Tumour-necrosis-factor-related apoptosis-inducing ligand (TRAIL) is a novel cytokine characterized by selective killing activity against tumour cells. We recently found that β-amyloid-induced apoptosis in a human neuronal cell line was mediated via induction of TRAIL. Here, we show that TRAIL is specifically expressed in the brain of Alzheimer's disease (AD) patients and completely absent in the brain of non-demented patients. TRAIL-like immunoreactivity was localized in AD affected regions, such as cerebral cortex, often in the proximity of Congo-red-positive amyloid plaques. These findings suggest that neurons represent an independent and potential source of TRAIL, suggesting that the latter acts redundantly with other noxious stimuli in neurodegenerative diseases characterized by amyloidosis and neuroinflammation.
High concentrations of the "peripheral" benzodiazepine (pBZD) binding site ("receptor") have been described in the hypothalamus, the pituitary and the adrenal glands. This study was undertaken to examine the effects of ligands of this binding site on the hypothalamic-pituitary-adrenal axis (HPA). To accomplish this we administered graded doses of the pBZD receptor agonist 4-chloro-diazepam (Ro5-4864) i.v. to catheterized, freely moving adult male Sprague-Dawley rats. Serial blood samples for plasma adrenocorticotropin hormone (ACTH) and corticosterone determinations were drawn from the catheter before and after the injection of the drug. Ro5-4864 significantly stimulated ACTH and corticosterone secretion in a dose-dependent fashion. To examine whether this effect could be antagonized by the pBZD binding site antagonist PK 11195, we treated rats with PK 11195 at doses 10- and 50-times higher than Ro5-4864 before administration of a maximally effective dose of Ro5-4864. Neither dose of PK 11195 antagonized Ro5-4864-induced plasma ACTH or corticosterone elevations. However, this agent, given alone, stimulated ACTH and corticosterone release. Similarly, carbamazepine (CBZ), which binds to the pBZD binding site with low affinity, stimulated weakly the HPA in vivo, reaching statistical significance only at the highest dose tested. To examine the site(s) of action of these compounds on the HPA, we evaluated their effects on hypothalamic corticotropin-releasing hormone (CRH) and pituitary ACTH secretion in vitro. Ro5-4864 stimulated hypothalamic CRH, but not pituitary ACTH secretion. Neither PK 11195 nor CBZ had any agonist effect on hypothalamic CRH secretion in vitro, whereas both antagonized Ro5-4864-induced CRH secretion.(ABSTRACT TRUNCATED AT 250 WORDS)
Abstract Tumor necrosis factor related apoptosis inducing ligand (TRAIL) is involved in amyloid beta dependent neurotoxicity via the extrinsic pathway. Recently, several genes modulating TRAIL cytotoxicity have been characterized, providing evidence for a role of wingless‐type mouse mammary tumor virus integration site family (Wnt), Jun‐N‐terminal kinase and other pathways in increased cell susceptibility to the cytokine. We investigated whether neurotoxic effects of TRAIL could be due to modulation of the Wnt signaling pathway. Western blot analysis of Wnt in SH‐SY5Y human neuroblastoma cells showed significantly decreased Wnt expression in cultures treated with TRAIL. Correspondingly, both phosphorylation of glycogen synthase kinase 3 beta and degradation of cytoplasmic β‐catenin were increased, as well as phosphorylation of the τ protein, bringing about the picture of neuronal damage. As a counterproof of the interaction of TRAIL with the Wnt pathway, the addition of the specific glycogen synthase kinase 3 beta inhibitor SB216763 resulted in rescue of a significant percent of cells from TRAIL‐induced apoptosis. The rescue was total when the caspase 8 inhibitor z‐IETD‐FMK was added in combination with SB216763. Results show that, probably, in addition to triggering caspase signaling, TRAIL also interferes with the Wnt pathway, additionally concurring to neuronal damage. These data suggest that the Wnt pathway substantially contributes to the TRAIL‐related neurotoxicity and indicate the TRAIL system as a candidate target for pharmacological treatment of Alzheimer’s disease and related disorders.
