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Attractive Therapeutic Target (attractive + therapeutic_target)
Selected AbstractsSmall molecule c-MET inhibitor PHA665752: Effect on cell growth and motility in papillary thyroid carcinomaHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 8 2008Chandrani Chattopadhyay PhD Abstract Background c-Met is upregulated in papillary thyroid carcinoma (PTC) and can be an attractive therapeutic target. We tested the effects of the small molecule c-met inhibitor PHA665752 in blocking c-met,dependent phenotypic effects in PTC cell lines. Methods PTC patient tissues and cell lines were evaluated for c-met expression. The effect of PHA665752 on c-met phosphorylation, downstream signaling, hepatocyte growth factor (HGF),dependent cell growth, and induction of apoptosis was studied. The IC50 of PHA665752 in c-met,expressing PTC cells was determined, and growth curves at 0.1×, 1×, and 10× IC50 concentrations were obtained. Poly(ADP-ribose) polymerase (PARP) and caspase-9-processing post-PHA665752 treatment were studied as markers of apoptosis, and assays analyzing HGF-dependent cell invasion and migration in the presence and absence of PHA665752 were done. Results c-Met was upregulated in most of the patient tissues with PTC and in many PTC cell lines. PHA665752 specifically inhibited c-met phosphorylation, c-met,dependent cell growth, signal transduction, cell survival, cell invasion, and migration in PTC cells with high c-met. Conclusions PHA665752 is an effective and specific inhibitor of c-met in PTC cells with high levels of c-met expression. © 2008 Wiley Periodicals, Inc. Head Neck, 2008 [source] CD4+ T-regulatory cells: toward therapy for human diseasesIMMUNOLOGICAL REVIEWS, Issue 1 2008Sarah E. Allan Summary T-regulatory cells (Tregs) have a fundamental role in the establishment and maintenance of peripheral tolerance. There is now compelling evidence that deficits in the numbers and/or function of different types of Tregs can lead to autoimmunity, allergy, and graft rejection, whereas an over-abundance of Tregs can inhibit anti-tumor and anti-pathogen immunity. Experimental models in mice have demonstrated that manipulating the numbers and/or function of Tregs can decrease pathology in a wide range of contexts, including transplantation, autoimmunity, and cancer, and it is widely assumed that similar approaches will be possible in humans. Research into how Tregs can be manipulated therapeutically in humans is most advanced for two main types of CD4+ Tregs: forkhead box protein 3 (FOXP3)+ Tregs and interleukin-10-producing type 1 Tregs (Tr1 cells). The aim of this review is to highlight current information on the characteristics of human FOXP3+ Tregs and Tr1 cells that make them an attractive therapeutic target. We discuss the progress and limitations that must be overcome to develop methods to enhance Tregs in vivo, expand or induce them in vitro for adoptive transfer, and/or inhibit their function in vivo. Although many technical and theoretical challenges remain, the next decade will see the first clinical trials testing whether Treg-based therapies are effective in humans. [source] Cyclic nucleotide phosphodiesterases and their role in immunomodulatory responses: Advances in the development of specific phosphodiesterase inhibitorsMEDICINAL RESEARCH REVIEWS, Issue 2 2005Ana Castro Abstract The activity of phosphodiesterases (PDEs) is associated with a wide variety of diseases and an intense effort toward the development of specific PDEs inhibitors has been generated for the last years. They are the enzymes responsible for the hydrolysis of intracellular cyclic adenosine and guanosine monophosphate, and their complexity, as well as their different functional role, makes these enzymes a very attractive therapeutic target. This review is focused on the role of PDEs played on immunomodulatory processes and the advance on the development of specific inhibitors, covering PDEs mainly related to the regulation of autoimmune processes, PDE4 and PDE7. The review also highlights the novel structural classes of PDE4 and PDE7 inhibitors, and the therapeutic potential that combined PDE4/PDE7 inhibitors offer as immunomodulatory agents. © 2004 Wiley Periodicals, Inc. Med Res Rev [source] S-phase kinase protein 2 is an attractive