2,074 pubs · 152,838 cites · h-index 187
Opinion article discusses membrane origins and mergers in exosome generation, highlighting diverse functions and implications for targeting exosomes in diseases.
Integrative multi-omic analysis identifies genetic alterations in uterine fibroids associated with abnormal uterine bleeding, suggesting new therapeutic avenues.
Experimental evaluation reduced population of Drosophila suzukii in raspberry, suggesting SIT as an effective strategy in pest management.
Most breast cancers express the estrogen receptor (ER), but the immune response of hormone receptor-positive (HR + ) breast cancer remains poorly characterized. Here, dendritic cells loaded with tumor lysate are used to identify tumor-reactive CD8 T cells, which are detected in most HR + breast cancer patients, especially those with early-stage tumors. When present, the circulating antitumor CD8 response contains cytotoxic T cells with diverse specificity and T cell receptor (TCR) repertoire. Additionally, patients with blood cancer-specific T cells have significantly more CD8 tumor-infiltrating lymphocytes (TILs). Moreover, tumor-reactive TCR sequences are detected in the tumor, but at a significantly lower proportion in patients with lymph node involvement. Our data suggest that HR + breast cancer patients with lymph node metastasis lack tumor-specific CD8 T cells with capacity to infiltrate the tumor at significant levels. However, early-stage patients have a diverse antitumor CD8 response that could be harnessed to develop immunotherapeutic approaches for late-stage HR + patients.
Secretory proteins aggregate into non-soluble dense-core granules in recycling endosome-like compartments prior to regulated release. By contrast, aberrantly processed, secreted amyloid-β (Aβ) peptides derived from amyloid precursor protein (APP) form pathological extracellular amyloidogenic aggregations in late-stage Alzheimer's disease (AD). By examining living Drosophila prostate-like secondary cells, we show that both APP and Aβ peptides affect normal biogenesis of dense-core granules. These cells generate dense-core granules and secreted nanovesicles called Rab11-exosomes via evolutionarily conserved mechanisms within highly enlarged secretory compartments with recycling endosomal identity. The fly APP homologue, APP-like (APPL), associates with these vesicles and the compartmental limiting membrane, from where its extracellular domain modulates protein aggregation. Proteolytic release of this domain permits mini-aggregates to coalesce into a large central dense-core granule. Mutant Aβ expression disrupts this process and compartment motility, and increases aberrant lysosomal targeting, mirroring previously unexplained early-stage pathological events in AD. It also promotes cell-to-cell propagation of these endolysosomal defects, again phenocopying changes observed in AD. Our data therefore demonstrate physiological roles for APP in membrane-dependent protein aggregation, involving molecular mechanisms, which when disrupted by Aβ peptides, trigger Alzheimer's disease-relevant pathologies.
The cellular response to hypoxia is driven by hypoxia-inducible factors (HIFs), which regulate genes involved in glycolysis, angiogenesis, and cell proliferation, as well as inflammation and tumor progression. HIF activation is well-characterized and is primarily regulated by oxygen-dependent prolyl hydroxylation and subsequent degradation. SET1B, a histone H3 lysine 4 (H3K4) methyltransferase, has recently emerged as a key modulator of HIF target gene transcription, but evidence suggests that it plays a broader role in modulating HIF transcriptional activity beyond histone methylation. Here, we revealed that SET1B interacts with RNA polymerase II to coordinate sustained HIF-mediated transcriptional activity through multiple functional domains. In clear cell renal cell carcinoma (ccRCC), SET1B was critical for sustained HIF activity, and SET1B expression correlated with disease progression and metastasis in patient samples. Moreover, SET1B depletion enhanced the efficacy of HIF-2 inhibitors. These findings establish SET1B as a driver of tumor progression and potential therapeutic target in ccRCC.
We prepared cellulose-composited ionic-covalent entanglement (ICE) network gelatin methacrylate/alginate (G/A) hydrogels using microfibrillated cellulose (MFC) and nanofibrillated cellulose (NFC), of which the mechanical properties were evaluated at two different length scales. Macro-compression shows that cellulose improves the toughness, compression resistance, and Young's moduli of ICE hydrogels, attributed to the synergistic interaction between the cellulose fiber network and ICE due to hydrogen bonding. Pure MFC (363.43 kPa) or NFC (325.75 kPa) alone, compared to a blend of the two with varied contents (261.5-288.5 kPa), displays a more pronounced improvement in the Young's moduli of ICE hydrogels, because homogeneous fiber networks enhance the structural integrity of the system. Micro-indentation reveals that hydrogen bonds between cellulose and ICE weaken the time-dependent deformation of cellulose-composited ICE hydrogel. Mapping of Young's modulus and hardness distribution of the hydrogel suggests that there are three forms of enhancement within cellulose-composited ICE hydrogel: cellulose fiber networks, ICE synergistic network, and synergies between cellulose fiber network and ICE. Creep results highlight that the excellent confinement effect of MFC contributes to creep resistance of cellulose-composited ICE hydrogels. In conclusion, the multiscale characterization unravels the mechanical reinforcing mechanisms of cellulose fibres in ICE hydrogels, which demonstrates the possible strategies for improving the mechanical properties of hydrogels.
