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Riise Mejer posted an update 3 days, 8 hours ago
Signal transducer and activator of transcription (STAT) proteins are latent transcription factors that reside in the cytoplasm of several types of cells. In canonical signaling, upon stimulation by cytokines and growth factors, STATs get activated and translocate into the nucleus to transcribe target genes. Among STATs, the STAT3 variant has been studied extensively and implicated in diverse human malignancies. Transcriptionally, STAT3 can upregulate the expression of genes associated with cell proliferation, antiapoptosis, prosurvival, angiogenesis, metastasis, and immune evasion. STAT3 can be constitutively activated in a broad range of human cancers including solid as well as hematological tumors and overexpression of STAT3 has been observed in a wide-range of patient-derived tumor tissue samples that may contribute to dismal prognosis. In contrast, blockade of STAT3 activation using inhibitors or knockdown systems can markedly suppress tumor progression, thus highlighting the significance of abrogating STAT3 signaling cascade in cancer therapy. In this review, we have provided a comprehensive overview of mechanisms of STAT3 signal transduction and its endogenous negative modulators, the role of STAT3 in oncogenesis, the interplay of miRNAs in STAT3 signaling, and mechanisms involved in persistent activation of STAT3. Furthermore, the review also provides a detailed overview of STAT3 signaling inhibition by selected natural compounds, which have displayed potent activity in various preclinical cancer model. CALGB (Alliance) 100001 was a phase II study evaluating autologous stem cell transplant (ASCT) followed by non-myeloablative allogeneic stem cell transplant (alloSCT) in patients with multiple myeloma who had received no more than 18 months of prior therapy and had experienced no more than one prior progression event. Conditioning for ASCT was with high-dose melphalan (200 mg/m2). The alloSCT reduced-intensity conditioning (RIC) regimen consisted of fludarabine (30 mg/m2/day IV on days -7 through -3) and cyclophosphamide (1 g/m2/day IV on days -4 through -3). The primary objective was to determine the six-month post-alloSCT treatment-related mortality (TRM) rate. Additional objectives included determining the proportion of patients who could complete this tandem ASCT-alloSCT approach in a cooperative group setting, overall response rates, rates of donor chimerism, rates of graft-versus-host (GVHD), disease-free survival (DFS) and overall survival (OS). Sixty patients were enrolled, of which 57 (95%) completed ASCT and 49 (82%) completed tandem ASCT-alloSCT. The TRM rate was 2% (1/49, 90% CI 0.10-9.3%). Moderate to severe (grade 2-3) acute GVHD was observed in 13 of 49 alloSCT patients (27%). One patient died due to GVHD within 9 months of alloSCT. Twenty-seven of the 49 patients (55%) who underwent alloSCT reported chronic GVHD as either limited (15/49; 31%) or extensive (12/49; 24%) in the first year post-alloSCT and prior to the start of non-protocol therapy for progressive disease. With a median follow-up for survival of 11 years, the median OS time is 6.6 years and the median time to disease progression is 3.6 years. Similar to other studies, this study confirmed that tandem ASCT/alloSCT is associated with durable disease control in a subset of patients. This study demonstrated the feasibility of performing tandem ASCT/alloSCT in a cooperative group setting and determined that a fludarabine/cyclophosphamide RIC regimen is associated with a very low TRM rate. Microbial interactions may impact patient’s diagnosis, prognosis and treatment. Sporotrichosis is a hyperendemic neglected zoonosis in Brazil, caused by Sporothrix brasiliensis. Four pairs of clinical isolates of Sporothrix were recovered from four diseased cats (CIM01-CIM04, two isolates per animal) raising the possibility of coinfection in a sporotrichosis hyperendemic area, Brazil. Each isolate of the pair had distinct pigmentation in mycological culture, and was designated as “Light” or “Dark”, for low and high pigmentation, respectively. Dark isolates reacted strongly with monoclonal antibodies to melanin (p ≤ 0.05) by both ELISA and FACS quantitation, and displayed a ring pattern with some regions exhibiting higher punctuated labeling at cell wall by immunofluorescence. TTK21 cost In turn, Light isolates reacted less intensely, with few and discrete punctuated labeling at the cell wall. PCR identified all isolates as S. brasiliensis, MAT1-2 idiomorph. Sequencing of β-tubulin and calmodulin genes followed by phylog phenotypic parameters it is quite possible that coinfection represents a common occurrence in the hyperendemic area, with potential clinical implications on feline sporotrichosis dynamics. Alternatively, future studies will address if this specie may have, as reported for other fungi, broad phenotypic plasticity. The ubiquitin proteasome system is critical for the regulation of protein turnover, which is implicated in the modulation of a wide array of biological processes in eukaryotes, ranging from cell senescence to virulence in plant and human hosts. Proteins to be marked for ubiquitination and subsequent degradation are bound by F-box proteins, which are interchangeable substrate-recognising receptors. These F-box proteins bind a wide range of substrates and associate with the adaptor protein Skp1 and the scaffold Cul1 to form Skp1-Cul1-F-box (SCF) complexes. SCF complex components are highly conserved in eukaryotes, ranging from yeast to humans. However, information regarding the composition of these complexes and the biological roles of F-box proteins is limited, specifically in filamentous fungal species like the genus Aspergillus. In this study, we have identified 51 and 55 fbx-encoding genes in the genomes of two pathogenic fungi, A. fumigatus and A. flavus, respectively. Immunoprecipitations of the HA-tagged SkpA adaptor protein revealed that 26 F-box proteins in A. fumigatus and 30 F-box proteins in A. flavus are involved in SCF complex formation during vegetative growth. These interactome data also revealed that a diverse array of SCF complex conformations exist in response to various exogenous stressors. Lastly, we have provided evidence that the F-box protein Fbx45 interacts with SkpA in both species in response to Amphotericin B. Orthologs of the fbx45 gene are highly conserved in Aspergillus species, but are not present within the genomes of organisms such as yeast, plants or humans. This suggests that Fbx45 could potentially be a novel F-box protein that is unique to specific filamentous fungi such as Aspergillus species.