Battista Borghi

In vivo supplementation with coenzyme Q10 enhances the recovery of human lymphocytes from oxidative DNA damage

We investigated the effect of in vitro and in vivo CoQ10 supplementation on the recovery of lymphocytes from oxidative DNA damage. Furthermore, we investigated whether CoQ10 supplementation modulates the activity of DNA repair enzymes by using cellular extracts from lymphocytes. Exposure of lymphocytes to oxidizing agents leads to an increase of DNA strand breaks, oxidized purines, and pyrimidines. Enrichment of cells with CoQ10 prevents DNA strand‐break formation and affects the kinetics of repair, which occurs faster in enriched than in native lymphocytes. In contrast, CoQ10 supplementation neither prevents endogenous formation of oxidized bases nor affects their repair. DNA repair enzyme activity is enhanced by in vivo CoQ10 supplementation. Changes in the redox state of several transcriptional factors have been proposed as mechanisms regulating cell proliferation and apoptosis. Because CoQ10 is mainly present as ubiquinol‐10, both in plasma and lymphocytes, it can feasibly modulate the intracellular redox potential involved in the regulation of gene expression. The redox mechanism implicated in the enzyme transactivation could explain the property of CoQ10 to enhance the DNA repair activity and protect DNA from oxidative damage.

Coenzyme Q blocks biochemical but not receptor-mediated apoptosis by increasing mitochondrial antioxidant protection

Generation of free radicals is often associated with the induction and progression of apoptosis. Therefore, antioxidants can prove anti‐apoptotic, and can help to elucidate specific apoptotic pathways. Here we studied whether coenzyme Q, present in membranes in reduced (ubiquinol) or oxidised (ubiquinone) forms, can affect apoptosis induced by various stimuli. Exposure of Jurkat cells to α‐tocopheryl succinate (α‐TOS), hydrogen peroxide, anti‐Fas IgM or TRAIL led to induction of apoptosis. Cell death due to the chemical agents was suppressed in cells enriched with the reduced form of coenzyme Q. However, coenzyme Q did not block cell death induced by the immunological agents. Ubiquinol‐10 inhibited reactive oxygen species (ROS) generation in cells exposed to α‐TOS, and a mitochondrially targeted coenzyme Q analogue also blocked apoptosis triggered by α‐TOS or hydrogen peroxide. Therefore, it is plausible that ubiquinol‐10 protects cells from chemically‐induced apoptosis by acting as an antioxidant in mitochondria. Our results also indicate that generation of free radicals may not be a critical step in induction of apoptosis by immunological agents.

α-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 α‐tocopheryl succinate (α‐TOS) to sensitise TRAIL‐resistant malignant mesothelioma (MM) cells to TRAIL‐induced apoptosis. We show that α‐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 α‐TOS restored expression of DR4 and DR5. The ability of α‐TOS to modulate expression of pro‐apoptotic genes may play a role in sensitisation of tumour cells to immunological stimuli.

Profiling Tumor-Associated Markers for Early Detection of Malignant Mesothelioma: An Epidemiologic Study

Improved detection methods for diagnosis of asymptomatic malignant mesothelioma (MM) are essential for an early and reliable detection and treatment of this type of neoplastic disease. Thus, focus has been on finding tumor markers in the blood that can be used for noninvasive detection of MM. Ninety-four asbestos-exposed subjects defined at high risk, 22 patients with MM, and 54 healthy subjects were recruited for evaluation of the clinical significance of 8-hydroxy-2′-deoxyguanosine (8OHdG) in WBCs and plasma concentrations of soluble mesothelin-related peptides (SMRPs), angiogenic factors [platelet-derived growth factor β, hepatocyte growth factor, basic fibroblast growth factor, and vascular endothelial growth factor β (VEGFβ)], and matrix proteases [matrix metalloproteinase (MMP) 2, MMP9, tissue inhibitor of metalloproteinase (TIMP) 1, and TIMP2] for potential early detection of MM. The area under receiver operating characteristic (ROC) curves indicate that 8OHdG levels can discriminate asbestos-exposed subjects from healthy controls but not from MM patients. Significant area under ROC curve values were found for SMRPs, discriminating asbestos-exposed subjects from MM patients but not from healthy controls. Except for platelet-derived growth factor β, the hepatocyte growth factor, basic fibroblast growth factor, and VEGFβ can significantly differentiate high-risk individuals from healthy control and cancer groups. No diagnostic value was observed for MMP2, MMP9, TIMP1, and TIMP2. In addition to the diagnostic performance defined by the ROC analysis, the sensitivity and specificity results of markers with clinical significance were calculated at defined cutoffs. The combination of 8OHdG, VEGFβ, and SMRPs best distinguished the individual groups, suggesting a potential indicator of early and advanced MM cancers. The combination of blood biomarkers and radiographic findings could be used to stratify the risk of mesothelioma in asbestos-exposed populations. (Cancer Epidemiol Biomarkers Prev 2008;17(1):163–70)

