Lipid peroxidation and antioxidant system in the blood of patients with Hodgkin's disease

Identification and Interpretation of eQTL and eGenes for Hodgkin Lymphoma Susceptibility

Genome-wide association studies (GWAS) have revealed approximately 100 genomic signals associated with Hodgkin lymphoma (HL); however, their target genes and underlying mechanisms causing HL susceptibility remain unclear. In this study, transcriptome-wide analysis of expression quantitative trait loci (eQTL) was conducted to identify target genes associated with HL GWAS signals. A mixed model, which explains polygenic regulatory effects by the genomic covariance among individuals, was implemented to discover expression genes (eGenes) using genotype data from 462 European/African individuals. Overall, 80 eGenes were identified to be associated with 20 HL GWAS signals. Enrichment analysis identified apoptosis, immune responses, and cytoskeletal processes as functions of these eGenes. The eGene of rs27524 encodes ERAP1 that can cleave peptides attached to human leukocyte antigen in immune responses; its minor allele may help Reed-Sternberg cells to escape the immune response. The eGene of rs7745098 encodes ALDH8A1 that can oxidize the precursor of acetyl-CoA for the production of ATP; its minor allele may increase oxidization activity to evade apoptosis of pre-apoptotic germinal center B cells. Thus, these minor alleles may be genetic risk factors for HL susceptibility. Experimental studies on genetic risk factors are needed to elucidate the underlying mechanisms of HL susceptibility and improve the accuracy of precision oncology.

Free-Radical-Initiated Phospholipid Oxidations at the Air-Water Interface: The Oxidation of Unsaturated and Saturated Fatty Acid Chains

Lipid oxidations initiated by free radicals are usually considered to undergo peroxidation, a chain process starting with hydrogen abstraction by an initiator, followed by O₂ uptake. While this peroxidation mechanism is widely accepted and sometimes taken for granted, here we provide evidence of the oxidation of both of the unsaturated and saturated fatty acid chains in phospholipids initiated by photoinitiator 2,4,6-trimethylbenzoyl diphenylphosphine oxide (TMDPO) at the air-water interface, and no peroxidation products are observed in these reactions. A unique field-induced droplet ionization mass spectrometry (FIDI-MS) methodology which is capable of the selective online sampling of monolayers of molecules that reside at the air-water interface is employed to detect the products. We have shown that the double bonds on the oleyl chains of the lipids are first oxidized into epoxides, after which other saturated carbon atoms are oxidized into carbonyl groups. We anticipate that this work will draw more attention to the complexity of the lipid oxidation chemistry initiated by free radicals.

Protein Carbonylation and Lipid Peroxidation in Hematological Malignancies

Among the different mechanisms involved in oxidative stress, protein carbonylation and lipid peroxidation are both important modifications associated with the pathogenesis of several diseases, including cancer. Hematopoietic cells are particularly vulnerable to oxidative damage, as the excessive production of reactive oxygen species and associated lipid peroxidation suppress self-renewal and induce DNA damage and genomic instability, which can trigger malignancy. A richer understanding of the clinical effects of oxidative stress might improve the prognosis of these diseases and inform therapeutic strategies. The most common protein carbonylation and lipid peroxidation compounds, including hydroxynonenal, malondialdehyde, and advanced oxidation protein products, have been investigated for their potential effect on hematopoietic cells in several studies. In this review, we focus on the most important protein carbonylation and lipid peroxidation biomarkers in hematological malignancies, their role in disease development, and potential treatment implications.

Oxidant–Antioxidant Status in Canine Multicentric Lymphoma and Primary Cutaneous Mastocytoma

Oxidative stress is a prominent event in several acute and chronic diseases including neoplasia. Although its direct involvement in carcinogenesis still remains to be clearly defined, a deeper knowledge of oxidative stress in oncologic patients could help to monitor their clinical outcome and to develop new therapeutic approaches. Therefore, the present study was undertaken to explore redox status in blood of neoplastic dogs affected either by multicentric lymphoma or by primary cutaneous mastocytoma. Superoxide anion (O2 •−), nitric oxide (NO) and hydroperoxides (ROOH) were measured. Detoxifying enzyme superoxide dismutase (SOD) and total non-enzymatic antioxidant capacity (ferric reducing-antioxidant power (FRAP)) were assessed. The oxidative stress index (OSi) both for enzymatic (OSiE) and non-enzymatic (OSiNE) scavengers were evaluated. Both pathologies, showed a reduced NO generation, while O2 •− levels were decreased only in mastocytoma. The oxidative stress indexes showed a significant decrease in mastocytoma patients, only for OSiE.

