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Biology subjects

Moens, T.

Publications and source records attributed to Moens, T..

3 recordsLinked to original sources

Functional Exploration of African Colorectal Cancer Patients Using Personalised Drosophila Avatars

Colorectal cancer across sub-Saharan Africa presents a growing global health burden, with increasing cases and mortality linked to late diagnosis, limited healthcare access and lack of effective treatments. African patients typically present with aggressive disease marked by distinct genomic signatures, indicating the need for targeted treatment approaches. We integrated genetic modelling, phenotypic scoring, imaging and biochemical analysis to explore how mutations found in individual Nigerian colorectal cancer patients influence drug responsiveness. We used the data from Cancer Genome Atlas to identify mutation profiles specific to Nigerian patients. We then generated ten stable Drosophila melanogaster personalised patient avatar lines designed to model patient genomic profiles. This study focused on three lines; each line included oncogenic RAS plus targeting patient-specific variants. These models exhibited various phenotypes including altered larval size, gut size and reduced survival. Two of the three avatar lines showed improved survival, reduced hindgut proliferation zone expansion and restored redox balance after treatment with regorafenib and trametinib. Mirroring clinical patient responses, we found that response to therapy is dependent on the specific genetic profile of the tumour. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=111 SRC="FIGDIR/small/714433v1_ufig1.gif" ALT="Figure 1"> View larger version (31K): org.highwire.dtl.DTLVardef@db03forg.highwire.dtl.DTLVardef@ae2750org.highwire.dtl.DTLVardef@196f89dorg.highwire.dtl.DTLVardef@9c1577_HPS_FORMAT_FIGEXP M_FIG C_FIG O_LIAfrican colorectal cancer showed distinct mutation patterns that contribute to tumour heterogeneity. C_LIO_LIPatient-derived Drosophila avatars were engineered using tumour-specific genetic mutations with key features of human colorectal cancer. C_LIO_LITreatment with targeted therapies showed responses patterned by tumour genotype. C_LIO_LIResponse patterns indicated the need for personalised for colorectal cancer therapies among diverse populations. C_LI

cancer biology↗

PP2A and GSK3 act as modifiers of FUS-ALS by modulating mitochondrial transport

ALS is a fatal neurodegenerative disease which currently lacks effective treatments. Mutations in the RNA-binding protein FUS are a common cause of familial ALS, accounting for around 4% of fALS cases. Studying the mechanisms by which mutant FUS is toxic to neurons may provide insight into the pathogenesis of both familial and sporadic forms of ALS. Here we identify Protein Phosphatase 2A (PP2A) and Glycogen Synthase Kinase 3 (GSK3) as novel modifiers of FUS-ALS in vivo, looking from fly to human. PP2A-C and GSK3{beta} inhibition rescued FUS-induced toxicity in Drosophila and disease-relevant phenotypes in human iPSC-derived spinal motor neurons (sMNs). In both Drosophila and human iPSC-sMNs, we observed reduced GSK3{beta} inhibitory phosphorylation, suggesting that FUS dysfunction results in GSK3{beta} hyperactivity. We found that PP2A acts upstream of GSK3, affecting its inhibitory phosphorylation, and in synergy they modulate mitochondrial transport through the motor protein kinesin. Our data provide in vivo evidence that PP2A and GSK3 are disease modifiers, and reveal an unexplored mechanistic link between PP2A, GSK3 and kinesin in FUS-associated ALS.

neuroscience↗

Spatio-temporal Proteomic Analysis of Stress Granule disassembly using APEX Reveals Regulation by SUMOylation and links to ALS pathogenesis

Cytoplasmic stress granules (SG) form in response to a variety of cellular stresses by phase-separation of proteins associated with non-translating mRNAs. SG provide insight into the biology of neurodegeneration, including amyotrophic lateral sclerosis (ALS) because they approximate some of the molecular conditions for nucleation of insoluble aggregates in neuropathological inclusions. Whereas much has been learned about SG formation, a major gap remains in understanding the compositional changes SG undergo during normal disassembly and under disease conditions. Here, we address this gap by proteomic dissection of SG temporal disassembly sequence, using multi-bait APEX proximity-proteomics. We discover 109 novel SG-proteins and characterize at proteomic resolution two biophysically distinct SG substructures. We further demonstrate that dozens of additional proteins are recruited to SG specifically during disassembly, indicating that it is a highly regulated process. The involved proteins link SG disassembly, to mitochondrial biology and the cytoskeleton. Parallel analysis with C9ORF72-associated dipeptides, which are found in patients with ALS and frontotemporal dementia, demonstrated compositional changes in SG during the course of disassembly and focused our attention on the roles SUMOylation in SG disassembly. We demonstrate that broad SUMOylation of SG-proteins is required for SG disassembly and is impaired by C9ORF72-associated dipeptides, representing an unexplored potential molecular mechanism of neurodegeneration. Altogether, out study fundamentally increases the knowledge about SG composition in human cells by dissecting the SG spatio-temporal proteomic landscape, provides an in-depth resource for future work on SG function and reveals basic and disease-relevant mechanisms of SG disassembly. HighlightsO_LIMulti bait APEX proximity labelling reveals 109 novel SG proteins and two distinct SG substructures. C_LIO_LIProteomic dissection of SG temporal disassembly under basal conditions and with a model of neurodegeneration. C_LIO_LIDisassembly-engaged proteins (DEPs) include SUMO ligases that are recruited during normal disassembly and dysregulated in ALS-like conditions. C_LIO_LIPervasive SG protein SUMOylation during SG disassembly is impaired by ALS-like conditions. C_LI O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=168 SRC="FIGDIR/small/830133v1_ufig1.gif" ALT="Figure 1"> View larger version (45K): org.highwire.dtl.DTLVardef@15899daorg.highwire.dtl.DTLVardef@1dcd399org.highwire.dtl.DTLVardef@c7ef12org.highwire.dtl.DTLVardef@20c096_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