184 research outputs found

    Pharmacogenetics of telatinib, a VEGFR-2 and VEGFR-3 tyrosine kinase inhibitor, used in patients with solid tumors

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    Purpose Telatinib is an orally active small-molecule tyrosine kinase inhibitor of kinase insert domain receptor (KDR; VEGFR-2) and fms-related tyrosine kinase 4 (FLT4; VEGFR-3). This study aims at the identification of relationships between single nucleotide polymorphisms (SNPs) in genes encoding for transporter proteins and pharmacokinetic parameters in order to clarify the significant interpatient variability in drug exposure. In addition, the potential relationship between target receptor polymorphisms and toxicity of telatinib is explored. Methods Blood samples from 33 patients enrolled in a phase I dose-escalation study of telatinib were analyzed. For correlation with dose normalized AUC(0–12), ATP-binding cassette (ABC) B1 (ABCB1), ABCC1, and ABCG2 were the genes selected. For correlation with telatinib toxicity, selected genes were the drug target genes KDR and FLT4. Results No association between dose normalized AUC(0–12) and drug transporter protein polymorphisms was observed. In addition, no association between toxicity and KDR or FLT4 genotype or haplotype was seen. Conclusions Our pharmacogenetic analysis could not reveal a correlation between relevant gene polymorphisms and clinical and pharmacokinetic observations of telatinib

    The role of the ubiquitination–proteasome pathway in breast cancer: Ubiquitin mediated degradation of growth factor receptors in the pathogenesis and treatment of cancer

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    Aberrant activity of growth factor receptors has been implicated in the pathogenesis of a wide variety of malignancies. The negative regulation of signaling by growth factor receptors is mediated in large part by the ubiquitination, internalization, and degradation of the activated receptor. Over the past few years, considerable insight into the mechanisms that control receptor downregulation has been gained. There are also data suggesting that mutations that lead to inhibition of downregulation of growth factor receptors could play a role in the pathogenesis of cancer. Therapies directed at enhancing the degradation of growth factor receptors offer a promising approach to the treatment of malignancies

    An Excellent Monitoring System for Surface Ubiquitination-Induced Internalization in Mammals

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    Background. At present, it is difficult to visualize the internalization of surface receptors induced by ubiquitination that is taken place at the plasma membrane in mammals. This problem makes it difficult to reveal molecular basis for ubiquitinationmediated internalization in mammals. Methodology/Principle Findings. In order to overcome it, we have generated T-REx-c-MIR, a novel mammalian Tet-on B cell line using a constitutively active E3 ubiquitin ligase, c-MIR, and its artificial target molecule. By applying the surface biotinylation method to T-REx-c-MIR, we succeeded to monitor the fate of surface target molecules after initiation of ubiquitination process by doxycycline (Dox)-induced c-MIR expression. Target molecules that preexisted at the plasma membrane before induction of c-MIR expression were oligo-ubiquitinated and degraded by Dox-induced c-MIR expression. Dox-induced c-MIR expression initiated rapid internalization of surface target molecules, and blockage of the internalization induced the accumulation of the surface target molecules that were newly ubiquitinated by c-MIR. Inhibition of the surface ubiquitination by down-regulating ubiquitin conjugating enzyme E2 impaired the internalization of target molecules. Finally, a complex of c-MIR and target molecule was detected at the plasma membrane. Conclusions/ Significances. These results demonstrate that in T-REx-c-MIR, surface target molecule is ubiquitinated at the plasma membrane and followed by being internalized from the plasma membrane. Thus, T-REx-c-MIR is a useful experimental tool t

    Influence of pharmacogenetic variability on the pharmacokinetics and toxicity of the aurora kinase inhibitor danusertib