Tumor hypoxia drives metabolic shifts, cancer progression, and therapeutic resistance. Challenges in quantifying hypoxia have hindered the exploitation of this potential "Achilles' heel." While gene expression signatures have shown promise as surrogate measures of hypoxia, signature usage is heterogeneous and debated. Here, we present a systematic pan-cancer evaluation of 70 hypoxia signatures and 14 summary scores in 104 cell lines and 5,407 tumor samples using 472 million length-matched random gene signatures. Signature and score choice strongly influenced the prediction of hypoxia in vitro and in vivo. In cell lines, the Tardon signature was highly accurate in both bulk and single-cell data (94% accuracy, interquartile mean). In tumors, the Buffa and Ragnum signatures demonstrated superior performance, with Buffa/mean and Ragnum/interquartile mean emerging as the most promising for prospective clinical trials. This work delivers recommendations for experimental hypoxia detection and patient stratification for hypoxia-targeting therapies, alongside a generalizable framework for signature evaluation.
Immune checkpoint inhibitors have an established role in non-small cell lung cancer (NSCLC) therapy. The loss of HLA-class-I expression allows cancer cell evasion from immune surveillance, disease progression, and failure of immunotherapy. The restoration of HLA-class-I expression may prove to be a game-changer in current immunotherapy strategies. Autophagic activity has been recently postulated to repress HLA-class-I expression in cancer cells.
Supplementary Figures S1-S11
Abstract GTP cyclohydrolase (GCH1) is the rate-limiting enzyme for tetrahydrobiopterin (BH4) biosynthesis. The catalysis of BH4 biosynthesis is tightly regulated for physiological neurotransmission, inflammation, and vascular tone. Paradoxically, BH4 has emerged as an oncometabolite regulating tumor growth, but the effects on tumor development remain controversial. Here we found that GCH1 potentiates the growth of triple-negative breast cancer (TNBC) and HER2+ breast cancer and transforms non-tumor breast epithelial cells. Independent of BH4 production, GCH1 protein induced epithelial-to-mesenchymal transition IEMT) by binding to Vim, which was mediated by HSP90. Conversely, GCH1 ablation impaired tumor growth, suppressed Vim in TNBC, and inhibited EGFR/ERK signaling while activating the p53 pathway in estrogen receptor-positive tumor cells. GCH1 deficiency increases tumor cell sensitivity to HSP90 inhibition and endocrine treatments. Additionally, high GCH1 corelated with poor breast cancer survival. Together, this study reveals an enzyme-independent oncogenic role of GCH1, presenting it as a potential target for therapeutic development.
Supplementary Figures S1-S11
Current prognostic biomarkers fall short in stratifying Oestrogen receptor (ER)-negative breast cancer patients regarding tumour progression risk at diagnosis. The role of AIPL1 in activating its tumour suppressor client protein, NEDD8 Ultimate Buster-1 (NUB1) remains unknown in cancer. Our study demonstrated how downregulated AIPL1 results in the deactivated NUB1 protein under hypoxic conditions. We examined the AIPL1-NUB1 pathwayin vitro using cell lines i.e. MCF-7, MDA-MB-231, RCC4 etc. NUB1 expression was assessed using Oncomine, and cBioPortal was performed to assess NUB1's prognostic significance in human cancers. In the John Radcliffe Hospital cohort (n = 122), immunohistochemistry analysis revealed downregulated AIPL1 (Log2 fold change=-0.28; p < 0.001) and upregulated NUB1 transcripts (Log2 fold change=0.59; p < 0.001) compared to adjacent normal tissues. In severe chronic hypoxia, multimerised AIPL1 localisedin the cytoplasm while NUB1 protein migrated to the nucleus, where the absence of NUB1 nuclear localisation led to cell cycle arrest. Biopsies showed that patients with lower cytoplasmic NUB1 expression (n = 57) had poorer overall survival compared to those with higher cytoplasmic expression (n = 57), HR=1.78; 95 % CI=1.01-3.35, p = 0.048. Low NUB1 protein levels in both normoxic and hypoxic conditions were associated with cell cycle arrest and upregulation ofp21 and p27 in breast cancer cell lines, correlating significantly withpoorer survival outcomes in all breast cancer and ER-negative breast cancer patients.
