Co-axial hydrogel spinning for facile biofabrication of prostate cancer-like 3D models.

Glandular cancers are amongst the most prevalent types of cancer, which can develop in many different organs, presenting challenges in their detection as well as high treatment variability and failure rates. For that purpose, anticancer drugs are commonly tested in cancer cell lines grown in 2D tissue culture on plastic dishesin vitro, or in animal modelsin vivo. However, 2D culture models diverge significantly from the 3D characteristics of living tissues and animal models require extensive animal use and time. Glandular cancers, such as prostate cancer-the second leading cause of male cancer death-typically exist in co-centrical architectures where a cell layer surrounds an acellular lumen. Herein, this spatial cellular position and 3D architecture, containing dual compartments with different hydrogel materials, is engineered using a simple co-axial nozzle setup, in a single step utilizing prostate as a model of glandular cancer. The resulting hydrogel soft structures support viable prostate cancer cells of different cell lines and enable over-time maturation into cancer-mimicking aggregates surrounding the acellular core. The biofabricated cancer mimicking structures are then used as a model to predict the inhibitory efficacy of the poly ADP ribose polymerase inhibitor, Talazoparib, and the antiandrogen drug, Enzalutamide, in the growth of the cancer cell layer. Our results show that the obtained hydrogel constructs can be adapted to quickly obtain 3D cancer models which combine 3D physiological architectures with high-throughput screening to detect and optimize anti-cancer drugs in prostate and potentially other glandular cancer types.

Associations between genetic variants in vitamin D metabolism and asthma characteristics in young African Americans: a pilot study.

INTRODUCTION: Low vitamin D levels have been associated with asthma severity in children. Young, urban African Americans (AAs) have high rates of hypovitaminosis D and asthma. Our objective was to determine associations between variants in vitamin D metabolism genes and asthma characteristics in a pilot study of young urban AAs. MATERIALS AND METHODS: Two urban AA cohorts of subjects aged 6 to 20 years (139 subjects with asthma and 74 subjects without asthma) were genotyped for 12 single nucleotide polymorphisms (SNPs) in 3 vitamin D metabolism genes: VDR (vitamin D receptor), CYP24A1 (cytochrome P450 vitamin D 24-hydroxylase), and CYP2R1 (cytochrome P450 vitamin D 25-hydroxylase). In a case-control analysis, SNPs were studied for associations with an asthma diagnosis. Within the asthmatic cohort, SNPs were analyzed for associations with quantitative asthma characteristics. All analyses were adjusted for age, sex, and body mass index percentile. RESULTS: Only the CYP2R1 SNP rs10766197 homozygous minor genotype was associated with asthma (P = 0.044). CYP24A1 SNP rs2248137 was associated with lower vitamin D levels (P = 0.006). Within the asthma cohort, multiple significant associations between SNPs and asthma characteristics were identified; VDR SNP rs2228570 was associated with the higher nighttime asthma morbidity scores (P = 0.04), lower baseline spirometric measures (P < 0.05), 1 or more positive aeroallergen skin test (P = 0.003), and increased immunoglobulin E levels (P < 0.001). DISCUSSION: This pilot study demonstrates that variants in vitamin D metabolism genes are associated with quantitative asthma characteristics in young, urban AAs. The collection of these associations provides evidence for the need for a large population-based study of vitamin D-relevant SNPs in this cohort.

P-glycoprotein transporter expression on a549 respiratory epithelial cells is positively correlated with intracellular dexamethasone levels.

BACKGROUND: Several mechanisms of glucocorticoid resistance in asthma have been proposed. P-glycoprotein (P-gp), a ubiquitous efflux transport protein, is associated with variability in the disposition of many drugs and interindividual variability in drug treatment response. This study was undertaken to determine the effect of P-gp expression on glucocorticoid efflux from airway epithelial cells. HYPOTHESIS: Decreasing respiratory epithelial P-gp expression in dexamethasone-exposed airway epithelial cells in vitro will increase intracellular dexamethasone concentration. METHODS: A549 lung epithelial cells, transfected with small interfering RNA (siRNA) targeted at messenger RNA for the gene encoding P-gp, were exposed to 100-nM dexamethasone for 15 minutes. Transfection efficiency of siRNA, P-gp expression, and intracellular dexamethasone were measured with flow cytometry. RESULTS: Cells transfected with both negative siRNA and siRNA targeted at P-gp exhibited a positive correlation of P-gp expression with intracellular dexamethasone. The mean ± SEM correlation coefficients were 0.78 ± 0.07 for cells transfected with negative siRNA and 0.79 ± 0.08 for cells transfected with siRNA targeted at P-gp. DISCUSSION: Contrary to our hypothesis, the positive correlation between P-gp expression and intracellular dexamethasone suggests that P-gp is not a primary transporter of glucocorticoids from airway epithelial cells. Increased P-gp expression is unlikely to be an important mechanism of glucocorticoid resistance in asthma.