Characterization of the cytotoxic effects of the combination of cisplatin and flavanol (-)-epicatechin on human lung cancer cell line A549. An isobolographic approach.

BACKGROUND: Among malignancies, lung cancer is a leading cause of death. Platinum-based therapeutic compounds used to treat lung cancer have not been able to increase the survival of patients and such compounds have a high incidence of adverse and toxic effects. It has been proposed that flavonoids such as catechins may significantly reduce the risk of developing cancer, alongside with other health benefits. The aim of this work was to determine the effect of (-)-epicatechin, the main flavanol found in cocoa, on the proliferation of the lung non-small cell adenocarcinoma cancer cell line A549, and to determine its effects when added simultaneously with cisplatin. MATERIALS AND METHODS: Concentration-response curves for cisplatin and epicatechin were obtained, inhibitory concentrations calculated and an isobolographic analysis was then performed. RESULTS: We found that epicatechin has a concentration-dependent inhibitory effect on proliferation of tumor cells and the isobolographic analysis reveals that the effect of its combination with cisplatin is synergistic. It was also observed that epicatechin promotes cell death by apoptosis. CONCLUSIONS: Epicatechin might be considered for future studies to explore its possible use as coadjuvant in cisplatin-based treatments.

Dysregulation of mitochondrial function and biogenesis modulators in adipose tissue of obese children.

BACKGROUND/OBJECTIVES: We aimed to evaluate mitochondrial biogenesis (MB), structure, metabolism and dysfunction in abdominal adipose tissue from male pediatric patients with obesity. SUBJECTS/METHODS: Samples were collected from five children with obesity (percentile ⩾95) and five eutrophic boys (percentile ⩾5/⩽85) (8-12 years old) following parental informed consent. We analyzed the expression of key genes involved in MB (sirtuin-1 (SIRT1), peroxisome proliferator-activated receptor-γ (PPARγ), PPARγ coactivator-1α (PGC1α), nuclear respiratory factors 1 and 2 (NRF1, NRF2) and mitochondrial transcription factor A (TFAM) and surrogates for mitochondrial function/structure/metabolism (porin, TOMM20, complex I and V, UCP1, UCP2, SIRT3, SOD2) by western blot. Citrate synthase (CS), complex I (CI) activity, adenosine triphosphate (ATP) levels, mitochondrial DNA (mtDNA) content and oxidative stress end points were also determined. RESULTS: Most MB proteins were significantly decreased in samples from children with obesity except complex I, V and superoxide dismutase-2 (SOD2). Similarly, CS and CI activity showed a significant reduction, as well as ATP levels and mtDNA content. PPARγ, PGC1α, complex I and V and SOD2 were hyperacetylated compared with lean samples. Concurrently, in samples from children with obesity, we found decreased SOD2 activity and redox state imbalance highlighted by decreased reduced glutathione/oxidized glutathione (GSH/GSSG) ratio and significant increases in protein carbonylation. CONCLUSIONS: Adipose tissue from children with obesity demonstrates a dysregulation of key modulators of MB and organelle structure, and displays hyperacetylation of key proteins and altered expression of upstream regulators of cell metabolism.

Expression analysis of the SG-SSPN complex in smooth muscle and endothelial cells of human umbilical cord vessels.

Recently, participation of the sarcoglycan (SG)-sarcospan (SSPN) complex in the development of cardiomyopathy in patients with limb-girdle muscular dystrophy has been shown, and presence of the complex in smooth muscle may be important for the contraction/dilation process of vessels. However, there are few studies determining the SG-SSPN complex in vascular smooth muscle and endothelial cells of vessels. In this study, we analyzed by reverse transcriptase-polymerase chain reaction and immunofluorescence the expression of different components of the complex in vein/artery smooth muscle and endothelial cells of the human umbilical cord. By RNA analysis, we observed expression of alpha-, beta-, gamma-, delta-, epsilon-SG, and SSPN in smooth muscle cells. In endothelial cells, RNA expression was restricted to beta-, delta-, epsilon-SG, and SSPN. At protein level, we observed in smooth muscle the presence of beta-, delta-, epsilon-SG, and SSPN. In endothelial cells, immunostaining only evidenced the presence of epsilon-SG and SSPN. However, colocalization of SGs and SSPN with dystrophin and utrophin was noted. These results, interestingly, suggest that the SG-SSPN complex may either form with dystrophin or utrophin in smooth muscle cells, and with utrophin in endothelial cells. Additionally, we also observed in some smooth muscle regions the colocalization of the SG-SSPN complex with caveolin, with colocalization being more pronounced between epsilon-SG-SSPN and caveolin in endothelial cells.