The Role of Bcl-2 and Beclin-1 Complex in "Switching" between Apoptosis and Autophagy in Human Glioma Cells upon LY294002 and Sorafenib Treatment.

BACKGROUND: Gliomas are the most malignant tumors of the central nervous system. One of the factors in their high drug resistance is avoiding programmed death (PCD) induction. This is related to the overexpression of intracellular survival pathways: PI3K-Akt/PKB-mTOR and Ras-Raf-MEK-ERK. Apoptosis and autophagy are co-existing processes due to the interactions between Bcl-2 and beclin-1 proteins. Their complex may be a molecular "toggle-switch" between PCD types. The aim of this research was to investigate the role of Bcl-2:beclin-1 complex in glioma cell elimination through the combined action of LY294002 and sorafenib. METHODS: Drug cytotoxicity was estimated with an MTT test. The type of cell death was evaluated using variant microscopy techniques (fluorochrome staining, immunocytochemistry, and transmission electron microscopy), as well as the Bcl-2:beclin-1 complex formation and protein localization. Molecular analysis of PCD indicators was conducted through immunoblotting, immunoprecipitation, and ELISA testing. SiRNA was used to block Bcl-2 and beclin-1 expression. RESULTS: The results showed the inhibitors used in simultaneous application resulted in Bcl-2:beclin-1 complex formation and apoptosis becoming dominant. This was accompanied by changes in the location of the tested proteins. CONCLUSIONS: "Switching" between apoptosis and autophagy using PI3K and Raf inhibitors with Bcl-2:beclin-1 complex formation opens new therapeutic perspectives against gliomas.

Effect of Supplementation with the Combination of Se-Enriched Lentinula edodes Mycelium, Exogenous Enzymes, Acidifiers, Sodium Butyrate and Silicon Dioxide Nanoparticle Feed Additives on Selected Parameters in Calves.

During the initial months of calves' lives, the young animals are exposed to bacterial and viral infections, and during this period, crucial physiological changes take place in their organisms. Offering calves feed additives that will have a beneficial influence on their organisms and improve their growth while reducing the morbidity rate is the optimal task of feeding. This is the first study to investigate the effect of experimental supplementation for calves with the combination of two feed additives­one containing Lentinula edodes enriched with selenium (Se), and the second containing pancreatic-like enzymes, fat-coated organic acids, sodium butyrate, and silicon dioxide nanoparticles­on the serum Se concentration, selected immune parameters, and the average daily gains in the calves. During the study, the serum Se concentration was examined by means of inductively coupled plasma mass spectrometry, and the immunoglobulin and cytokine concentrations with ELISA assays. The white blood cell (WBC) count with leukocyte differentiation was examined with the use of a hematological analyzer, and the percentages of subpopulations of T lymphocytes and monocytes, phagocytic activity, and oxidative burst of monocytes and granulocytes with the use of a flow cytometer. The average daily gains of the calves were also evaluated. In summary, the supplementation of the experimental calves with the combination of two feed additives resulted in significantly higher serum Se concentrations, and the immune systems of the calves were not suppressed while the examined feed additives were being delivered. Although not statistically significant, some positive effects on the calves were seen: a tendency towards the improvement of some of the immune parameters evaluated, and a tendency for higher average daily gains in the calves.