168 research outputs found
Could the Anti-Chaperone VER155008 Replace Temozolomide for Glioma Treatment
Cancer inducible molecular chaperone HSP90 is of great importance as an anticancer target. Proteomic analysis showed that inhibiting HSP90 by the geldanamycin derivative, 17-AAG elevated the expression of the co-chaperone Hsp70. In this study we used HSP90 selective inhibitor 17-AAG and HSP70/90 dual inhibitor, VER155008 (VER) in U87-MG glioma cells. miRNAs microarray technology was used to evaluate the efficacy of these inhibitory drugs compared with temozolomide (TMZ), used as a standard treatment for glioma. Microarrays data identified 154 differentially expressed miRNAs using stringent or unstringent parameters. 16 miRNAs were overlapped between treatments, 13 upregulated and one downregulated miRNA were overlapped between TMZ and VER. The miRNA target prediction software was used for these overlapped miRNAs and identified 6 of the 13 upregulated miRNAs target methyltransferase genes. The IC50, together with Akt and HSP70 and 90 protein level data favour VER and TMZ to 17-AAG, however due to the selectivity of VER to cancer cells as a potent antichaperon, it may be more favourable to the standard TMZ
Could Upregulated Hsp70 Protein Compensate for the Hsp90-Silence-Induced Cell Death in Glioma Cells?
The molecular chaperone heat shock protein 90 alpha (Hsp90Ī±) has been recognized in various tumours including glioma. This pilot study using a proteomic approach analyses the downstream effects of Hsp90 inhibition using 17-allylamino-17-demethoxygeldanamycin (17AAG) and a short hairpin RNA (shRNA) oligonucleotide targeting hsp90Ī± (shhsp90Ī±) in the U87-MG glioma cell line. Preliminary data coupled with bioinformatic analysis identified several known and unknown Hsp90 client proteins that demonstrated a change in their protein expression after Hsp90 inhibition, signifying an alteration in the canonical pathways of cell cycle progression, apoptosis, cell invasion, angiogenesis, and metastasis. Members of the glycolysis pathway were upregulated, demonstrating increased dependency on glycolysis for energy source by the treated glioma cells. Upregulated proteins also include Hsp70 and members of its family such as Hsp27 and gp96, thereby suggesting the role of Hsp90 co-chaperones in compensating for Hsp90 function after Hsp90 inhibition. Considering Hsp70ās role in antiapoptosis, it was postulated that a combination therapy involving a multitarget approach could be carried out. Consequently inhibition of both Hsp90 and Hsp70 in U87-MG glioma cells resulted in 60% cell death indicating the importance of combination therapy for glioma therapeutics
Could Upregulated Hsp70 Protein Compensate for the Hsp90-Silence-Induced Cell Death in Glioma Cells?
The molecular chaperone heat shock protein 90 alpha (Hsp90Ī±) has been recognized in various tumours including glioma. This pilot study using a proteomic approach analyses the downstream effects of Hsp90 inhibition using 17-allylamino-17-demethoxygeldanamycin (17AAG) and a short hairpin RNA (shRNA) oligonucleotide targeting hsp90Ī± (shhsp90Ī±) in the U87-MG glioma cell line. Preliminary data coupled with bioinformatic analysis identified several known and unknown Hsp90 client proteins that demonstrated a change in their protein expression after Hsp90 inhibition, signifying an alteration in the canonical pathways of cell cycle progression, apoptosis, cell invasion, angiogenesis, and metastasis. Members of the glycolysis pathway were upregulated, demonstrating increased dependency