The expression of the pS2 gene, which is induced by estrogen in the breast cancer cell line MCF-7, has been investigated in breast cancers by using pS2 mRNA determination in tumor specimens and immunocytochemistry to identify pS2 protein in paraffin-embedded sections. Using these assays we show that determination of pS2 gene expression allows the definition of subclasses of estrogen-receptor-containing breast cancers that may be used to more precisely identify estrogen-dependent tumors. Tumor specimens have also been analyzed for the presence of mRNAs for the estrogen receptor and for the ERBB2 oncogene. No evidence for the presence of truncated forms of estrogen-receptor mRNA has been found, and overexpression ofthe ERBB2 oncogene did not correlate with the steroid receptor status or pS2 gene expression.
Background and purpose: Pulmonary arterial hypertension (PAH) is associated with increased contraction and proliferation of pulmonary vascular smooth muscle cells. The anti‐diabetic drug metformin has been shown to have relaxant and anti‐proliferation properties. We thus examined the effect of metformin in PAH. Experimental approach: Metformin effects were analysed in hypoxia‐ and monocrotaline‐induced PAH in rats. Ex vivo and in vitro analyses were performed in lungs, pulmonary artery rings and cells. Key results: In hypoxia‐ and monocrotaline‐induced PAH, the changes in mean pulmonary arterial pressure and right heart hypertrophy were nearly normalized by metformin treatment (100 mg·kg−1·day−1). Pulmonary arterial remodelling occurring in both experimental models of PAH was also inhibited by metformin treatment. In rats with monocrotaline‐induced PAH, treatment with metformin significantly increased survival. Metformin increased endothelial nitric oxide synthase phosphorylation and decreased Rho kinase activity in pulmonary artery from rats with PAH. These effects are associated with an improvement of carbachol‐induced relaxation and reduction of phenylephrine‐induced contraction of pulmonary artery. In addition, metformin inhibited mitogen‐activated protein kinase activation and strongly reduced pulmonary arterial cell proliferation during PAH. In vitro, metformin directly inhibited pulmonary artery smooth muscle cell growth. Conclusions and implications: Metformin protected against PAH, regardless of the initiating stimulus. This protective effect may be related to its anti‐remodelling property involving improvement of endothelial function, vasodilatory and anti‐proliferative actions. As metformin is currently prescribed to treat diabetic patients, assessment of its use as a therapy against PAH in humans should be easier.
We determined serum levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), and triglycerides (TGs) in 125 healthy children and in 119 children with epilepsy who had been receiving carbamazepine (58 children), phenobarbital (22 children), or valproic acid (39 children) for 7 months to 10.5 years (mean, 5.8 years). None of the variables considered was significantly correlated with time elapsed since start of treatment or with drug concentration in serum. In the groups receiving carbamazepine or phenobarbital, mean TC, HDL-C, and LDL-C levels were higher than in the control group, the differences being statistically significant for all except LDL-C in the phenobarbital group. In neither group did mean TC/HDL-C ratio or mean LDL-C/HDL-C ratio differ significantly from the corresponding control-group mean. In the group receiving valproic acid, mean TC level, mean LDL-C level, mean TC/HDL-C ratio, and mean LDL-C/HDL-C ratio were significantly lower than in the control group. In none of the treated groups did mean VLDL-C or TG level differ significantly from the corresponding control-group mean. Our results suggest, in contrast to previous reports, that the effects on the serum lipid profile of long-term treatment with hepatic-enzyme-inducing antiepileptic drugs (such as carbamazepine and phenobarbital) are probably not beneficial as regards risk of atherosclerosis-related disease. Our results additionally suggest a need for careful monitoring of serum cholesterol levels in children with epilepsy receiving carbamazepine or phenobarbital.
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