Project description:Pancreatic cancer is mainly driven by mutations in the KRAS oncogene. While this cancer has shown remarkable therapy resistance, new approaches to inhibit mutated KRAS, KRAS activators and effectors show promise in breaking this therapeutic deadlock. Here, we review these innovations in therapies that target RAS signaling in pancreatic cancer from a clinical point of view. A number of promising approaches are currently in clinical trials or in clinical development. We focus on small-molecule drugs but also discuss immunotherapies and tumor vaccines.
Project description:For gaining additional insights into the composition of the testicular proteome of the domestic pig (Sus scrofa domestica), we conducted 2DE-MS. Two-dimensional SDS PAGE was run on testicular lysates of three boars, with three gels per boar. Upon matching across gels, we arbitrarily selected protein spots for mass spectrometry analysis. Excised slices were vacuum dried and soaked with digestion buffer containing trypsin (0.01 μg/μl), followed by overnight incubation at 37°C in the same buffer without trypsin. Subsequently, peptides were extracted in solvents of increasing acetonitrile content, by sonication. Upon vacuum-centrifugation, peptides were reconstituted in 0.1% formic acid (FA). Following this, peptides were fractionated by reversed phase liquid chromatography (C18; buffer A: 0.1% FA dissolved in HPLC-H2O; buffer B: 0.1% FA, dissolved in CAN; flow-rate: 0.4 µL/min; gradient: 2-30% in 30 minutes). Eluted peptides were injected via an electrospray ionization interface into a Q-TOF mass spectrometer (one boar, Q TOF Ultima, Micromass/Waters, Manchester, UK) and an ion-trap mass spectrometer (two other boars, XCT ion-trap, Agilent Technologies, Waldbronn, Germany). We used ProteomeDiscoverer 2.4 (Thermo Fisher Scientific, San Jose, USA) for peptide and protein identification. Using Sequest HT, we searched peak lists (*.mgf) against the Sus scrofa reference proteome database (UniProt Proteome ID: UP000008227, 49,793 proteins).
Project description:Pseudomonas aeruginosa is the most common human opportunistic pathogen associated with nosocomial diseases. In 2017, the World Health Organization has classified P. aeruginosa as a critical agent threatening human health, and for which the development of new treatments is urgently necessary. One interesting avenue is to target virulence factors to understand P. aeruginosa pathogenicity. Thus, characterising exoproteins of P. aeruginosa is a hot research topic and proteomics is a powerful approach that provides important information to gain insights on bacterial virulence. The aim of this review is to focus on the contribution of proteomics to the studies of P. aeruginosa exoproteins, highlighting its relevance in the discovery of virulence factors, post-translational modifications on exoproteins and host-pathogen relationships.
Project description:Tumour-associated KRAS mutations are the most prevalent in the three RAS-family isoforms and involve many different amino-acids. Therefore, molecules able to interfere with mutant KRAS protein are potentially important for wide-ranging tumour therapy. We describe the engineering of two RAS degraders based on protein macromolecules (macrodrugs) fused to specific E3 ligases. A KRAS-specific DARPin fused to the VHL E3 ligase is compared to a pan-RAS intracellular single domain antibody (iDAb) fused to the UBOX domain of the CHIP E3 ligase. We demonstrate that while the KRAS-specific DARPin degrader induces specific proteolysis of both mutant and wild type KRAS, it only inhibits proliferation of cancer cells expressing mutant KRAS in vitro and in vivo. Pan-RAS protein degradation, however, affects proliferation irrespective of the RAS mutation. These data show that specific KRAS degradation is an important therapeutic strategy to affect tumours expressing any of the range of KRAS mutations.
Project description:One of the most common drivers in human cancer is the mutant KRAS protein. Not so long ago KRAS was considered as an undruggable oncoprotein. After a long struggle, however, we finally see some light at the end of the tunnel as promising KRAS targeted therapies are in or approaching clinical trials. In recent years, together with the promising progress in RAS drug discovery, our understanding of KRAS has increased tremendously. This progress has been accompanied with a resurgence of publicly available KRAS structures, which were limited to nine structures less than ten years ago. Furthermore, the ever-increasing computational capacity has made biologically relevant timescales accessible, enabling molecular dynamics (MD) simulations to study the dynamics of KRAS protein in more detail at the atomistic level. In this minireview, my aim is to provide the reader an overview of the publicly available KRAS structural data, insights to conformational dynamics revealed by experiments and what we have learned from MD simulations. Also, I will discuss limitations of the current data and provide suggestions for future research related to KRAS, which would fill out the existing gaps in our knowledge and provide guidance in deciphering this enigmatic oncoprotein.
