Biology subjects

Vanderhyden, B. C.

Publications and source records attributed to Vanderhyden, B. C..

9 recordsLinked to original sources

bioRxiv2025

BRCA mutation alters the stromal landscape in normal ovaries

For BRCA mutation (BRCA+) carriers, the risk of ovarian cancer can be as high as 59% compared with 1.4% for the general population. While the impact of BRCA mutations on epithelial cell transformation has been extensively studied, we hypothesize that these mutations cause structural changes that prematurely transform the ovary into a rich metastatic niche that supports the early onset of ovarian cancer. Analysis of collagen content and organization in human ovaries revealed increased coherence associated with fibrosis in premenopausal BRCA+ ovaries relative to those without a BRCA mutation. Brca1 deficiency and haploinsufficiency in murine ovarian fibroblasts triggered the expression of hallmarks of senescence, including Cdkn2a (p16) and acidic {beta}-galactosidase activity. Brca1-deficient fibroblasts also acquired an antigen-presenting myofibroblastic phenotype, characterized by expression of MHC-II molecules, -SMA and extracellular matrix components, suggesting the capacity to modulate immune activity and drive structural changes resembling fibrosis. These results provide insight into the mechanisms contributing to accelerated ovarian aging in BRCA+ carriers. TeaserBRCA mutation promotes fibroblast hyperactivity and senescence that changes the stromal architecture of the ovarian niche.

molecular biology↗

bioRxiv2023

Comparative analysis of syngeneic mouse models of high-grade serous ovarian cancer

Ovarian cancers often exhibit high rates of recurrence and poor treatment response. Preclinical models that recapitulate the heterogeneity of human disease are critical to develop new therapeutic approaches. While patient-derived models are a powerful tool for testing various therapeutics, their dependence on immune-compromised mice is severely limiting. Syngeneic mouse models, however, allow for the generation of tumours comprising the full repertoire of non-malignant cell types. Here we have performed a comparative analysis of diverse models of high-grade serous ovarian cancer based on transcriptomic profiling of 22 cell line models, and intrabursal and intraperitoneal tumours from 12 models. Among cell lines, we identify distinct features in signalling activity, such as elevated inflammatory signalling in STOSE and OVE16 models, and MAPK/ERK signalling in ID8 and OVE4 models; metabolic features, such as predicted reduction in glycolysis associated with subsets of engineered ID8 subclones; and relevant functional properties, including differences in EMT activation, PD-L1 and MHC class I expression, and predicted chemosensitivity. Finally, we evaluate variability in properties of the tumour microenvironment among models. We anticipate that this work will serve as a valuable resource, providing new insight to help in the selection of models for specific experimental objectives.

cancer biology↗

bioRxiv2022

Alterations in neural stem cell quiescence and activation in the 3xTG-AD model of Alzheimers Disease

Alzheimers Disease (AD) is the most common form of dementia with progressive cognitive deficits and mood disorders (Knopman et al., 2021). Recent studies have associated AD pathology with the impairment of adult neurogenesis, as indicated by impaired neural stem cell (NSCs) homeostasis (Bond et al., 2015). Recent work has further associated AD progression with a decline in the number and maturation of adult-born neurons in the SGZ, distinct from typical age-related decline (Moreno-Jimenez et al., 2019). In 3xTG-AD mice, a well-established mouse model of AD, our and other groups have demonstrated impairments to NSC pool and neural progenitor proliferation, as well as adult-born neurons, before the onset of A{beta} plaques and NFTs (Hamilton et al., 2010, 2015; Rodriguez et al., 2008, 2009). However, the regulatory mechanisms underlying the functional impairment of adult NSCs remain to be resolved. Here, we employ single-cell RNA-Seq to establish population-specific defects in the 3xTG-AD mouse model during adult SGZ neurogenesis. Relative to control mice, we observe a dramatic AD-induced decrease in the primed and activated NSC population, which results in a progressive loss of cells committed to neurogenesis. Transcriptome measurements suggest that 3xTG-AD NSCs and their progeny represent enhanced ribosomal and mitochondrial biogenesis, and disturbed Notch signaling pathway. RNA velocity analysis reveals reduced NSC activation as evidenced by a large fraction of Ascl1-postive cells, instead of entering cell cycle, returning to the primed and quiescent state. This is further supported by reduced numbers of Lpar1-expressing cells, a marker of neural progenitor cells, in the SGZ. Our work explores, at a stage-specific resolution, changes in the regulatory networks guiding adult neurogenesis, and identifies niche disturbances in the regulation of NSC quiescence and activation. These NSC deficits underlying impaired neurogenesis identified in AD mice, may be key contributors underlying the compromised hippocampal function in AD.

neuroscience↗

bioRxiv2021

Single-cell RNA sequencing-based characterization of resident lung mesenchymal stromal cells in bronchopulmonary dysplasia

