3-nitrotyrosine and Carcinoma

The source of many diseases, including tumors, lies in an increased generation of reactive oxygen species resulting in oxidative stress. We investigated the relationships between advanced oxidation protein products (AOPPs), nitrotyrosine (NT), protein carbonyls (PCO) content, and the prooxidant-antioxidant balance (PAB) in patients with lung cancer.. A total of 14 age-matched healthy controls, 14 subjects with non-lung cancer pulmonary disease, and 41 patients with lung cancer were included in this study. Spectrophotometry was used to examine plasma AOPP, serum FRAP, and PAB, while serum PCO and NT were assessed with western blot analysis.. A significant difference in AOPP levels were found between patients and controls (p < 0.01). Also, there was a highly significant difference in NT levels between patients and controls (p < 0.001). PAB showed negative correlation with albumin (r = -0.340, p = 0.011) and positive correlation with CRP (r = 0.342, p = 0.011). AOPP, albumin, gender, and smoking were the significant independent variables found by backward stepwise multiple logistic regression (MLR) analysis method. MLR analysis revealed that AOPP was the variable that had a significant effect on lung cancer [(p = 0.006, OR = 1.074, (95% CI) (1.020-1.131)].. The use of non-invasive diagnostic biochemical parameters would represent a very important contribution to our diagnostic armamentarium in lung cancer, considering the high incidence of this deadly disease. In this regard, AOPP and NT levels have appeared to play a prominent role, although further studies are certainly warranted.

Topics: Advanced Oxidation Protein Products; Aged; Aged, 80 and over; Antioxidants; Blotting, Western; Carcinoma; Case-Control Studies; Female; Humans; Lung Neoplasms; Male; Middle Aged; Protein Carbonylation; Tyrosine

Oxidative stress markers and peroxiredoxins are connected to cancer. A large set of urinary bladder carcinomas were studied for the expression of nitrotyrosine and 8-hydroxydeguanosine (8OHdG), two markers indicating oxidative damage. Serum and urine 8-OHdG were assessed in a subset of patients. We also analysed immunohisto-chemically the expression of nrf2, keap1, all six peroxiredoxins (prx) and thioredoxin (trx) in these tumors. 15 % of the cases showed 8OHdG and 36 % nitrotyrosine positivity. Expression of nitrotyrosine and 8OHdG associated with a poor prognosis (p=0.050, p=0.011, respectively). Peroxiredoxin positivity ranged from 39 % to 84 % lowest expression being for prx 4 and highest for prx 3. Prx 4 expression associated with a poor prognosis (p=0.025) with high grade (p=0.044) and larger tumors (p=0.023). Cytoplasmic trx positivity was seen in 91 % and nuclear in 59 % of tumors. Nuclear and cytoplasmic trx associated with each other (p<0.001), and nuclear trx associated with prx 6 (p=0.001), prx 2 (p<0.001), and prx 5 (p<0.001). 8OHdG associated with nuclear trx positivity (p=0.002), inversely with prx 1 (p=0.025) and with keap1 (p=0.020). Nuclear nrf2 was associated with nitrotyrosine (p=0.042). The results show that the amount of oxidative stress in urinary bladder tumors affects the prognosis of the patients. Of antioxidative enzymes, prx4 associated with an unfavourable prognosis. Selective inhibition of prx4 expression might then be one additional option of treatment of bladder cancer.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Biomarkers, Tumor; Carcinoma; Cell Nucleus; Cytoplasm; Deoxyguanosine; Enzyme-Linked Immunosorbent Assay; Humans; Immunohistochemistry; Intracellular Signaling Peptides and Proteins; Kaplan-Meier Estimate; Kelch-Like ECH-Associated Protein 1; NF-E2-Related Factor 2; Oxidative Stress; Peroxiredoxins; Prognosis; Statistics, Nonparametric; Thioredoxins; Tyrosine; Urinary Bladder Neoplasms