Tumour growth is tightly related to new blood vessel formation, tissue remodelling and invasiveness capacity. A number of tissular factors fuel the growth of glioblastoma multiforme, the most aggressive brain neoplasm. In fact, gene array analyses demonstrated that the proapoptotic cytokine tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) inhibited mRNA expression of VEGF, along with those of matrix metalloproteinase-2 (MMP-2), its inhibitor tissue inhibitor of matrix metalloproteinases-2 (TIMP-2), as well as the tumour invasiveness-related gene secreted protein acid rich in cysteine (SPARC) in different human glioblastoma cell lines. Particularly, VEGF mRNA and protein expression and release from glioblastoma cells were also inhibited by TRAIL. The latter also exerted antimitogenic effects on human umbilical vein endothelial cells (HUVECs). With the same cells, TRAIL inhibited new vessel formation in the in vitro matrigel model, as well as it exerted powerful inhibition of blood vessel formation induced by an angiogenic cocktail administered in subcutaneous pellets in vivo in the C57 mouse. Moreover, the expression of MMP-2, its inhibitor TIMP-2 and the tumour invasiveness-related protein SPARC were effectively inhibited by TRAIL in glioblastoma cell lines. In conclusion, our data indicate that TRAIL inhibits the orchestra of factors contributing to glioblastoma biological aggressiveness. Thus, the TRAIL system could be regarded as a molecular target to exploit for innovative therapy of this type of tumour.
Sorafenib (BAY 43-9006) is an inhibitor of multiple-receptor tyrosine kinases involved in tumor growth and angiogenesis, which can be advantageously administered orally. Initially used as monotherapy in advanced renal cell carcinoma, sorafenib was proven to increase progression-free survival while enhancing disease control. Clinical trials on sorafenib are at present ongoing for the treatment of various malignancies, including thyroid cancer (TC).Specifically, in two phase II studies recently conducted on papillary TC, although the respective results were not entirely compatible as regard partial response rate and progression-free survival, sorafenib demonstrated a relatively favorable benefit/risk profile. In another more recent phase II study, whose primary endpoint was the reinduction of radioactive iodine uptake at 26 weeks, although no reinduction of radioactive iodine uptake was observed, 59% had a beneficial response and 34% had stable disease. Sorafenib hence appears to be a valid alternative to conventional treatment of metastatic papillary TC refractory to radioiodine therapy.Further prospective investigations are required to define the characteristics of tumor response to the drug and the factors inducing resistance to treatment. A major issue demanding immediate attention involves optimization of sorafenib treatment: this concerns multidrug combination with different tyrosine kinase inhibitors or immunomodulating agents with the aim of reducing doses and thereby improving drug tolerability and antineoplastic capability.
The practical effectiveness of second-generation antipsychotics in children and adolescents is an understudied issue. It is a crucial area of study, though, because such patients are often treated for long-lasting disorders.We carried out a 24-month (March 2012-March 2014) observational study on an unselected population of pediatric outpatients treated with risperidone, aripiprazole, olanzapine, or quetiapine aiming to (1) describe drug use, (2) compare post hoc the discontinuation rates due to specific causes and dose adjustments by Kaplan-Meier analyses between drugs, and (3) analyze predictors influencing these outcomes by Cox multivariate models.Among 184 pediatric patients, 77% patients were prescribed risperidone, and 18% were prescribed aripiprazole. Olanzapine or quetiapine were scantly used; therefore, they were excluded from analyses. Risperidone was prevalent in younger, male patients with disruptive behavioral disorders; aripiprazole, in patients with tic disorders. Overall, discontinuations occurred mostly in the first 6 months, and, at 24 months, the discontinuation numbers were similar between users of risperidone and aripiprazole (41.5% vs 39.4%). In univariate analyses, dose reduction was higher for aripiprazole (P = .033). Multivariate analyses yielded the following predictors: for all-cause discontinuation, baseline severity (hazard ratio [HR] = 1.48, P = .001) and dose increase (HR = 3.55, P = .001); for patient-decided discontinuation, dose change (increase: HR = 6.43, P = .004; reduction: HR = 7.89, P = .049) and the presence of concomitant drugs (HR = 4.03, P = .034), while autistic patients discontinued less (HR = 0.23, P = .050); for clinician-decided discontinuation due to adverse drug reactions, baseline severity (HR = 1.96, P = .005) and dose increase (HR = 5.09, P = .016); for clinician-decided discontinuation due to inefficacy, baseline severity (HR = 2.88, P = .014) and the use of aripiprazole (HR = 5.55, P = .013); for dose increase, none; for dose reduction, the occurrence of adverse drug reactions (HR = 4.74, P = .046), while dose reduction was less probable in autistic patients (HR = 0.22, P = .042).The findings of this study show a similarity between the overall effectiveness of risperidone and aripiprazole in a real-life pediatric outpatient setting.