Late lung development is a period of alveolar and microvascular formation, which is pivotal in ensuring sufficient and effective gas exchange. Defects in late lung development manifest in premature infants as a chronic lung disease named bronchopulmonary dysplasia (BPD). Numerous studies demonstrated the therapeutic properties of exogenous bone marrow and umbilical cord-derived mesenchymal stromal cells (MSCs) in experimental BPD. However, very little is known regarding the regenerative capacity of resident lung MSCs (L-MSCs) during normal development and in BPD. In this study we aimed to characterize the L-MSC population in homeostasis and upon injury. We used single-cell RNA sequencing (scRNA-seq) to profile in situ Ly6a+ L-MSCs in the lungs of normal and O2-exposed neonatal mice (a well-established model to mimic BPD) at three developmental timepoints (postnatal days 3, 7 and 14). Hyperoxia exposure increased the number, and altered the expression profile of L-MSCs, particularly by increasing the expression of multiple pro-inflammatory, pro-fibrotic, and anti-angiogenic genes. In order to identify potential changes induced in the L-MSCs transcriptome by storage and culture, we profiled 15,000 Ly6a+ L-MSCs after in vitro culture. We observed great differences in expression profiles of in situ and cultured L-MSCs, particularly those derived from healthy lungs. Additionally, we have identified the location of L-MSCs in the developing lung and propose Serpinf1 as a novel, culture-stable marker of L-MSCs. Finally, cell communication analysis suggests inflammatory signals from immune and endothelial cells as main drivers of hyperoxia-induced changes in L-MSCs transcriptome.

cell biology↗

bioRxiv2021

Transcriptional census of epithelial-mesenchymal plasticity in cancer

Epithelial-mesenchymal plasticity (EMP) contributes to tumour progression, promoting therapy resistance and immune cell evasion. Definitive molecular features of this plasticity have largely remained elusive due to the limited scale of most studies. Leveraging scRNA-seq data from 160 tumours spanning 8 different cancer types, we identify expression patterns associated with intratumoural EMP. Integrative analysis of these programs confirmed a high degree of diversity among tumours. These diverse programs are associated with combinations of various common regulatory mechanisms initiated from cues within the tumour microenvironment. We highlight that inferring regulatory features can inform effective therapeutics to restrict EMP.

cancer biology↗

bioRxiv2020

Transcriptional heterogeneity of stemness phenotypes in the ovarian epithelium

The ovarian surface epithelium (OSE) is a monolayer of epithelial cells covering the surface of the ovary. During ovulation, the OSE is ruptured to allow release of the oocyte. This wound is quickly repaired, but mechanisms of this repair are poorly understood. The contribution of tissue-resident stem cells in the homeostasis of several epithelial tissues is widely accepted, such as the intestinal epithelium, airway epithelium, and skin, but their involvement in OSE maintenance is unclear. While putative stem cell populations in the OSE have been described, how they are regulated is poorly defined. We show that traits associated with stem cells (stemness) can be increased in OSE following exposure to the cytokine TGFB1, overexpression of the transcription factor Snai1, or deletion of Brca1. By assessing the gene expression profiles of these populations, we show that stemness is often linked to mesenchymal-associated gene expression and higher activation of ERK signalling, but it is not consistently dependent on their activation. Expression profiles of these populations are extremely context specific, suggesting that stemness may not correspond to a single, distinct population, but rather is a heterogenous state that can possibly emerge from diverse environmental cues. Together, these findings support that the OSE may not require distinct stem cell populations for long-term maintenance, and may achieve this through transient dedifferentiation into a stem-like state.

cell biology↗

bioRxiv2020

Cre-mediated deletion of SMARCA5 disrupts pluripotency in mouse embryonic stem cells

In embryonic stem cells (ESCs), the SWI/SNF, CHD, and INO80 families of ATP-dependent chromatin remodellers have been implicated in maintaining pluripotency-associated gene expression. At the time of this study, the importance of ISWI family remodellers had yet to be defined, and we had sought to assess their involvement. During this time, Barisic et al. (Nature, 2019) elegantly demonstrated that the ISWI homologue SNF2H (Smarca5) is important for nucleosomal periodicity, the binding of select transcription factors, and proper differentiation of mouse ESCs. While we do not dispute their findings to any extent, our experiments have led to slightly different conclusions, and we have chosen to use this platform to share our results. Here, we explore the importance of SNF2H by deriving a conditional knockout mouse ESC line and observing the consequences of SNF2H depletion on the pluripotent state. Cre-mediated deletion of Snf2h disrupts hallmark characteristics of pluripotency, resulting in distinct morphological changes; reduced expression of the master transcription factors Oct4, Sox2, and Nanog; and reduced alkaline phosphatase activity. To understand the mechanisms of SNF2H-mediated regulation, we mapped SNF2H-bound nucleosomes genome-wide. SNF2H is broadly distributed across the genome but is preferentially enriched at active regulatory regions and transcription factor binding sites.

