RNA interference (RNAi) technology used for the functional analysis of Caenorhabditis elegans genes frequently leads to phenotypes with low penetrance or even proves completely ineffective. The methods previously developed to solve this problem were built on mutant genetic backgrounds, such as those defective for rrf-3, in which endogenous RNAi pathways are overexpressed. These mutations, however, interferes with many other genetic pathways so that the detected phenotype cannot always be clearly linked to the RNAi-exposed gene. In addition, using RNAi-overexpressing mutant backgrounds requires time-consuming genetic crossing. Here, we present an improved RNAi vector that produces specific double-stranded RNA species only, and thereby significantly stronger phenotypes than the standard gene knockdown vector. The further advantage of the new RNAi vector is that the detected phenotype can be specifically linked to the gene silenced. We also created a new all-in-one C. elegans Cas9 vector whose spacer sequence is much easier to replace. Both new vectors include a novel CRISPR/Cas9-based auto-cloning vector system rendering needless the use of restriction and ligase enzymes in generating DNA constructs. This novel, efficient RNAi and auto-cloning Cas9 systems can be easily adapted to any other genetic model.

Pheochromocytomas and paragangliomas are the most heritable endocrine tumors. In addition to the inherited mutation other driver mutations have also been identified in tumor tissues. All these genetic alterations are clustered in distinct groups which determine the pathomechanisms. Most of these tumors are benign and their surgical removal will resolve patient management. However, 5–15% of them are malignant and therapeutical possibilities for them are limited. This review provides a brief insight about the tumorigenesis associated with pheochromocytomas/paragangliomas in order to present them as potential therapeutical targets.

Endocytosis provides the cellular nutrition and homeostasis of organisms, but pathogens often take advantage of this entry point to infect host cells. This is counteracted by phagocytosis that plays a key role in the protection against invading microbes both during the initial engulfment of pathogens and in the clearance of infected cells. Phagocytic cells balance two vital functions: preventing the accumulation of cell corpses to avoid pathological inflammation and autoimmunity, whilst maintaining host defence. In this review, we compare elements of phagocytosis in mammals and the nematode Caenorhabditis elegans. Initial recognition of infection requires different mechanisms. In mammals, pattern recognition receptors bind pathogens directly, whereas activation of the innate immune response in the nematode rather relies on the detection of cellular damage. In contrast, molecules involved in efferocytosis—the engulfment and elimination of dying cells and cell debris—are highly conserved between the two species. Therefore, C. elegans is a powerful model to research mechanisms of the phagocytic machinery. Finally, we show that both mammalian and worm studies help to understand how the two phagocytic functions are interconnected: emerging data suggest the activation of innate immunity as a consequence of defective apoptotic cell clearance.

Background DNA demethylation and inhibitory effect of Aspirin on pituitary cell proliferation have been demonstrated. Our objective was to clarify the molecular mechanisms behind the Aspirin-related effects in pituitary cells. Materials and Methods DNA methylome and whole transcriptome profile were investigated in RC4-B/C and GH3 pituitary cell lines upon Aspirin treatment. Effects of Aspirin and demethylation agent, decitabine, were further tested in vitro. PTTG1 expression in 41 human PitNET samples and whole genome gene and protein expression data of 76 PitNET and 34 control samples (available in Gene Expression Omnibus) were evaluated. Results Aspirin induced global DNA demethylation and consequential transcriptome changes. Overexpression of Tet enzymes and their cofactor Uhrf2 were identified behind the increase of 5-hydroxymethylcytosine (5hmC). Besides cell cycle, proliferation and migration that were validated by functional experiments, Aspirin increased Tp53 activity through p53 acetylation and decreased E2f1 activity. Among the p53 controlled genes, Pttg1 and its interacting partners were downregulated upon Aspirin treatment by inhibiting Pttg1 promoter activity. 5hmC positively correlated with Tet1-3, Tp53 expression, and negatively correlated with Pttg1 expression that was reinforced by the effect of decitabine. Additionally, high overlap (20.15%) was found between Aspirin regulated genes and dysregulated genes in PitNET tissue samples. Conclusion A novel regulatory network has been revealed, where Aspirin regulated global demethylation, Tp53 activity and Pttg1 expression along with decreased cell proliferation and migration. 5hmC, a novel tissue biomarker in PitNET, indicated Aspirin antitumoral effect in vitro too. Our findings suggest the potential beneficial effect of Aspirin in PitNET.

The conserved B-subunit of succinate dehydrogenase (SDH) participates in the TCA cycle and mitochondrial electron transport. The Arg230His mutation in SDHB causes heritable pheochromocytoma/paraganglioma (PPGL). In C. elegans, we generated an in vivo PPGL model (SDHB-1 Arg244His; equivalent to human Arg230His) which manifests delayed development, shortened lifespan, attenuated ATP production and reduced mitochondrial number. Although succinate is elevated in both missense and null sdhb-1(gk165) mutants, transcriptomic comparison suggests very different causal mechanisms that are supported by metabolic analysis where only Arg244His (not null) worms elevate lactate/pyruvate levels, pointing to a missense-induced, ‘Warburg’-like aberrant glycolysis. In silico predictions of the SDHA-B dimer structure demonstrate that Arg230His modifies the catalytic cleft despite the latter's remoteness from the mutation site. We hypothesise that Arg230His SDHB mutation rewires metabolism, reminiscent of metabolic reprogramming in cancer. Our tractable model provides a novel tool to investigate the metastatic propensity of this familial cancer and our approach may illuminate wider SDH pathology.