Targeting BRAF in thyroid cancer ESPINOSA, A. V; PORCHIA, L; RINGEL, M. D
British journal of cancer,
01/2007, Letnik:
96, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Activating mutations in the gene encoding BRAF are the most commonly identified oncogenic abnormalities in papillary thyroid cancer. In vitro and in vivo models have demonstrated that overexpression ...of activated BRAF induces malignant transformation and aggressive tumour behaviour. BRAF and other RAF kinases are frequently activated by other thyroid oncogenes and are important mediators of their biological effects including dedifferentiation and proliferation. Because current therapeutic options for patients with thyroid cancers that are aggressive and/or do not respond to standard therapies are limited, BRAF and its downstream effectors represent attractive therapeutic targets. In this review, data supporting a role for BRAF activation in thyroid cancer development and establishing the potential therapeutic efficacy of BRAF-targeted agents in patients with thyroid cancer will be reviewed.
Virulent Newcastle disease viruses (NDV) have been present in Mexico since 1946, and recently, multiple outbreaks have been reported in the country. Here, we characterized eleven NDV isolated from ...apparently healthy wild birds and backyard chickens in three different locations of Jalisco, Mexico in 2017. Total RNA from NDV was reverse-transcribed, and 1285 nucleotides, which includes 3/4 of the fusion gene, was amplified and sequenced using a long-read MinION sequencing method. The sequences were 99.99–100% identical to the corresponding region obtained using the Illumina MiSeq. Phylogenetic analysis using MinION sequences demonstrated that nine virulent NDV from wild birds belonged to sub-genotypes Vc and VIn, and two backyard chicken isolates were of sub-genotype Vc. The sub-genotype Vc viruses had nucleotide sequence identity that ranged from 97.7 to 98% to a virus of the same sub-genotype isolated from a chicken in Mexico in 2010. Three viruses from pigeons had 96.3–98.7% nucleotide identity to sub-genotype VIn pigeon viruses, commonly referred to as pigeon paramyxovirus, isolated in the USA during 2000–2016. This study demonstrates that viruses of sub-genotype Vc are still present in Mexico, and the detection of this sub-genotype in both chickens and wild birds suggests that transmission among these species may represent a biosecurity risk. This is the first detection and complete genome sequencing of genotype VI NDV from Mexico. In addition, the utilization of an optimized long-read sequencing method for rapid virulence and genotype identification using the Oxford nanopore MinION system is demonstrated.
While changes in intracellular calcium levels is a central step in platelet activation and thrombus formation, the contribution and mechanism of receptor-operated calcium entry (ROCE) via transient ...receptor potential channels (TRPCs) in platelets remains poorly defined. In previous studies, we have shown that TRPC6 regulates hemostasis and thrombosis, in mice. In the present studies, we employed a knockout mouse model system to characterize the role of TRPC6 in ROCE and platelet activation. It was observed that the TRPC6 deletion (Trpc6−/−) platelets displayed impaired elevation of intracellular calcium, i.e., defective ROCE. Moreover, these platelets also exhibited defects in a host of functional responses, namely aggregation, granule secretion, and integrin αIIbβ3. Interestingly, the aforementioned defects were specific to the thromboxane receptor (TPR), as no impaired responses were observed in response to ADP or the thrombin receptor-activating peptide 4 (TRAP4). The defect in ROCE in the Trpc6−/− was also observed with 1-oleoyl-2-acetyl-sn-glycerol (OAG). Finally, our studies also revealed that TRPC6 regulates clot retraction. Taken together, our findings demonstrate that TRPC6 directly regulates TPR-dependent ROCE and platelet function. Thus, TRPC6 may serve as a novel target for the therapeutic management of thrombotic diseases.
•TRPC6 regulates TPR-mediated/receptor-operated calcium entry.•TRPC6 regulates TPR-dependent platelet aggregation, secretion and integrin activation.•TRPC6 regulates clot retraction.•TRPC6 expression levels are age-dependent in platelets.
► The transient receptor potential channel 6 (TRPC6) plays a key role in hemostasis. ► TRPC6 plays a key role in the pathogenesis of occlusive thrombotic disorders. ► TRPC6 may define a new ...therapeutic target for managing thrombosis-based disorders.
