Unusual Domestic Source of Lead Poisoning

Non-occupational lead poisoning is not rare, mainly occurring in domestic situations in children, but also in adults. Lead poisoning was observed in a 65 years-old woman non-exposed to risk that caught our attention with a diagnostic suspicion of acute intermittent porphyria according to recurrent episodes of abdominal pain and neuropathy of upper limbs. Acute intermittent porphyria was excluded by a laboratory investigation that showed instead severe lead poisoning. After several thorough examinations of the domestic environment, the source of intoxication has been detected in some cooking pots that released high concentrations of lead. Ethylenediamine tetracetic acid disodium calcium therapy (three cycles) reduced consistently blood lead concentration and, after one year, neuropathy was almost entirely recovered.

CuII and AuIII Complexes with Glycoconjugated Dithiocarbamato Ligands for Potential Applications in Targeted Chemotherapy

This work is focused on the synthesis, characterization, and preliminary biological evaluation of bio-conjugated Au^III and Cu^II complexes with the aim of overcoming the well-known side effects of chemotherapy by improving the selective accumulation of an anticancer metal payload in malignant cells. For this purpose, carbohydrates were chosen as targeting agents, exploiting the Warburg effect that accounts for the overexpression of glucose-transporter proteins (in particular GLUTs) in the phospholipid bilayer of most neoplastic cells. We linked the dithiocarbamato moiety to the C1 position of three different monosaccharides: d-glucose, d-galactose, and d-mannose. Altogether, six complexes with a 1:2 metal-to-ligand stoichiometry were synthesized and in vitro tested as anticancer agents. One of them showed high cytotoxic activity toward the HCT116 colorectal human carcinoma cell line, paving the way to future in vivo studies aimed at evaluating the role of carbohydrates in the selective delivery of whole molecules into cancerous cells.

Synthesis, chemical characterization and cancer cell growth-inhibitory activities of Cu(ii) and Ru(iii) aliphatic and aromatic dithiocarbamato complexes

The effects mediated by different cyclic dithiocarbamic ligands on three classes of antiproliferative coordination compounds were studied.

Absence of Neurofibromin Induces an Oncogenic Metabolic Switch via Mitochondrial ERK-Mediated Phosphorylation of the Chaperone TRAP1

Mutations in neurofibromin, a Ras GTPase-activating protein, lead to the tumor predisposition syndrome neurofibromatosis type 1. Here, we report that cells lacking neurofibromin exhibit enhanced glycolysis and decreased respiration in a Ras/ERK-dependent way. In the mitochondrial matrix of neurofibromin-deficient cells, a fraction of active ERK1/2 associates with succinate dehydrogenase (SDH) and TRAP1, a chaperone that promotes the accumulation of the oncometabolite succinate by inhibiting SDH. ERK1/2 enhances both formation of this multimeric complex and SDH inhibition. ERK1/2 kinase activity is favored by the interaction with TRAP1, and TRAP1 is, in turn, phosphorylated in an ERK1/2-dependent way. TRAP1 silencing or mutagenesis at the serine residues targeted by ERK1/2 abrogates tumorigenicity, a phenotype that is reverted by addition of a cell-permeable succinate analog. Our findings reveal that Ras/ERK signaling controls the metabolic changes orchestrated by TRAP1 that have a key role in tumor growth and are a promising target for anti-neoplastic strategies.

Gold(III)-pyrrolidinedithiocarbamato Derivatives as Antineoplastic Agents

Transition metals offer many possibilities in developing potent chemotherapeutic agents. They are endowed with a variety of oxidation states, allowing for the selection of their coordination numbers and geometries via the choice of proper ligands, leading to the tuning of their final biological properties. We report here on the synthesis, physico-chemical characterization, and solution behavior of two gold(III) pyrrolidinedithiocarbamates (PDT), namely [Au^IIIBr₂(PDT)] and [Au^IIICl₂(PDT)]. We found that the bromide derivative was more effective than the chloride one in inducing cell death for several cancer cell lines. [Au^IIIBr₂(PDT)] elicited oxidative stress with effects on the permeability transition pore, a mitochondrial channel whose opening leads to cell death. More efficient antineoplastic strategies are required for the widespread burden that is cancer. In line with this, our results indicate that [Au^IIIBr₂(PDT)] is a promising antineoplastic agent that targets cellular components with crucial functions for the survival of tumor cells.

