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Biology subjects

Ang, C.

Publications and source records attributed to Ang, C..

6 recordsLinked to original sources

Menin regulates oncogenic cell identity transcriptional networks in multiple myeloma

Multiple myeloma (MM) is a heterogenous cancer that remains mostly incurable. A unifying feature of MM cells is a highly interconnected network of transcription factors and co-factors that coordinate the activity of super-enhancers to enforce myeloma cell identity. Targeting this network offers a promising avenue for therapeutic intervention across genetically diverse myeloma sub-types. Using integrated molecular and functional genomic approaches we identified Menin as a key driver of oncogenic gene expression in MM cells. Menin and its co-factor KMT2A bind at super-enhancers and maintain expression of essential myeloma genes, including IRF4. We demonstrate that Menin inhibitors, which have recently been approved for treatment of acute myeloid leukaemia, are highly active in myeloma cell lines and in vivo models. Combining Menin inhibitors with other super-enhancer targeting therapies such EP300/CREBBP inhibitors or immunomodulatory drugs (IMiDs) overcomes epigenetic plasticity in cells resistant to single agent treatment.

Cancer Biology↗

Dynamic, single-cell monitoring of CAR T cell identity and activation with Raman spectroscopy

Chimeric antigen receptor (CAR) T cell therapies have reshaped treatment for cancers and immune-mediated diseases, yet their safety and efficacy depend on both the proliferation of engineered cells and their dynamic functional state -- features that remain challenging to monitor in real-time clinical settings. Current methods require targeted labels, extensive processing, and provide only static snapshots of cell identity and activation. Here, we introduce a surface-enhanced Raman spectroscopy (SERS) and machine learning (ML) approach that enables single-cell identification of engineered CAR T cells without molecularly-targeted labels and time-resolved, semi-continuous monitoring of their functional activation state through a single physical readout spanning donor-derived cells and patient blood. From intrinsic vibrational signatures of live cells, we detect spectral differences resulting from engineered receptor expression in donor-derived CD19- and GD2-targeted CAR T cells (nine and five donors, respectively) with 81-85% donor-level accuracy, and resolve dynamic antigen-specific activation trajectories with temporal precision. Applying this same SERS-ML method to longitudinal samples from a four-patient CD19-CAR T therapy cohort, we classify patient peripheral blood mononuclear cells across pre-and post-infusion timepoints with a mean patient-level accuracy of 84%, and show that isolated CAR-positive T cells are distinguishable from both CAR-negative T cells and background populations with average 86-88% accuracies. These capabilities stem from biochemical signatures consistent with processes such as receptor expression, tonic signalling, and immune synapse formation, demonstrating a single method that reports both cellular identity and activation state with biochemical specificity across cell engineering and clinical monitoring contexts. Our results extend CAR T cell monitoring beyond static phenotyping and support the potential of SERS-ML analysis for rapid, point-of-care assessment of engineered immune cells across the therapeutic lifecycle.

bioengineering↗

Bacteroidetes promote hepatocellular carcinoma progression and resistance to immunotherapy

Background and AimsGrowing evidence highlight the critical role of the gut microbiome in tumorigenesis and response to immunotherapies. However, the impact of gut microbes on hepatocellular carcinoma (HCC) progression and response to immune-checkpoint blockade (ICB) remains unclear due to the lack of combined preclinical and clinical studies. Approach & ResultsWe performed 16S rRNA of cross-cohort stool samples from 10 HCC responders (R) and 40 non-responders (NR) to ICB at baseline and on-treatment time-points. We identified an enrichment of Bacteroidetes in NR. To study the role of the microbiome in the cancer immune response, we generated an immunogenic mouse model of HCC via hydrodynamic tail-vein injection (HDTVI) of DNA plasmids mimicking common HCC alterations and immunogenicity by expressing model antigens (MYC-lucOS;CTNNB1 tumors). We found that antibiotic (ABX)-induced dysbiosis promoted a pro-tumorigenic effect in the MYC-lucOS;CTNNB1 HCC model by the expansion of a specific Bacteroidetes, Parabacteroides distasonis. Colonization of mice carrying MYC-lucOS;CTNNB1 HCCs with Parabacteroides distasonis confirmed its pro-tumorigenic effect in vivo. Furthermore, we explored the effects of colonizing with microbiotas from patients and showed that microbiota from a NR donor enriched in Bacteroidetes promoted faster tumorigenesis than microbiota from a R donor with reduced Bacteroidetes. We isolated 6 Bacteroidetes species from the NR donor, cultured them, and used them as a cocktail to colonize mice; similarly, mice transplanted with this cocktail showed increased tumorigenesis and reduced survival. ConclusionsThis study identified Bacteroidetes enrichment as a potential biomarker of ICB resistance in HCC and, by using immunogenic mouse models, established that Bacteroidetes abundance influences tumor development.

