Serum levels of epidermal growth factor, transforming growth factor, and c-erbB2 in ovarian cancer.

OBJECTIVE: This study aimed to investigate serum levels of epidermal growth factor (EGF), transforming growth factor α (TGF-α), and c-erbB2 in patients with ovarian cancer. MATERIALS AND METHODS: In this retrospective cohort study, the study and control groups were composed of 43 women with a prediagnosis of ovarian cancer and 43 healthy women, respectively. Blood samples from all women were obtained and studied by enzyme-linked immunosorbent assay kits for EGF, TGF-α, and c-erbB2. After surgery of the study group, ovarian cancer was confirmed and compared with control group. Stage, grade, and histological types were defined after histopathologic examination, and subgroups were constructed and compared. RESULTS: Serum EGF, TGF-α, and c-erbB2 levels were significantly increased in study group compared with those in the control group (P < 0.001). There were no differences in serum levels of EGF, TGF-α, and c-erbB2 among all stages, grades, and histological types of ovarian cancer. If 47.90 pg/mL was selected as the cutoff value, EGF has an 80% sensitivity and a 65% specificity for detecting ovarian cancer. The cutoff value of 41,095.00 pg/mL for TGF-α has a 90% sensitivity and a 72% specificity for detecting ovarian cancer. The c-erbB2 level of 4.63 pg/mL as the cutoff value has an 83% sensitivity and a 76% specificity for predicting ovarian cancer. CONCLUSIONS: Serum levels of EGF, TGF-α, and c-erbB2 may be used for diagnosing ovarian cancer.

DNA damage and glutathione level in children with asthma bronchiale: effect of antiasthmatic therapy.

When the production of reactive oxygen species (ROS) exceeds the capacity of antioxidant defences, a condition known as oxidative stress occurs and it has been implicated in many pathological conditions including asthma. Interaction of ROS with DNA may result in mutagenic oxidative base modifications such as 8-hydroxydeoxyguanosine (8-oxo-dGuo) and DNA strand breaks. Reduced glutathione (GSH) serves as a powerful antioxidant against harmful effects of ROS. The aim of this study was to describe DNA damage as level of DNA strand breaks and formamidopyrimidine DNA glycosylase (Fpg)-sensitive sites, which reflects oxidative DNA damage and GSH level in children with mild-to-moderate persistent asthma; and to examine the effect of antiasthmatic therapy on these DNA damage parameters and GSH level. Before and after 8 wk of antiasthmatic therapy blood samples were taken, DNA strand breaks and Fpg-sensitive sites in peripheral leukocytes were determined by comet assay, GSH level of whole blood was measured by spectrophotometric method. DNA strand breaks and Fpg-sensitive sites in the asthma group were found to be increased as compared with control group. GSH level in the asthma group was not significantly different from those in the control group. Levels of strand breaks, Fpg-sensitive sites and GSH were found to be decreased in the asthma group after the treatment. In conclusion, oxidative DNA damage (strand breaks and Fpg-sensitive sites) is at a high level in children with asthma. DNA damage parameters and GSH level were found to be decreased after therapy. Our findings imply that antiasthmatic therapy including glucocorticosteroids not only controls asthma but also decreases mutation risk in children with asthma bronchiale.

Leukocyte DNA damage in children with iron deficiency anemia: effect of iron supplementation.

Iron deficiency is frequently associated with anemia. Iron is a transition-metal ion, and it can induce free radical formation, which leads to formation of various lesions in DNA, proteins, and lipids. The aim of this study was to investigate baseline oxidative DNA damage and to clarify the role of the administration of a therapeutic dose of iron on DNA oxidation in children with iron deficiency anemia (IDA). Twenty-seven children with IDA and 20 healthy children were enrolled in the study. Leukocyte DNA damage (strand breaks and Fpg-sensitive sites) was assessed using comet assay before and after 12 weeks of daily iron administration. Before the iron administration, the frequency of DNA strand breaks in the children with IDA was found to be lower than those in the control group (P < 0.05), but there was not a significant difference for frequency of Fpg-sensitive sites. After 12 weeks of iron administration, the frequency of both DNA strand breaks and Fpg-sensitive sites were found to be increased (P < 0.01). No significant association was determined between DNA damage parameters and hemoglobin, hematocrit, serum iron, total iron binding capacity, and ferritin. In conclusion, basal level of DNA strand breaks is at a low level in children with IDA. After iron administration, DNA strand breaks and Fpg-sensitive sites, which represent oxidatively damaged DNA, increased. However, this increase was unrelated to serum level of iron and ferritin.

