RESUMEN
Rationale: Melanoma is an aggressive tumor of the skin and drug resistance is still a major problem in melanoma therapy. Novel targets and effective agents to overcome drug resistant melanoma are urgently needed in clinical therapy. Methods: Gene Expression Omnibus (GEO) database analysis, pathway enrichment analysis, and survival rate analysis were utilized to identify a candidate target. An anchorage-independent cell growth assay, flow cytometry, Western blot, and a xenograft mouse model were used to study the function of Aurora kinase B (AURKB) in both drug-sensitive and drug-resistant melanoma. Next, HI-511, a novel dual-target inhibitor targeting both AURKB and BRAF V600E, was designed and examined by an in vitro kinase assay. Methods as indicated above in addition to a BRAF V600E/PTEN-loss melanoma mouse model were used to demonstrate the effect of HI-511 on melanoma development in vitro and in vivo. Results: AURKB is highly expressed in melanoma and especially in vemurafenib-resistant melanoma and the expression was correlated with patient survival rate. Knocking down AURKB inhibited cell growth and induced apoptosis in melanoma, which was associated with the BRAF/MEK/ERKs and PI3-K/AKT signaling pathways. Importantly, we found that HI-511, a novel dual-target inhibitor against AURKB and BRAF V600E, suppresses both vemurafenib-sensitive and vemurafenib-resistant melanoma growth in vitro and in vivo by inducing apoptosis and mediating the inhibition of the BRAF/MEK/ERKs and PI3K/AKT signaling pathways. Conclusion: AURKB is a potential target for melanoma treatment. HI-511, a novel dual-target inhibitor against both AURKB and BRAF V600E, could achieve durable suppression of melanoma growth, even drug-resistant melanoma growth.
Asunto(s)
Aurora Quinasa B/metabolismo , Resistencia a Antineoplásicos/efectos de los fármacos , Melanoma/tratamiento farmacológico , Melanoma/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas B-raf/metabolismo , Animales , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Humanos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Ratones , Fosfatidilinositol 3-Quinasas/metabolismo , Transducción de Señal/efectos de los fármacos , Vemurafenib/farmacologíaRESUMEN
The key functional molecules involved in inflammatory bowel disease (IBD) and IBD-induced colorectal tumorigenesis remain unclear. In this study, we found that the apoptosis repressor with caspase recruitment domain (ARC) protein plays critical roles in IBD. ARC-deficient mice exhibited substantially higher susceptibility to dextran sulfate sodium (DSS)-induced IBD compared with wild-type mice. The inflammatory burden induced in ARC-deficient conditions was inversely correlated with CCL5 and CXCL5 levels in immune cells, especially CD4-positive T cells. Pathologically, ARC expression in immune cells was significantly decreased in clinical biopsy specimens from patients with IBD compared with normal subjects. In addition, ARC levels inversely correlated with CCL5 and CXCL5 levels in human biopsy specimens. ARC interacted with TNF receptor associated factor (TRAF) 6, regulating ubiquitination of TRAF6, which was associated with NF-κB signaling. Importantly, we identified a novel ubiquitination site at lysine 461, which was critical in the function of ARC in IBD. ARC played a critical role in IBD and IBD-associated colon cancer in a bone marrow transplantation model and azoxymethane/DSS-induced colitis cancer mouse models. Overall, these findings reveal that ARC is critically involved in the maintenance of intestinal homeostasis and protection against IBD through its ubiquitination of TRAF6 and subsequent modulation of NF-κB activation in T cells. SIGNIFICANCE: This study uncovers a crucial role of ARC in the immune system and IBD, giving rise to a novel strategy for IBD and IBD-associated colon cancer therapy.
