Redox Biomarkers and Matrix Remodeling Molecules in Ovarian Cancer.

Ovarian cancer (OC) has emerged as the leading cause of death due to gynecological malignancies among women. Oxidative stress and metalloproteinases (MMPs) have been shown to influence signaling pathways and afflict the progression of carcinogenesis. Therefore, the assessment of matrix-remodeling and oxidative stress intensity can determine the degree of cellular injury and often the severity of redox-mediated chemoresistance. The study group comprised 27 patients with serous OC of which 18% were classified as Federation of Gynecology and Obstetrics (FIGO) stages I/II, while the rest were diagnosed grades III/IV. The control group comprised of 15 ovarian tissue samples. The results were compared with genetic data from The Cancer Genome Atlas. Nitro-oxidative stress, inflammation and apoptosis biomarkers were measured colorimetrically/fluorometrically or via real-time PCR in the primary ovarian tumor and healthy tissue. Stratification of patients according to FIGO stages revealed that high-grade carcinoma exhibited substantial alterations in redox balance, including the accumulation of protein glycoxidation and lipid peroxidation products. TCGA data demonstrated only limited prognostic usefulness of the studied genes. In conclusion, high-grade serous OC is associated with enhanced tissue oxidative/nitrosative stress and macromolecule damage that could not be overridden by the simultaneously augmented measures of antioxidant defense. Therefore, it can be assumed that tumor cells acquire adaptive mechanisms that enable them to withstand the potential toxic effects of elevated reactive oxygen species.

The Effect of α-Lipoic Acid on Oxidative Stress in Adipose Tissue of Rats with Obesity-Induced Insulin Resistance.

BACKGROUND/AIMS: Correlation between type 2 diabetes and other abnormalities such as obesity with redox balance disturbance was analyzed in many reports. Nonetheless, antioxidants impact on parameters accompanying these conditions is still unknown. Currently the role of redox imbalance in the adipose tissue has gained a lot of attention. METHODS: We investigated the impact of α-lipoic acid (ALA) on plasma glucose and insulin concentrations, oxidative stress and inflammation parameters in the subcutaneous (SAT) and visceral (VAT) adipose tissue of high fat diet-fed (HFD) rats. Male Wistar rats were randomly divided into three groups (n = 6) - control diet (CTRL), HFD and HFD with α-lipoic acid (HFD+ALA). RESULTS: HFD increased body weight, plasma insulin and glucose as well as leads to oxidative stress parameters in the adipose tissue. ALA supplementation reduced body weight and oxidative stress parameters more effectively in the visceral than subcutaneous adipose tissue of insulin resistant rats. CONCLUSION: Insulin resistance led to increased enzymatic and non-enzymatic antioxidant systems, protein and lipid glycoxidation, nitrosative stress, and selected inflammatory parameters more in VAT than in SAT of insulin resistant rats. Moreover, ALA inhibited HFD consequences mainly in VAT mostly through glutathione (GSH) biosynthesis.

Diverse impact of N-acetylcysteine or alpha-lipoic acid supplementation during high-fat diet regime on fatty acid transporters in visceral and subcutaneous adipose tissue.

PURPOSE: Adipose tissue's (AT) structural changes accompanying obesity may alter lipid transport protein expression and, thus, the fatty acids (FAs) transport and lipid balance of the body. Metabolic abnormalities within AT contribute to the elevated production of reactive oxygen species and increased oxidative/nitrosative stress. Although compounds such as N-acetylcysteine (NAC) and α-lipoic acid (ALA), which restore redox homeostasis, may improve lipid metabolism in AT, the mechanism of action of these antioxidants on lipid metabolism in AT is still unknown. This study aimed to examine the impact of NAC and ALA on the level and FA composition of the lipid fractions, and the expression of FA transporters in the visceral and subcutaneous AT of high-fat diet-fed rats. MATERIALS AND METHODS: Male Wistar rats were randomly divided into four groups. The mRNA levels and protein expression of FA transporters were assessed using real-time PCR and Western Blot analyses. The collected samples were subjected to histological evaluation. The level of lipids (FFA, DAG, and TAG) was measured using gas-liquid chromatography. RESULTS: We found that antioxidants affect FA transporter expressions at both the transcript and protein levels, and, therefore, they promote changes in AT's lipid pools. One of the most remarkable findings of our research is that different antioxidant molecules may have a varying impact on AT phenotype. CONCLUSION: NAC and ALA exert different influences on AT, which is reflected in histopathological images, FA transport proteins expression patterns, or even the lipid storage capacity of adipocytes.