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    Objectives Danusertib is a serine/threonine kinase inhibitor of multiple kinases, including aurora-A, B, and C. This explorative study aims to identify possible relationships between single nucleotide polymorphisms in genes coding for drug metabolizing enzymes and transporter proteins and clearance of danusertib, to clarify the interpatient variability in exposure. In addition, this study explores the relationship between target receptor polymorphisms and toxicity of danusertib. Methods For associations with clearance, 48 cancer patients treated in a phase I study were analyzed for ABCB1, ABCG2 and FMO3 polymorphisms. Association analyses between neutropenia and drug target receptors, including KDR, RET, FLT3, FLT4, AURKB and AURKA, were performed in 30 patients treated at recommended phase II dose-levels in three danusertib phase I or phase II trials. Results No relationships between danusertib clearance and drug metabolizing enzymes and transporter protein polymorphisms were found. Only, for the one patient with FMO3 18281AA polymorphism, a significantly higher clearance was noticed, compared to patients carrying at least 1 wild type allele. No effect of target receptor genotypes or haplotypes on neutropenia was observed. Conclusions As we did not find any major correlations between pharmacogenetic variability in the studied enzymes and transporters and pharmacokinetics nor toxicity, it is unlikely that danusertib is highly susceptible for pharmacogenetic variation. Therefore, no dosing alterations of danusertib are expected in the future, based on the polymorphisms studied. However, the relationship between FMO3 polymorphisms and clearance of danusertib warrants further research, as we could study only a small group of patients

    Measuring quality of life in people living with and beyond cancer in the UK

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    Purpose: The aim of this study was to identify the most appropriate measure of quality of life (QoL) for patients living with and beyond cancer. Methods: One hundred eighty-two people attending cancer clinics in Central London at various stages post-treatment, completed a series of QoL measures: FACT-G, EORTC QLQ-C30 , IOCv2 (positive and negative subscales) and WEMWBS, a wellbeing measure. These measures were chosen as the commonest measures used in previous research. Correlation tests were used to assess the association between scales. Participants were also asked about pertinence and ease of completion. Results: There was a significant positive correlation between the four domain scores of the two health-related QoL measures (.32 ≀ r ≀.72, P <.001), and a significant large negative correlation between these and the negative IOCv2 subscale scores (βˆ’.39 ≀ r ≀ βˆ’.63, P <.001). There was a significant moderate positive correlation between positive IOCv2 subscale and WEMWBS scores (r =.35, P <.001). However, neither the FACT-G nor the EORTC showed any significant correlation with the positive IOCv2 subscale. Participants rated all measures similarly with regards to pertinence and ease of use. Conclusion: There was little to choose between FACT-G, EORTC, and the negative IOC scales, any of which may be used to measure QoL. However, the two IOCv2 subscales capture unique aspects of QoL compared to the other measures. The IOCv2 can be used to identify those cancer survivors who would benefit from interventions to improve their QoL and to target specific needs thereby providing more holistic and personalised care beyond cancer treatment

    CT-guided iodine-125 seed permanent implantation for recurrent head and neck cancers

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    <p>Abstract</p> <p>Background</p> <p>To investigate the feasibility, and safety of <sup>125</sup>I seed permanent implantation for recurrent head and neck carcinoma under CT-guidance.</p> <p>Results</p> <p>A retrospective study on 14 patients with recurrent head and neck cancers undergone <sup>125</sup>I seed implantation with different seed activities. The post-plan showed that the actuarial D90 of <sup>125</sup>I seeds ranged from 90 to 218 Gy (median, 157.5 Gy). The follow-up was 3 to 60 months (median, 13 months). The median local control was 18 months (95% CI, 6.1-29.9 months), and the 1-, 2-, 3-, and 5- year local controls were 52%, 39%, 39%, and 39%, respectively. The 1-, 2-, 3-, and 5- survival rates were 65%, 39%, 39% and 39%, respectively, with a median survival time of 20 months (95% CI, 8.7-31.3 months). Of all patients, 28.6% (4/14) died of local recurrence, 7.1% (1/14) died of metastases, one patient died of hepatocirrhosis, and 8 patients are still alive to the date of data analysis.</p> <p>Conclusion</p> <p>CT-guided <sup>125</sup>I seed implantation is feasible and safe as a salvage or palliative treatment for patients with recurrent head and neck cancers.</p

