RESUMEN
Akt, a serine-threonine protein kinase, is regulated by class-I PI3K signaling. Akt regulates a wide variety of cell processes including cell proliferation, survival, and angiogenesis through serine/threonine phosphorylation of downstream targets including mTOR and glycogen-synthase-kinase-3-beta (GSK3ß). Targeting cancer-specific overexpression of Akt protein could be an efficient way to control cancer-cell proliferation. However, the ATP-competitive inhibitors are challenged by the highly conserved ATP binding site, and by competition with high cellular concentrations of ATP. We previously developed an allosteric inhibitor, 2-arylidene-4, 7-dimethyl indan-1-one (FXY-1) that showed promising activity against several lung cancer models. In this work, we designed a congeneric series of molecules based on FXY-1 and optimized lead based on computational, in vitro assays. Computational screening followed by enzyme-inhibition and cell-proliferation assays identified a derivative (FCX-146) as a new lead molecule with threefold greater potency than the parent compound. FCX-146 increased apoptosis in HL-60 cells, mediated in part through decreased expression of antiapoptotic Bcl-2 protein and increased levels of Bax-2 and Caspase-3. Molecular-dynamic simulations showed stable binding of FCX-146 to an allosteric (i.e., noncatalytic) pocket in Akt. Together, we propose FCX-146 as a potent second-generation arylidene indanone compound that binds to the allosteric pocket of Akt and potently inhibits its activation.
Asunto(s)
Indanos , Simulación de Dinámica Molecular , Neoplasias , Inhibidores de Proteínas Quinasas , Proteínas Proto-Oncogénicas c-akt , Transducción de Señal/efectos de los fármacos , Regulación Alostérica/efectos de los fármacos , Proteínas Reguladoras de la Apoptosis/biosíntesis , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Células HL-60 , Humanos , Indanos/química , Indanos/farmacología , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Neoplasias/patología , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-akt/química , Proteínas Proto-Oncogénicas c-akt/metabolismoRESUMEN
In eukaryotes the ubiquitin proteasome pathway plays an important role in cellular homeostasis and also it exerts a critical role in regulating a wide variety of cellular pathways, including cell growth and proliferation, apoptosis, DNA repair, transcription and immune response. Defects in these pathways have been implicated in a number of human pathologies. Inhibition of the ubiquitin proteasome pathway by proteasome inhibitors may be a rational therapeutic approach for various diseases, such as cancer and inflammatory diseases. Many of the critical cytokine and chemokine mediators of the progression of rheumatoid arthritis are regulated by nuclear factor kappa B (NF-κB). In peptidoglycan/polysaccharide-induced polyarthritis, proteasome inhibitors limit the overall inflammation, reduce NF-κB activation, decrease cellular adhesion molecule expression, inhibit nitric oxide synthase, attenuate circulating levels of proinflammatory cytokine interleukin-6 and reduce the arthritis index and swelling in the joints of the animals. Since proteasome inhibitors exhibit anti-inflammatory and anti proliferative effects, diseases characterized by both of these processes such as rheumatoid arthritis might also represent clinical opportunities for such drugs. The regulation of the proteasomal complex by proteasome inhibitors also has implications and potential benefits for the treatment of rheumatoid arthritis. This review summarizes the ubiquitin proteasome pathway, the structure of 26S proteasomes and types of proteasome inhibitors, with their actions, and clinical applications of proteasome inhibitors in various diseases.
Asunto(s)
Antiinflamatorios/uso terapéutico , Antineoplásicos/uso terapéutico , Antirreumáticos/uso terapéutico , Inhibidores de Proteasas/uso terapéutico , Inhibidores de Proteasoma , Animales , Proliferación Celular/efectos de los fármacos , Humanos , Mediadores de Inflamación/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Transducción de Señal , UbiquitinaciónRESUMEN
AIM: To assess the oxidative stress status in rheumatoid arthritis by measuring markers of free radical production, systemic activity of disease, free radical mediated tissue destruction and levels of antioxidant. METHODS: Peripheral blood samples were used for all the assays. Total nitric oxide (NO) was quantitatively measured using immunoassay kit. Malondialdehyde (MDA) and vitamin E were measured by spectrophotometric methods. RESULTS: Statistically significant changes were observed in the levels of MDA, vitamin E, total NO and erythrocyte sedimentation rate (ESR) in the patient group. Significant differences were also observed in ESR and vitamin E levels in patients with active disease. CONCLUSIONS: Increased oxidative stress status exists, which may lead to connective tissue degradation leading to joint and periarticular deformities in rheumatoid arthritis.