Previous studies have suggested the importance of reactive oxygen species in all the steps of carcinogenesis. Antioxidant enzymes are considered as the most specific and efficient way to protect cells from reactive oxygen species. The purpose of the current study was to identify the role of oxidative stress and major antioxidant enzymes in ovarian carcinomas.. The material consisted of 68 invasive ovarian carcinomas which were studied by immunohistochemistry with antibodies to antioxidant enzymes peroxiredoxins (Prxs) I-VI and thioredoxin and oxidative stress markers nitrotyrosine and 8-hydroxydeoxyguanosine (8-OHdG). Both the intensity and the extent of the stainings were assessed, and the nuclear and cytoplasmic expressions were evaluated separately.. The study revealed the hydroxyl radical-derived oxidative stress marker in DNA, 8-OHdG, to be a powerful prognostic factor in ovarian carcinoma (Kaplan-Meier survival log-rank-analysis P = 0.003; risk of death to ovarian carcinoma 2.69; 95% confidence interval 1.35-5.35. 8-OHdG was also associated with poor differentiation (P = 0.053), higher stage (P < 0.001), and non-optimal surgical outcome (P = 0.002). High cytoplasmic Prx IV immunostaining was associated with a better prognosis (P = 0.024), and elevated cytoplasmic expression rates of Prxs V (P = 0.043) and VI (P = 0.032) were associated with a higher stage.. To conclude, it appears that hydroxyl radical-derived oxidative stress, but not nitric oxide radical-derived oxidative stress, plays a significant role in ovarian carcinogenesis. Immunohistochemical assessment of 8-OHdG could provide a useful prognostic marker in ovarian cancer.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Antioxidants; Biomarkers, Tumor; Carcinoma; Cell Nucleus; Cytoplasm; DNA Adducts; Female; Guanine; Humans; Immunohistochemistry; Neoplasm Staging; Ovarian Neoplasms; Oxidative Stress; Prognosis; Survival Analysis; Tyrosine

The C-terminus of the alpha-chain of tubulin is subject to reversible incorporation of tyrosine by tubulin tyrosine ligase and removal by tubulin carboxypeptidase. Thus, microtubules rich in either tyrosinated or detyrosinated tubulin can coexist in the cell. Substitution of the terminal tyrosine by 3-nitrotyrosine has been claimed to cause microtubule dysfunction and consequent injury of epithelial lung carcinoma A549 cells. Nitrotyrosine is formed in cells by nitration of tyrosine by nitric oxide-derived species. We studied properties of tubulin modified by in vitro nitrotyrosination at the C-terminus of the alpha-subunit, and the consequences for cell functioning. Nitrotyrosinated tubulin was a good substrate of tubulin carboxypeptidase, and showed a similar capability to assemble into microtubules in vitro to that of tyrosinated tubulin. Tubulin of C6 cells cultured in F12K medium in the presence of 500 micro m nitrotyrosine became fully nitrotyrosinated. This nitrotyrosination was shown to be reversible. No changes in morphology, proliferation, or viability were observed during cycles of nitrotyrosination, denitrotyrosination, and re-nitrotyrosination. Similar results were obtained with CHO, COS-7, HeLa, NIH-3T3, NIH-3T3(TTL-), and A549 cells. C6 and A549 cells were subjected to several passages during 45 days or more in the continuous presence of 500 micro m nitrotyrosine without noticeable alteration of morphology, viability, or proliferation. The microtubular networks visualized by immunofluorescence with antibodies to nitrotyrosinated and total tubulin were identical. Furthermore, nitrotyrosination of tubulin in COS cells did not alter the association of tubulin carboxypeptidase with microtubules. Our results demonstrate that substitution of C-terminal tyrosine by 3-nitrotyrosine has no detrimental effect on dividing cells.

Topics: 3T3 Cells; Animals; Brain; Carboxypeptidases; Carcinoma; Cell Death; Cells, Cultured; CHO Cells; COS Cells; Cricetinae; HeLa Cells; Humans; Kinetics; Lung Neoplasms; Mice; Microtubules; Rats; Tubulin; Tyrosine