on glycolysis for energy source by the treated glioma cells. Upregulated proteins also include Hsp70 and members of its family such as Hsp27 and gp96, thereby suggesting the role of Hsp90 co-chaperones in compensating for Hsp90 function after Hsp90 inhibition. Considering Hsp70ās role in antiapoptosis, it was postulated that a combination therapy involving a multitarget approach could be carried out. Consequently inhibition of both Hsp90 and Hsp70 in U87-MG glioma cells resulted in 60% cell death indicating the importance of combination therapy for glioma therapeutics
A novel series of phenolic temozolomide (TMZ) esters with 4 to 5-fold increased potency, compared to TMZ, against glioma cells irrespective of MGMT expressionā
The standard of care treatment for patients diagnosed with glioblastoma multiforme (GBM) is temozolomide (TMZ). Tumour resistance to TMZ results in significantly limited clinical effectiveness. There is therefore an inherent need for alternatives to TMZ capable of overcoming resistance associated with MGMT and MMR. In the present study, a series of ester and amide analogues of TMZ, modified at position 8 on the imidazole ring, were prepared and investigated for antiproliferative properties. It was found that phenolic ester analogues of TMZ displayed increased potency, of up to 5-fold, against specified glioblastoma cell lines. The encouraging results displayed by the phenolic TMZ esters prompted further investigations against patient-derived primary glioblastoma cultures. The primary cultures, BTNW914 and BTNW374, were MGMT positive and MGMT negative, respectively. Lead phenolic TMZ esters were found to decrease viability in primary cells at clinically relevant concentrations, irrespective of MGMT expression. Furthermore, TMZ was found to be ineffective against the same primary cells at clinically relevant concentrations. The novel phenyl ester analogues of TMZ, described in this study, could have potential chemotherapeutic properties for the treatment of GBM, overcoming the resistance associated with the expression of MGMT
Identifying Reliable Diagnostic/Predictive Biomarkers for Rheumatoid Arthritis
Introduction and objective:
Elevated C-reactive protein is usually a good indicator of rheumatoid arthritis (RA); however, there are limitations that compromise its specificity and therefore there is an urgent need to identify more reliable diagnostic biomarkers to detect early stages of RA. In addition, identifying the correct therapeutic biomarker for the treatment of RA using methotrexate (MTX) would greatly increase the benefits experienced by the patients.
Materials and methods:
Primary normal synoviocytes human fibroblast-like synoviocytes (HFLS) and its phenotype rheumatic HFLS-RA cells were chosen for this study. The HFLS-RAāuntreated and MTX-treated cells were subjected to microarray analysis.
Results:
Microarray data identified 74 differentially expressed genes. These genes were mapped against an RA inflammatory pathway, shortlisting 10 candidate genes. Gene expression profiling of the 10 genes were studied. Fold change (FC) was calculated to determine the differential expression of the samples.
Discussion:
The transcription profiles of the 10 candidate genes were highly induced in HFLS-RA cells compared with HFLS cells. However, on treating the HFLS-RA cells with MTX, the transcription profiles of these genes were highly downregulated. The most significant expression FC difference between HFLS and HFLS-RA (treated and untreated) was observed with HSPA6, MMP1, MMP13, and TNFSF10 genes.
