Anticancer Properties of PPARα-Effects on Cellular Metabolism and Inflammation

Peroxisome proliferator-activated receptors (PPARs) have lately attracted much attention as therapeutic targets. Previously, PPAR ligands were associated with the treatment of diabetes, hyperlipidemia and cardiovascular diseases, as they modulate the expression of genes regulating glucose and lipid metabolism. Recently, PPAR ligands have been also considered as potential anticancer agents, with relatively low systemic toxicity. The emerging evidence for antiproliferative, proapoptotic, antiinflammatory and potential antimetastatic properties of PPARα ligands prompted us to discuss possible roles of PPARα in tumor suppression. PPARα activation can target cancer cells energy balance by blocking fatty acid synthesis and by promoting fatty acid β-oxidation. In the state of limited nutrient availability, frequently presents in the tumor microenvironment, PPARα cooperates with AMP-dependent protein kinase in: (i) repressing oncogenic Akt activity, (ii) inhibiting cell proliferation, and (iii) forcing glycolysis-dependent cancer cells into “metabolic catastrophe.” Other potential anticancer effects of PPARα include suppression of inflammation, and upregulation of uncoupling proteins (UCPs), which attenuates mitochondrial reactive oxygen species production and cell proliferation. In conclusion, there are strong premises that the low-toxic and well-tolerated PPAR ligands should be considered as new therapeutic agents to fight disseminating cancer, which represents the major challenge for modern medicine and basic research

Vzájomné pôsobenie citrinínu a resveratrolu a ich vplyv na rast Caco-2 buniek

The aim of this study was to use Caco-2 cells as an in vitro model of human intestina barrier. This model was employed to investigate interaction of citrinin and resveratrol and to determine the doses that affect cell number. Citrinin (CTN) is a toxic secondary metabolite produced by fungi of the genera Penicillium, Aspergillus and Monascus. It is contaminant of cereals, grains, food and feed products. Previous studies have shown that CTN has teratogenic, nephrotoxic, hepatotoxic and embryotoxic effects. Resveratrol (RES) is polyphenol belongs to the group of stilbenes. At lower doses it has positive effects on human health and higher doses may induce apoptosis. The results of study indicate a significant (P < 0.05) decrease in cell number in all conditions: A (RES 20 μM), B (CTN 100 μg*ml-1), C (CTN 250 μg*ml-1), D (CTN 100 μg*ml-1 + RES 20 μM), E (CTN 250 μg*ml-1 + RES 20 μM) in comparison with the control group of non-treated cells (NT) and control group with ethanol (Ce). A significant (P <0.05) decrease in the cells number was observed between groups A - E, B - C and D - E. Citrinin effect seems to be dose-dependent.Cieľom práce bolo použitie Caco-2 buniek ako in vitro model črevnej bariéry na zistenie vzájomného pôsobenia citrinínu a resveratrolu a stanovenie dávok, ktoré majú vplyv na počet buniek. Citrinín (CTN) je toxický sekundárny metabolit, ktorý produkujú mikroskopické huby patriace do rodov Aspergillus, Penicillium a Monascus. Kontaminuje cereálie, obilniny, potraviny a krmivá. Predchádzajúce štúdie ukázali, že CTN má teratogénne, nefrotoxické, hepatotoxické a embryotoxické účinky. Resveratrol (RES) je polyfenol, ktorý patrí do skupiny stilbénov. Pri nižších dávkach má pozitívne účinky na ľudské zdravie a pri vyšších spôsobuje apoptózu buniek. Výsledky štúdie poukazujú na signifikantný (P < 0.05) pokles počtu buniek vo všetkých experimentálnych skupinách A (RES 20 μM), B (CTN 100 μg*ml-1), C (CTN 250 μg*ml-1), D (CTN 100 μg*ml-1 + RES 20 μM), E (CTN 250 μg*ml-1 + RES 20 μM) v porovnaní s kontrolnou skupinou s neošetrenými bunkami (NT) a kontrolnou skupinou s prídavkom etanolu (Ce). Významný (P < 0.05) pokles buniek sa zaznamenal medzi skupinami A - E, B - C a D - E. Pôsobenie citrinínu je dávkovo závislé