Asunto(s)
Proteínas Reguladoras de la Apoptosis/metabolismo , Neoplasias Colorrectales/etiología , Enfermedades Inflamatorias del Intestino/metabolismo , Enfermedades Inflamatorias del Intestino/patología , Proteínas Musculares/metabolismo , Animales , Proteínas Reguladoras de la Apoptosis/química , Proteínas Reguladoras de la Apoptosis/genética , Azoximetano/toxicidad , Trasplante de Médula Ósea , Linfocitos T CD4-Positivos/inmunología , Quimiocina CCL5/metabolismo , Quimiocina CXCL5/metabolismo , Colitis/inducido químicamente , Neoplasias Colorrectales/inducido químicamente , Sulfato de Dextran/toxicidad , Modelos Animales de Enfermedad , Femenino , Humanos , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Células Jurkat , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas Musculares/química , Proteínas Musculares/genética , UbiquitinaciónRESUMEN
The identification of oncogenic biomolecules as drug targets is an unmet need for the development of clinically effective novel anticancer therapies. In this study, we report for the first time that opsin 4/melanopsin (OPN4) plays a critical role in the pathogenesis of non-small cell lung cancer (NSCLC) and is a potential drug target. Our study has revealed that OPN4 is overexpressed in human lung cancer tissues and cells, and is inversely correlated with patient survival probability. Knocking down expression of OPN4 suppressed cells growth and induced apoptosis in lung cancer cells. We have also found that OPN4, a G protein-coupled receptor, interacted with Gα11 and triggered the PKC/BRAF/MEK/ERKs signaling pathway in lung adenocarcinoma cells. Genetic ablation of OPN4 attenuated the multiplicity and the volume of urethane-induced lung tumors in mice. Importantly, our study provides the first report of AE 51310 (1-[(2,5-dichloro-4-methoxyphenyl)sulfonyl]-3-methylpiperidine) as a small-molecule inhibitor of OPN4, suppressed the anchorage-independent growth of lung cancer cells and the growth of patient-derived xenograft tumors in mice. IMPLICATIONS: Overall, this study unveils the role of OPN4 in NSCLC and suggests that targeting OPN4 with small molecules, such as AE 51310 would be interesting to develop novel anticancer therapies for lung adenocarcinoma.
Asunto(s)
Adenocarcinoma del Pulmón/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Opsinas de Bastones/metabolismo , Bibliotecas de Moléculas Pequeñas/administración & dosificación , Regulación hacia Arriba/efectos de los fármacos , Células A549 , Adenocarcinoma del Pulmón/inducido químicamente , Adenocarcinoma del Pulmón/metabolismo , Animales , Carcinoma de Pulmón de Células no Pequeñas/inducido químicamente , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Progresión de la Enfermedad , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Neoplasias Pulmonares/inducido químicamente , Neoplasias Pulmonares/metabolismo , Ratones , Bibliotecas de Moléculas Pequeñas/farmacología , Uretano/efectos adversos , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND: Barrett's esophagus (BE), a complication of gastroesophageal reflux disease (GERD), predisposes patients to esophageal adenocarcinoma (EAC). Reliable biomarkers for early detection and discovery of potential drug targets are urgently needed for improved BE and EAC patient outcomes. METHODS: Patient biopsy samples were evaluated for COX1/2, and thromboxane A2 synthase (TBXAS) expression. Circulating prostaglandins biosynthesis was determined using enzyme immunoassay kits. Anchorage-independent cell growth assay, crystal violet staining assay, and xenograft experiments were conducted to assess BE and EAC cell growth. A surgical mouse model of reflux (i.e., esophagoduodenostomy) was established and samples were analyzed using an enzyme immunoassay kit, immunohistochemistry, immunoblotting, or RT-PCR. Esophageal biopsy samples (pre- and post-intervention) were obtained from a randomized clinical trial in which participants were administered esomeprazole (40â¯mg) twice daily in combination with an acetylsalicylic acid (ASA) placebo or 81 or 325â¯mg ASA for 28 days. Esophageal biopsy specimens before and after the intervention period were analyzed. FINDINGS: COX2 and TBXAS are highly expressed in BE and EAC patients accompanied by a pronounced elevation of circulating TXA2 levels. ASA suppressed BE and EAC growth by targeting the TXA2 pathway. Additionally, biopsies from 49 patients (with similar baseline characteristics) showed that ASA substantially decreased serum TXA2 levels, resulting in reduced inflammation. INTERPRETATION: This study establishes the importance of the COX1/2-driven TXA2 pathway in BE and EAC pathophysiology and lays the groundwork for introducing a TXA2-targeting strategy for EAC prevention and early detection. FUNDING: Hormel Foundation, Exact Sciences, Pentax Medical, Intromedic and National Cancer.
Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Esófago de Barrett/tratamiento farmacológico , Carcinogénesis/patología , Ciclooxigenasa 1/metabolismo , Ciclooxigenasa 2/metabolismo , Neoplasias Esofágicas/tratamiento farmacológico , Terapia Molecular Dirigida , Transducción de Señal , Tromboxano A2/metabolismo , Adenocarcinoma/sangre , Animales , Aspirina/farmacología , Esófago de Barrett/sangre , Carcinogénesis/metabolismo , Línea Celular Tumoral , Proliferación Celular , Modelos Animales de Enfermedad , Neoplasias Esofágicas/sangre , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Femenino , Humanos , Inflamación/patología , Masculino , Ratones Endogámicos C57BL , Persona de Mediana Edad , Factor de Transcripción STAT3/metabolismo , Tromboxano A2/sangreRESUMEN
OBJECTIVE: This study examined the effect of a 12-week table tennis exercise on motor skills and executive functions in children with ADHD. METHOD: Fifteen children with ADHD received the intervention, whereas 15 children with ADHD and 30 typically developing children did not. The Test of Gross Motor Development-2, Stroop, and Wisconsin Card Sorting Test (WCST) were conducted before and after the intervention. RESULTS: After the intervention, the ADHD training group scored significantly higher in the locomotor as well as object-control skills, Stroop Color-Word condition, and WCST total correct performance compared with the ADHD non-training group, and we noted improvements in the locomotor as well as object-control skills, Stroop Color-Word condition, and three aspects of the WCST performances of the ADHD training group over time. CONCLUSION: A 12-week table tennis exercise may have clinical relevance in motor skills and executive functions of children with ADHD.
Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad/terapia , Terapia por Ejercicio/métodos , Destreza Motora/fisiología , Niño , Desarrollo Infantil/fisiología , Función Ejecutiva/fisiología , Ejercicio Físico/fisiología , Femenino , Humanos , Masculino , Proyectos Piloto , Test de Clasificación de Tarjetas de WisconsinRESUMEN
Inflammation is a complex biological host reaction to tissue damage, infection and trauma. Extensive study of the inflammatory response has led to the identification of several protein kinases that are essential for signaling and could be potential therapeutic targets. The RSK family of kinases has multiple cellular functions. In our study, we found that RSK2 is a mediator for inflammation signaling and interacts with TRAF6. In vitro kinase assay results indicated that RSK2 strongly phosphorylates TRAF6 at serines 46, 47 and 48. Ectopic overexpression of TRAF6 or knocking down RSK2 expression confirmed that RSK2 is a positive regulator of TRAF6 K63 ubiquitination. TRAF6 is also required for RSK2 ubiquitination. TRAF6 bridges the TNF receptor superfamily and intracellular signaling for the induction of proinflammatory cytokines. We developed a colon inflammation model using RSK2 wild type (WT) and knockout (KO) mice. As expected, F4/80 and CD3 infiltration were significantly upregulated in WT mice compared to RSK2 KO mice. Furthermore, inflammation signaling, including Ikkα/ß, p38 and JNKs, was dramatically upregulated in WT mice. Colon tissue immunoprecipitation results further confirmed that TRAF6 K63 ubiquitination was lower in RSK2 KO mice. Overall, these results indicate that phosphorylation of TRAF6 (S46, 47, 48) by RSK2 is required for TRAF6 K63 ubiquitination and inflammation signaling.
Asunto(s)
Colitis/patología , Colon/patología , Proteínas Quinasas S6 Ribosómicas 90-kDa/genética , Factor 6 Asociado a Receptor de TNF/metabolismo , Animales , Antígenos de Diferenciación/metabolismo , Complejo CD3/metabolismo , Línea Celular Tumoral , Colon/inmunología , Femenino , Células HEK293 , Humanos , Inflamación/patología , Péptidos y Proteínas de Señalización Intracelular , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Sistema de Señalización de MAP Quinasas , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Inhibidor NF-kappaB alfa/metabolismo , Fosforilación , Células RAW 264.7 , Ubiquitinación/genética , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
Metastasis is a major cause of cancer-related deaths. Approximately 80% of patients with colorectal cancer develop liver metastasis and 20% develop lung metastasis. We found that at different stages of colon cancer, IFNγ secretion from peripheral blood mononuclear cells was decreased compared with healthy controls. The ribosomal S6 kinase (RSK) family of kinases has multiple cellular functions, and we examined their roles in this observed IFNγ decrease. Flow cytometry analysis of wild-type (WT) and RSK2 knockout (KO) mice revealed significantly lower levels of IFNγ in the RSK2 KO mice compared with the WT mice. Since IFNγ is a component of immunity, which contributes to protection against metastatic carcinomas, we conducted a colon cancer liver metastasis experiment. We found significantly greater metastasis in RSK2 KO mice compared with WT mice. Transcription factor T-bet can directly activate Ifnγ gene transcription. In vitro kinase assay results showed that RSK2 phosphorylated T-bet at serines 498 and 502. We show that phosphorylation of T-bet by RSK2 is required for IFNγ expression, because knockdown of RSK2 expression or overexpression of mutant T-bet reduces IFNγ mRNA expression. To verify the function of the phosphorylation sites, we overexpressed a constitutively active mutant T-bet (S498E/S502E) in bone marrow. Mutant T-bet restored the IFNγ mRNA levels and dramatically reduced the metastasis rate in these mice. Overall, these results indicate that phosphorylation of T-bet is required for the inhibition of colon cancer metastasis and growth through a positive regulation of RSK2/T-bet/IFNγ signaling.