Relationship of job satisfaction, psychological distress and stress-related biological parameters among healthy nurses: a longitudinal study.

Relationship of Job Satisfaction, Psychological Distress and Stress‐Related Biological Parameters among Healthy Nurses: A Longitudinal Study: Monica Amati, et al. Department of Molecular Pathology and Innovative Therapies, Clinic of Occupational Medicine, Polytechnic University of Marche, Italy

Alpha-Tocopheryl Succinate Inhibits Autophagic Survival of Prostate Cancer Cells Induced by Vitamin K3 and Ascorbate to Trigger Cell Death

Background The redox-silent vitamin E analog α-tocopheryl succinate (α-TOS) was found to synergistically cooperate with vitamin K3 (VK3) plus ascorbic acid (AA) in the induction of cancer cell-selective apoptosis via a caspase-independent pathway. Here we investigated the molecular mechanism(s) underlying cell death induced in prostate cancer cells by α-TOS, VK3 and AA, and the potential use of targeted drug combination in the treatment of prostate cancer. Methodology/Principal Findings The generation of ROS, cellular response to oxidative stress, and autophagy were investigated in PC3 prostate cancer cells by using drugs at sub-toxic doses. We evaluated whether PARP1-mediated apoptosis-inducing factor (AIF) release plays a role in apoptosis induced by the combination of the agents. Next, the effect of the combination of α-TOS, VK3 and AA on tumor growth was examined in nude mice. VK3 plus AA induced early ROS formation associated with induction of autophagy in response to oxidative stress, which was reduced by α-TOS, preventing the formation of autophagosomes. α-TOS induced mitochondrial destabilization leading to the release of AIF. Translocation of AIF from mitochondria to the nucleus, a result of the combinatorial treatment, was mediated by PARP1 activation. The inhibition of AIF as well as of PARP1 efficiently attenuated apoptosis triggered by the drug combination. Using a mouse model of prostate cancer, the combination of α-TOS, VK3 and AA was more efficient in tumor suppression than when the drugs were given separately, without deleterious side effects. Conclusions/Significance α-TOS, a mitochondria-targeting apoptotic agent, switches at sub-apoptotic doses from autophagy-dependent survival of cancer cells to their demise by promoting the induction of apoptosis. Given the grim prognosis for cancer patients, this finding is of potential clinical relevance.

Combined circulating epigenetic markers to improve mesothelin performance in the diagnosis of malignant mesothelioma

OBJECTIVESnMalignant mesothelioma (MM) is a highly aggressive tumor with poor prognosis. A major challenge is the development and application of early and highly reliable diagnostic marker(s). Serum biomarkers, such as soluble mesothelin-related proteins (SMRPs), is the most studied and frequently used in MM. However, the low sensitivity of SMRPs for early MM limits its value; therefore, additional biomarkers are required. In this study, two epigenetically regulated markers in MM (microRNA-126, miR-126, and methylated thrombomodulin promoter, Met-TM) were combined with SMRPs and evaluated as a potential strategy to detect MM at an early stage.nnnMATERIALS AND METHODSnA total of 188 subjects, including 45 MM patients, 99 asbestos-exposed subjects, and 44 healthy controls were prospectively enrolled, serum samples collected, and serum levels of SMRPs, miR-126 and Met-TM evaluated. Logistic regression analysis was performed to evaluate the diagnostic value of the three biomarkers. Using this approach, the performance of the 3-biomarker classifier was tested by calculating the overall probability score of the MM and control samples, respectively, and the ROC curve was generated.nnnRESULTS AND CONCLUSIONnThe combination of the three biomarkers was the best predictor to differentiate MM patients from asbestos-exposed subjects and healthy controls. The accuracy and cancer specificity was confirmed in a second validation cohort and lung cancer population. We propose that the combination of the two epigenetic biomarkers with SMRPs as a diagnosis for early MM overcomes the limitations of using SMRPs alone.