Evaluation of Salivary Antioxidants and Oxidative Stress Markers in Male Smokers

BACKGROUND

Cigarette smoke free radicals can cause cellular damage and different diseases. All the body fluids have antioxidants which protect against free radicals.

OBJECTIVE

The aim of this study was to evaluate salivary total antioxidant capacity and peroxidase, uric acid and malondialdehyde levels in smokers and a nonsmoking control group.

METHODS

Unstimulated saliva was collected from 510 males. A total of 259 subjects were current smokers and 251 were non-smokers. The levels of salivary total antioxidant capacity, uric acid, peroxidase and malondialdehyde were measured using standard procedures. Data were analyzed with t test and ANOVA.

RESULTS

The smokers were younger and dental hygiene index was higher than healthy nonsmoking controls. The mean total antioxidant capacity in smokers and nonsmokers was 0.13±0.07 and 0.21±011, respectively (P=0.001). Smokers had significantly lower peroxidase and uric acid levels than healthy controls. In addition, the mean malondialdehyde levels in the smokers and nonsmokers were 4.55 ±2.61 and 2.79 ±2.21, respectively (P=0.001).

CONCLUSION

Cigarette smoke produces free radical and oxidative stress, causing many side effects. Salivary antioxidant levels decreased and malondialdehyde levels increased in smokers, indicating the high oxidative stress among smokers compared to nonsmokers. Cigarette smoke had deleterious effects on main salivary antioxidants levels.

Evaluation of Salivary Lipid Peroxidation End Product Level in Dental Caries

BACKGROUND

Tissue destruction can be measured by the level of lipid peroxidation (LP) end products. Since free radicals are very reactive with low survival time, the level of free radicals and oxidative stress activity are measured indirectly by tissue damage end product assessment, i.e. Malondialdehyde (MDA) that is a final end product of LP.

OBJECTIVE

The aim of this study was to evaluate salivary MDA level as an indicator of oxidative stress; in caries-active and caries-free students.

METHODS

A total of 100 male and female students, 15-17 years of age, participated in this casecontrol study. Five mL of whole saliva was obtained. Salivary MDA level was measured spectrophotometrically. Statistical comparisons were performed with Student's t-test, using SPSS 13.

RESULTS

Salivary MDA level was significantly higher in the caries-active group compared to the control caries-free group. MDA was also slightly lower in males.

CONCLUSION

Higher MDA level might indicate caries-induced oxidative stress. In this study there was a relationship between salivary MDA level and dental caries. Therefore oxidative stress suppression might prevent caries initiation and progression.

Parthenolide attenuates 7,12-dimethylbenz[a]anthracene induced hamster buccal pouch carcinogenesis

Over the decades, the survival rates for oral cancer have not improved despite development in novel diagnostic and therapeutic strategies. Therefore, the present study is aimed at investigating the chemopreventive potential of parthenolide in DMBA-induced hamster buccal pouch carcinogenesis. The hamsters were divided into 4 groups (n = 6/group). Group I was treated as control. Groups II and III were painted with a solution of 0.5% DMBA three times per week for 14 weeks on the left buccal pouches. In addition, group III were orally administrated with parthenolide 2 mg/kg b.w on days alternate to the DMBA application. Group IV received only parthenolide. At the end of 14th week all hamsters were sacrificed. Buccal tissues from all hamsters were evaluated for histopathology. Biochemical studies were carried out using plasma, liver, and buccal mucosa of control and experimental hamsters. Gene and protein expression studies of apoptotic markers p53, Bcl-2, and Bax were performed. The results showed 100% tumor formation and marked alterations in histopathology, status of detoxification enzymes, lipid peroxidation, and antioxidant profile in group II hamsters. Oral administration of parthenolide completely prevented tumor formation and significantly reduced the severity of histopathological changes in group III hamsters. The status of detoxification enzymes, lipid peroxidation, and antioxidants were significantly restored in parthenolide treated group compared to group II hamsters. The apoptotic gene p53 and antiapoptotic gene Bcl-2 were significantly down regulated; whereas, pro-apoptotic gene Bax was up regulated in group III hamsters compared to group II. The results of the present study suggest that parthenolide have potent chemopreventive, antioxidant, and apoptotic effect in DMBA-induced oral carcinogenesis.