Asunto(s)
Neoplasias del Colon/genética , Regulación Neoplásica de la Expresión Génica , Interferón gamma/genética , Neoplasias Hepáticas/genética , Neoplasias Pulmonares/genética , Proteínas Quinasas S6 Ribosómicas/genética , Proteínas de Dominio T Box/genética , Animales , Trasplante de Médula Ósea , Neoplasias del Colon/inmunología , Neoplasias del Colon/patología , Femenino , Humanos , Interferón gamma/inmunología , Isoenzimas/genética , Isoenzimas/inmunología , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/patología , Neoplasias Hepáticas/inmunología , Neoplasias Hepáticas/prevención & control , Neoplasias Hepáticas/secundario , Neoplasias Pulmonares/inmunología , Neoplasias Pulmonares/prevención & control , Neoplasias Pulmonares/secundario , Masculino , Ratones , Fosforilación , Proteínas Quinasas S6 Ribosómicas/inmunología , Serina/metabolismo , Transducción de Señal , Proteínas de Dominio T Box/inmunología , Transfección , Irradiación Corporal TotalRESUMEN
This study examined the effects of a 12-week physical activity intervention on the motor skill proficiency and executive function of 22 boys (aged 9.08 ± 1.75 years) with autism spectrum disorder. In Phase I of the 12 weeks, 11 boys with autism spectrum disorder (Group A) received the intervention, whereas the other 11 boys with autism spectrum disorder (Group B) did not (true control, no intervention). The arrangement was reversed in Phase II, which lasted an additional 12 weeks. The Bruininks-Oseretsky Test of Motor Proficiency, Second Edition, and the Wisconsin Card Sorting Test were conducted three times for each participant (Group A, primary grouping: baseline (T1), post-assessment (T2), and follow-up assessment (T3); Group B, control grouping: T1-T2; intervention condition, T2-T3). The main findings were that both groups of children with autism spectrum disorder significantly exhibited improvements in motor skill proficiency (the total motor composite and two motor-area composites) and executive function (three indices of the Wisconsin Card Sorting Test) after 12 weeks of physical activity intervention. In addition, the effectiveness appeared to have been sustained for at least 12 weeks in Group A. The findings provide supporting evidence that physical activity interventions involving table tennis training may be a viable therapeutic option for treating children with autism spectrum disorder.
Asunto(s)
Trastorno del Espectro Autista/terapia , Terapia por Ejercicio , Trastorno del Espectro Autista/psicología , Niño , Estudios Cruzados , Función Ejecutiva , Ejercicio Físico , Terapia por Ejercicio/métodos , Humanos , Masculino , Destreza Motora , Resultado del TratamientoRESUMEN
Esophageal cancer is one of the least studied and deadliest cancers worldwide with a poor prognosis due to limited options for treatment. Chemotherapy agents such as the microtubule-targeting compounds are the mainstay of palliation for advanced esophageal cancer treatment. However, the toxicity and side effects of tubulin-binding agents (TBAs) have promoted the development of novel, more potent but less toxic TBAs. Herein, we identified 2-[4-(3,4-dimethoxyphenyl)-3-methyl-1H-pyrazol-5-yl]-5-[(2-methylprop-2-en-1-yl)oxy] phenol (PPMP) as a novel TBA for esophageal cancer treatment. PPMP markedly inhibited tubulin polymerization, and decreased viability and anchorage-independent growth of esophageal cancer cell lines, effects that were accompanied by G2/M arrest and apoptosis. Importantly, we produced patient-derived esophageal cancer xenografts to evaluate the therapeutic effect of PPMP in a setting that best mimics the clinical context in patients with esophageal cancer. Overall, we identified PPMP as a novel microtubule-destabilizing compound and as a new therapeutic agent against esophageal carcinoma.