[Release of metals from metal-on-metal hip prostheses]

The present study examined blood and urinary concentrations of Cr and Co in 30 patients with metal-on-metal hip prostheses without signs of wear and 6 patients with prosthetic bearing and clear signs of wear and metallosis. The determination in biological fluids showed in patients with not signs of wear the geometric mean concentration of metals only modestly increased (CoS 0.5 microg/l, CoU 5.7 microg/l, CrS 0.8 microg/l, CrU 3.4 microg/l) compared to the reference values, while the wear caused a significant increase in the concentration of both Co (CoS 94.6 microg/l, CoU 334.5 microg/l) and Cr (CrS 57.7 microg/l, CrU 89.4 microg/I). As the results, the not functioning implants are a risks to the patients and are associated with high levels of metals in biological fluids. Currently, the patients with metallosis had not signs and symptoms associated with metal toxicity, but high concentrations could to cause kidney, peripheral nervous system, heart, and thyroid damage.

Soluble phenyl valerate esterases of hen sciatic nerve and the potentiation of organophosphate induced delayed polyneuropathy

Contrary to some organophosphorus esters (OPs), certain esterase inhibitors including sulfonyl halides, carbamates and phosphinates do not cause axonal neuropathy, but they may exacerbate traumatic and some chemical insults to axons. This phenomenon is referred to as the promotion/potentiation of axonopathies. We report here promotion studies of the organophosphate induced delayed polyneuropathy (OPIDP). This neuropathy correlates with inhibition/aging of neuropathy target esterase, but this enzyme is not the target of promotion. Soluble phenyl valerate (PV) esterases in peak I (V(0)) of hen sciatic nerve were analysed. When these activities were inhibited in vitro by a mixture containing mipafox - an OP that causes OPIDP - paraoxon and p-toluene sulfonyl fluoride - two esterase inhibitors that do not cause either neuropathy or promotion-, then the remaining activity was sensitive to classical promoters such as phenylmethane sulfonyl fluoride (PMSF) and phenylmethyl benzyl carbamate. This PV-activity was not inhibited in sciatic nerves of hens treated with di-isopropyl phosphorofluoridate, at a dose that causes OPIDP. When these birds were further dosed with PMSF a dose-response relationship was observed between inhibition of PV-esterases, as above defined, and the severity of clinical responses. These data suggest that the target of promotion is embraced in peak I (V(0)) of soluble proteins of hen sciatic nerve.

The Mitochondrial Effects of Small Organic Ligands of BCL-2

We have investigated the mitochondrial effects of BH3I-2', Chelerythrine, and HA14-1, small organic molecules that share the ability to bind the BH3 domain of BCL-2. All compounds displayed a biphasic effect on mitochondrial respiration with uncoupling at low concentrations and respiratory inhibition at higher concentrations, the relative uncoupling potency being BH3I-2' (half-maximal uncoupling at about 80 nm) > Chelerythrine (half-maximal uncoupling at about 2 microm) > HA14-1 (half-maximal uncoupling at about 20 microm). At concentrations lower than required for uncoupling all compounds sensitized the permeability transition pore (PTP) to opening both in isolated mitochondria and intact cells. To assess whether the effects on BCL-2 binding, PTP induction and respiration could be due to different structural determinants we have tested a set of HA14-1 analogs from the Hoffmann-La Roche chemical library. We have identified 5-(6-chloro-2,4-dioxo-1,3,4,10-tetrahydro-2H-9-oxa-1,3-diaza-anthracen-10-yl)-pyrimidine-2,4,6-trione (EM20-25) as a molecule devoid of effects on respiration that is able to induce PTP opening, to disrupt the BCL-2/BAX interactions in situ and to activate caspase-9 in BCL-2-overexpressing cells. EM20-25 neutralized the antiapoptotic activity of overexpressed BCL-2 toward staurosporine and sensitized BCL-2-expressing cells from leukemic patients to the killing effects of staurosporine, chlorambucil, and fludarabine. These results provide a proof of principle that the potentially toxic effects of BCL-2 ligands on mitochondrial respiration are not essential for their antiapoptotic activity and represent an important step forward in the development of tumor-selective drugs acting on BCL-2.