These findings suggest that a blunted adrenocortical response to stress may represent a common feature of chronic allergic inflammatory processes that may be relevant in different forms of chronic manifestation of atopy.

Cell lines are essential tools to standardize and compare experimental findings in basic and translational cancer research. The current dogma states that cancer stem cells feature an increased tumor initiation capacity and are also chemoresistant. Here, we identified and comprehensively characterized three morphologically distinct cellular subtypes in the non–small cell lung cancer cell line A549 and challenge the current cancer stem cell dogma. Subtype-specific cellular morphology is maintained during short-term culturing, resulting in the formation of holoclonal, meroclonal, and paraclonal colonies. A549 holoclone cells were characterized by an epithelial and stem-like phenotype, paraclone cells featured a mesenchymal phenotype, whereas meroclone cells were phenotypically intermediate. Cell-surface marker expression of subpopulations changed over time, indicating an active epithelial-to-mesenchymal transition (EMT), in vitro and in vivo. EMT has been associated with the overexpression of the immunomodulators PD-L1 and PD-L2, which were 37- and 235-fold overexpressed in para- versus holoclone cells, respectively. We found that DNA methylation is involved in epigenetic regulation of marker expression. Holoclone cells were extremely sensitive to cisplatin and radiotherapy in vitro, whereas paraclone cells were highly resistant. However, inhibition of the receptor tyrosine kinase AXL, whose expression is associated with an EMT, specifically targeted the otherwise highly resistant paraclone cells. Xenograft tumor formation capacity was 24- and 269-fold higher in holo- than mero- and paraclone cells, respectively. Our results show that A549 subpopulations might serve as a unique system to explore the network of stemness, cellular plasticity, tumor initiation capacity, invasive and metastatic potential, and chemo/radiotherapy resistance.

BackgroundAberrant DNA methylation in gene promoters is associated with aging and cancer, but the circumstances determining methylation change are unknown. We investigated the impact of lifestyle modulators of colorectal cancer (CRC) risk on the stability of gene promoter methylation in the colonic mucosa.MethodsWe measured genome-wide promoter CpG methylation in normal colon biopsies (n = 1092) from a female screening cohort, investigated the interaction of lifestyle factors with age-dependent increase in methylation with log-linear multivariable regression, and related their modifying effect to hypermethylation in CRC. All statistical tests were two-sided.ResultsOf 20025 promoter-associated CpGs analyzed, 1713 showed statistically significant age-dependent methylation gains. Fewer CpGs acquired methylation in users of aspirin (≥2 years) and hormonal replacement therapy (HRT age ≥50 years) compared with nonusers (43 vs 1355; 1 vs1377, respectively), whereas more CpGs were affected in smokers (≥20 years) and individuals with a body mass index (BMI) of 25kg/m2 and greater compared with control groups (180 vs 39; 554 vs 144, respectively). Fifty percent of the CpGs showing age-dependent methylation were found hypermethylated in CRC (odds ratio [OR] = 20; 95% confidence interval [CI] = 18 to 23; P < 2×10–16). These loci gained methylation with a higher median rate compared with age-only methylated sites (P = 2×10–76) and were enriched for polycomb regions (OR = 3.67). Importantly, aspirin (P < .001) and HRT use (P < .001) reduced the methylation rate at these cancer-related genes, whereas smoking (P < .001) and high BMI (P = .004) increased it.ConclusionsLifestyle, including aspirin use, modulates age-associated DNA methylation change in the colonic epithelium and thereby impacts the evolution of cancer methylomes.

The split hydronephrotic kidney preparation was used to directly observe the effects of locally applied dopamine on the in vivo diameters of renal vessels. Dopamine (1 X 10(-6) to 3 X 10(-5) M) produced a concentration-dependent dilation of the arcuate and interlobular arteries and afferent arterioles. Efferent arterioles near the glomeruli also dilated to dopamine but the dilation was less than that of the preglomerular vessels. Higher dopamine concentrations (3 X 10(-4) and 1 X 10(-3) M) produced more variable effects, with a tendency for the arcuate and interlobular arteries and the afferent and efferent arterioles away from the glomeruli to decrease in diameter. After pretreatment with haloperidol, dopamine (1 X 10(-6) to 1 X 10(-4) M) did not dilate any pre- or postglomerular vascular segment, but the tendency for pre- and postglomerular constrictions with higher dopamine concentrations were not abolished. Pretreatment with phentolamine and propranolol enhanced the dilator response of the pre- and postglomerular vessels (except the afferent arterioles near glomeruli and efferent arterioles near welling points) to dopamine (3 X 10(-5) and 1 X 10(-4) M), and abolished the reductions in diameter produced by the high dopamine levels. These data indicate that the dilator effect of dopamine is mediated by interactions with specific dopaminergic receptors, while alpha and beta adrenergic receptors appear to mediate a constrictor influence observed with high dopamine concentrations. The overall effect of dopamine on the renal vessel diameters thus appears to depend on the balance of dilator and constrictor stimuli mediated by multiple receptors.