The in vitro digestates from Brussels sprouts processed with various hydrothermal treatments affect the intestinal epithelial cell differentiation, mitochondrial polarization and glutathione level

Brussels sprouts provide bioactive compounds with widely acknowledged health-promoting effects observed in various levels: single cells, organs and tissues, or the whole organism. However, the choice of the appropriate hydrothermal processing is critical to sustain the nutritional values and cytoprotective activities, as Brussels sprouts are rarely eaten raw. The aim of this study was to evaluate the impact of various culinary methods (boiling, steaming, and sous-vide in comparison to raw plant material) applied to Brussels sprouts on the chosen functions of liver and intestinal cell lines (HepG2 and Caco-2, respectively): the markers of enterocyte differentiation (alkaline phosphatase and sucrase-isomaltase activities and protein level), glutathione store management (total GSH concentration and Glu, Gly, Cys and Met amino acids analysis) and mitochondrial polarization (JC-1 staining analysis). The in vitro digestates from raw Brussels sprouts had a stronger positive effect on the enterocyte marker enzymes in the Caco-2 cultures as compared to the digestates from the hydrothermally processed vegetables (boiled, steamed, and sous-vide). The sous-vide method diminished the intracellular glutathione stores. Hydrothermal processing, particularly steaming and sous-vide had a negative impact on the mitochondrial abundance and polarization as compared to raw vegetables. Our results suggest that shorter processing is more beneficial to retain glutathione and mitochondrial polarization than longer hydrothermal treatment

RIPK4 downregulation impairs Wnt3A-stimulated invasiveness via Wnt/β\beta-catenin signaling in melanoma cells and tumor growth in vivo

Purpose The role of Wnt signaling in oncogenesis and drug resistance is well known. Receptor-interacting protein kinase (RIPK4) contributing to the increased activity of many signaling pathways, including Wnt/$\beta$-catenin, may be an important target for designing new drugs for metastatic melanoma, but its role in melanoma is not fully understood. Methods We tested the effect of genetic manipulation of RIPK4 (CRISPR/Cas9) on xenograft growth. In addition, immunohistochemistry was used to detect active $\beta$-catenin, Ki67 and necrosis in xenografts. Wnt signaling pathway activity was examined using Western blot and Top-Flash. The effect of RIPK4 knockout on melanoma cells in vitro stimulated Wnt3A on wound overgrowth, migration and invasion ability was then evaluated. Results Our study showed that CRISPR/Cas9-mediated RIPK4 knockout (KO) significantly reduced tumor growth in a mouse model of melanoma, particularly of WM266.4 cells. RIPK4 KO tumors exhibited lower percentages of $Ki67^{+}$ cells as well as reduced necrotic area and decreased levels of active $\beta$-catenin. In addition, we observed that RIPK4 knockout impaired Wnt3A-induced activation of LRP6 and $\beta$-catenin, as manifested by a decrease in the transcriptional activity of $\beta$-catenin in Top-Flash in both tested melanoma cell lines, A375 and WM266.4. Prolonged incubation (48 h) with Wnt3A showed reduced level of MMP9, C-myc, and increased SOX10, proteins whose transcription is also dependent on $\beta$-catenin activity. Moreover, RIPK4 knockout led to the inhibition of scratch overgrowth, migration and invasion of these cells compared to their controls. Conclusion RIPK4 knockdown inhibits melanoma tumor growth and Wnt3A stimulated migration and invasion indicating that RIPK4 might be a potential target for melanoma therapy

Genetic variants in PDSS1 and SLC16A6 of the ketone body metabolic pathway predict cutaneous melanoma-specific survival

