/protein analysis. Bioactive peptide nanofiber-treated burn wounds formed well-organized and collagen-rich granulation tissue layers, produced a greater density of newly formed blood vessels, and exhibited increased re-epithelialization and skin appendage development with minimal crust formation, while non-bioactive peptide nanofibers and the commercial wound dressing 3M™ Tegaderm™ did not exhibit significant efficiency over sucrose controls. Overall, the heparin-mimetic peptide nanofiber gels increased the rate of repair of burn injuries and can be used as an effective means of facilitating wound healing.