cancer biology↗

HIV Virion Capturing Liposomes for Therapeutic Vaccination

HIV infection currently has no effective cures and requires lifelong antiretroviral treatments. Cures have failed due to HIVs immune evasion and rapid mutation rate. Here we present a first in class HIV therapeutic vaccine, termed nanotrap therapeutic vaccines (NTVs) that are designed to capture circulating HIV virions and facilitate internalization by local antigen presenting cells. NTVs are modified liposomes that display the CD4 mimetic molecule, CJF-III-288, on their surfaces and have the TLR 7/8 agonist R848 loaded into their core. We show that NTVs can 1) bind gp120 and capture pseudoviral particles, 2) facilitate uptake by antigen presenting cells and 3) generate robust anti-HIV CD8 T cell immunity in transient infection mouse models. NTVs have translational potential to generate patient-specific HIV immunity.

bioengineering↗

Dietary fibre controls blood pressure and cardiovascular risk by lowering large intestinal pH and activating the proton-sensing receptor GPR65

High blood pressure (BP) is the most common cause of death globally, due to increasing the risk of cardiovascular diseases. Dietary fiber regulates BP through gut microbial production of acidic metabolites known as short-chain fatty acids (SCFAs). The specific mechanisms of how SCFAs regulate BP are still emerging. In a phenome-wide association study, we identified that the proton-sensing G-protein-coupled receptor GPR65 gene is associated with hypertension and its associated end-organ damage phenotypes. We hypothesized that acidic metabolites produced from the gut microbiota may activate GPR65, thus conferring BP regulating effects. We found that dietary fiber levels determined the luminal and interstitial tissue pH in the large intestine through production of SCFAs by the gut microbiota. We identified that low pH produced by high fiber intake, acting via GPR65 signaling, increased cAMP production and phosphorylation of CREB, and restricted the production of hypertension-promoting inflammatory cytokines by CD8+ T cells. Gpr65-/- mice spontaneously developed higher BP, cardiac and renal hypertrophy and fibrosis. We showed that the benefits of a diet high in fiber, which prevented hypertension and associated end-organ damage, were decreased in Gpr65-/- mice. Finally, adoptive transfers revealed that GPR65 deficiency in CD8+ T cells causally explained this phenotype. In conclusion, we showed that pH sensing by GPR65 in CD8+ T cells mediates much of the cardiovascular benefits of dietary fiber. pH sensing represents a novel gene-by-environment interaction of gut microbiota-to-host biological effects and may form the basis for new therapeutic strategies for hypertension.

molecular biology↗

High throughput droplet single-cell Genotyping of Transcriptomes (GoT) reveals the cell identity dependency of the impact of somatic mutations

Defining the transcriptomic identity of clonally related malignant cells is challenging in the absence of cell surface markers that distinguish cancer clones from one another or from admixed non-neoplastic cells. While single-cell methods have been devised to capture both the transcriptome and genotype, these methods are not compatible with droplet-based single-cell transcriptomics, limiting their throughput. To overcome this limitation, we present single-cell Genotyping of Transcriptomes (GoT), which integrates cDNA genotyping with high-throughput droplet-based single-cell RNA-seq. We further demonstrate that multiplexed GoT can interrogate multiple genotypes for distinguishing subclonal transcriptomic identity. We apply GoT to 26,039 CD34+ cells across six patients with myeloid neoplasms, in which the complex process of hematopoiesis is corrupted by CALR-mutated stem and progenitor cells. We define high-resolution maps of malignant versus normal hematopoietic progenitors, and show that while mutant cells are comingled with wildtype cells throughout the hematopoietic progenitor landscape, their frequency increases with differentiation. We identify the unfolded protein response as a predominant outcome of CALR mutations, with significant cell identity dependency. Furthermore, we identify that CALR mutations lead to NF-{kappa}B pathway upregulation specifically in uncommitted early stem cells. Collectively, GoT provides high-throughput linkage of single-cell genotypes with transcriptomes and reveals that the transcriptional output of somatic mutations is heavily dependent on the native cell identity.

cancer biology↗