Although changes in the intracellular levels of calcium (Ca2+) are a central step in platelet activation, the underlying mechanism of Ca2+ entry is still unclear. Previous studies have demonstrated that TRPC6, a member of the canonical transient receptor potential channel (TRPC) family is expressed in platelets in a significant amount, and is predominantly found on the plasma membrane. Based on these considerations, we hypothesized that TRPC6 plays a critical role in platelet function. To characterize the role of TRPC6 in platelet function in vivo, we employed a genetic approach, subjecting TRPC6 knockout mice to the tail bleeding time test and a carotid artery injury thrombosis model. We found that TRPC6-deficient animals displayed a prolonged bleeding time, and an increased time for occlusion of the injured carotid artery, compared to their wild-type littermates. Taken together, our data demonstrate for the first time, that TRPC6 deletion in mice results in defects in hemostasis and protection against thrombogenesis, suggesting a vital role in platelet function. Furthermore, TRPC6 may define a new therapeutic target for managing multiple thrombosis-based disorders.
BACKGROUNDDespite the well-established role for the thromboxane A2 receptor (TPR) in the development of thrombotic disorders, none of the antagonists developed to date has been approved for clinical ...use. To this end, we have previously shown that an antibody targeted against TPR's ligand-binding domain inhibits platelet activation and thrombus formation, without exerting any effects on hemostasis. Thus, the goal of the present studies is to design a novel TPR-based vaccine, demonstrate its ability to trigger an immune response, and characterize its antiplatelet and antithrombotic activity.METHODS AND RESULTSWe used a mouse keyhole limpet hemocyanin/peptide-based vaccination approach rationalized over the TPR ligand-binding domain (ie, the C-terminus of the second extracellular loop). The biological activity of this vaccine was assessed in the context of platelets and thrombotic diseases, and using a host of in vitro and in vivo platelet function experiments. Our results revealed that the TPR C-terminus of the second extracellular loop vaccine, in mice: (1) triggered an immune response, which resulted in the development of a C-terminus of the second extracellular loop antibody; (2) did not affect expression of major platelet integrins (eg, glycoprotein IIb-IIIa); (3) selectively inhibited TPR-mediated platelet aggregation, platelet-leukocyte aggregation, integrin glycoprotein IIb-IIIa activation, as well as dense and α granule release; (4) significantly prolonged thrombus formation; and (5) did so without impairing physiological hemostasis.CONCLUSIONSCollectively, our findings shed light on TPR's structural biological features, and demonstrate that the C-terminus of the second extracellular loop domain may define a new therapeutic target and a TPR vaccine-based approach that should have therapeutic applications.
Abstract Drug addiction is a state of altered brain reward and self-regulation mediated by both neurotransmitter and hormonal systems. Although an organism's internal system attempts to maintain ...homeostasis when challenged by exogenous opiates and other drugs of abuse, it eventually fails, resulting in the transition from drug use to drug abuse. We propose that the attempted maintenance of hormonal homeostasis is achieved, in part, through alterations in levels of processing enzymes that control the ratio of active hormone to pro-hormone. Two pro-hormone convertases, PC1/3 and PC2 are believed to be responsible for the activation of many neurohormones and expression of these enzymes is dependent on the presence of a cyclic-AMP response element (CRE) in their promoters. Therefore, we studied the effects of short-term (24-h) and long-term (7-day) morphine treatment on the expression of hypothalamic PC1/3 and PC2 and levels of phosphorylated cyclic-AMP-response element binding protein (P-CREB). While short-term morphine exposure down-regulated, long-term morphine exposure up-regulated P-CREB, PC1/3 and PC2 protein levels in the rat hypothalamus as determined by Western blot analysis. Quantitative immunofluorescence studies confirmed these regulatory actions of morphine in the paraventricular and dorsomedial nucleus of the hypothalamus. Specific radioimmunoassays demonstrated that the increase in PC1/3 and PC2 levels following long-term morphine led to increased TRH biosynthesis as evidence by increased TRH/5.4 kDa C-terminal proTRH-derived peptide ratios in the median eminence. Promoter activity experiments in rat somatomammotrope GH3 cells containing the mu-opioid receptor demonstrated that the CRE(s) in the promoter of PC1/3 and PC2 is required for morphine-induced regulation of PC1/3 and PC2. Our data suggest that the regulation of the prohormone processing system by morphine may lead to alterations in the levels of multiple bioactive hormones and may be a compensatory mechanism whereby the organism tries to restore its homeostatic hormonal milieu. The down-regulation of PC1/3, PC2 and P-CREB by short-term morphine and up-regulation by long-term morphine treatment may be a signal mediating the switch from drug use to drug abuse.