A few single-nucleotide polymorphisms (SNPs) have been identified to be associated with cutaneous melanoma (CM) survival though genome-wide association studies, but stringent multiple testing corrections required for the hypothesis-free testing may have masked some true associations. Using a hypothesis-driven analysis approach, we sought to evaluate associations between SNPs in ketone body metabolic pathway genes and CM survival. We comprehensively assessed associations between 4,196 (538 genotyped and 3,658 imputed) common SNPs in ketone body metabolic pathway genes and CM survival, using a dataset of 858 patients of a case-control study from The University of Texas M.D. Anderson Cancer Center as the discovery set and another dataset of 409 patients from the Nurses’ Health Study and the Health Professionals Follow-up Study as the replication set. There were 95/858 (11.1%) and 48/409 (11.5%) patients who died of CM, respectively. We identified two independent SNPs (i.e., PDSS1 rs12254548 G>C and SLC16A6 rs71387392 G>A) that were associated with CM survival, with allelic hazards ratios of 0.58 (95% confidence interval [CI]=0.44-0.76, P=9.00×10−5) and 1.98 (95% CI=1.34-2.94, P=6.30×10−4), respectively. Additionally, associations between genotypes of the SNPs and mRNA expression levels of their corresponding genes support the biologic plausibility of a role for these two variants in CM tumor progression and survival. Once validated by larger studies, PDSS1 rs12254548 and SLC16A6 rs71387392 may be biomarker for CM survival

Control In Competitive Sport As Exemplified By A Women Basketball Team In The Polish First League

This article aims to present elements of control within the selected areas of motor preparation in competitive athletes established at rest and after exercise. Identifying the effect of fatigue on the values of the controlled coefficients allows assessing training effectiveness, comparing athletes for performance, as well as determining the kinetics of oxygen deficit, oxygen debt, oxygen uptake or the level of lactate concentration at different stages of continued exercise. This type of research provides both athletes and their coaches with immediate information on how well the former are prepared and enables the control of training results.This article aims to present elements of control within selected areas of motor preparation in competitive athletes established both at rest and after exercise. Identifying the effect of fatigue on the values of the controlled coefficients allows for assessing training effectiveness. Comparing athletes for performance, as well as determining the kinetics of oxygen deficit, oxygen debt, oxygen uptake or the level of lactate concentration at different stages of continued exercise. This type of research provides both athletes and their coaches with direct information on how well the former are prepared and enables the control of training results

PPARβ activation inhibits melanoma cell proliferation involving repression of the Wilms’ tumour suppressor WT1

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors that strongly influence molecular signalling in normal and cancer cells. Although increasing evidence suggests a role of PPARs in skin carcinogenesis, only expression of PPARγ has been investigated in human melanoma tissues. Activation of PPARα has been shown to inhibit the metastatic potential, whereas stimulation of PPARγ decreased melanoma cell proliferation. We show here that the third member of the PPAR family, PPARβ/δ is expressed in human melanoma samples. Specific pharmacological activation of PPARβ using GW0742 or GW501516 in low concentrations inhibits proliferation of human and murine melanoma cells. Inhibition of proliferation is accompanied by decreased expression of the Wilms’ tumour suppressor 1 (WT1), which is implicated in melanoma proliferation. We demonstrate that PPARβ directly represses WT1 as (1) PPARβ activation represses WT1 promoter activity; (2) in chromatin immunoprecipitation and electrophoretic mobility shift assays, we identified a binding element for PPARβ in the WT1 promoter; (3) deletion of this binding element abolishes repression by PPARβ and (4) the WT1 downstream molecules nestin and zyxin are down-regulated upon PPARβ activation. Our findings elucidate a novel mechanism of signalling by ligands of PPARβ, which leads to suppression of melanoma cell growth through direct repression of WT1

Challenge and promise: the role of miRNA for pathogenesis and progression of malignant melanoma

microRNAs are endogenous noncoding RNAs that are implicated in gene regulation. More recently, miRNAs have been shown to play a pivotal role in multiple cellular processes that interfere with tumorigenesis. Here we summarize the essential role of microRNAs for human cancer with special focus on malignant melanoma and the promising perspectives for cancer therapies