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Stirzaker, C.

Publications and source records attributed to Stirzaker, C..

8 recordsLinked to original sources

Pulsed priming with the FAK inhibitor narmafotinib enhances both gemcitabine/Abraxane and FOLFIRINOX chemotherapy response in pancreatic cancer

BackgroundPancreatic ductal adenocarcinoma (PDAC) is a particularly lethal malignancy with few treatment options available. Extensive remodelling of extracellular matrix (ECM) generates a highly fibrotic tumour landscape, which impairs therapeutic response. ObjectiveWe investigated whether stromal priming via the highly specific Focal Adhesion Kinase (FAK) inhibitor narmafotinib (AMP945) in combination with the two major standard-of-care chemotherapies in PDAC, gemcitabine/Abraxane and FOLFIRINOX, reduces fibrosis and enhances treatment efficacy. Design3D organotypic matrices, intravital imaging, and in vivo subcutaneous and orthotopic PDAC models were used to provide a rationale for a first-line priming regimen of narmafotinib prior to chemotherapy. ResultsNeoadjuvant chemotherapy induces fibrosis in PDAC indicating a need for upfront first-line priming of the ECM to normalise the stroma for optimal treatment response. Narmafotinib is a new potent small molecule FAK inhibitor. Phase I safety data shows excellent safety, tolerability, and pharmacokinetics following oral administration in humans. We reveal that narmafotinib treatment during early ECM remodelling ( priming) reduces fibrosis, while limiting subsequent PDAC invasion. Moreover, intravital imaging demonstrates real-time FAK inactivation and cell cycle stalling, leading to improved chemotherapeutic efficacy upon narmafotinib priming in vivo. Long-term assessment in patient-derived models shows that narmafotinib priming prior to gemcitabine/Abraxane or FOLFIRINOX reduces PDAC progression and extends survival in both chemotherapy settings. ConclusionsOur results using these Phase II-ready drug combinations strongly support the clinical assessment of narmafotinib in PDAC. Narmafotinib is currently in Phase Ib/IIa trials, assessing a pulsed dosing regimen prior to gemcitabine/Abraxane, and warrants further clinical assessment in combination with FOLFIRINOX. SIGNIFICANCE OF THIS STUDYO_ST_ABSWhat is already known on this topicC_ST_ABSO_LIPancreatic cancer (PC) is one of the most lethal malignancies and is characterised by a dense, fibrotic stroma, which impairs chemotherapy efficacy. C_LIO_LIThe non-receptor tyrosine kinase FAK is known to promote cancer fibrosis and therefore represents a therapeutic target to normalise the PC stroma and to improve chemotherapy performance. C_LI What this study addsO_LINeoadjuvant chemotherapy induces early fibrosis indicating a need for upfront first-line priming of the ECM to blunt or normalise stromal fibrosis for optimal response to therapy. C_LIO_LIThe small molecule inhibitor narmafotinib (which is currently under Phase Ib/IIa clinical trial assessment) shows high specificity towards FAK as well as desirable pharmacokinetics and pharmacodynamics in healthy human volunteers. C_LIO_LIEarly short-term narmafotinib priming reduces fibrosis and improves the efficacy of subsequent standard-of-care gemcitabine/Abraxane chemotherapy. C_LIO_LIFOLFIRINOX (oxaliplatin, irinotecan, leucovorin and 5-fluorouracil) is a multi-agent chemotherapy preferentially used in PDAC patients with good performance status. Our results demonstrate that narmafotinib priming also improves FOLFIRINOX efficacy, leading to extended survival in patient-derived PDAC models. C_LI How this study might affect research, practice, or policyO_LIThis study supports the clinical development of narmafotinib in combination with both gemcitabine/Abraxane (ACCENT trial) and further FOLFIRINOX standard-of-care chemotherapies for PDAC patient treatment. C_LIO_LIThe first-line priming strategy and early ECM normalisation used in this study may also be applicable to other combination therapy settings and warrants further investigation in ongoing clinical studies. C_LI

cancer biology↗

Targeting DNA Methylation Reactivates Type I Interferon Signalling in Bone-Metastatic Breast Cancer

Bone metastasis remains a major clinical challenge in advanced breast cancer. Downregulation of type I interferon signalling, a critical immunomodulatory pathway in anti-cancer immunity and disease progression, is a defining feature of this process. Here, we utilised an IFN-reporter system to perform unbiased epigenetic compound screens to identify agents that could restore type I IFN signalling. This screen identified Decitabine, a DNA hypomethylating agent, that enhanced tumor immunogenicity across a broad range of mouse and human breast cancer cell lines, including bone-derived lines. Mechanistically, suppression of interferon-stimulated genes is highly correlated with elevated DNMT1 expression in bone metastasis compared with primary tumor, in both mouse models and matched human samples. Decitabine treatment was sufficient to reactivate interferon stimulated genes in bone-derived 4T1.2 cell lines via hypomethylation of type I interferon pathway gene promoter regions. Correspondingly, in the syngeneic 4T1.2 metastasis mouse model, Decitabine treatment conferred a survival benefit and reduced metastatic potential, particularly in bone. Our findings reveal DNA methylation as a key regulator of the transcriptional programs underlying bone metastasis, providing mechanistic insight into how Decitabine reactivates type I interferon signalling and reduces metastatic potential, highlighting epigenetic reprogramming as a promising approach for targeting metastatic breast cancer. STATEMENT OF SIGNIFICANCEBone metastasis remains a major clinical challenge and a key mechanism of progression to bone is the suppression of tumor-inherent type I interferon signalling. We identified Decitabine, a DNA hypomethylating agent, as a promising therapeutic agent to enhance tumor immunogenicity across a broad range of breast cancer cell lines, including bone metastasis-derived lines. Our findings support DNA methylation as a key regulator of transcriptional programs associated with bone metastatic progression, and provide mechanistic insight into how Decitabine reactivates type I interferon signalling and reduces metastatic potential in vivo. These results highlight epigenetic reprogramming as a promising approach for targeting metastatic breast cancer.