Objective: Tumor metastasis is a critical determinant of death from cancer. Metastin, a product of the KiSS-1 gene, is an endogenously expressed metastasis suppressor that is the ligand for G ...protein-coupled receptor 54 (GPR54), a Gq/11-coupled receptor. In the present study, our goal was to define the basis of GPR54 action using thyroid cancer cells as a model.
Design and Results: We used GPR54-null thyroid cancer cells to create a stable GPR54 overexpression model. Cell growth and cell migration of the GPR54-expressing lines were inhibited by recombinant metastin, and metastin stimulated the protein kinase C, ERK, and phosphatidylinositol-3-kinase pathways. To identify metastin-regulated genes, we performed microarray analyses using RNA isolated from GPR54 stable transfectants before and after 1 and 24 h of metastin stimulation. Consistent increases in expression of the gene encoding myocyte-enriched calcineurin interacting protein 1 (MCIP-1), an inhibitor of calcineurin, were identified and confirmed using real-time RT-PCR and Western blot. Functionally, metastin treatment of GPR54-expressing cells initially increased calcineurin activity, followed by a prolonged reduction in calcineurin activity for 24 and 48 h, consistent with the pattern of MCIP-1 expression. In addition, treatment with cyclosporin A, a calcineurin inhibitor, blocked cell migration. Lymph node metastasis in papillary thyroid cancers demonstrated loss of MCIP-1 expression in comparison with primary tumors.
Conclusions: These data suggest a role for MCIP-1 and calcineurin inhibition in GPR54-mediated metastasis suppression in human cancers.
Leptospira interrogans has been identified to cause leptospirosis, a widespread zoonotic disease that has been identified in domestic and wild animals. This work analyzed kidneys from two species of ...wild rodents from the state of Campeche, Mexico. Analyses were made by PCR using specific primers for detection of Leptospira interrogans DNA. The rodent species that tested positive were Heteromys gaumeri and Ototylomys phyllotis, both of which are new hosts for the bacteria in Southeastern Mexico. These records provide new insights into the disease's transmission that should be studied carefully in order to identify other potential host species, including humans, which are at risk of becoming infected if they are in contact with infected wildlife.
The premise of targeted therapy was born from an intimate understanding of the unique biological pathways and endpoints which are implicated in the development of different disease states and ...conditions. In addition, the identification of the most appropriate drugs to use for targeted drug therapy has aided in growing interest of the pharmaceutical industry to allocate more resources to monoclonal antibody (mAb) therapeutics. This being the case, it is important to understand antibody based therapeutics, some of the currently Food and Drug Administration (FDA)-approved mAbs in different disease states, as well as the future direction of mAb therapies. In this article, we will provide a critical overview, and discuss a selection of antibody based therapeutics, including their bioengineered structural and functional elements. Furthermore, a segment of the currently FDA-approved mAb antibody therapies, those in research, or in investigation for disease states and conditions ranging from autoimmune disease, inflammatory response, immunosuppression, cancer, including antibody-drug conjugates, immunotherapy, and exciting prospects for antiplatelet and antithrombotic monoclonal antibody therapeutics will be reviewed. Finally, we will discuss our predictions and aspirations for the future directions of mAb-based therapeutic interventions.
•Stone-on-stone contact (SOSC) of permeable friction course (PFC) mixtures was analyzed.•Image analyses proved irregular distributions of SOSC in compacted PFC mixtures.•Verification of both SOSC and ...Cantabro loss was recommended for improving the PFC mixture design.•Compaction control was recommended for PFC mixtures to ensure fully developed SOSC.
The main features that differentiate permeable friction course (PFC) mixtures from dense-graded asphalt mixtures are the high total air voids content—18 to 22%—and stone-on-stone contact condition in the coarse-aggregate fraction of the PFC mixtures. The main purpose of ensuring these features is providing improved functional properties to the PFC mixtures, including high drainability, surface texture, and noise reduction capacity. In this context, the research objective was to evaluate the PFC mixture internal structure, in terms of the quantification of stone-on-stone contact based on the analysis of digital images. PFC mixtures fabricated with both asphalt rubber and polymer-modified asphalt were characterized. Corresponding analyses of the relationship between the microstructure- and macroscopic-parameters used to characterize the stone-on-stone contact supported the importance of verifying both the voids in the coarse aggregate ratio and Cantabro loss to properly screening the PFC mixture performance. In addition, controlling the compaction process is required to fully develop the stone-on-stone contact condition and consequently ensure adequate resistance to both mixture disintegration and permanent deformation.
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