Project description:Migraines constitute a common neurological and headache disorder affecting around 15% of the world's population. In addition to other mechanisms, neurogenic neuroinflammation has been proposed to play a part in migraine chronification, which includes peripheral and central sensitization. There is therefore considerable evidence suggesting that inflammation in the intracranial meninges could be a key element in addition to calcitonin gene-related peptide (CGRP), leading to sensitization of trigeminal meningeal nociceptors in migraines. There are several studies that have utilized this approach, with a strong focus on using inflammatory animal models. Data from these studies show that the inflammatory process involves sensitization of trigeminovascular afferent nerve terminals. Further, by applying a wide range of different pharmacological interventions, insight has been gained on the pathways involved. Importantly, we discuss how animal models should be used with care and that it is important to evaluate outcomes in the light of migraine pathology.
Project description:In Mitchell's chemiosmotic theory, membrane potential Δψ was given as the electric potential difference across the membrane. However, its physical origin for membrane potential Δψ was not well explained. Using the Lee proton electrostatic localization model with a newly formulated equation for protonic motive force (pmf) that takes electrostatically localized protons into account, membrane potential has now been better understood as the voltage difference contributed by the localized surface charge density ([HL+]+∑i=1n[MLi+]) at the liquid-membrane interface as in an electrostatically localized protons/cations-membrane-anions capacitor. That is, the origin of membrane potential Δψ is now better understood as the electrostatic formation of the localized surface charge density that is the sum of the electrostatically localized proton concentration [HL+] and the localized non-proton cations density ∑i=1n[MLi+] at the liquid membrane interface. The total localized surface charge density equals to the ideal localized proton population density [HL+]0 before the cation-proton exchange process; since the cation-proton exchange process does not change the total localized charges density, neither does it change to the membrane potential Δψ . The localized proton concentration [HL+] represents the dominant component, which accounts about 78% of the total localized surface charge density at the cation-proton exchange equilibrium state in animal mitochondria. Liquid water as a protonic conductor may play a significant role in the biological activities of membrane potential formation and utilization.
Project description:The Kirsten rat sarcoma (KRAS) oncogene was considered "undruggable" until the development of sotorasib, a KRASG12C selective inhibitor that shows favorable effects against lung cancers. MRTX1133, a novel KRASG12D inhibitor, has shown promising results in basic research, although its effects against pancreatic cancer are limited when used alone. Therefore, there is an urgent need to identify effective drugs that can be used in combination with KRAS inhibitors. In this study, we found that administration of the KRAS inhibitors sotorasib or MRTX1133 upregulated STAT3 phosphorylation and reactivated ERK through a feedback reaction. The addition of the MEK inhibitor trametinib and the JAK2 inhibitor fedratinib successfully reversed this effect and resulted in significant growth inhibition in vitro and in vivo. Analyses of sotorasib- and MRTX1133-resistant cells showed that trametinib plus fedratinib reversed the resistance to sotorasib or MRTX1133. These findings suggest that the JAK2-mediated pathway and reactivation of the MAPK pathway may play key roles in resistance to KRAS inhibitors in pancreatic cancers. Accordingly, simultaneous inhibition of KRAS, MEK, and JAK2 could be an innovative therapeutic strategy against KRAS-mutant pancreatic cancer.
Project description:The Kirsten rat sarcoma viral oncogene homolog (KRAS) is mutated in approximately 25% of all human cancers and is known to be a major player promoting and maintaining tumorigenesis through the RAS/MAPK pathway. Over the years, a large number of studies have identified strategies at different regulatory levels to tackle this 'difficult-to-target' oncoprotein. Yet, the most ideal strategy to overcome KRAS and its downstream effects has yet to be uncovered. This review summarizes the role of KRAS activating mutations in multiple cancer types as well as the key findings for potential strategies inhibiting its oncogenic behavior. A comprehensive analysis of the different pathways and mechanisms associated with KRAS activity in tumors will ultimately pave the way for promising future work that will identify optimum therapeutic strategies.