Biomedical subjects

Renata Alleva

Publications and source records attributed to Renata Alleva.

8 recordsLinked to original sources

PubMed2006

Alpha-tocopheryl succinate induces DR4 and DR5 expression by a p53-dependent route: implication for sensitisation of resistant cancer cells to TRAIL apoptosis.

We evaluated the ability of alpha-tocopheryl succinate (alpha-TOS) to sensitise TRAIL-resistant malignant mesothelioma (MM) cells to TRAIL-induced apoptosis. We show that alpha-TOS activates expression of DR4/DR5 in a p53-dependent manner and re-establishes sensitivity of resistant MM cells to TRAIL-mediated apoptosis, as documented in p53wt MM cells but not in their p53null counterparts. MM cells selected for TRAIL resistance expressed low cell surface levels of DR4 and DR5. Treatment with sub-lethal doses of alpha-TOS restored expression of DR4 and DR5. The ability of alpha-TOS to modulate expression of pro-apoptotic genes may play a role in sensitisation of tumour cells to immunological stimuli.

Apoptosis↗

PubMed2006

Alpha-tocopheryl succinate alters cell cycle distribution sensitising human osteosarcoma cells to methotrexate-induced apoptosis.

alpha-Tocopheryl succinate (alpha-TOS) exerts pleiotrophic responses in malignant cells leading to cell cycle arrest, differentiation and apoptosis. We tested the ability of alpha-TOS to induce apoptosis or cell cycle perturbation in three human osteosarcoma (OS) cell lines which differ in their pRB and p53 status. We found high levels of apoptosis in OS cells carrying wild-type p53 gene when exposed to alpha-TOS, while the mutant p53 cells were resistant. A S/G2 transition arrest was observed in two OS cell lines exposed to alpha-TOS, which sensitised them to methotrexate, an agent whose activity is cell cycle-dependent. We propose that alpha-TOS may be used as a drug or an adjuvant for treatment of osteosarcomas.

Apoptosis↗

PubMed2005

alpha-Lipoic acid supplementation inhibits oxidative damage, accelerating chronic wound healing in patients undergoing hyperbaric oxygen therapy.

Hyperbaric oxygen (HBO) therapy is successfully used for the treatment of a variety of conditions. However, prolonged exposure to high concentrations of oxygen induces production of reactive oxygen species, causing damage to the cells. Thus, antioxidant supplementation has been proposed as an adjuvant to attenuate such deleterious secondary effects. We evaluated the effects of alpha-lipoic acid (LA) in patients affected by chronic wounds undergoing HBO treatment. LA supplementation efficiently reduces both the lipid and DNA oxidation induced by oxygen exposure. LA exerted its antioxidant activity by directly interacting with free radicals or by recycling vitamin E. An inhibitory effect of LA on the pro-inflammatory cytokine interleukin-6 was observed. Taken together, we demonstrated an adjuvant effect of LA in HBO therapy used for impaired wound healing treatment. We propose that LA may be used to further promote the beneficial effects of HBO therapy.

Administration, Oral↗

PubMed2005

Alpha-tocopheryl succinate induces cytostasis and apoptosis in osteosarcoma cells: the role of E2F1.

Alpha-tocopheryl succinate (alpha-TOS), a redox-inactive analog of vitamin E, induces cell cycle arrest, differentiation, and triggers apoptosis. We examined the ability of alpha-TOS to induce cytostasis and/or apoptosis in two human osteosarcoma cell lines, which carry wild-type pRb but differ in the p53 status. In the wt-p53 cells, alpha-TOS induced apoptosis, which was associated with p53 activation and enhanced E2F1 expression. Mutant p53 cells failed to undergo apoptosis when challenged with alpha-TOS. The cell growth arrest after alpha-TOS treatment was associated with a reduced expression of E2F1. Knocking down E2F1 rendered the alpha-TOS-sensitive cells rather resistant to the apoptotic stimulus inducing a marked and prolonged cell growth arrest. We conclude that alpha-TOS induces cell growth arrest or apoptosis involving E2F1.

Apoptosis↗

PubMed2005

Effect of different anesthesia techniques on red blood cell endogenous recovery in hip arthroplasty.