Circulating p53 and cytochrome c levels in acute myocardial infarction patients.

BACKGROUND: Apoptosis causes myocardiocyte loss during and after myocardial infarction. Therapeutic approaches designed to arrest apoptosis would be a significant new development in the recovery of acute myocardial infarction (AMI). In order to examine apoptotic markers in the circulation, serum levels of p53 and cytochrome c were assessed in patients with AMI. METHODS: Blood samples were taken on admission (before initiation of therapy) and on the 3rd and 7th days of hospitalization. Serum levels of p53 and cytochrome c were measured by enzyme-linked immunassay. RESULTS: The serum level of p53 was higher in AMI patients on admission compared to the control group. A time-dependent decrease was observed in the serum level of p53, but there was no significant change in the serum level of cytochrome c during therapy. CONCLUSIONS: p53, but not cytochrome c, appears to have potential as a biomarker for reporting on apoptosis following myocardial infarction.

DNA oxidation and antioxidant status in breast cancer.

PURPOSE: : Oxidant/antioxidant balance has been suggested as an important factor for initiation and progression of cancer. The objective of this study was to determine 8-hydroxydeoxyguanosine (8-OHdG) level as a marker of oxidative DNA damage, glutathione peroxidase (G-Px), and superoxide dismutase (SOD) activities as antioxidant activity, in sera from women with breast cancer. METHODS: : Forty-nine patients with malign breast tumor were included in the study. Blood samples were collected before the surgical operation. Serum level of 8-OHdG was measured with a competitive enzyme-linked immunusorbent assay kit, SOD, and G-Px activities were measured by spectrophotometric kits. RESULTS: : 8-Hydroxydeoxyguanosine level and SOD activity were found to be increased in breast cancer group as compared with control group. Glutathione peroxidase activity in the breast cancer group was lower than those in the control group. The ratio of 8-OHdG/G-Px in breast cancer patients was found to be higher than those in the controls. There were correlations between 8-OHdG and CA19-9 (r = 0.77; P < 0.01); age and G-Px (r = -0.84; P < 0.05) in the breast cancer group. CONCLUSIONS: : Data show that serum levels of 8-OHdG and SOD activities are higher in patients with breast cancer. Glutathione peroxidase activity is lower in the breast cancer group. Increased ratio of 8-OHdG/G-Px in breast cancer patients is the evidence for impaired oxidant/ antioxidant balance in breast cancer.

Oxidative DNA damage and antioxidant defense after reperfusion in acute myocardial infarction.

PURPOSE: Myocardial damage mediated by oxidative stress during acute myocardial infarction (MI) has been suggested as an obstructive factor on recovery after an MI. 8-Hydroxydeoxyguanosine (8-OHdG) is a marker for oxidative DNA damage; superoxide dismutase (SOD) and glutathione peroxidase (G-Px) are major antioxidant enzymes. We determined changes in the plasma level of 8-OHdG and activities of SOD and G-Px in patients with MI and examined the relations between those changes and other cardiac markers. METHODS: Blood samples were taken at the beginning of the therapy, on the third day of hospitalization, and on the day patients were discharged home. Plasma level of 8-OHdG and SOD and G-Px activities were measured by enzyme-linked immunosorbent assay and spectrophotometric kits, respectively. RESULTS: 8-Hydroxydeoxyguanosine level at the beginning of the therapy was found to be decreased on the third day of therapy and on the day patients were discharged home. With respect to the treatment way, 8-OHdG level was found to be slightly decreased on the third day of therapy and then remained stable in the group treated with thrombolytic agents. However, 8-OHdG level was found to be sharply decreased on the third day of therapy in the group that underwent primary percutaneous transluminal coronary angioplasty. No significant relations were determined between those measured parameters and serum levels of cardiac markers. CONCLUSION: Although not correlated with other cardiac markers, plasma level of 8-OHdG shows a decrease after reperfusion therapy in patients with MI, and primary percutaneous transluminal coronary angioplasty seems much more effective than thrombolytic therapy for providing a low level of 8-OHdG.