Cancer Biology↗

Androgen stimulation rapidly reorganizes temporal 3D genome and epigenome states to trigger AR-mediated transcription in prostate cancer.

Androgen receptor (AR)-mediated transcription drives prostate cancer progression and remains a critical therapeutic target. AR activation by androgens triggers nuclear translocation, DNA binding at AR regulatory elements (AREs) and transcription initiation. This process involves co-factors such as FOXA1, epigenetic modifications, and 3D chromatin interactions. However, the temporal coordination of these events during AR-mediated transcription remains poorly understood. Using a time-course androgen stimulation model in prostate cancer cells, we integrated temporal multi-omics data within the MOFA+ framework to dissect AR-mediated transcriptional dynamics. Our analysis revealed that rapid AR binding at gene promoters is crucial for initiating nascent transcription of AR target genes. We identified H3K27 acetylation at flanking AREs, pre-marked by constitutive FOXA1 binding, occurs prior to AR recruitment. Additionally, androgen stimulation induced a temporal early shift in nascent transcription from MYC to AR target genes, associated with transient disruption of 3D chromatin interactions. Finally, we showed that CRISPR-mediated inhibition of AR-associated chromatin contacts suppresses distal linked target genes, demonstrating that dynamic genome architecture is functionally required for AR-driven transcription. Together these findings uncover the dynamic reorganization of 3D chromatin structure and transcription factor binding post-androgen stimulation, resulting in distinct temporal epigenomic states. This work provides new insights into the mechanisms governing AR-mediated transcriptional activation in prostate cancer and highlights the interplay between MYC and AR in regulating transcription in hormone-driven cancers.

genomics↗

Unraveling cfDNA Fragmentation Patterns: Linking Chromatin Architecture to Cancer Diagnostic Sensitivity

Circulating cell-free DNA (cfDNA) liquid biopsies offer a powerful, non-invasive approach for cancer diagnostics, leveraging DNA fragments primarily released during apoptosis. Using droplet digital PCR on cfDNA samples from 88 breast and colorectal cancer patients, we uncovered highly consistent nucleosome breakpoints across individuals. Proximity to these cfDNA breakpoints diminishes the sensitivity of somatic mutation assays, including those targeting IDH1 and NRAS hotspot mutations, underscoring the importance of precise nucleosome positioning data. We introduce a probabilistic nucleosome protection scoring method that enables high-resolution mapping of nucleosome positions and cfDNA breakpoints. These maps reveal distinct nucleosome spacing patterns between heterochromatin and euchromatin, corresponding to different chromatin fiber topologies. Analysis of X-chromosome inactivation further supports the topoisomer model: heterochromatins 187 bp nucleosome repeat length differs from euchromatins 182 bp, generating wave interference patterns in nucleosome signals. Our findings suggest that loop-mediated transitions from T2 to T1 topoisomers shape chromatin accessibility and cfDNA fragmentation, advancing the diagnostic potential of liquid biopsy assays. HighlightsO_LINucleosome breakpoint conservation impacts somatic mutation assay sensitivity C_LIO_LIProbabilistic protection scoring enhances cfDNA nucleosome peak resolution C_LIO_LIChromatin states exhibit unique nucleosome spacing linked to distinct topologies, influencing cfDNA fragmentation C_LIO_LIChromosome X-inactivation phasing analyses reveal waveform interference in nucleosome positioning signals C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=198 SRC="FIGDIR/small/623159v1_ufig1.gif" ALT="Figure 1"> View larger version (58K): org.highwire.dtl.DTLVardef@65893corg.highwire.dtl.DTLVardef@14c986org.highwire.dtl.DTLVardef@ba9306org.highwire.dtl.DTLVardef@10a7364_HPS_FORMAT_FIGEXP M_FIG C_FIG

genomics↗

Epigenetic therapy suppresses endocrine-resistant breast tumour growth by re-wiring ER-mediated 3D chromatin interactions