Nitric oxide (NO) is produced by a group of synthase enzymes (NOS). By means of different pathways, NO exerts several functions in benign and malignant human bladder tissues. The current paper describes the NO/guanylate cyclase (sGC)/cyclic guanosine monophosphate (cGMP) and the NO/oxidative pathways in human bladder tissues.. Bladder carcinoma tissues were collected from 18 patients by transurethral resection procedures. Normal benign vesical tissue specimens from a further eight patients with benign diseases served as controls. Immunohistochemistry was conducted for localization of sGC, cGMP, and nitrotyrosine in benign and malignant vesical tissues, evaluating two-three tissue sections per patient.. Positive immunolabeling for sGC and cGMP was detected in vascular endothelial cells of normal and malignant vesical tissues. Those signals were most intense in bladder carcinoma tissues. Immunolabeling for sGC and cGMP was also detected in normal urothelial cells. In bladder carcinoma cells, a heterogeneous immunolabeling for sGC and cGMP was seen, with a wide spectrum of signal intensity. Positive immunostaining for sGC and cGMP was also observed in stromal round cells in benign and malignant bladder tissues. Immunolabeling for nitrotyrosine was mainly observed in endothelial cells, with a much stronger immunolabeling in bladder carcinoma tissues compared to normal benign controls. A weak immunolabeling for nitrotyrosine was also observed in bladder carcinoma cells. Normal urothelial cells did not show such nitrotyrosine expression.. The current report provides evidences that NO play several roles through different pathways in benign and malignant vesical tissues. The influences generated by NO molecules can be divided into cGMP-mediated effects (those resulting from the NO/sGC/cGMP pathway) and non-cGMP-mediated effects (those resulting from the NO/oxidative pathway). Increased angiogenesis is a cGMP-mediated effect, while nitrotyrosine production is a non cGMP-mediated oxidative effect. Such an NO/oxidative pathway is observed more often in bladder carcinoma.

Topics: Aged; Blotting, Western; Carcinoma; Cell Transformation, Neoplastic; Cyclic GMP; Free Radical Scavengers; Guanylate Cyclase; Humans; Immunohistochemistry; Neovascularization, Pathologic; Nitric Oxide; Nitric Oxide Synthase; Oxidation-Reduction; Tyrosine; Urinary Bladder Neoplasms

An increased expression of nitric oxide synthase (NOS) has been observed in human colon carcinoma cell lines as well as in human gynecological, breast, and central nervous system tumors. This observation suggests a pathobiological role of tumor-associated NO production. Hence, we investigated NOS expression in human colon cancer in respect to tumor staging, NOS-expressing cell type(s), nitrotyrosine formation, inflammation, and vascular endothelial growth factor expression. Ca2+-dependent NOS activity was found in normal colon and in tumors but was significantly decreased in adenomas (P < 0.001) and carcinomas (Dukes' stages A-D: P < 0.002). Ca2+-independent NOS activity, indicating inducible NOS (NOS2), is markedly expressed in approximately 60% of human colon adenomas (P < 0.001 versus normal tissues) and in 20-25% of colon carcinomas (P < 0.01 versus normal tissues). Only low levels were found in the surrounding normal tissue. NOS2 activity decreased with increasing tumor stage (Dukes' A-D) and was lowest in colon metastases to liver and lung. NOS2 was detected in tissue mononuclear cells (TMCs), endothelium, and tumor epithelium. There was a statistically significant correlation between NOS2 enzymatic activity and the level of NOS2 protein detected by immunohistochemistry (P < 0.01). Western blot analysis of tumor extracts with Ca2+-independent NOS activity showed up to three distinct NOS2 protein bands at Mr 125,000-Mr 138,000. The same protein bands were heavily tyrosine-phosphorylated in some tumor tissues. TMCs, but not the tumor epithelium, were immunopositive using a polyclonal anti-nitrotyrosine antibody. However, only a subset of the NOS2-expressing TMCs stained positively for 3-nitrotyrosine, which is a marker for peroxynitrite formation. Furthermore, vascular endothelial growth factor expression was detected in adenomas expressing NOS2. These data are consistent with the hypothesis that excessive NO production by NOS2 may contribute to the pathogenesis of colon cancer progression at the transition of colon adenoma to carcinoma in situ.

Topics: Adenoma; Blotting, Western; Carcinoma; Colon; Colonic Neoplasms; Disease Progression; DNA Primers; DNA, Neoplasm; Endothelial Growth Factors; Endothelium, Vascular; Humans; Immunohistochemistry; Lymphokines; Neoplasm Proteins; Neovascularization, Pathologic; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Phosphorylation; Polymerase Chain Reaction; Tyrosine; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors