Modulating RNA structure and catalysis: lessons from small cleaving ribozymes

RNA is a key molecule in life, and comprehending its structure/function relationships is a crucial step towards a more complete understanding of molecular biology. Even though most of the information required for their correct folding is contained in their primary sequences, we are as yet unable to accurately predict both the folding pathways and active tertiary structures of RNA species. Ribozymes are interesting molecules to study when addressing these questions because any modifications in their structures are often reflected in their catalytic properties. The recent progress in the study of the structures, the folding pathways and the modulation of the small ribozymes derived from natural, self-cleaving, RNA motifs have significantly contributed to today’s knowledge in the field

Epithelial NOTCH signaling rewires the tumor microenvironment of colorectal cancer to drive poor-prognosis subtypes and metastasis

The metastatic process of colorectal cancer (CRC) is not fully understood and effective therapies are lacking. We show that activation of NOTCH1 signaling in the murine intestinal epithelium leads to highly penetrant metastasis (100% metastasis; with >80% liver metastases) in KrasG12D-driven serrated cancer. Transcriptional profiling reveals that epithelial NOTCH1 signaling creates a tumor microenvironment (TME) reminiscent of poorly prognostic human CRC subtypes (CMS4 and CRIS-B), and drives metastasis through transforming growth factor (TGF) β-dependent neutrophil recruitment. Importantly, inhibition of this recruitment with clinically relevant therapeutic agents blocks metastasis. We propose that NOTCH1 signaling is key to CRC progression and should be exploited clinically. In a genetically engineered mouse model, Jackstadt et al. show that NOTCH1 activation drives metastasis in KRASG12D-driven serrated colorectal cancer (CRC) through TGFβ-dependent neutrophil recruitment. Thus, targeting neutrophil recruitment is a potential therapeutic approach in metastatic CRC

Metabolic host response to intracellular infections

The interaction between intracellular bacterial pathogens with the host immune response can result in multiple outcomes that range from asymptomatic clearance to the establishment of infection. At its core, these interactions result in multiple metabolic adaptations of both the pathogen and its host cell. There is growing evidence that the host metabolic response plays a key role in the development of immune responses against the invading pathogen. However, successful intracellular pathogens have developed multiple mechanisms to circumvent the host response to thrive in the intracellular compartment. Here, we provide a brief overview on the crucial role of fundamental metabolic host responses in the generation of protective immunity to intracellular bacterial pathogens and discuss some of the mechanisms used by these pathogens to exploit the host metabolic response to their own advantage. This understanding will further our knowledge in host-pathogen interactions and may provide new insights for the development of novel therapies.(undefined)info:eu-repo/semantics/publishedVersio