29 research outputs found
Outcomes of Children and Adolescents with Advanced Hereditary Medullary Thyroid Carcinoma Treated with Vandetanib.
Purpose: Vandetanib is well-tolerated in patients with advanced medullary thyroid carcinoma (MTC). Long-term outcomes and mechanisms of MTC progression have not been reported previously.Experimental Design: We monitored toxicities and disease status in patients taking vandetanib for hereditary, advanced MTC. Tumor samples were analyzed for molecular mechanisms of disease progression.Results: Seventeen patients [8 male, age 13 (9-17)* years] enrolled; 16 had a RET p.Met918Thr germline mutation. The duration of vandetanib therapy was 6.1 (0.1-9.7+)* years with treatment ongoing in 9 patients. Best response was partial response in 10, stable disease in 6, and progressive disease in one patient. Duration of response was 7.4 (0.6-8.7+)* and 4.9 (0.6-7.8+)* years in patients with PR and SD, respectively. Six patients died 2.0 (0.4-5.7)* years after progression. Median progression-free survival (PFS) was 6.7 years [95% confidence interval (CI): 2.3 years-undefined] and 5-year overall survival (OS) was 88.2% (95% CI: 60.6%-96.9%). Of 16 patients with a RET p.Met918Thr mutation, progression-free survival was 6.7 years (95% CI: 3.1-undefined) and 5-year overall survival was 93.8% (95% CI: 63.2%-99.1%). No patients terminated treatment because of toxicity. DNA sequencing of tissue samples (n = 11) identified an increase in copy number alterations across the genome as a potential mechanism of drug resistance [*median (range)].Conclusions: This study demonstrates that vandetanib is safe and results in sustained responses in children and adolescents with hereditary MTC. Our preliminary molecular data suggest that an increase in copy number abnormalities may be associated with tumor progression in hereditary MTC patients treated with vandetanib. Clin Cancer Res; 24(4); 753-65. ©2017 AACR
Diurnal variation of the human adipose transcriptome and the link to metabolic disease.
BackgroundCircadian (diurnal) rhythm is an integral part of the physiology of the body; specifically, sleep, feeding behavior and metabolism are tightly linked to the light-dark cycle dictated by earth's rotation.MethodsThe present study examines the effect of diurnal rhythm on gene expression in the subcutaneous adipose tissue of overweight to mildly obese, healthy individuals. In this well-controlled clinical study, adipose biopsies were taken in the morning, afternoon and evening from individuals in three study arms: treatment with the weight loss drug sibutramine/fasted, placebo/fed and placebo/fasted.ResultsThe results indicated that diurnal rhythm was the most significant driver of gene expression variation in the human adipose tissue, with at least 25% of the genes having had significant changes in their expression levels during the course of the day. The mRNA expression levels of core clock genes at a specific time of day were consistent across multiple subjects on different days in all three arms, indicating robust diurnal regulation irrespective of potential confounding factors. The genes essential for energy metabolism and tissue physiology were part of the diurnal signature. We hypothesize that the diurnal transition of the expression of energy metabolism genes reflects the shift in the adipose tissue from an energy-expending state in the morning to an energy-storing state in the evening. Consistent with this hypothesis, the diurnal transition was delayed by fasting and treatment with sibutramine. Finally, an in silico comparison of the diurnal signature with data from the publicly-available Connectivity Map demonstrated a significant association with transcripts that were repressed by mTOR inhibitors, suggesting a possible link between mTOR signaling, diurnal gene expression and metabolic regulation.ConclusionDiurnal rhythm plays an important role in the physiology and regulation of energy metabolism in the adipose tissue and should be considered in the selection of novel targets for the treatment of obesity and other metabolic disorders
Lipid Microdomain Formation: Characterization by Infrared Spectroscopy and Ultrasonic Velocimetry
We demonstrate the use of vibrational infrared spectroscopy applied to characterize lipid microdomain sizes derived from a model raft-like system consisting of nonhydroxy galactocerebroside, cholesterol, and dipalmitoylphosphatidylcholine components. The resulting spectroscopic correlation field components of the lipid acyl chain CH2 methylene deformation modes, observed when lipid multilamellar assemblies are rapidly frozen from the liquid crystalline state to the gel phase, indicate the existence of lipid microdomains on a scale of several nanometers. The addition of cholesterol disrupts the glycosphingolipid selectively but perturbs the di-saturated chain phospholipid matrix. Complementary acoustic velocimetry measurements indicate that the microdomain formation decreases the total volume adiabatic compressibilities of the multilamellar vesicle assemblies. The addition of cholesterol, however, disrupts the galactocerebroside domains, resulting in a slight increase in the lipid assemblies' total adiabatic compressibility. The combination of these two physical approaches offers new insight into microdomain formation and their properties in model bilayer systems