Glioblastoma multiforme is resistant to conventional anti-tumoral treatments due to its infiltrative nature and capability of relapse; therefore, research efforts focus on characterizing gliomagenesis and identifying molecular targets useful on therapy. New therapeutic strategies are being tested in patients, such as Histone deacetylase inhibitors (HDACi) either alone or in combination with other therapies. Here two HDACi included in clinical trials have been tested, suberanilohydroxamic acid (SAHA) and valproic acid (VPA), to characterize their effects on glioma cell growth in vitro and to determine the molecular changes that promote cancer cell death. We found that both HDACi reduce glioma cell viability, proliferation and clonogenicity. They have multiple effects, such as inducing the production of reactive oxygen species (ROS) and activating the mitochondrial apoptotic pathway, nevertheless cell death is not prevented by the pan-caspase inhibitor Q-VD-OPh. Importantly, we found that HDACi alter cell cycle progression by decreasing the expression of G2 checkpoint kinases Wee1 and checkpoint kinase 1 (Chk1). In addition, HDACi reduce the expression of proteins involved in DNA repair (Rad51), mitotic spindle formation (TPX2) and chromosome segregation (Survivin) in glioma cells and in human glioblastoma multiforme primary cultures. Therefore, HDACi treatment causes glioma cell entry into mitosis before DNA damage could be repaired and to the formation of an aberrant mitotic spindle that results in glioma cell death through mitotic catastrophe-induced apoptosis.

Infections by the fungus Monilinia laxa, the main cause of brown rot in Europe, result in considerable losses of stone fruit. Herein, we present a comprehensive transcriptomic approach to unravel strategies deployed by nectarine fruit and M. laxa during their interaction. We used M. laxa-inoculated immature and mature fruit, which was resistant and susceptible to brown rot, respectively, to perform a dual RNA-Seq analysis. In immature fruit, host responses, pathogen biomass, and pathogen transcriptional activity peaked at 14–24 h post inoculation (hpi), at which point M. laxa appeared to switch its transcriptional response to either quiescence or death. Mature fruit experienced an exponential increase in host and pathogen activity beginning at 6 hpi. Functional analyses in both host and pathogen highlighted differences in stage-dependent strategies. For example, in immature fruit, M. laxa unsuccessfully employed carbohydrate-active enzymes (CAZymes) for penetration, which the fruit was able to combat with tightly regulated hormone responses and an oxidative burst that challenged the pathogen’s survival at later time points. In contrast, in mature fruit, M. laxa was more dependent on proteolytic effectors than CAZymes, and was able to invest in filamentous growth early during the interaction. Hormone analyses of mature fruit infected with M. laxa indicated that, while jasmonic acid activity was likely useful for defense, high ethylene activity may have promoted susceptibility through the induction of ripening processes. Lastly, we identified M. laxa genes that were highly induced in both quiescent and active infections and may serve as targets for control of brown rot.

Within Saccharomyces cerevisiae, Hcm1is a member of the forkhead transcription factor family with a role in chromosome organization. Our group recently described its involvement in mitochondrial biogenesis and stress resistance, and reports here that Hcm1 played a role in adaptation to respiratory metabolism when glucose or nitrogen was decreased. Regulation of Hcm1 activity occurs in at least three ways: i) protein quantity, ii) subcellular localization, and iii) transcriptional activity. Transcriptional activity was measured using a reporter gene fused to a promoter that contains a binding site for Hcm1. We also analyzed the levels of several genes whose expression is known to be regulated by Hcm1 levels and the role of the main kinases known to respond to nutrients. Lack of sucrose-nonfermenting (Snf1) kinase increases cytoplasmic localization of Hcm1, whereas Δtor1 cells showed a mild increase in nuclear Hcm1. In vitro experiments showed that Snf1 clearly phosphorylates Hcm1 while Sch9 exerts a milder phosphorylation. Although in vitroTor1 does not directly phosphorylate Hcm1, in vivo rapamycin treatment increases nuclear Hcm1. We conclude that Hcm1 participates in the adaptation of cells from fermentation to respiratory metabolism during nutrient scarcity. According to our hypothesis, when nutrient levels decrease, Snf1 phosphorylates Hcm1. This results in a shift from the cytoplasm to the nucleus and increased transcriptional activity of genes involved in respiration, use of alternative energy sources, NAD synthesis and oxidative stress resistance.