Conclusions:
The data from this study suggest the use of HSPA6, MMP1, MMP13, and TNFSF10 gene expression profiles as potential diagnostic biomarkers. In addition, these gene profiles can help in predicting the therapeutic efficacy of MTX
A Novel Therapeutic Strategy for the Treatment of Glioma, Combining Chemical and Molecular Targeting of Hsp90a
Hsp90Ī±'s vital role in tumour survival and progression, together with its highly inducible expression profile in gliomas and its absence in normal tissue and cell lines validates it as a therapeutic target for glioma. Hsp90Ī± was downregulated using the post-transcriptional RNAi strategy (sihsp90Ī±) and a post-translational inhibitor, the benzoquinone antibiotic 17-AAG. Glioblastoma U87-MG and normal human astrocyte SVGp12 were treated with sihsp90Ī±, 17-AAG and concurrent sihsp90Ī±/17-AAG (combined treatment). Both Hsp90Ī± gene silencing and the protein inhibitor approaches resulted in a dramatic reduction in cell viability. Results showed that sihsp90Ī±, 17-AAG and a combination of sihsp90Ī±/17-AAG, reduced cell viability by 27%, 75% and 88% (p < 0.001), respectively, after 72 h. hsp90Ī± mRNA copy numbers were downregulated by 65%, 90% and 99% after 72 h treatment with sihsp90Ī±, 17-AAG and sihsp90Ī±/17-AAG, respectively. The relationship between Hsp90Ī± protein expression and its client Akt kinase activity levels were monitored following treatment with sihsp90Ī±, 17-AAG and sihsp90Ī±/17-AAG. Akt kinase activity was downregulated as a direct consequence of Hsp90Ī± inhibition. Both Hsp90Ī± and Akt kinase levels were significantly downregulated after 72 h. Although, 17-AAG when used as a single agent reduces the Hsp90Ī± protein and the Akt kinase levels, the efficacy demonstrated by combinatorial treatment was found to be far more effective. Combination treatment reduced the Hsp90Ī± protein and Akt kinase levels to 4.3% and 43%, respectively, after 72 h. hsp90Ī± mRNA expression detected in SVGp12 was negligible compared to U87-MG, also, the combination treatment did not compromise the normal cell viability. Taking into account the role of Hsp90Ī± in tumour progression and the involvement of Akt kinase in cell signalling and the anti-apoptotic pathways in tumours, this double targets treatment infers a novel therapeutic strategy
Unequal gender norms are related to Symptoms of Depression Among Young Adolescents: A Cross-Sectional, Cross-Cultural Study
Purpose: This study was undertaken among 10- to 14-year-old girls and boys in disadvantaged areas of Shanghai, China; Cuenca, Ecuador; Flanders, Belgium; and Denpasar and Semarang, Indonesia. It aimed to assess whether gender norms are related to depressive symptomatology, and to examine whether sex differences in depressive symptoms can be explained by differences in gender norm perceptions. Methods: We examined the distributions of depressive symptoms and two gender norms scales, gender stereotypical traits (GST), and sexual double standard (SDS), across sites and by sex. We next assessed crude and adjusted associations between each of the gender norms scales and depressive symptoms. Finally, we conducted path analysis to examine the mediating role of gender perceptions in sex differences in depressive symptoms. Results: Girls reported more depressive symptoms than boys in all sites except Denpasar. SDS perceptions were more unequal among girls in most sites, while GST perceptions were more unequal among boys in all sites except Semarang. Gender-equal SDS and GST perceptions were associated with fewer depressive symptoms, while unequal perceptions were related to more symptoms. Gendered perceptions about traits and relationships appeared to partially mediate relationships between sex and depressive symptoms in Shanghai, Cuenca, and Semarang. Conclusions: Unequal gender norm perceptions were linked to poor mental health among boys and girls, suggesting that gender norms may play a role in psychological wellbeing for adolescents of both sexes. Gender norm perceptions appear to play a role in mental health sex disparities we observed across site
Resistance of stem-like cells from neuroblastoma cell lines to commonly used chemotherapeutic agents
Background Cancer stem cell theory suggests that the presence of tumor initiating stem-like cells in cancers may be responsible for cancer progression and relapse. CD133 cell surface maker expression has been used to identify stem-like cells in cancer cell lines. Our goal was to identify such cells in neuroblastoma cell lines and to study the cytotoxicity of common anticancer drugs for those cells. Materials and Methods CD133+ cells from SK-N-SH and SK-N-BE cell lines were isolated using magnetic microbeads. Cytotoxicity of four anticancer drugs was studied on CD133+ and CD133ā populations. The percentage of live, apoptotic, and dead cells in each population after drug treatment was estimated by MTT and PI/Annexin-binding assays. Western blot analyses were used to identify differences in the expression of kinases. Results Eight to 10% of SK-N-SH and 3ā5% of SK-N-BE cells were CD133+. These cells were more resistant than CD133ā cells to all four chemotherapeutic agents tested in the MTT assay. Decreased apoptosis was observed in CD133+ cells compared to CD133ā cells by PI/Annexin V-binding assay. Western blot analysis showed that CD133+ cells expressed less MKP-1. Phosphorylated forms of both ERK and P-38 kinases were expressed at higher levels in CD133+ cells than in CD133ā cells. Conclusions This study suggests that CD133+ cells are more resistant to anticancer drugs than CD133ā cells. Differences in the expression and phosphorylation of kinases could be partially responsible for this difference. Targeting CD133-expressing cells could be a strategy to develop more effective treatments for neuroblastoma. Pediatr Blood Cancer 2010;54:361ā368. Ā© 2009 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/64907/1/22351_ftp.pd
Temperature and Solvent Facilitated Extrusion Based 3D Printing for Pharmaceuticals.