cell biology↗

bioRxiv2019

Comparing transcriptional dynamics of the epithelial-mesenchymal transition

Epithelial-mesenchymal (E/M) heterogeneity is ubiquitous within all epithelial tissues and the reversible transition between these two states provides cells with plasticity that contributes to organogenesis in the developing embryo, tissue homeostasis in adults, and tumour progression1. While the epithelial-mesenchymal transition (EMT) has been extensively studied, no common, EMT-defining gene expression program has been identified2. Here, we leverage highly multiplexed single-cell RNA sequencing (scRNA-seq) to compare the transcriptional program associated with the EMT across a variety of contexts, assessing 103,999 cells from 960 samples, comprising 12 EMT time course experiments and 16 independent kinase inhibitor screens. We demonstrate that the EMT is not simply a linear transition between E/M states, and transcriptional dynamics are widely variable across contexts, regardless of the cell type and cytokine used to induce the transition. While many canonical EMT genes were poor markers of the transition in our models, we identified 86 conserved mesenchymal-associated genes also coexpressed in a variety of mouse and human epithelial and carcinoma tissues. Despite the heterogeneous transcriptional responses, we identified a core set of largely conserved transcription factors coordinating these dynamics, including RELB and SOX4. Finally, we found that the EMT is associated with a broad increase in expression of secreted factors. Kinase inhibitor screens revealed multiple paracrine dependencies of the EMT, including a novel association between TGFB1 and the TNF-associated kinase RIPK1. Together, these results comprehensively highlight the complexity and diversity of the EMT, but also reveal dynamics conserved across contexts. This work will provide the foundation for understanding the nature of E/M heterogeneity and its functional consequences, which could elucidate various physiological processes and be leveraged for cancer treatments.

cancer biology↗

bioRxiv2017

Ponatinib shows potent antitumor activity in small cell carcinoma of the ovary hypercalcemic type (SCCOHT) through multi-kinase inhibition

Structured AbstractPurpose: Subunits of the SWI/SNF chromatin-remodeling complex are tumor suppressors inactivated in [~]20% of all cancers. Yet, few targeted treatments for SWI/SNF-mutant cancers exist. Small cell carcinoma of the ovary, hypercalcemic type (SCCOHT) is a rare, aggressive ovarian cancer in young women that is universally driven by loss of the SWI/SNF ATPase subunits, SMARCA4 and SMARCA2. Given poor two-year survival rates for these women, a great need exists for effective targeted therapies.\n\nExperimental Design: To identify underlying therapeutic vulnerabilities in SCCOHT, we conducted high-throughput siRNA and drug screens. Complementary proteomics approaches comprehensively profiled kinases inhibited by ponatinib. Ponatinib was tested for efficacy in two PDX models and one cell line xenograft model of SCCOHT.\n\nResults: FGFRs and PDGFRs were overlapping hits between screens and the receptor tyrosine kinase (RTK) family was enriched in the siRNA screen hits. Evaluation of eleven RTK inhibitors in three SCCOHT cell lines identified ponatinib, an inhibitor of multiple RTKs, as the most effective clinically approved agent. Proteomics approaches confirmed inhibition of known targets of ponatinib and more than 20 non-canonical ponatinib targets. Ponatinib also delayed tumor doubling time 4-fold in SCCOHT-1 xenografts and reducing final tumor volumes in two SCCOHT patient-derived xenograft (PDX) models by 58.6% and 42.5%.\n\nConclusion: Ponatinib is an effective agent for SCCOHT in both in vitro and in vivo preclinical models through its inhibition of multiple kinases. Clinical investigation of this FDA-approved oncology drug in SCCOHT is warranted.\n\nAdditional InformationThis work was supported by research funds from the Canadian Cancer Society Research Institute 34 (#703458, D.G.H.), the National Institutes of Health (R01 CA195670-01, B.E.W., D.G.H., and 35 J.M.T., and T32 HL007106-39 to E.M.C), the Terry Fox Research Institute Initiative New Frontiers Program in Cancer (#1021, D.G.H.), the British Columbia Cancer Foundation (D.G.H.), the VGH & UBC Foundation (D.G.H.), the Anne Rita Monahan Foundation (P.R.), the Marsha Rivkin Center for Ovarian Cancer Research (J.M.T.), the Ovarian Cancer Alliance of Arizona (J.M.T.), the Small Cell Ovarian Cancer Foundation (P.R., J.D.L., B.V., and J.M.T.), and philanthropic support to the TGen Foundation (J.M.T.).\n\nCOI disclosure statement: The authors declare no potential conflicts of interest.

cancer biology↗