Thyroid hormones (THs) are major regulators of biological processes essential for correct development and energy homeostasis. Although thyroid disruptors can deeply affect human health, the impact of ...exogenous chemicals and in particular mixture of chemicals on different aspects of thyroid development and metabolism is not yet fully understood. In this study we have used the highly versatile zebrafish model to assess the thyroid axis disrupting effects of cadmium (Cd) and dibenzothiophene (DBT), two environmental endocrine disruptors found to be significantly correlated in epidemiological co-exposure studies. Zebrafish embryos (5hpf) were exposed to low concentrations of Cd (from 0.05 to 2 μM) and DBT (from 0.05 to 1 μM) and to mixtures of them. A multilevel assessment of the pollutant effects has been obtained by combining in vivo morphological analyses allowed by the use of transgenic fluorescent lines with liquid chromatography mass spectrometry determination of TH levels and quantification of the expression levels of key genes involved in the Hypothalamic-Pituitary-Thyroid Axis (HPTA) and TH metabolism. Our results underscore for the first time an important synergistic toxic effect of these pollutants on embryonic development and thyroid morphology highlighting differences in the mechanisms through which they can adversely impact on multiple physiological processes of the HPTA and TH disposal influencing also heart geometry and function.
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•Dibenzothiophene (DBT) synergizes with Cadmium (Cd) in inducing zebrafish morphological defects.•Low DBT and Cd concentrations impact thyroid development and homeostasis through different mechanisms.•DBT-Cd mix induces a dose-dependent increase of thyroid hormone receptor expression.•Low DBT and Cd slightly impact cardiac development but triggers hypothyroid-like bradycardia.
Cocaine self-administration decreases type 5 metabotropic glutamate receptor (mGluR5) tissue concentrations in laboratory rats during early abstinence. These changes are thought to influence the ...drug's reinforcing properties and the ability of drug-related cues to induce relapse. Here, our goal was to measure brain regional mGluR5 availability in recently abstinent cocaine dependent humans. Participants meeting DSM-IV diagnostic criteria for current cocaine dependence (n=9) were recruited from the general population. mGluR5 availability (binding potential, non-displaceable; BPND) was measured with high-resolution positron emission tomography (PET HRRT) and 11CABP688. Compared to age- and sex-matched healthy controls (n=9), cocaine dependent subjects showed significantly lower BPND values in the ventral (bilateral: −28.2%, p=0.011), associative (right: −21.4%, p=0.043), and sensorimotor striatum (bilateral: −21.7%, p=0.045), amygdala (left: −26%, p=0.046) and insula (right: −23.3%, p=0.041). Among the cocaine users, receptor availabilities were related to abstinence (range: 2 to 14days). The longer the duration of abstinence, the lower the BPND values in the sensorimotor striatum (r=−0.71, p=0.034), left amygdala (r=−0.73, p=0.026) and right insula (r=−0.67, p=0.046). Compared to healthy controls, BPND values were significantly reduced in those who tested negative for cocaine on the PET test session in the ventral (p=0.018) and sensorimotor striatum (p=0.017), left amygdala (p=0.008), and right insula (p=0.029), but not in those who tested positive. Together, these results provide evidence of time-related mGluR5 alterations in striatal and limbic regions in humans during early cocaine abstinence.
•mGluR5 has been proposed to modulate the reinforcing properties of cocaine.•We measured mGluR5 availability in cocaine dependents using 11CABP688 PET ligand.•Cocaine use was associated with lower mGluR5 levels in the limbic system.•Longer abstinence from cocaine was associated with lower mGluR5 availability.•Changes in mGluR5 might reflect changes in susceptibility to drug use and relapse.
Mammalian target of rapamycin (mTOR) is a key protein kinase controlling signal transduction from various growth factors and upstream proteins to the level of mRNA translation and ribosome ...biogenesis, with pivotal regulatory effects on cell cycle progression, cellular proliferation and growth, autophagy and angiogenesis. The mTOR pathway, and its upstream regulators in the PI3K/PTEN/AKT cascade, are altered in a variety of experimental and human malignancies.This has led to the prediction that mTOR inhibitors may be used as anticancer agents. With the recent approval of two mTOR-targeted drugs (temsirolimus and everolimus) for the treatment of renal cell carcinoma and mantle cell lymphoma, this paradigm has been effectively translated into the clinical setting. In this review, we discuss mTOR biology and regulation, the mode of action of mTOR inhibitors as anti-cancer agents, and current clinical evidence supporting the use of rapamycin-like mTOR inhibitors in cancer treatment.