Asbestos exposure affects poly(ADP-ribose) polymerase-1 activity: role in asbestos-induced carcinogenesis

Asbestos is known to induce malignant mesothelioma (MM) and other asbestos-related diseases. It is directly genotoxic by inducing DNA strand breaks and cytotoxic by promoting apoptosis in lung target cells. Poly(ADP-ribose) polymerase-1 (PARP1) is a nuclear zinc-finger protein with a function as a DNA damage sensor. To determine whether PARP1 is involved in asbestos-induced carcinogenesis, PARP1 expression and activity as well as DNA damage and repair were evaluated in circulating cells of asbestos-exposed subjects, MM patients and age-matched controls. PARP1 expression and activity were also evaluated in pleural biopsies of MM patients and compared with normal tissue. Accumulation of the pre-mutagenic 8-hydroxy-2-deoxyguanosine and elevated PARP1 expression were found both in asbestos-exposed subjects and MM patients. Although PARP1 was highly expressed, its activity was relatively low. Low DNA repair efficiency was observed in lymphocytes from MM patients. High expression of PARP1 associated with low PARP activity was also found in MM biopsies. To mimic PARP1 dysfunction, PARP1 expression and activity were induced in immortalised mesothelial cells by their exposure to asbestos in the presence of a PARP1 inhibitor, which resulted in transformation of the cells. We propose that exposure to asbestos inhibits the PARP1 activity possibly resulting in higher DNA instability, thus causing malignant transformation.

Organic honey supplementation reverses pesticide-induced genotoxicity by modulating DNA damage response.

SCOPEnGlyphosate (GLY) and organophosphorus insecticides such as chlorpyrifos (CPF) may cause DNA damage and cancer in exposed individuals through mitochondrial dysfunction. Polyphenols ubiquitously present in fruits and vegetables, have been viewed as antioxidant molecules, but also influence mitochondrial homeostasis. Here, honey containing polyphenol compounds was evaluated for its potential protective effect on pesticide-induced genotoxicity.nnnMETHODS AND RESULTSnHoney extracts from four floral organic sources were evaluated for their polyphenol content, antioxidant activity, and potential protective effects on pesticide-related mitochondrial destabilization, reactive oxygen and nitrogen species formation, and DNA damage response in human bronchial epithelial and neuronal cells. The protective effect of honey was, then evaluated in a residential population chronically exposed to pesticides. The four honey types showed a different polyphenol profile associated with a different antioxidant power. The pesticide-induced mitochondrial dysfunction parallels ROS formation from mitochondria (mtROS) and consequent DNA damage. Honey extracts efficiently inhibited pesticide-induced mtROS formation, and reduced DNA damage by upregulation of DNA repair through NFR2. Honey supplementation enhanced DNA repair activity in a residential population chronically exposed to pesticides, which resulted in a marked reduction of pesticide-induced DNA lesions.nnnCONCLUSIONnThese results provide new insight regarding the effect of honey containing polyphenols on pesticide-induced DNA damage response.

Pulsed Venous Flow Pattern with Hemodilution

Venous flow pattern changes and venous flow were assessed in relation to the degree of hemodilution. Femoral vein flow was measured with a duplex scanner in two groups of 11 patients 20 days and 5 days preoperatively, and 1 day postoperatively. In group I, hemodilution was used and patients gave three autologous blood predonations between day 20 and day 5. Perioperative blood loss was reintegrated by electrolyte solution. In group II, hemodilution was not used and autologous blood predonations were not carried out. These patients received a perioperative homologous blood transfusion of 800 mL. Hemoglobin was lower on day 5 (11.3 ±1.4 vs 13.1 ±1 g/dL, p<0.05) and on postoperative day 1 (8.9 ±1.6 vs 10.6 ±1, p<0.05) in group I. The decrease in hemoglobin was associated with an increase in blood flow and a pulsed venous flow pattern in 14 of 22 veins after autologous blood predonation and in 21 of 22 veins on postoperative day 1 (p < 0.05). Increased venous flow in hemodilution is associated with a pulsed venous flow pattern.