Asunto(s)
Neoplasias Esofágicas/tratamiento farmacológico , Meperidina/análogos & derivados , Moduladores de Tubulina/farmacología , Animales , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/patología , Puntos de Control de la Fase G2 del Ciclo Celular/efectos de los fármacos , Humanos , Puntos de Control de la Fase M del Ciclo Celular/efectos de los fármacos , Masculino , Meperidina/farmacología , Ratones , Persona de Mediana Edad , Modelos Moleculares , Tubulina (Proteína)/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND: Recent evidence suggests that childhood obesity is increasing in children with typical development (TD) and in children with autism spectrum disorders (ASD). The associations between physical activity (PA) levels and physical fitness components have not yet been objectively examined in this population but may have clinical implications for the development of secondary health complications. OBJECTIVE: The aims of this study were: (1) to compare PA and physical fitness between secondary school-aged male students with ASD and their peers with TD and (2) to assess possible interrelationships between PA and physical fitness levels in each group. DESIGN: This was a cross-sectional study. METHODS: Physical activity was recorded every 10 seconds by using accelerometry in 70 male students with (n=35) and without (n=35) ASD for up to 5 weekdays and 2 weekend days. The Brockport Physical Fitness Test was used to assess physical fitness. RESULTS: The primary findings were: (1) participants with ASD were less physically active overall and engaged in moderate-to-vigorous PA for a lower percentage of time compared with participants with TD during weekdays; (2) participants with ASD had significantly lower scores on all physical fitness measures, except body composition; and (3) group-dependent relationships existed between physical fitness profiles and PA levels. LIMITATIONS: The study design limits causal inference from the results. CONCLUSION: Specific interventions for maximizing PA and physical fitness levels in secondary school-aged male students with ASD are urgently needed.
Asunto(s)
Trastorno del Espectro Autista/epidemiología , Actividad Motora , Aptitud Física , Estudiantes , Acelerometría , Adolescente , Estudios de Casos y Controles , Niño , Estudios Transversales , Prueba de Esfuerzo , Conductas Relacionadas con la Salud , Humanos , Masculino , Taiwán/epidemiologíaRESUMEN
Non-small cell lung cancer (NSCLC) is the most lethal cancer, causing more than 150,000 deaths in the United States in 2013. The receptor tyrosine kinase inhibitors such as gefitinib are not perfect clinical therapeutic agents for NSCLC treatment due to primary or acquired tyrosine kinase inhibitor resistance. Herein, 3,6,2',4',5'-pentahydroxyflavone (36245-PHF) was identified as a multiple kinase inhibitor for NSCLC treatment based on the computational screening of a natural products database. 36245-PHF was shown to inhibit PI3K and Aurora A and B kinases and overcome gefitinib-resistant NSCLC growth. Our data clearly showed that 36245-PHF markedly inhibited anchorage-independent growth of gefitinib-resistant NSCLC cell lines and exerted a substantial chemotherapeutic effect following oral administration in a gefitinib-resistant NSCLC xenograft model. The evidence from three different subsequent methodological approaches, in vitro, ex vivo, and in vivo, all confirmed that 36245-PHF as a multiple protein kinase inhibitor. Overall, we identified 36245-PHF as a multiple protein kinase inhibitor and as a novel therapeutic agent to overcome gefitinib-resistant NSCLC growth, which could provide a new option for clinical NSCLC oral treatment.
Asunto(s)
Antineoplásicos/farmacología , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Flavonoides/farmacología , Regulación Neoplásica de la Expresión Génica , Neoplasias Pulmonares/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/farmacología , Quinazolinas/farmacología , Animales , Aurora Quinasa A/antagonistas & inhibidores , Aurora Quinasa A/genética , Aurora Quinasa A/metabolismo , Aurora Quinasa B/antagonistas & inhibidores , Aurora Quinasa B/genética , Aurora Quinasa B/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/patología , Adhesión Celular , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Resistencia a Antineoplásicos/efectos de los fármacos , Femenino , Gefitinib , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Fosfatidilinositol 3-Quinasas/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Inhibidores de las Quinasa Fosfoinosítidos-3 , Transducción de Señal , Carga Tumoral/efectos de los fármacosRESUMEN
Solar UV (SUV) irradiation is a major factor in skin carcinogenesis, the most common form of cancer in the United States. The MAPK cascades are activated by SUV irradiation. The 90 kDa ribosomal S6 kinase (RSK) and mitogen and stress-activated protein kinase (MSK) proteins constitute a family of protein kinases that mediate signal transduction downstream of the MAPK cascades. In this study, phosphorylation of RSK and MSK1 was upregulated in human squamous cell carcinoma (SCC) and SUV-treated mouse skin. Kaempferol, a natural flavonol, found in tea, broccoli, grapes, apples, and other plant sources, is known to have anticancer activity, but its mechanisms and direct target(s) in cancer chemoprevention are unclear. Kinase array results revealed that kaempferol inhibited RSK2 and MSK1. Pull-down assay results, ATP competition, and in vitro kinase assay data revealed that kaempferol interacts with RSK2 and MSK1 at the ATP-binding pocket and inhibits their respective kinase activities. Mechanistic investigations showed that kaempferol suppresses RSK2 and MSK1 kinase activities to attenuate SUV-induced phosphorylation of cAMP-responsive element binding protein (CREB) and histone H3 in mouse skin cells. Kaempferol was a potent inhibitor of SUV-induced mouse skin carcinogenesis. Further analysis showed that skin from the kaempferol-treated group exhibited a substantial reduction in SUV-induced phosphorylation of CREB, c-Fos, and histone H3. Overall, our results identify kaempferol as a safe and novel chemopreventive agent against SUV-induced skin carcinogenesis that acts by targeting RSK2 and MSK1.