therapeutic target in a subset of diffuse large B-cell lymphoma,THE JOURNAL OF PATHOLOGY, Issue 4 2008S Uddin Abstract S-phase kinase protein 2 (SKP2), an F-box protein, targets cell-cycle regulators including cycle-dependent kinase inhibitor p27KiP1 via ubiquitin-mediated degradation. SKP2 is frequently overexpressed in a variety of cancer cells and has been implicated in oncogenesis; however, its role in diffuse large B-cell lymphoma (DLBCL) has not been elucidated. Therefore, we investigated the role of SKP2 and its ubiquitin-proteasome pathway in a large series (301) of DLBCL patient samples and a panel of DLBCL cell lines. Using immunohistochemistry, SKP2 was detected in 41.6% of DLBCL tumours and was inversely associated with p27Kip1 protein level. The DLBCL subset with high SKP2 and low p27Kip1 showed a strong correlation with the proliferating index marker Ki-67 (p < 0.0001) and also with the germinal centre phenotype (p = 0.0147). Treatment of DLBCL cell lines with bortezomib or expression of SKP2-specific siRNA causes down-regulation of SKP2 and accumulation of p27Kip1, leading to suppression of growth by inducing apoptosis. Furthermore, treatment of DLBCL cells with bortezomib causes apoptosis via involving the mitochondrial pathway and activation of caspases. Finally, treatment of DLBCL cells with bortezomib down-regulated the expression of XIAP, cIAP1, and survivin. Altogether, these results suggest that SKP2 and the ubiquitin-proteasome pathway may be a potential target for therapeutic intervention in DLBCL. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source] The critical role of kinase activity of interleukin-1 receptor,associated kinase 4 in animal models of joint inflammationARTHRITIS & RHEUMATISM, Issue 6 2009Magdalena Koziczak-Holbro Objective We have previously reported that the kinase activity of interleukin-1 receptor,associated kinase 4 (IRAK-4) is important for Toll-like receptor and interleukin-1 receptor signaling in vitro. Using mice devoid of IRAK-4 kinase activity (IRAK-4 KD mice), we undertook this study to determine the importance of IRAK-4 kinase function in complex disease models of joint inflammation. Methods IRAK-4 KD mice were subjected to serum transfer,induced (K/BxN) arthritis, and migration of transferred spleen lymphocytes into joints and cartilage and bone degradation were assessed. T cell response in vivo was tested in antigen-induced arthritis (AIA) by measuring the T cell,dependent antigen-specific IgG production and frequency of antigen-specific T cells in the spleen and lymph nodes. T cell allogeneic response was tested in vitro by mixed lymphocyte reaction (MLR). Results Lipopolysaccharide-induced local neutrophil influx into subcutaneous air pouches was impaired in IRAK-4 KD mice. These mice were also protected from inflammation in the K/BxN and AIA models, as shown by reduced swelling of joints. Histologic analysis of joints of K/BxN serum,injected mice revealed that bone erosion, osteoclast formation, and cartilage matrix proteoglycan loss were reduced in IRAK-4 KD mice. Assessment of T cell response by MLR, by frequency of antigen-specific clones, and by production of antigen-specific IgG did not reveal substantial differences between IRAK-4 KD and wild-type mice. Conclusion These results demonstrate that IRAK-4 is a key component for the development of proarthritis inflammation, but that it is not crucial for T cell activation. Therefore, the kinase function of IRAK-4 appears to be an attractive therapeutic target in chronic inflammation. [source] Emodin, a natural product, selectively inhibits 11,-hydroxysteroid dehydrogenase type 1 and ameliorates metabolic disorder in diet-induced obese miceBRITISH JOURNAL OF PHARMACOLOGY, Issue 1 2010Ying Feng BACKGROUND AND PURPOSE 11,-Hydroxysteroid dehydrogenase type 1 (11,-HSD1) is an attractive therapeutic target of type 2 diabetes and metabolic syndrome. Emodin, a natural product and active ingredient of various Chinese herbs, has been demonstrated to possess multiple biological activities. Here, we investigated the effects of emodin on 11,-HSD1 and its ability to ameliorate metabolic disorders in diet-induced obese (DIO) mice. EXPERIMENTAL APPROACH Scintillation proximity assay was performed to evaluate inhibition of emodin against recombinant human and