Serum levels of p53 and cytochrome c in subjects with type 2 diabetes and impaired glucose tolerance.

PURPOSE: To examine apoptotic markers in serum of subjects with diabetes and impaired glucose tolerance (IGT). Serum levels of p53 and cytochrome c, regulator molecules for apoptosis, were measured in subjects with type 2 diabetes, subjects with IGT and healthy controls. METHODS: Forty one subjects with type 2 diabetes, 27 with IGT and 27 healthy volunteers were included in the study. Serum level of cytochrome c and p53 were measured with competitive ELISA. RESULTS: Serum levels of p53 were lower in the group of subjects with type 2 diabetes (085+/-0.39 U/ml) than in controls (1.09+/-0.49 U/ml) (P < 0.05) and in the subjects with IGT (0.98+/-0.37 U/ml) (P < 0.05). There was no significant difference between the group with IGT and controls. Also, there was no difference for serum level of cytochrome c among the groups. In the group of subjects with type 2 diabetes, serum level of cytochrome c was mildly correlated with HbA1c (r:0.39, P < 0.05). CONCLUSION: The present study shows that the serum level of p53 is lower in the patients with type 2 diabetes than in controls or in subjects with IGT. No difference was seen among the the groups for the serum level of cytochrome c.

Assessment of DNA oxidation and antioxidant activity in hypertensive patients with chronic kidney disease.

The aim of this study was to evaluate the oxidative DNA damage, antioxidant activity, and effects of antihypertensive drugs on oxidative stress in hypertensive patients with different stages of chronic kidney disease (CKD). Fifty-three non-dialyzed hypertensive CKD patients were included by the study. Serum and urinary 8-hydroxydeoxy guanosine (8-OHdG) levels (as a marker of oxidative DNA damage), serum superoxide dismutase (SOD), and glutathione peroxidase (G-Px) activities (as antioxidant enzymes) were measured. SOD activity was higher and G-Px activity was lower in the patient group as compared to control group. Serum and urinary 8-OHdG levels were found to be higher in the patients with proteinuria greater than 3 g/day than those in the patients with proteinuria less than 3 g/day. It has been determined that G-Px activity and urinary 8-OHdG level were lower in the patients treated with angiotensin-converting enzyme (ACE) inhibitor compared to patients treated with calcium channel blocker. The present data show oxidative DNA damage at a higher level in the patients with proteinuria greater than 3 g/day. In comparison to a calcium channel blocker, an ACE inhibitor seems much more protective against oxidative DNA damage in hypertensive patients with different stages of CKD.

Diagnostic potential of YKL-40 in bladder cancer.

OBJECTIVES: YKL-40 is a glycoprotein, which is thought to play a role in inflammatory conditions and tissue remodeling. Although it has been investigated in numerous cancers, there is very limited knowledge about the role of YKL-40 in bladder cancer. In this study, our aim was to determine the levels of YKL-40 in the sera and urines of the patients with bladder cancer, and compare it to urinary bladder tumor antigen (BTA), a tumor marker that can be used in the diagnosis of bladder cancer. METHODS: The study was comprised of 2 major groups as 65 healthy controls and 67 patients with bladder cancer. The patient group was also divided into subgroups according to tumor stage and grade. Serum and urine YKL-40 levels and urine BTA levels in controls and patients were determined using commercially available enzyme-linked immunosorbent assay kits. RESULTS: Serum YKL-40 and urinary BTA levels were significantly elevated in patients and all patient subgroups compared to healthy controls. Urine YKL-40 levels, on the other hand, were significantly elevated in all subgroups except low stage (Ta) and low grade, compared to controls. Although serum YKL-40 levels could not differentiate any subgroup from one another, urinary BTA could only differentiate low stage (Ta) from all invasive (T1-T4) cancers. However, urine YKL-40 levels were significantly elevated in all invasive subgroups (T1, T2-T4, and T1-T4), compared to low stage (Ta). CONCLUSIONS: In summary, urine YKL-40 levels can be used to assist BTA in the diagnosis of bladder cancer as a marker for early invasiveness and thus help determine its treatment regimen.