Asunto(s)
Antineoplásicos/farmacología , Carcinoma de Células Escamosas/metabolismo , Quempferoles/farmacología , Proteínas Quinasas S6 Ribosómicas 90-kDa/metabolismo , Neoplasias Cutáneas/metabolismo , Animales , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/prevención & control , Humanos , Inmunohistoquímica , Ratones , Fosforilación/efectos de la radiación , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/prevención & control , Luz Solar/efectos adversos , Rayos Ultravioleta/efectos adversosRESUMEN
TRAF2 has an important function in mediating the TNF-R signaling pathway toward activation of NF-κB and JNKs. Here we reveal a novel function of TRAF2 in the epidermal growth factor (EGF) signaling pathway. Knockdown of TRAF2 blocked EGF-induced AP-1 activity and anchorage- independent cell transformation. Notably, we showed that EGF induces ribosomal S6 kinase 2 (RSK2) ubiquitination, and knocking down TRAF2 suppresses ubiquitination of RSK2 induced by EGF. We also found that TRAF2 affects RSK2 activity through RSK2 ubiquitination. RSK2 plays a critical role in AP-1 activity mediated through CREB and c-Fos, which regulates anchorage-independent cell transformation. In addition, TRAF2 is overexpressed in colon cancer and required for colon cancer development, suggesting that TRAF2 might be a potential molecular target for cancer prevention and treatment.
Asunto(s)
Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Factor de Crecimiento Epidérmico/fisiología , Proteínas Proto-Oncogénicas c-fos/metabolismo , Proteínas Quinasas S6 Ribosómicas 90-kDa/metabolismo , Factor 2 Asociado a Receptor de TNF/metabolismo , Animales , Línea Celular Tumoral , Proliferación Celular , Transformación Celular Neoplásica/metabolismo , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Femenino , Técnicas de Silenciamiento del Gen , Humanos , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Poliubiquitina/metabolismo , Unión Proteica , Procesamiento Proteico-Postraduccional , Transducción de Señal , Factor 2 Asociado a Receptor de TNF/genética , Factor de Transcripción AP-1/metabolismo , Transcripción Genética , Carga Tumoral , UbiquitinaciónRESUMEN
To further explore the mechanism of p38 MAP kinase in regulation of JB6 Cl41 cell transformation. cDNA array was employed to scan the differential expression genes between DN-p38 cells and CMV-neo JB6 Cl41 cells after EGF stimuli. We found that up-expression genes including oncogenes and tumor suppressor genes, p53-associated protein, transcription repressors, apoptosis-associated genes, and growth arrest and DNA damage-inducible protein 153 were detected in DN-p38 cells, but low expression in CMV-neo JB6 Cl41 cells after EGF treatment. Meanwhile, some proto-oncogenes, such as c-Myc, and signal transducer and activator of transcription 1 (STAT1) were lowly expressed in EGF-stimulated DN-p38 cells, but had relatively high expression level in CMV-neo JB6 Cl41 cells under the same stimuli. Four of the differential expression genes were further confirmed by quantitative RT-PCR analysis. Our results indicate that p38 MAP kinase is involved in EGF-induced JB6 Cl41 cell transformation through effecting on more genes expression levels including transcription factors, proto-oncogene, apoptosis-related genes and growth arrest genes.
