Small-molecule inhibitor - tyrphostin AG1296 regulates proliferation, survival and migration of rhabdomyosarcoma cells.

Rhabdomyosarcoma (RMS) is the most commonly occurring malignant soft tissue tumor in children. Despite improving its treatment methods, the current outcome in the advanced stages of this tumor is not satisfactory. RMS cells are characterized by abnormal cellular signaling due to the changes in the activity of the tyrosine kinases. Thus, substances blocking the mitogenic signal transmitted by receptors with tyrosine kinase activity raise hopes for inhibition of the uncontrolled cell growth. In this study, we examined the anticancer activity of tyrphostin AG1296, a tyrosine kinase inhibitor that binds to the intracellular domain of the PDGF (platelet-derived growth factor) receptor in human RMS alveolar and embryonal cell lines. We have discovered that tyrphostin AG1296 completely inhibited cell proliferation and effectively inhibited cell viability. Tyrphostin AG1296 induced apoptosis of the RMS cells and significantly inhibited their migration. Additionally, investigated inhibitor slightly inhibited expression of AKT and phosphorylation of ERK in alveolar RMS cells. Importantly, the inhibitor exerted also potent effects on the nanomechanical properties and cytoskeleton organization of RMS cells. To conclude, tyrphostin AG1296 is a promising compound in the treatment of alveolar RMS. Undoubtedly, a better knowledge of receptor pathomechanism of tyrosine kinases may contribute to developing new, more effective ways of RMS treatment.

Ambulatory blood pressure monitoring for risk stratification in obese and non-obese subjects from 10 populations.

Overweight clusters with high blood pressure (BP), but the independent contribution of both risk factors remains insufficiently documented. In a prospective population study involving 8467 participants (mean age 54.6 years; 47.0% women) randomly recruited from 10 populations, we studied the contribution of body mass index (BMI) to risk over and beyond BP, taking advantage of the superiority of ambulatory over conventional BP. Over 10.6 years (median), 1271 participants (15.0%) died and 1092 (12.9%), 637 (7.5%) and 443 (5.2%) experienced a fatal or nonfatal cardiovascular, cardiac or cerebrovascular event. Adjusted for sex and age, low BMI (<20.7 kg m(-2)) predicted death (hazard ratio (HR) vs average risk, 1.52; P<0.0001) and high BMI (> or = 30.9 kg m(-2)) predicted the cardiovascular end point (HR, 1.27; P=0.006). With adjustments including 24-h systolic BP, these HRs were 1.50 (P<0.001) and 0.98 (P=0.91), respectively. Across quartiles of the BMI distribution, 24-h and nighttime systolic BP predicted every end point (1.13 < or = standardized HR < or = 1.67; 0.046 < or = P<0.0001). The interaction between systolic BP and BMI was nonsignificant (P > or = .22). Excluding smokers removed the contribution of BMI categories to the prediction of mortality. In conclusion, BMI only adds to BP in risk stratification for mortality but not for cardiovascular outcomes. Smoking probably explains the association between increased mortality and low BMI.

Blood pressure, cardiovascular outcomes and sodium intake, a critical review of the evidence.

Consideration of the role of NaCl (salt) in the pathogenesis and treatment of essential hypertension is one of the overriding research themes both in experimental and clinical medicine. The evidence relating blood pressure to salt intake in humans originates from population studies and randomized clinical trials of interventions on dietary salt intake. Estimates from meta-analyses of trials in normotensive subjects generally are similar to estimates derived from prospective population studies (+ 1.7-mmHg increase in systolic blood pressure per 100 mmol increment in 24­hour urinary sodium). This estimate, however, does not translate into an increased risk of incident hypertension in subjects consuming a high-salt diet. Prospective studies relating health outcomes to 24­h urinary sodium excretion produced inconsistent results. Taken together, available evidence does not support the current recommendations of a generalized and indiscriminate reduction of salt intake at the population level. The public should be properly educated about the pros and cons of a decrease in sodium intake, in particular if they are healthy.

Modulation of inflammatory response by pentoxifylline is independent of heme oxygenase-1 pathway.

OBJECTIVE: It was reported that some effects of pentoxifylline (PTX) are mediated by heme oxygenase-1 (HO-1) induction. We investigated the role of HO-1 in anti-inflammatory activity of PTX. METHODS: Experiments were performed in human and murine monocytes and endothelial cells and in HO-1 deficient mice. RESULTS: PTX dose-dependently decreased expression of HO-1 in cell lines studied. As expected, PTX reduced also production of TNF. This effect was independent of HO-1 activity, as demonstrated in cells treated with HO-1 activators and inhibitors or in cells overexpressing HO-1. Moreover, inhibition of TNF was the same in human endothelial cells of different HO-1 genotypes, showing that PTX is similarly efficient in carriers of more and less active HO-1 promoter variants. In mice, PTX did not influence HO-1 expression, as measured in liver, kidney, spleen, heart, and skin. Accordingly, the response of PTX treated animals to LPS was the same in wild type and HO-1 deficient mice. PTX to a similar extent increased influx of leukocyte into peritoneal cavity, decreased production of TNF and reduced expression of VCAM-1 in vascular intima. CONCLUSION: PTX inhibits production of TNF and may decrease inflammatory reaction both in vitro and in vivo, but these effects are independent of HO-1.

Thermodynamic analysis of the low frequency relaxation time in the smectic A and C phases of a liquid crystal.

Pressure-temperature-volume (pVT) measurements were carried out on 2-(4-hexyloxyphenyl)-5-octyl-pyrimidine, a substance exhibiting nematic and smectic A and C polymorphism. Analysis of the longitudinal relaxation times obtained recently for elevated pressures [Czub et al., Z. Naturforsch. A: Phys. Sci. 58, 333 (2003)] was performed for isobaric, isothermal, and isochoric conditions within the two smectic phases. Several relationships linking the dynamical and thermodynamical quantities, derived recently for isotropic glass formers [Roland et al. Rep. Prog. Phys. 68, 1405 (2005)], were found to hold for the liquid crystal, revealing a striking similarity of behaviors for these two types of materials. The parameter gamma characterizing the steepness of the interaction potential was derived in different ways. It is interesting that the liquid crystal gives relaxation time versus TV(-gamma) plots that are linear, unlike results for glass formers, implying that the dynamics of the former is thermally activated.