Unveiling the signaling network of FLT3-ITD AML improves drug sensitivity prediction

Currently, the identification of patient-specific therapies in cancer is mainly informed by personalized genomic analysis. In the setting of acute myeloid leukemia (AML), patient-drug treatment matching fails in a subset of patients harboring atypical internal tandem duplications (ITDs) in the tyrosine kinase domain of the FLT3 gene. To address this unmet medical need, here we develop a systems-based strategy that integrates multiparametric analysis of crucial signaling pathways, and patient-specific genomic and transcriptomic data with a prior knowledge signaling network using a Boolean-based formalism. By this approach, we derive personalized predictive models describing the signaling landscape of AML FLT3-ITD positive cell lines and patients. These models enable us to derive mechanistic insight into drug resistance mechanisms and suggest novel opportunities for combinatorial treatments. Interestingly, our analysis reveals that the JNK kinase pathway plays a crucial role in the tyrosine kinase inhibitor response of FLT3-ITD cells through cell cycle regulation. Finally, our work shows that patient-specific logic models have the potential to inform precision medicine approaches.

Mechanism of action of ECT in major depressive disorders: a neuroendocrine interpretation

Electroconvulsive therapy (ECT) is often efficacious in severe depression, and it is occasionally used in the treatment of schizophrenia. The mechanism of action of ECT is still poorly understood. We evaluated thyroid-stimulating hormone (TSH) and prolactin responses to thyrotropin-releasing hormone (TRH) after a first ECT and at the end of a series of seven ECTs in eight unipolar depressed patients with blunted basal TSH/TRH response, eight unipolar depressed patients with normal TSH/TRH response, and eight schizophrenic patients. The hormone patterns obtained after the first ECT showed an increase in prolactin and a decrease in TSH in all groups of patients, suggesting a nonspecific response. At the end of the therapeutic course, TSH responses increased in both groups of depressed patients, and the elevation was more relevant in depressed patients with normal TSH/TRH. Our data suggest that the mechanism of action of ECT becomes more specific when it is performed chronically and differs according to the organic substrate underlying different mental disorders. Moreover, an aminergic activation in the two groups of depressed patients seems to take place.

[Behavior of aldosterone and plasma renin activity after ACTH administration and insulin-induced hypoglycemia in patients with essential arterial hypertension]

The response of plasma aldosterone (PA) and plasma renin activity (PRA) to ACTH stimulation (0.25 mg Tetracosactide infusion/10 h) and to insulin-induced hypoglycemia (0.1 U/kg b.w.) has been studied in 34 essential hypertensive (EH) patients. Corticotrophin stimulation increases significantly PA, the percent increase being higher in normal PRA EH patients than in controls but comparable to controls in low PRA EH patients. PRA shows a slight and transient elevation. A significant increase in PA is observed also during the insulin test, but the percent increase is lower than that under ACTH stimulation. The possibility that aldosterone is involved, under severe and frequent stress, in the genesis of essential hypertension is discussed.

18-hydroxy-11-deoxycorticosterone response to ACTH, insulin and furosemide administration in essential hypertensive patients

Investigations were carried out on the behavior of 18-hydroxy-11-deoxycorticosterone (18-OH-DOC) in essential hypertension (EH) under exogenous administration of synthetic ACTH and insulin. 40 stable EH patients and 21 normal subjects were included in the study. The increase (12-fold basal values) in plasma 18-OH-DOC in normal subjects under Tetracosactide was significantly higher than cortisol (4-fold basal values). Furthermore, insulin hypoglycemia increased 18-OH-DOC levels 5-fold, whilst basal values of cortisol were increased 2-fold. An increase in 18-OH-DOC and cortisol was also observed in EH patients: in the subgroup with normal and low plasma renin activity, however, the rise in these two steroids was significantly lower than in normal subjects both under Tetracosactide and insulin. No significant hormonal modifications were observed after furosemide administration either in the normal subjects or in the EH patients. 18-OH-DOC by itself does not, therefore, appear to play a pathogenetic role in EH.