Asunto(s)
Transformación Celular Neoplásica/genética , Factor de Crecimiento Epidérmico/farmacología , Proteínas Quinasas p38 Activadas por Mitógenos/fisiología , Línea Celular , Expresión Génica , Perfilación de la Expresión Génica , Humanos , Análisis de Secuencia por Matrices de Oligonucleótidos , Proto-Oncogenes Mas , Transfección , Proteínas Quinasas p38 Activadas por Mitógenos/genéticaRESUMEN
In addition to capsaicin, a transient receptor potential channel vanilloid subfamily 1 (TRPV1) agonist, two kinds of antagonists against this receptor are used as therapeutic drugs for pain relief. Indeed, a number of small molecule TRPV1 antagonists are currently undergoing Phase I/II clinical trials to determine their effect on relieving chronic inflammatory pain and migraine headache pain. However, we previously reported that the absence of TRPV1 in mice results in a striking increase in skin carcinogenesis, suggesting that chronic blockade of TRPV1 might increase the risk of tumor development. In this study, we found that a typical TRPV1 antagonist, AMG9810, promotes mouse skin tumor development. The topical application of AMG9810 resulted in a significant increase in the expression level of the epidermal growth factor receptor (EGFR) and its downstream Akt/mammalian target of rapamycin (mTOR)-signaling pathway. This increase was not only observed in AMG9810-treated tumor tissue but was also found in skin tissue treated with AMG9810. In telomerase-immortalized primary human keratinocytes, AMG9810 promoted proliferation that was mediated through the EGFR/Akt/mTOR-signaling pathway. In summary, our data suggest that the TRPV1 antagonist, AMG9810, promotes mouse skin tumorigenesis mediated through EGFR/Akt/mTOR signaling. Thus, the application of this compound for pain relief might increase the risk of skin cancer.
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Acrilamidas/toxicidad , Compuestos Bicíclicos Heterocíclicos con Puentes/toxicidad , Receptores ErbB/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Neoplasias Cutáneas/inducido químicamente , Neoplasias Cutáneas/patología , Canales Catiónicos TRPV/antagonistas & inhibidores , 9,10-Dimetil-1,2-benzantraceno/toxicidad , Acrilamidas/administración & dosificación , Animales , Western Blotting , Compuestos Bicíclicos Heterocíclicos con Puentes/administración & dosificación , Carcinógenos/toxicidad , Proliferación Celular , Transformación Celular Neoplásica/efectos de los fármacos , Células Cultivadas , Cocarcinogénesis , Femenino , Humanos , Queratinocitos/citología , Queratinocitos/efectos de los fármacos , Queratinocitos/metabolismo , Masculino , Ratones , Ratones Pelados , Transducción de Señal/efectos de los fármacos , Neoplasias Cutáneas/metabolismo , Canales Catiónicos TRPV/metabolismoRESUMEN
Histone H2AX is a histone H2A variant that is ubiquitously expressed throughout the genome. It plays a key role in the cellular response to DNA damage and has been designated as the histone guardian of the genome. Histone H2AX deficiency decreases genomic stability and increases tumor susceptibility of normal cells and tissues. However, the role of histone H2AX phosphorylation in malignant transformation and cancer development is not totally clear. Herein, we found that ribosomal S6 kinase 2 (RSK2) directly phosphorylates histone H2AX at Ser139 and also at a newly discovered site, Ser16. Epidermal growth factor (EGF)-induced phosphorylation of histone H2AX at both sites was decreased in RSK2 knockout cells. Phosphorylated RSK2 and histone H2AX colocalized in the nucleus following EGF treatment, and the phosphorylation of histone H2AX by RSK2 enhanced the stability of histone H2AX and prevented cell transformation induced by EGF. RSK2 and DNA-PK, but not ATM or ATR, are required for EGF-induced phosphorylation of H2AX at Ser139; however, only RSK2 is required for phosphorylation of H2AX at Ser16. Phosphorylation of histone H3 was suppressed in cells expressing wild-type H2AX compared with H2AX knockout (H2AX-/-) cells. EGF-associated AP-1 transactivation activity was dramatically lower in H2AX-/- cells overexpressing wild-type H2AX than H2AX-/- cells expressing mutant H2AX-AA. Thus, the RSK2/H2AX signaling pathway negatively regulates the RSK2/histone H3 pathway and therefore maintains normal cell proliferation.