On demand manufacturing of patient-specific oral doses provides significant advantages to patients and healthcare staff. Several 3D printing (3DP) technologies have been proposed as a potential digital alternative to conventional manufacturing of oral tablets. For additive manufacturing approach to be successful for on-demand preparation, a facile process with minimal preparation steps and training requirements is needed. A novel hybrid approach to the 3D printing process is demonstrated here based on combined both a solvent and heating to facilitate extrusion. The system employed a moderate elevated temperature range (65-100 C), a brief drying period, and a simple set-up. In this approach, a compact material cylinder is used as a pharmaceutical ink to be extruded in a temperature-controlled metal syringe. The process proved compatible with hygroscopic polymers [Poly(vinyl alcohol (PVA)Ā and polyvinylpyrrolidone (PVP)] and a number of pharmaceutical fillers (lactose, sorbitol and D-mannitol). The fabricated tablets demonstrated compendial acceptable weight and content uniformity as well as mechanical resistance. In vitro drug release of theophylline from 3D printed tablets was dependant on the nature of the polymer and its molecular weight. This reported approach offers significant advantages compared to other 3DP technologies: simplification of pre-product, the use of a moderate temperature range, a minimal drying period, and avoiding the use of mechanically complicated machinery. In the future, we envisage the use of this low-cost and facile approach to fabricate small batches of bespoke tablets. [Abstract copyright: Copyright Ā© 2020. Published by Elsevier B.V.
The TERT rs2736100 Polymorphism and Cancer Risk: A Meta-analysis Based on 25 Case-Control Studies
<p>Abstract</p> <p>Background</p> <p>The association between the <it>TERT rs2736100 </it>single nucleotide polymorphism (SNP) and cancer risk has been studied by many researchers, but the results remain inconclusive. To further explore this association, we performed a meta-analysis.</p> <p>Methods</p> <p>A computerized search of PubMed and Embase database for publications on the <it>TERT rs2736100 </it>polymorphism and cancer risk was performed and the genotype data were analyzed in a meta-analysis. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the association. Sensitivity analysis, test of heterogeneity, cumulative meta-analysis and assessment of bias were performed in our meta-analysis.</p> <p>Results</p> <p>A significant association between the <it>TERT rs2736100 </it>polymorphism and cancer susceptibility was revealed by the results of the meta-analysis of the 25 case-control studies (GG versus TT: OR = 1.72, 95% CI: 1.58, 1.88; GT versus TT: OR = 1.38, 95% CI: 1.29, 1.47; dominant model-TG + GG versus TT: OR = 1.47, 95% CI: 1.37, 1.58; recessive model-GG versus TT + TG: OR = 1.37, 95% CI 1.31, 1.43; additive model-2GG + TG versus 2TT + TG: OR = 1.30, 95% CI: 1.25, 1.36). Moreover, increased cancer risk in all genetic models was found after stratification of the SNP data by cancer type, ethnicity and source of controls.</p> <p>Conclusions</p> <p>In all genetic models, the association between the <it>TERT rs2736100 </it>polymorphism and cancer risk was significant. This meta-analysis suggests that the <it>TERT rs2736100 </it>polymorphism may be a risk factor for cancer. Further functional studies between this polymorphism and cancer risk are warranted.</p
- ā¦