Three-dimensional (3D) epigenome remodelling is an important mechanism of gene deregulation in cancer. However, its potential as a target to overcome therapy resistance remains largely unaddressed. Here we show that FDA-approved epigenetic therapy Decitabine (5-Aza-mC) suppresses tumour growth in preclinical metastatic ER+ breast tumour xenograft models. Decitabine-induced genome-wide DNA hypomethylation results in large-scale 3D epigenome deregulation, including de-compaction of higher order chromatin structure and loss of topologically associated domain boundary insulation. Significant DNA hypomethylation at ER-enhancer elements was associated with gain in ER binding, creation of ectopic 3D enhancer-promoter interactions and concordant activation of ER-mediated transcription pathways. Importantly long-term withdrawal of epigenetic therapy partially restores methylation at ER-enhancer elements, resulting in loss of ectopic 3D enhancer-promoter interactions and associated gene repression. Our study illustrates how epigenetic therapy has potential to target ER+ endocrine-resistant breast cancer by DNA methylation-dependent rewiring of 3D chromatin interactions associated with suppression of tumour growth.

molecular biology↗

DNA methylation is required to maintain DNA replication timing precision and 3D genome integrity

DNA replication timing and three-dimensional (3D) genome organisation occur across large domains associated with distinct epigenome patterns to functionally compartmentalise genome regulation. However, it is still unclear if alternations in the epigenome, in particular cancer-related DNA hypomethylation, can directly result in alterations to cancer higher order genome architecture. Here, we use Hi-C and single cell Repli-Seq, in the colorectal cancer DNMT1 and DNMT3B DNA methyltransferases double knockout model, to determine the impact of DNA hypomethylation on replication timing and 3D genome organisation. First, we find that the hypomethylated cells show a striking loss of replication timing precision with gain of cell-to-cell replication timing heterogeneity and loss of 3D genome compartmentalisation. Second, hypomethylated regions that undergo a large change in replication timing also show loss of allelic replication timing, including at cancer-related genes. Finally, we observe the formation of broad ectopic H3K4me3-H3K9me3 domains across hypomethylated regions where late replication is maintained, that potentially prevent aberrant transcription and loss of genome organisation after DNA demethylation. Together, our results highlight a previously underappreciated role for DNA methylation in maintenance of 3D genome architecture.

molecular biology↗

MethPanel: a parallel pipeline and interactive analysis tool for multiplex bisulphite PCR sequencing to assess DNA methylation biomarker panels for disease detection

BackgroundMultiplex bisulphite PCR sequencing is a convenient and scalable method to comprehensively profile DNA methylation at selected loci. The method is useful for validation of methylation biomarker panels on large clinical cohorts, as it can be applied to DNA isolated from fresh tissue, archival formalin fixed paraffin embedded tissue (FFPET) or circulating cell free DNA in plasma. However, successful clinical implementation of DNA methylation biomarkers for disease detection using multiplex bisulphite PCR sequencing, requires user-friendly sample analysis methods and a diversity of visualisation options, which are not met by current tools. ResultsWe have developed a computational pipeline with an interactive graphical interface, called MethPanel, in order to rapidly analyse multiplex bisulphite PCR sequencing data. MethPanel comprises a complete analysis workflow from genomic alignment to DNA methylation calling and supports an unlimited number of PCR amplicons and input samples. Moreover, MethPanel offers important and unique features, such as calculation of a polymorphism score and bisulphite PCR bias correction capabilities. MethPanel is designed so that the methylation data from all samples can be run in parallel on either a personal computer or a high performance computer. The outputs are also automatically forwarded to a shinyApp for convenient display, visualisation and sharing data with collaborators and clinicians. Importantly the data is centralised in one location, which aids storage management. Availability and ImplementationMethPanel is freely available at https://github.com/thinhong/MethPanel ConclusionMethPanel provides a novel parallel pipeline and interactive analysis tool for multiplex bisulphite PCR sequencing to assess DNA methylation marker panels for disease detection.

bioinformatics↗

Replication timing shapes the cancer epigenome and the nature of chromosomal rearrangements

HighlightsO_LIReplication timing alterations are conserved in cancers of different cell origins\nC_LIO_LILong-range epigenetic deregulation in cancer involves altered replication timing\nC_LIO_LICancer late-replicating loci are hypomethylated and acquire facultative heterochromatin\nC_LIO_LIReplication timing status potentiates cis and trans chromosomal rearrangements\nC_LI\n\nSummaryReplication timing is known to facilitate the establishment of epigenome, however, the intimate connection between DNA replication timing and changes to the genome and epigenome in cancer remain uncharted. Here, we perform Repli-Seq and integrated epigenome analysis and show that early-replicating loci are predisposed to hypermethylation and late-replicating loci to hypomethylation, enrichment of H3K27me3 and concomitant loss of H3K9me3. We find that altered replication timing domains correspond to long-range epigenetically deregulated regions in prostate cancer, and a subset of these domains are remarkably conserved across cancers from different tissue origins. Analyses of 214 prostate and 35 breast cancer genomes reveal that late-replicating DNA is prone to cis and early-replicating DNA to trans chromosomal rearrangements. We propose that differences in epigenetic deregulation related to spatial and temporal positioning between early and late replication potentiate the landscape of chromosomal rearrangements in cancer.

genomics↗