Exosomes are secreted vesicles made intracellularly in the endosomal system. We have previously shown that exosomes are not only made in late endosomes, but also in recycling endosomes marked by the monomeric G‐protein Rab11a. These vesicles, termed Rab11a‐exosomes, are preferentially secreted under nutrient stress from several cancer cell types, including HCT116 colorectal cancer (CRC) cells. HCT116 Rab11a‐exosomes have particularly potent signalling activities, some mediated by the epidermal growth factor receptor (EGFR) ligand, amphiregulin (AREG). Mutant activating forms of KRAS, a downstream target of EGFR, are often found in advanced CRC. When absent, monoclonal antibodies, such as cetuximab, which target the EGFR and block the effects of EGFR ligands, such as AREG, can be administered. Patients, however, inevitably develop resistance to cetuximab, either by acquiring KRAS mutations or via non‐genetic microenvironmental changes. Here we show that nutrient stress in several CRC cell lines causes the release of AREG‐carrying Rab11a‐exosomes. We demonstrate that while soluble AREG has no effect, much lower levels of AREG bound to Rab11a‐exosomes from cetuximab‐resistant KRAS‐mutant HCT116 cells, can suppress the effects of cetuximab on KRAS‐wild type Caco‐2 CRC cells. Using neutralising anti‐AREG antibodies and an intracellular EGFR kinase inhibitor, we show that this effect is mediated via AREG activation of EGFR, and not transfer of activated KRAS. Therefore, presentation of AREG on Rab11a‐exosomes affects its ability to compete with cetuximab. We propose that this Rab11a‐exosome‐mediated mechanism contributes to the establishment of resistance in cetuximab‐sensitive cells and may explain why in cetuximab‐resistant tumours only some cells carry mutant KRAS.
Summary Secretory proteins frequently aggregate into non-soluble dense-core granules (DCGs) in recycling endosome-like compartments prior to release. By contrast, aberrantly processed Aβ-peptides derived from Amyloid Precursor Protein (APP) form pathological amyloidogenic aggregations in late-stage Alzheimer’s Disease (AD) after secretion. By examining living Drosophila prostate-like secondary cells, we show both APP and Aβ-peptides affect normal DCG biogenesis. These cells generate DCGs and secreted nanovesicles called Rab11-exosomes within enlarged recycling endosomes. The fly APP homologue, APP-like (APPL), associates with Rab11-exosomes and the compartmental limiting membrane, from where its extracellular domain controls protein aggregation. Proteolytic release of this membrane-associated domain permits aggregates to coalesce into a large central DCG. Mutant Aβ-peptide expression, like Appl loss-of-function, disrupts this assembly step and compartment motility, and increases lysosomal targeting, mirroring pathological events reported in early-stage AD. Our data therefore reveal a physiological role for APP in membrane-dependent protein aggregation, which when disrupted, rapidly triggers AD-relevant intracellular pathologies.
Cancer risk is associated with the widely debated measure body mass index (BMI). Fat mass and fat-free mass measurements from bioelectrical impedance may further clarify this association. The UK Biobank is a rare resource in which bioelectrical impedance and BMI data was collected on ~ 500,000 individuals. Using this dataset, a comprehensive analysis using regression, principal component and genome-wide genetic association, provided multiple levels of evidence that increasing whole body fat (WBFM) and fat-free mass (WBFFM) are both associated with increased post-menopausal breast cancer risk, and colorectal cancer risk in men. WBFM was inversely associated with prostate cancer. We also identified rs615029[T] and rs1485995[G] as associated in independent analyses with both PMBC (p = 1.56E–17 and 1.78E–11) and WBFFM (p = 2.88E–08 and 8.24E–12), highlighting splice variants of the intriguing long non-coding RNA CUPID1 (LINC01488) as a potential link between PMBC risk and fat-free mass.
Deregulated metabolism is one of the hallmarks of cancer. It is well-known that tumour cells tend to metabolize glucose via glycolysis even when oxygen is available and mitochondrial respiration is functional. However, the lower energy efficiency of aerobic glycolysis with respect to mitochondrial respiration makes this behaviour, namely the Warburg effect, counter-intuitive, although it has now been recognized as source of anabolic precursors. On the other hand, there is evidence that oxygenated tumour cells could be fuelled by exogenous lactate produced from glycolysis. We employed a multi-scale approach that integrates multi-agent modelling, diffusion-reaction, stoichiometric equations, and Boolean networks to study metabolic cooperation between hypoxic and oxygenated cells exposed to varying oxygen, nutrient, and inhibitor concentrations. The results show that the cooperation reduces the depletion of environmental glucose, resulting in an overall advantage of using aerobic glycolysis. In addition, the oxygen level was found to be decreased by symbiosis, promoting a further shift towards anaerobic glycolysis. However, the oxygenated and hypoxic populations may gradually reach quasi-equilibrium. A sensitivity analysis using Latin hypercube sampling and partial rank correlation shows that the symbiotic dynamics depends on properties of the specific cell such as the minimum glucose level needed for glycolysis. Our results suggest that strategies that block glucose transporters may be more effective to reduce tumour growth than those blocking lactate intake transporters.