Significance of the O6-methylguanine-DNA methyltransferase and glutathione S-transferase activity in the sera of patients with malignant and benign ovarian tumors.

OBJECTIVE: To demonstrate O6-methylguanine-DNA methyltransferase (MGMT) and glutathione S-transferase (GST) activities by analyzing the sera separately obtained from patients with malignant ovarian tumors, benign ovarian tumors, and healthy individuals. STUDY DESIGN: Fourty-nine patients with ovarian cancer, nine patients with benign tumors, and 22 healthy women were included in this study. Blood samples were obtained from all the subjects in the malignant-tumor, benign-tumor, and control groups. Patients with malignant tumors underwent second and third phlebotomies one week following the surgery and after the chemotherapy regimen, respectively. MGMT, GST, and protein levels were measured for each serum sample. GST activity of the samples was measured by the method of Habig et al. using l-chloro-2-4 dinitrobenzene (CDNB) as substrate. MGMT activity was measured by the transfer of radio labelled methyl groups from a prepared MG-DNA substrate to the enzyme fraction of serum. Protein concentration was measured by biuret method. RESULTS: Our work demonstrated that untreated patients with malignant ovarian tumors revealed significantly greater MGMT and GST activities in their sera than did both healthy individuals and patients with benign ovarian tumors, while no significant difference was found between the healthy group and the patients with benign ovarian tumors with respect to their sera MGMT and GST activities. GST activity following chemotherapy was significantly lower than the postoperative values preceding chemotherapy. A relationship between sera MGMT and GST activities, tumor histology and pathology was not found in this study. CONCLUSION: Our work suggests the fact that detection of sera MGMT and GST activities is important in diagnostic and therapeutic approaches during the course of ovarian cancer.

Effect of oxidative stress on glutathione pathway in red blood cells from patients with insulin-dependent diabetes mellitus.

Recently, increased oxidative stress and impaired antioxidant defense have been suggested as a contributory factor for initiation and progression of complications in diabetes. Although glutathione (GSH) and the enzymes included by glutathione redox cycle have an important role for protection of cells against free radical-mediated damage, they may be susceptible to oxidation themselves. We examined the susceptibility of the GSH pathway to oxidation and inactivation in subjects with well-controlled and poorly controlled insulin-dependent diabetes mellitus (IDDM) versus controls and the effect of glycemic control on this susceptibility. Red blood cells (RBCs) were isolated, RBC level of GSH, activity of glutathione peroxidase (G-Px), and glutathione reductase (G-Red) were measured at the baseline and after a 2-hour incubation with hydrogen peroxide. Significant decreases were observed in the GSH level and in the activity of GSH peroxidase and GSH reductase in all the groups after the incubation with hydrogen peroxide. Maximum decrease was observed in the poorly controlled diabetic group for all parameters. This result indicates that the GSH pathway is susceptible to oxidation; and this susceptibility increases in poorly controlled diabetics. Therefore, insufficient antioxidant defense by the GSH pathway may be one of the factors responsible for development of complications in patients with IDDM.

Susceptibility of glutatione and glutathione-related antioxidant activity to hydrogen peroxide in patients with type 2 diabetes: effect of glycemic control.

OBJECTIVES: The aim of the present study was to examine the susceptibility of glutathione (GSH) and glutathione related antioxidant enzymes to oxidation in type 2 diabetic patients with and without glycemic control. DESIGN AND METHODS: Erythrocyte glutathione level and activities of glutathione peroxidase (G-Px), glutathione reductase (G-Red) and glutathione S-transferase (GST) in controls, well controlled and poorly controlled type 2 diabetics were measured by spectrophotometric assays before and after the incubation in vitro with H2O2. RESULTS: GSH level, G-Px and G-Red activities decreased but GST activity increased in the erythrocytes from all the groups after the incubation with H2O2. Percentage of decrease in GSH was independent from glycemic control, whereas the percentage of decreases in G-Px and G-Red was related to glycemic control. The percentage of increase in GST was found to be independent from diabetes. CONCLUSIONS: GSH and GSH-related antioxidant enzymes in human erythrocytes are susceptible to oxidation, particularly, G-Px and G-Red which were found to be more susceptible to oxidation in erythrocytes from poorly controlled type 2 diabetic patients.

Relation of aging with oxidative protein damage parameters in the rat skeletal muscle.