mouse 11,-HSDs. The ability of emodin to inhibit prednisone- or dexamethasone-induced insulin resistance was investigated in C57BL/6J mice and its effect on metabolic abnormalities was observed in DIO mice. KEY RESULTS Emodin is a potent and selective 11,-HSD1 inhibitor with the IC50 of 186 and 86 nM for human and mouse 11,-HSD1, respectively. Single oral administration of emodin inhibited 11,-HSD1 activity of liver and fat significantly in mice. Emodin reversed prednisone-induced insulin resistance in mice, whereas it did not affect dexamethasone-induced insulin resistance, which confirmed its inhibitory effect on 11,-HSD1 in vivo. In DIO mice, oral administration of emodin improved insulin sensitivity and lipid metabolism, and lowered blood glucose and hepatic PEPCK, and glucose-6-phosphatase mRNA. CONCLUSIONS AND IMPLICATIONS This study demonstrated a new role for emodin as a potent and selective inhibitor of 11,-HSD1 and its beneficial effects on metabolic disorders in DIO mice. This highlights the potential value of analogues of emodin as a new class of compounds for the treatment of metabolic syndrome or type 2 diabetes. [source] Small interfering RNA-mediated down-regulation of SPAG9 inhibits cervical tumor growthCANCER, Issue 24 2009Manoj Garg PhD Abstract BACKGROUND: The expression of the SPAG9 is associated with various human malignancies. Earlier work revealed a significant association of SPAG9 expression with the early spread of cervical cancer, making it an attractive therapeutic target. Here, the authors investigated the role of SPAG9 in carcinogenesis of squamous cell carcinoma (SCC) of the cervix. Furthermore, they sought to determine whether ablation of SPAG9 expression reduces the tumor growth of cervical SCC in vivo. METHODS: A plasmid-based small interfering RNA approach was used to specifically knock down the expression of SPAG9 in SiHa cells derived from SCC of the cervix in vitro and in vivo. Reverse transcriptase polymerase chain reaction, immunofluorescence staining, flow cytometry, cellular growth, colony formation, migration, invasion, and wound healing assays were studied to characterize SPAG9 in vitro. Furthermore, a cervical cancer xenograft model in nude mice was established to investigate whether knockdown of SPAG9 reduces the tumor growth of cervical SCC in vivo. RESULTS: The results demonstrated that silencing the SPAG9 by small interfering RNA resulted in inhibition of cell growth, colony formation, migration, and invasion. The authors showed for the first time that the knockdown of SPAG9 expression by small interfering RNA significantly suppressed the tumor growth of cervical SCC in vivo. CONCLUSIONS: These results suggest that SPAG9 expression may play a pivotal role in tumor growth and could contribute to the early spread of cervical cancer. Small interfering RNA-mediated down-regulation of SPAG9 represents a promising therapeutic approach for the treatment of cervical cancer. Cancer 2009. © 2009 American Cancer Society. [source] PAMAM Dendrimers Mediate siRNA Delivery to Target Hsp27 and Produce Potent Antiproliferative Effects on Prostate Cancer CellsCHEMMEDCHEM, Issue 8 2009Xiao-xuan Liu Abstract RNA interference (RNAi) holds great promise for the treatment of inherited and acquired diseases, provided that safe and efficient delivery systems are available. Herein we report that structurally flexible triethanolamine (TEA) core PAMAM dendrimers are able to deliver an Hsp27 siRNA effectively into prostate cancer (PC-3) cells by forming stable nanoparticles with siRNA, protecting the siRNA nanoparticles from enzymatic degradation, and enhancing cellular uptake of siRNA. The Hsp27 siRNA resulted in potent and specific gene silencing of heat-shock protein,27, an attractive therapeutic target in castrate-resistant prostate cancer. Silencing of the hsp27 gene led to induction of caspase-3/7-dependent apoptosis and inhibition of PC-3 cell growth in,vitro. In addition, the siRNA,dendrimer complexes are non-cytotoxic under the conditions used for siRNA delivery. Altogether, TEA core PAMAM dendrimer-mediated siRNA delivery, in combination with RNAi that specifically targets Hsp27, may constitute a promising approach for combating castrate-resistant prostate cancer, for which there is no efficacious treatment. [source] | |||||||||||||