Detection of megalocytivirus in Oreochromis niloticus and Pseudoplatystoma corruscans in Brazil.

The infectious spleen and kidney necrosis virus (ISKNV) belongs to the genus Megalocytivirus (MCV), a group of double-stranded DNA genome viruses. The aim of this study was to retrospectively analyze samples from suspected foci of MCV infection in freshwater fish in Brazil. Samples were collected from infected fish between 2017 and 2021. Phylogenetic analysis revealed 2 groups of MCV circulating in the country. A genetically homogeneous group formed a clade with ISKNV samples from different parts of the world. Only 2 of the sequences from the state of Goiás showed a small genetic distance when compared to the larger group in the same clade. This study describes the validation of 3 qPCR methods and the presence of MCV in Brazil since 2017, including a genotype not previously described.

Quercetin increases mitochondrial proteins (VDAC and SDH) and downmodulates AXL and PIM-1 tyrosine kinase receptors in NRAS melanoma cells.

Melanoma is a type of skin cancer with low survival rates after it has metastasized. In order to find molecular differences that could represent targets of quercetin in anti-melanoma activity, we have chosen SKMEL-103 and SKMEL-28 melanoma cells and human melanocytes as models. Firstly, we observed that quercetin was able in reducing SKMEL-103 cell viability, but not in SKMEL-28. Besides that, quercetin treatment caused inhibition of AXL in both cell lines, but upregulation of PIM-1 in SKMEL-28 and downregulation in SKMEL-103. Moreover, HIF-1 alpha expression decreased in both cell lines. Interestingly, quercetin was more effective against SKMEL-103 than kinases inhibitors, such as Imatinib, Temsirolimus, U0126, and Erlotinib. Interestingly, we observed that while the levels of succinate dehydrogenase and voltage-dependent anion channel increased in SKMEL-103, both proteins were downregulated in SKMEL-28 after quercetin's treatment. Furthermore, AKT, AXL, PIM-1, ABL kinases were much more active and chaperones HSP90, HSP70 and GAPDH were highly expressed in SKMEL-103 cells in comparison with melanocytes. Our findings indicate, for the first time, that the efficacy of quercetin to kill melanoma cells depends on its ability in inhibiting tyrosine kinase and upregulating mitochondrial proteins, at least when SKMEL-103 and SKMEL-28 cells response were compared.