OBJECTIVES: An increase in oxidative stress may contribute to the development of oxidative protein damage in the aging rat skeletal muscle. Our aim was to reveal protein carbonyl (PCO), advanced oxidation protein products (AOPP), a novel marker of oxidative stress, and protein thiol (P-SH) levels as markers of protein oxidation, as well as lipid hydroperoxide (LHP) levels as a marker of lipid peroxidation, and relation of nitrotyrosine (NT) levels with these markers in skeletal muscle tissue of young, adult, and old male Wistar rats. DESIGN AND METHODS: In the present study, we investigated the relation between aging and oxidative protein damage parameters such as PCO, NT, AOPP, and P-SH, as well as oxidative stress parameters such as total thiol, nonprotein thiol, and LHP in the skeletal muscle tissue of young, adult, and old Wistar rats. RESULTS: PCO and NT levels of old rats were significantly increased compared with those of young and adult rats. Skeletal muscle AOPP levels were significantly increased in old rats compared with those of adult rats. P-SH levels were significantly decreased in old rats compared with those of young rats. CONCLUSIONS: The finding that the increase in PCO levels of young vs. old group was more significant than that of adult vs. old group may suggest that PCO formation is an early specific marker of aging process in skeletal muscle. In addition, increased levels of nitrotyrosine in the skeletal muscle of the old rat group may be a novel specific marker of oxidative protein damage in the aging muscle. The absence of correlation between oxidative protein damage markers mentioned above and LHP levels may indicate that protein oxidation and lipid peroxidation in the aging rat skeletal tissue are two distinct mechanisms.

Evaluation of O6-methylguanine DNA methyltransferase activity in patients with gastric cancer.

O6-Methylguanine DNA methyltransferase (O6-MGMT) reverses DNA alkylation damage produced alkylating agents. O6-MGMT is also a major determinant of cellular resistance to adjuvant chemotherapy with alkylating drugs. O6-MGMT activity was measured in samples from patients with gastric cancer, including tumor, adjacent normal appearing mucosa, and peripheral blood leukocytes (PBL). O6-MGMT activity of PBL from healthy individuals was evaluated as control. There was no significant difference between controls and patients for O6-MGMT activity in PBL. O6-MGMT activity was significantly increased in tumor tissue. Tumor O6-MGMT activity was found to be independent from tumor subgroups and tumor grade. A positive correlation was determined between O6-MGMT activity in tumor and in circulating PBL. The results indicate that O6-MGMT, a defense protein against alkylating agent-mediated carcinogenesis, increased in gastric tumors. This may explain the low response rate to drug combinations, including chloroethylnitrosoureas, exhibited by patients with gastric cancer.

O(6)-methylguanine DNA methyltransferase activity in diabetic patients.

In the present study, we evaluated O(6)-methylguanine-DNA methyltransferase (MGMT) activity in diabetic patients. The study was performed on 27 patients with Type 1 diabetes, and 42 with Type 2 diabetes. Patients with complications were excluded from the study. 36 non-diabetic volunteers, non-smokers who do not consume alcoholic beverage, were chosen from the medical staff as control subjects. MGMT activity was measured by the transfer of radiolabeled methyl groups from a prepared methylguanine-DNA substrate to the enzyme fraction of leukocyte extract. Leukocyte MGMT activity was significantly reduced in both Type 1 and Type 2 diabetes patients as compared with control subjects (P<0.001). The present study demonstrates decreased MGMT activity in leukocytes from patients with Type 1 and Type 2 diabetes.

Assessment of DNA base oxidation and glutathione level in patients with type 2 diabetes.