STUDY OBJECTIVE: To compare the magnitude of postoperative red blood cell (RBC) recovery with 3 different anesthetic techniques, general anesthesia (GA), epidural anesthesia (EA) alone, and the combination of these 2 techniques (CA), in patients undergoing total hip arthroplasty. DESIGN: Randomized, controlled study. SETTING: Seven university or hospital departments of anesthesia. PATIENTS: Two hundred ten patients with American Society of Anesthesiologists physical status I to III were randomly selected to receive EA, GA, or CA. INTERVENTION: Patients undergoing total hip replacement were randomly assigned to 3 statistically comparable groups based on the type of anesthesia received: GA, EA, and CA groups. MEASUREMENTS AND MAIN RESULTS: Intra- and postoperative blood loss was evaluated as either compensated or noncompensated blood loss by using Nadler's formula. The intra- and postoperative bleeding, referred to as compensated blood loss, was similar among groups. The circulating RBC mass, noncompensated blood loss, dropped on the first postoperative day to a similar extent among the groups. The endogenous recovery of the RBC is carried out on the fifth day after surgery in patients who underwent EA, whereas no RBC recovery was observed in those who had received GA alone or GA combined with EA. CONCLUSIONS: Patients who had received EA had a faster recovery of the circulating erythrocyte mass than those who had had GA or CA. The presence of nitrous oxide in the anesthetic gas mixture might inhibit erythropoiesis by altering vitamin B(12) functions.

Adult↗

PubMed2004

alpha-Tocopheryl succinate inhibits proliferation of mesothelioma cells by selective down-regulation of fibroblast growth factor receptors.

alpha-Tocopheryl succinate (alpha-TOS), a redox-silent analogue of vitamin E, inhibits malignant mesotheliomas (MM) in a pre-clinical model. Here we investigated the underlying mechanism. Exposure of MM cells to alpha-TOS triggered apoptosis at higher and inhibited proliferation at lower concentrations, while this effect was not observed in non-malignant mesothelial cells. Sub-apoptotic doses of alpha-TOS caused down-regulation of fibroblast growth factor receptor-1 (FGFR1) selectively in MM cells, while the effect on FGFR2 was only marginal. FGF1 and FGF2 enhanced MM cell proliferation that was suppressed by alpha-TOS. Over-expression of E2F1, a transcriptional factor of FGFR1, but not its dominant-negative counterpart, partially blocked the inhibitory activity of alpha-TOS on MM cell proliferation. Our data suggest a novel mechanism by which a clinically intriguing agent selectively suppresses proliferation of cancer cells, as shown here for the untreatable mesotheliomas.

Apoptosis↗

PubMed2004

Vitamin E analogues: a new class of inducers of apoptosis with selective anti-cancer effects.

In spite of unrelenting effort, the net incidence of neoplastic diseases appears not to have been curbed. While some types of cancer have been suppressed significantly, others are either stagnating or on the increase. Therefore, the need for a cure is imperative, in particularly a drug or combination of drugs that would be selective for malignant cells, i.e. with as low secondary toxicity as possible. Recent data strongly suggest that analogues of vitamin E, epitomised by the most studied alpha-tocopheryl succinate (alpha-TOS), may meet the need for the coveted drugs with a selective anti-neoplastic effect. The reasons for this optimism are reviewed in this article.

Antineoplastic Agents↗

PubMed2003

Lymphocyte DNA damage precedes DNA repair or cell death after orthopaedic surgery under general anaesthesia.

Anaesthetics have gained a lot of attention for their potential mutagenic/carcinogenic effects. In the present study we have investigated the genotoxicity of the inhalation anaesthetic sevoflurane on DNA of lymphocytes isolated from 20 patients undergoing orthopaedic surgery. The genotoxicity of the anaesthetic was studied by assaying DNA damage, apoptosis, DNA repair enzyme activity and GSH content in peripheral lymphocytes before, 15 min after anaesthesia and 24 h after surgery. Lymphocytes isolated 15 min after anaesthesia showed an increase in oxidized purine and pyrimidine bases without DNA strand break formation. DNA strand breaks occurred on the first post-operative day, associated with an enhancement of DNA repair activity and a decrease in GSH. Formation of strand breaks could be the consequence of DNA repair activity. In fact, at 24 h after surgery most of the oxidized DNA bases were repaired. When DNA damage was not repaired, activation of the cell cycle checkpoint protein p53 could lead to apoptosis. An altered redox status may contribute to lymphocytopenia due to an apoptotic event as a consequence of surgical trauma. The presence of apoptotic cells at 1 day after surgery could support the hypothesis that highly damaged peripheral lymphocytes are committed to undergo programmed cell death if the damage is not repaired. In conclusion, the actual risk from anaesthesia is presumably extremely small. However, these findings contribute to our understanding of the regulation of DNA damage/repair and cell death.

Adult↗