Oxidative stress in oncohematologic diseases: an update

An increased risk of cancer in various organs has been related to oxidative stress and several studies have revealed the mechanism by which continued oxidative stress can lead to chronic inflammation, which in turn could mediate most chronic diseases including cancer. A variety of transcription factors may be activated in consequence of oxidative stress, leading to the expression of over 500 different genes, including those for growth factors, inflammatory cytokines, chemokines, cell cycle regulatory molecules and anti-inflammatory molecules. In this review, the data related to the action of oxidative stress on the onset of various oncohematologic diseases are summarized, thus bringing together some of the latest information available on the pathogenetic role of oxidative stress in cancer. The authors evaluate the most recent publications on this topic, and, in particular, show the newest evidence of a relationship between oxidative stress and hematological malignancies, such as chronic lymphocytic leukemia, Hodgkin's lymphoma, multiple myeloma and chronic Ph-negative myeloproliferative diseases. A separate section is devoted to the implications of a change of oxidative stress in patients undergoing bone marrow transplantation. Finally, particular attention is given to the new markers of oxidative stress, such as carbonyl groups, advanced glycation end products, advanced oxidation protein products and S-nitrosylated proteins, which are certainly more stable, reliable, cheaper and more easily identifiable than those already used in clinical practice. New approaches that aim to evaluate subcellular and microenvironment redox potential may be useful in developing cancer diagnostics and therapeutics.

Antioxidant status and biomarkers of oxidative stress in dogs with lymphoma

BACKGROUND

Oxidative stress might play a role in carcinogenesis, as well as impacting morbidity and mortality of veterinary cancer patients. The purpose of this study was to evaluate antioxidant concentrations and biomarkers of oxidative stress in dogs with newly diagnosed lymphoma before treatment and once in remission, with comparison with healthy controls.

HYPOTHESIS

Dogs with lymphoma have increased oxidant and reduced antioxidant concentrations compared with healthy controls, and that these abnormalities normalize once remission is achieved.

ANIMALS

Seventeen dogs with lymphoma and 10 healthy controls.

METHODS

Prospective, observational study. Measures of oxidative stress [malondialdehyde and total isoprostanes (isoP)] and antioxidants [alpha-tocopherol, gamma-tocopherol, oxygen radical absorbance capacity (ORAC), and glutathione peroxidase (GSHPx)] were assessed in dogs with newly diagnosed lymphoma before treatment compared with healthy control dogs. The same parameters were measured in the dogs with lymphoma on week 7 of the chemotherapy protocol when all dogs were in remission.

RESULTS

At baseline, dogs with lymphoma had significantly lower alpha-tocopherol (P <.001) and gamma-tocopherol (P= .003) but higher GSHPx (P= .05), ORAC (P= .001), and isoP (P < .001) compared with healthy controls. In the dogs with lymphoma, alpha-tocopherol concentrations were higher (P= .005) and ascorbic acid were lower (P= .04) after treatment.

CONCLUSIONS AND CLINICAL IMPORTANCE

Results suggest that dogs with lymphoma have alterations in oxidant and antioxidant concentrations and that the status of some of these biomarkers normalize after remission. Further studies are warranted to determine whether antioxidant interventions to correct these are beneficial in the treatment of canine lymphoma.

Enzymatic and non-enzymatic antioxidant status in stage (III) human oral squamous cell carcinoma and treated with radical radio therapy: influence of selenium supplementation

BACKGROUND

Oxidative stress is implicated in oral carcinogenesis and has been found to be aggravated during radiotherapy. A great deal of attention has been focused on the possible therapeutic implications of selenium as a potent antioxidant. We determined whether selenium supplementation to radiation treated oral cancer patients render improvement in the antioxidant status against oxidative stress.

METHOD

Blood samples were collected from stage (III) oral cancer patients before initiating radiotherapy (Group B) (n=63) and this group is bifurcated into Group C-patients given radiotherapy alone (n=27) and Group D-patients given radiotherapy and supplemented with selenium (400 mug/day for 6 months) (n=36). Both Group C and D were followed up for 6 months. We evaluated the plasma selenium concentration, non-enzymatic system including GSH, vitamins E, C, A and ceruloplasmin and enzymatic antioxidant system including superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glucose-6-phosphate dehydrogenase.

RESULTS

The concentrations of selenium, all non-enzymatic antioxidants and the activities of enzymatic antioxidants were found to be lowered in oral cancer patients (Group B), compared to normal (Group A) (p<0.05). Similar decrease in the concentration of selenium and antioxidants status was observed in radiotherapy group (Group C) (p<0.05). On the contrary, selenium group (Group D) showed marked increase in the concentrations of selenium and antioxidant status at 6 months compared to radiation group (Group C) (p<0.05).

CONCLUSION

The observed result represents the antioxidant property of selenium through the improvement of antioxidant defense system. Selenium supplementation could be of great interest in protecting cells against oxidative stress.