The first aim of the present study was to examine the relationship between reduced glutathione (GSH) level, a powerful cellular antioxidant, and oxidative damage to DNA; and secondly, to see the effect of glycemic control on oxidative DNA damage in type 2 diabetics. We determined GSH level and, using the comet assay, formamidopyrimidine DNA glycosylase (Fpg)-sensitive sites which indicates oxidised guanine in freshly isolated blood from age-matched type 2 diabetics and controls. We found significant differences between men and women in the control group for both GSH and Fpg-sensitive sites. Therefore, we compared the controls and type 2 diabetics separately in men and women. GSH level of whole blood was found to be lower, Fpg-sensitive sites in leukocytes was found to be higher in the both type 2 diabetic men and women, as compared with their respective controls. When the diabetic group was divided into two groups as well-controlled diabetics and poorly-controlled diabetics with respect to glycosylated haemoglobine levels, it was found that Fpg-sensitive sites was significantly higher in the poorly-controlled diabetics than in the well-controlled diabetics in both the men and women. GSH level was lower in the poorly-controlled diabetics but not significantly. Fpg-sensitive sites were found to be moderately correlated with both glycosylated haemoglobine and GSH, and weakly correlated with glucose. Data indicate that decreased GSH level may be a contributory factor for enhanced oxidative DNA damage in type 2 diabetics; and chronic hyperglycemia derived from poorly-controlled diabetic conditions may induce oxidative DNA damage in these patients.

DNA damage and antioxidant defense in peripheral leukocytes of patients with Type I diabetes mellitus.

We determined relationship among DNA damage, nitric oxide (NO) and antioxidant defense in leukocytes of patients with Type 1 DM. DNA damage was evaluated as strand breakage and formamidopyrimidine DNA glycosylase (Fpg)-sensitive sites by the comet assay in DNA from leukocytes of the subjects. Nitrite level, as a product of NO, superoxide dismutase (SOD) activity and glutathione peroxidase (G-Px) activity of the leukocytes were measured by spectrophotometric kits. Serum glucose level and glycosylated haemoglobin (HbA(1c)) were higher in the patients, as expected. Differences in measured parameters between controls and patients were assessed in men and women separately. There was no significant difference between patient and control groups in neither men nor women for nitrite level. Strand breakage and Fpg-sensitive sites were found to be increased, SOD and G-Px activities of the leukocytes were found to be decreased in both men and women of patient group as compared to their respective controls. Significant correlations were determined between strand breakage and HbA(1c) (r = 0.37, P<0.05); Fpg-sensitive sites and HbA(1c) (r = 0.59, P<0.01); Fpg-sensitive sites and glucose (r = 0.45, P<0.02); Fpg-sensitive sites and SOD (r = -0.48, P<0.02); HbA(1c) and SOD (r = -0.50, P<0.02). In conclusion, impaired antioxidant defense in leukocytes of patients with Type 1 DM may be one of the responsible mechanisms for increased DNA damage in those patients.

Glutathione and glutathione-related enzymes in colorectal cancer patients.

In recent years much attention has been focused on the role of glutathione (GSH) and GSH-related enzymes such as glutathione peroxidase (GSH Px), glutathione reductase (GSH Red), and glutathione S-transferase (GST) in the inhibition of free radical-induced carcinogenesis. In this study, erythrocyte GSH levels and activities of GSH Px, GSH Red, and GST were determined in patients with colorectal tumors (n = 20, mean age 54.5 +/- 8.3 yr). Erythrocyte GSH Red and GST activities were significantly higher in patients with colorectal tumors. Erythrocyte GSH levels and GSH Px activities were found to be significantly decreased in the patients. When the patients were classified based on their clinical grading (Dukes classifications), there was no significant difference in studied parameters between Dukes B and Dukes C. Our results suggest that oxidative stress may play an important role in colorectal tumorigenesis and that these events have no effect on the clinical grading of the colorectal tumor.

Relation between bladder cancer and protein oxidation.

DNA, protein oxidation and lipid peroxidation possess a major impact in carcinogenesis. Also, inflammatory and oxidative events have remarkable importance in bladder cancer. Thus, in this study total protein, protein carbonyl, nitrotyrosine, thiol residues, non-protein thiols, lipid peroxidation, and also, because of their relations to the above parameters, iron and iron binding levels have been investigated in patients with bladder cancer and in control group. Statistical evaluation of the results demonstrated significantly lower plasma protein levels in the patients with bladder cancer, as compared to the healthy control group. Serum iron levels in patients with invasive bladder cancer were found to be significantly lower when compared with non-invasive group. Protein carbonyl groups were remarkably higher in bladder cancer patients than in healthy controls. Patients with bladder cancer were demonstrated to have significantly lower levels of total thiol groups and protein-bound thiol groups as compared to healthy controls. Protein-bound thiol groups in patients with invasive bladder cancer revealed a more significant decline, than in non-invasive group.