    Neonatal CD8 T-cell Hierarchy Is Distinct from Adults and Is Influenced by Intrinsic T cell Properties in Respiratory Syncytial Virus Infected Mice

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    Following respiratory syncytial virus infection of adult CB6F1 hybrid mice, a predictable CD8+ T cell epitope hierarchy is established with a strongly dominant response to a Kd-restricted peptide (SYIGSINNI) from the M2 protein. The response to KdM282-90 is ∼5-fold higher than the response to a subdominant epitope from the M protein (NAITNAKII, DbM187-195). After infection of neonatal mice, a distinctly different epitope hierarchy emerges with codominant responses to KdM282-90 and DbM187-195. Adoptive transfer of naΓ―ve CD8+ T cells from adults into congenic neonates prior to infection indicates that intrinsic CD8+ T cell factors contribute to age-related differences in hierarchy. Epitope-specific precursor frequency differs between adults and neonates and influences, but does not predict the hierarchy following infection. Additionally, dominance of KdM282-90 –specific cells does not correlate with TdT activity. Epitope-specific VΞ² repertoire usage is more restricted and functional avidity is lower in neonatal mice. The neonatal pattern of codominance changes after infection at 10 days of age, and rapidly shifts to the adult pattern of extreme KdM282- 90 -dominance. Thus, the functional properties of T cells are selectively modified by developmental factors in an epitope-specific and age-dependent manner

    Strong Association of a Common Dihydropyrimidine Dehydrogenase Gene Polymorphism with Fluoropyrimidine-Related Toxicity in Cancer Patients

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    variations associated with enhanced drug toxicity.β€Š=β€Š0.001; the attributable risk was 56.9%. Comparing tumor-type matched sets of samples, correlation of c.496A>G with toxicity was particularly present in patients with gastroesophageal and breast cancer, but did not reach significance in patients with colorectal malignancies. polymorphism strongly contributes to the occurrence of fluoropyrimidine-related drug adverse effects. Carriers of this variant could benefit from individual dose adjustment of the fluoropyrimidine drug or alternate therapies

    Ex Vivo Expansion of Human CD8+ T Cells Using Autologous CD4+ T Cell Help

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    Background: Using in vivo mouse models, the mechanisms of CD4+ T cell help have been intensively investigated. However, a mechanistic analysis of human CD4+ T cell help is largely lacking. Our goal was to elucidate the mechanisms of human CD4+ T cell help of CD8+ T cell proliferation using a novel in vitro model. Methods/Principal Findings: We developed a genetically engineered novel human cell-based artificial APC, aAPC/mOKT3, which expresses a membranous form of the anti-CD3 monoclonal antibody OKT3 as well as other immune accessory molecules. Without requiring the addition of allogeneic feeder cells, aAPC/mOKT3 enabled the expansion of both peripheral and tumor-infiltrating T cells, regardless of HLA-restriction. Stimulation with aAPC/mOKT3 did not expand Foxp3+ regulatory T cells, and expanded tumor infiltrating lymphocytes predominantly secreted Th1-type cytokines, interferon-Ξ³ and IL-2. In this aAPC-based system, the presence of autologous CD4+ T cells was associated with significantly improved CD8+ T cell expansion in vitro. The CD4+ T cell derived cytokines IL-2 and IL-21 were necessary but not sufficient for this effect. However, CD4+ T cell help of CD8+ T cell proliferation was partially recapitulated by both adding IL-2/IL-21 and by upregulation of IL-21 receptor on CD8+ T cells. Conclusions: We have developed an in vitro model that advances our understanding of the immunobiology of human CD4+ T cell help of CD8+ T cells. Our data suggests that human CD4+ T cell help can be leveraged to expand CD8+ T cells in vitro
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