Asunto(s)
Transformación Celular Neoplásica/metabolismo , Histonas/metabolismo , Proteínas Quinasas S6 Ribosómicas 90-kDa/metabolismo , Proteínas de la Ataxia Telangiectasia Mutada , Adhesión Celular/fisiología , Proteínas de Ciclo Celular/metabolismo , Procesos de Crecimiento Celular/fisiología , Transformación Celular Neoplásica/patología , Proteína Quinasa Activada por ADN/metabolismo , Proteínas de Unión al ADN/metabolismo , Factor de Crecimiento Epidérmico/farmacología , Células HeLa , Histonas/biosíntesis , Humanos , Fosforilación , Proteínas Serina-Treonina Quinasas/metabolismo , Serina/metabolismo , Proteínas Supresoras de Tumor/metabolismo , UbiquitinaciónRESUMEN
The ribosomal S6 kinase 2 (RSK2) is a member of the p90 ribosomal S6 kinase (p90RSK) family of proteins and plays a critical role in proliferation, cell cycle, and cell transformation. Here, we report that RSK2 phosphorylates caspase-8, and Thr-263 was identified as a novel caspase-8 phosphorylation site. In addition, we showed that EGF induces caspase-8 ubiquitination and degradation through the proteasome pathway, and phosphorylation of Thr-263 is associated with caspase-8 stability. Finally, RSK2 blocks Fas-induced apoptosis through its phosphorylation of caspase-8. These data provide a direct link between RSK2 and caspase-8 and identify a novel molecular mechanism for caspase-8 modulation by RSK2.
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Apoptosis/fisiología , Caspasa 8/metabolismo , Proteínas Quinasas S6 Ribosómicas 90-kDa/metabolismo , Transducción de Señal/fisiología , Ubiquitinación/fisiología , División Celular/fisiología , Células HEK293 , Células HeLa , Humanos , Fosforilación/fisiología , Estabilidad Proteica , Treonina/metabolismoRESUMEN
MST1 (mammalian STE20-like kinase 1) is a serine/threonine kinase that is cleaved and activated by caspases during apoptosis. Overexpression of MST1 induces apoptotic morphological changes such as chromatin condensation, but the mechanism is not clear. Here we show that MST1 induces apoptotic chromatin condensation through its phosphorylation of histone H2AX at Ser-139. During etoposide-induced apoptosis in Jurkat cells, the cleavage of MST1 directly corresponded with strong H2AX phosphorylation. In vitro kinase assay results showed that MST1 strongly phosphorylates histone H2AX. Western blot and kinase assay results with a mutant S139A H2AX confirmed that MST1 phosphorylates H2AX at Ser-139. Direct binding of MST1 and H2AX can be detected when co-expressed in HEK293 cells and was also confirmed by an endogenous immunoprecipitation study. When overexpressed in HeLa cells, both the MST1 full-length protein and the MST1 kinase domain (MST1-NT), but not the kinase-negative mutant (MST1-NT-KN), could induce obvious endogenous histone H2AX phosphorylation. The caspase-3 inhibitor benzyloxycarbonyl-DEVD-fluoromethyl ketone (Z-DEVD-fmk) attenuates phosphorylation of H2AX by MST1 but cannot inhibit MST1-NT-induced histone H2AX phosphorylation, indicating that cleaved MST1 is responsible for H2AX phosphorylation during apoptosis. Histone H2AX phosphorylation and DNA fragmentation were suppressed in MST1 knockdown Jurkat cells after etoposide treatment. Taken together, our data indicated that H2AX is a substrate of MST1, which functions to induce apoptotic chromatin condensation and DNA fragmentation.
Asunto(s)
Regulación Neoplásica de la Expresión Génica , Factor de Crecimiento de Hepatocito/metabolismo , Histonas/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Apoptosis , Cromatina/química , Fragmentación del ADN , Etopósido/farmacología , Células HEK293 , Células HeLa , Histonas/química , Humanos , Células Jurkat , Fosforilación , Serina/químicaRESUMEN
The ribosomal S6 kinase 2 (RSK2) is a well-known serine/threonine kinase and a member of the p90 ribosomal S6 kinase (p90RSK) family of proteins. It is activated downstream of the MEK/ERKs cascade by mitogenic stimuli such as EGF or TPA. Here, we show that RSK2 is activated by treatment with tumor necrosis factor-alpha (TNF-alpha) and directly phosphorylates IkappaBalpha at Ser-32, leading to IkappaBalpha degradation. The phosphorylation of IkappaBalpha promotes the activation and translocation of the nuclear factor-kappaB (NF-kappaB) subunits p65 and p50 to the nucleus. The net result is an increased NF-kappaB activity, which serves as a mechanism for RSK2 blockade of TNF-alpha-induced apoptosis and enhanced cell survival.