This review summarises the recent evidence on preoperative therapeutic strategies in pancreatic cancer and discusses the rationale for an imminent need for a personalised therapeutic approach in ...non-metastatic disease. The molecular diversity of pancreatic cancer and its influence on prognosis and treatment response, combined with the failure of ‘all-comer’ treatments to significantly impact on patient outcomes, requires a paradigm shift towards a genomic-driven approach. This is particularly important in the preoperative, potentially curable setting, where a personalised treatment allocation has the substantial potential to reduce pancreatic cancer mortality.
•Molecular diversity of pancreatic cancer requires a paradigm shift towards a genomic-driven therapeutic approach.•Unselected treatment strategies demonstrate only limited efficacy in early-stage pancreatic cancer.•Personalised treatment in non-metastatic disease has potential to reduce pancreatic cancer mortality.•It is fundamental to implement preoperative clinical studies enriched for potential prognostic/predictive biomarkers.•Novel models of therapeutic development are warranted to accelerate progress in pancreatic cancer care and research.
Mutations and chromosomal translocations occur in leukemic cells that result in elevated expression or constitutive activation of various growth factor receptors and downstream kinases. The ...Raf/MEK/ERK, PI3K/PTEN/Akt/mTOR and Jak/STAT pathways are often activated by mutations in upstream genes. The Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR pathways are regulated by upstream Ras that is frequently mutated in human cancer. Recently, it has been observed that the FLT-3 and Jak kinases and the phosphatase and tensin homologue deleted on chromosome 10 (PTEN) phosphatase are also frequently mutated or their expression is altered in certain hematopoietic neoplasms. Many of the events elicited by the Raf/MEK/ERK, PI3K/PTEN/Akt/mTOR and Jak/STAT pathways have direct effects on survival pathways. Aberrant regulation of the survival pathways can contribute to uncontrolled cell growth and lead to leukemia. In this review, we describe the Raf/MEK/ERK, PI3K/PTEN/Akt/mTOR and Jak/STAT signaling cascades and summarize recent data regarding the regulation and mutation status of these pathways and their involvement in leukemia.
Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) are effective as first-line treatment of advanced non-small-cell lung cancer patients with EGFR mutations (EGFR-M+).
We ...conducted a literature-based meta-analysis to quantify the magnitude of benefit with upfront EGFR TKI in EGFR-M+ patients. Meta-regression and sensitivity analyses were also carried out to identify additional predictors of outcome and to assess the influence of trial design.
Five trials (805 patients) were identified (three trials prospectively enrolling EGFR-M+ patients and two retrospective analyses of EGFR-M+ patients). TKI significantly increased progression-free survival (PFS) hazard ratio (HR) 0.45, 95% confidence interval (CI) 0.36–0.58, P < 0.0001 and overall response rate (ORR) (HR 2.08, 95% CI 1.75–2.46, P < 0.0001) over chemotherapy, while significantly decreasing neutropenia. No significant difference was observed in overall survival. The rate of exon-19 mutations, female gender, and nonsmoking status were identified as additional predictors of outcome at meta-regression analysis. A significant interaction with trial design was found for both PFS (P = 0.028) and ORR (P = 0.008), suggesting a larger advantage for patients treated within prospective trials.
In EGFR-M+ patients, first-line TKI increase both PFS and ORR by ∼25%, while significantly decreasing toxicity. The role of additional predictive factors and the influence of trial design on the magnitude of the observed benefit warrant further investigation.
The role of second-line chemotherapy (CT) is not established in advanced biliary tract cancer (aBTC). We investigated the outcome of aBTC patients treated with second-line CT and devised a prognostic ...model.
Baseline clinical and laboratory data of 300 consecutive aBTC patients were collected and association with overall survival (OS) was investigated by multivariable Cox models.
The following parameters resulted independently associated with longer OS: Eastern Cooperative Oncology Group performance status of 0 (P<0.001; hazard ratio (HR), 0.348; 95% confidence interval (CI) 0.215-0.562), CA19.9 lower than median (P=0.013; HR, 0.574; 95% CI 0.370-0.891), progression-free survival after first-line CT ≥ 6 months (P=0.027; HR, 0.633; 95% CI 0.422-0.949) and previous surgery on primary tumour (P=0.027; HR, 0.609; 95% CI 0.392-0.945). We grouped the 249 patients with complete data available into three categories according to the number of fulfilled risk factors: median OS times for good-risk (zero to one factors), intermediate-risk (two factors) and poor-risk (three to four factors) groups were 13.1, 6.6 and 3.7 months, respectively (P<0.001).