Introduction Extracellular vesicles (EVs) are nanoized vesicles, which deliver bioactive cargoes to target cells. Our lab has shown that metabolic stress leads to changes in the trafficking and also the cargo and functions of EVs secreted from colorectal cancer (CRC) cells: a so-called “EV switch”. Proteomic analysis revealed that switched EVs carry increased levels of the EGFR-ligand Amphiregulin (AREG). The aim of this work was to investigate the pro-tumorigenic properties of switched EVs in vitro and in vivo. Methods Size exclusion chromatography was used to isolate EVs from HCT116 and Caco-2 CRC cells grown under glutamine-replete and -depleted conditions, and their effect on recipient cell growth measured using the IncuCyte Live Cell Imager. Co-incubation assays with an AREG-neutralising antibody were undertaken to test the role of switched EVs. The in vivo role of switched EVs were investigated using a novel chick embryo model. In addition, we tested whether the growth inhibitory effects of cetuximab could be reversed by co-treatment with switched EVs. Results Switched EVs from HCT116 and Caco-2 cells contain increased levels of AREG and promote EGFR-ERK dependent growth in recipient cells in vitro and in vivo. These effects were inhibited by co-treatment with an AREG neutralising antibody. Caco-2 (KRAS-wild type), but not HCT116 (KRAS-mutant), cell growth was inhibited by cetuximab, which was partially reversed by co-treatment with switched EVs. AREG neutralisation reversed this EV-induced cetuximab rescue. Conclusion Switched EVs mediate CRC cell growth and cetuximab resistance, and could serve as novel biomarkers to predict treatment response.
Background PDE6H encodes PDE6γ′, the inhibitory subunit of the cGMP-specific phosphodiesterase 6 in cone photoreceptors. Inhibition of PDE6, which has been widely studied for its role in light transduction, increases cGMP levels. The purpose of this study is to characterise the role of PDE6H in cancer cell growth. Methods From an siRNA screen for 487 genes involved in metabolism, PDE6H was identified as a controller of cell cycle progression in HCT116 cells. Role of PDE6H in cancer cell growth and metabolism was studied through the effects of its depletion on levels of cell cycle controllers, mTOR effectors, metabolite levels, and metabolic energy assays. Effect of PDE6H deletion on tumour growth was also studied in a xenograft model. Results PDE6H knockout resulted in an increase of intracellular cGMP levels, as well as changes to the levels of nucleotides and key energy metabolism intermediates. PDE6H knockdown induced G1 cell cycle arrest and cell death and reduced mTORC1 signalling in cancer cell lines. Both knockdown and knockout of PDE6H resulted in the suppression of mitochondrial function. HCT116 xenografts revealed that PDE6H deletion, as well as treatment with the PDE5/6 inhibitor sildenafil, slowed down tumour growth and improved survival, while sildenafil treatment did not have an additive effect on slowing the growth of PDE6γ′-deficient tumours. Conclusions Our results indicate that the changes in cGMP and purine pools, as well as mitochondrial function which is observed upon PDE6γ′ depletion, are independent of the PKG pathway. We show that in HCT116, PDE6H deletion replicates many effects of the dark retina response and identify PDE6H as a new target in preventing cancer cell proliferation and tumour growth.
Uterine fibroids (UFs), benign tumours prevalent in up to 80% of women of reproductive age, are associated with significant morbidity, including abnormal uterine bleeding, pain and infertility. Despite identification of key genomic alterations in MED12 and HMGA2, the pathogenic mechanisms underlying UFs and heavy menstrual bleeding (HMB) remain poorly understood. To correlate systematically genetic, transcriptional and proteomic phenotypes, our study involved an integrative analysis of fibroid, myometrium and endometrium tissues from 137 patients, utilising genome-wide SNP arrays, targeted sequencing, RNA sequencing and proteomics. Our findings reveal 39.7% of UFs possess MED12 mutations, alongside novel variants in genes such as COL4A5 and COL4A6. Multi-omics factor analysis of integrated protein and mRNA highlighted differential regulation related to extracellular matrix remodelling, proteolysis and homeostasis in fibroid versus myometrium tissues, and distinct gene sets associated with RNA splicing in the endometrium of patients with HMB, particularly in MED12-mutated fibroids. Our study proposes a model, which is supported by in vivo evidence, where altered signalling of MED12-mutated fibroids influences RNA transcript isoform expression in endometrium, potentially leading to abnormal uterine bleeding. This integrative approach unravels complex molecular pathways in UF pathogenesis and HMB, offering novel insights for targeted therapeutic development.