Oxidant/antioxidant parameters and their relationship with chemotherapy in Hodgkin's lymphoma

This study investigated changing levels of serum oxidant/antioxidant with chemotherapy and their relation to treatment in 34 Hodgkin's lymphoma patients. The patient population consisted of 19 males and 15 females. Mean age was 30.41 +/- 12.08 years. All patients received the adriamycin, bleomycin, vincristine and dexamethasone (ABVD) treatment protocol. Blood samples were taken before treatment, and on days 1 and 7 during treatment for measurement of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), malondialdehyde (MDA), nitric oxide (NO) and enzyme activities. After ABVD treatment, mean free radical levels were increased and antioxidant levels were significantly decreased in the serum. ABVD treatment results in an increase of free radical levels and a decrease of antioxidant levels in the serum of patients with Hodgkin's lymphoma.

The effects of oral zinc sulphate during radiotherapy on anti-oxidant enzyme activities in patients with head and neck cancer: a prospective, randomised, placebo-controlled study

The purpose was to determine the effects of oral zinc sulphate along with radiotherapy on anti-oxidant enzyme activities in patients with head and neck cancer. Thirty patients with head and neck cancer were randomly assigned to receive either zinc sulphate capsules (including 50 mg zinc) (n = 15) or placebo (n = 15) three times a day, starting on the day of the first radiotherapy fraction and continuing throughout the scheduled radiotherapy course including weekends and 6 weeks after radiotherapy. The patients were treated with telecobalt radiation at conventional fractionation of 2 Gy/fraction and five fractions/ week in 20-35 fractions for a period of 4-7 weeks. Blood samples for biochemical parameters were collected after an overnight fast (12 h) before radiotherapy, the first day and 6 weeks after radiotherapy. In the placebo group, three patients were excluded. No difference was detected in any final measurement activities of erythrocyte anti-oxidant enzyme such as copper-zinc superoxide dismutase (Cu-Zn SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in the direct comparison between the zinc sulphate and the placebo group, except erythrocyte SOD activities measured the first day after radiotherapy (p < 0.03). In the respective measurement analysis of the groups in themselves, in the zinc sulphate group, while the statistical analysis for the activities of erythrocyte CAT and GSH-Px were significantly different (chi2 = 12.4, p < 0.05; chi2 = 8.9, p < 0.05, respectively) before radiotherapy, the first day and 6 weeks after radiotherapy, the activities of SOD did not differ (chi2 = 4.2, p > 0.05). In these three measurements, there was no statistical significance in the activities of enzymes in erythrocyte Cu-Zn SOD, CAT and GSH-Px in the placebo group. Before radiotherapy, plasma zinc levels were normal in 16 patients (59.2%) and were lower in 11 patients (40.8%) compared with laboratory levels. It would be worthwhile studying the effect of oral zinc sulphate supplements to improve the anti-oxidant enzyme activity in radiation-treated cancer patients, in the hope of reducing radiation-induced toxicity.

Zinc sulfate in the prevention of radiation-induced oropharyngeal mucositis: a prospective, placebo-controlled, randomized study

PURPOSE

To determine the effect of oral zinc sulphate supplementation on radiation-induced oropharyngeal mucositis in patients with head-and-neck cancer.

MATERIALS AND METHODS

Thirty patients with head-and-neck cancer were randomly assigned to receive either zinc sulfate or placebo. Primary tumors were localized in the larynx in 14 patients, in the nasopharynx in 4, in the oral cavity in 4, in a salivary gland in 1, in the maxillary sinus in 1, in neck nodes (lymphoma presenting primarily) in 3 and in neck metastases from an unknown primary in 3. In the placebo group, 3 patients were excluded; 1 patient died during treatment, 1 left the study, and 1 did not come to the 6 week control visit. The patients were treated with telecobalt radiotherapy at conventional fractionation (2 Gy/fraction, five fractions weekly, for 20-35 fractions within 4-7 weeks). The median radiation dose was 6400 cGy (4000-7000 cGy). Oral mucositis was assessed by two independent physicians, experts in radiation oncology, using the Radiation Therapy Oncology Group Acute Radiation Morbidity Scoring criteria.

RESULTS

In the zinc sulfate group, Grade 3-4 mucositis was not detected in any patient; Grade 0 mucositis was detected in 2, and Grade 1 in 8, and Grade 2 in 5 patients. In the placebo group, Grade 2 mucositis was detected in 4 and Grade 3 in 8 patients. We observed that the degree of mucositis in the patients in the zinc sulfate group was significantly lower than that in the placebo group (p < 0.05). Confluent mucositis developed earlier in the placebo group than in the zinc sulfate group after the onset of treatment (p < 0.05) and started to improve sooner in the zinc sulfate group than in the placebo group (p < 0.05).

CONCLUSIONS

Zinc sulfate is beneficial in decreasing the severity of radiation-induced mucositis and oral discomfort. These results should be confirmed by additional evaluation in randomized studies with a larger number of patients.