Easily available clinical and laboratory factors predict prognosis of aBTC patients undergoing second-line CT. This model allows individual patient-risk stratification and may help in treatment decision and trial design.
Since the discovery of leukemic stem cells (LSCs) over a decade ago, many of their critical biological properties have been elucidated, including their distinct replicative properties, cell surface ...phenotypes, their increased resistance to chemotherapeutic drugs and the involvement of growth-promoting chromosomal translocations. Of particular importance is their ability to transfer malignancy to non-obese diabetic-severe combined immunodeficient (NOD-SCID) mice. Furthermore, numerous studies demonstrate that acute myeloid leukemia arises from mutations at the level of stem cell, and chronic myeloid leukemia is also a stem cell disease. In this review, we will evaluate the main characteristics of LSCs elucidated in several well-documented leukemias. In addition, we will discuss points of therapeutic intervention. Promising therapeutic approaches include the targeting of key signal transduction pathways (for example, PI3K, Rac and Wnt) with small-molecule inhibitors and specific cell surface molecules (for example, CD33, CD44 and CD123), with effective cytotoxic antibodies. Also, statins, which are already widely therapeutically used for a variety of diseases, show potential in targeting LSCs. In addition, drugs that inhibit ATP-binding cassette transporter proteins are being extensively studied, as they are important in drug resistance-a frequent characteristic of LSCs. Although the specific targeting of LSCs is a relatively new field, it is a highly promising battleground that may reveal the Holy Grail of cancer therapy.
The Raf/MEK/ERK, PI3K/PTEN/Akt/mTOR and Jak/STAT pathways are frequently activated in leukemia and other hematopoietic disorders by upstream mutations in cytokine receptors, aberrant chromosomal ...translocations as well as other genetic mechanisms. The Jak2 kinase is frequently mutated in many myeloproliferative disorders. Effective targeting of these pathways may result in suppression of cell growth and death of leukemic cells. Furthermore it may be possible to combine various chemotherapeutic and antibody-based therapies with low molecular weight, cell membrane-permeable inhibitors which target the Raf/MEK/ERK, PI3K/PTEN/Akt/mTOR and Jak/STAT pathways to ultimately suppress the survival pathways, induce apoptosis and inhibit leukemic growth. In this review, we summarize how suppression of these pathways may inhibit key survival networks important in leukemogenesis and leukemia therapy as well as the treatment of other hematopoietic disorders. Targeting of these and additional cascades may also improve the therapy of chronic myelogenous leukemia, which are resistant to BCR-ABL inhibitors. Furthermore, we discuss how targeting of the leukemia microenvironment and the leukemia stem cell are emerging fields and challenges in targeted therapies.
Vandetanib did not demonstrate any superiority alone or in combination with gemcitabine in the progression-free survival of patients affected by advanced biliary tract cancer compared with ...gemcitabine alone. The safety profile of vandetanib given (alone or in combination with gemcitabine) does not show any additional adverse events (AEs) or worsening of already known AEs.
The management of biliary tract cancers (BTCs) is complex due to limited data on the optimal therapeutic approach. This phase II multicenter study evaluated the efficacy and tolerability of vandetanib monotherapy compared with vandetanib plus gemcitabine or gemcitabine plus placebo in patients with advanced BTC.
Patients were randomized in a 1 : 1 : 1 ratio to three treatment groups: vandetanib 300 mg monotherapy (V), vandetanib 100 mg plus gemcitabine (V/G), gemcitabine plus placebo (G/P). Vandetanib (300 mg or 100 mg) or placebo was given in single oral daily doses. Gemcitabine 1000 mg/m2 was i.v. infused on day 1 and day 8 of each 21-day cycle. The primary end point was progression-free survival (PFS). Secondary end points were: objective response rate (ORR), disease control rate, overall survival, duration of response, performance status and safety outcomes.
A total of 173 patients (mean age 63.6 years) were recruited at 19 centers across Italy. Median (95% confidence intervals) PFS (days) were 105 (72–155), 114 (91–193) and 148 (71–225), respectively, for the V, V/G and G/P treatment groups, with no statistical difference among them (P = 0.18). No statistical difference between treatments was observed for secondary end points, except ORR, which slightly favored the V/G combination over other treatments. The proportion of patients reporting adverse events (AEs) was similar for the three groups (96.6% in V arm, 91.4% in the V/G arm and 89.3% in the G/P arm).
Vandetanib treatment did not improve PFS in patients with advanced BTC. The safety profile of vandetanib did not show any additional AEs or worsening of already known AEs.
NCT00753675.
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