Biology subjects

Pearce, D. R.

Publications and source records attributed to Pearce, D. R..

5 recordsLinked to original sources

bioRxiv2025

WS6 enables scalable ex vivo expansion and gene editing of epithelial basal stem cells

Modeling human epithelial diseases and developing cell-based therapies require robust methods to expand and manipulate epithelial stem and progenitor cells in vitro. Basal stem/progenitor cells from stratified epithelia can be expanded in 3T3-J2 fibroblast feeder cell co-culture systems, and the addition of the ROCK inhibitor Y-27632 enhances proliferation and culture longevity, a phenomenon described as conditional reprogramming. Here, we present a method incorporating the small molecule WS6 to further improve the proliferation and lifespan of cultured epithelial cells from multiple tissues, including airway, skin, and thymus. Cells maintained in this medium ( EpMED; FAD+Y+WS6) retain basal stem/progenitor cell identity and function, including the capacity to differentiate. We demonstrate their capacity to engraft in vivo in a tracheal transplantation model. In a second application, we generate clonal CRISPR-Cas9 genome edited nasal cultures, introducing targeted knockouts of DNAH5 or DNAI2 to create primary ciliary dyskinesia disease models. We anticipate that our method will have broad applications in epithelial cell biology, disease modeling, and regenerative medicine, while reducing reliance on immortalized or cancer cell lines and animal experimentation.

cell biology↗

bioRxiv2024

Compound screening in primary human airway basal cells identifies Wnt pathway activators as potential pro-regenerative therapies

Regeneration of the airway epithelium restores barrier function and mucociliary clearance following lung injury and infection. Basal cells are tissue-resident airway stem cells that enact regeneration, yet the mechanisms regulating their proliferation and differentiation remain incompletely understood. To identify compounds that promote primary human airway basal cell proliferation, we performed phenotype-based compound screening of 1,429 compounds (from the ENZO and Prestwick Chemical libraries) in 384-well format using primary cells transduced with lentiviral luciferase. 16 pro-proliferative compounds validated in independent donor cell cultures, with several hit compounds activating the Wnt signalling pathway. The effects of compounds on proliferation were further explored in concentration-response, colony formation and 3D organoid assays. Structurally and functionally-related compounds that more potently induced both Wnt activation and basal cell proliferation were investigated. One such compound, 1-azakenpaullone, induced Wnt target gene activation and basal cell proliferation in mice in the absence of tracheal injury. Our results demonstrate the pro-proliferative effect of small-molecule Wnt activators on airway basal cells. These findings contribute to the rationale to develop novel approaches to modulate Wnt signalling during airway epithelial repair. Summary statementIshii, Orr and colleagues perform a high-throughput screen of 1,429 compounds in primary human airway epithelial cells, identifying Wnt activating compounds as promoters of proliferation.

cell biology↗

bioRxiv2023

Imaging the master regulator of the antioxidant response in non-small cell lung cancer with positron emission tomography

Mutations in the NRF2-KEAP1 pathway are common in non-small cell lung cancer (NSCLC) and confer broad-spectrum therapeutic resistance, leading to poor outcomes. The cystine/glutamate antiporter, system xc-, is one of the >200 cytoprotective proteins controlled by NRF2, which can be non-invasively imaged by (S)-4-(3-18F-fluoropropyl)--glutamate ([18F]FSPG) positron emission tomography (PET). Through genetic and pharmacologic manipulation, we show that [18F]FSPG provides a sensitive and specific marker of NRF2 activation in advanced preclinical models of NSCLC. We validate imaging readouts with metabolomic measurements of system xc- activity and their coupling to intracellular glutathione concentration. A redox gene signature was measured in patients from the TRACERx 421 cohort, suggesting an opportunity for patient stratification prior to imaging. Furthermore, we reveal that system xc- is a metabolic vulnerability that can be therapeutically targeted for sustained tumour growth suppression in aggressive NSCLC. Our results establish [18F]FSPG as predictive marker of therapy resistance in NSCLC and provide the basis for the clinical evaluation of both imaging and therapeutic agents that target this important antioxidant pathway.

cancer biology↗

bioRxiv2023

Phenotyping of lymphoproliferative tumours generated in xenografts of non-small cell lung cancer

Patient-derived xenograft (PDX) models involve the engraftment of tumour tissue in immunocompromised mice and represent an important pre-clinixtcal oncology research. A limitation of non-small cell lung cancer (NSCLC) PDX model derivation in NOD-scid IL2Rgammanull (NSG) mice is that a subset of initial engraftments are of lymphocytic, rather than tumour origin. In the lung TRACERx PDX pipeline, lymphoproliferations occurred in 17.8% of lung adenocarcinoma and 10% of lung squamous cell carcinoma transplantations, despite none of these patients having a prior or subsequent clinical history of lymphoproliferative disease. Lymphoproliferations were predominantly human CD20+ B cells and had the immunophenotype expected for post-transplantation diffuse large B cell lymphoma. All lymphoproliferations expressed Epstein-Barr-encoded RNAs (EBER). Analysis of immunoglobulin light chain gene rearrangements in three tumours where multiple tumour regions had resulted in lymphoproliferations suggested that each had independent clonal origins. Overall, these data suggest the presence of B cell clones with lymphoproliferative potential within primary NSCLC tumours that are under continuous immune surveillance. Since these cells can be expanded following transplantation into NSG mice, our data highlight the value of quality control measures to identify lymphoproliferations within xenograft pipelines and support the incorporation of strategies to minimise lymphoproliferations during the early stages of xenograft establishment pipelines. To present the histology data herein, we developed a Python-based tool for generating patient-level pathology overview figures from whole-slide image files; PATHOverview is available on GitHub (https://github.com/EpiCENTR-Lab/PATHOverview).

cancer biology↗

bioRxiv2023

Genomic evolution of non-small cell lung cancer patient-derived xenograft models

Patient-derived xenograft (PDX) models of cancer, developed through injection of patient tumour cells into immunocompromised mice, have been widely adopted in preclinical studies, as well as in precision oncology approaches. However, the extent to which PDX models represent the underlying genetic diversity of a patients tumour and the extent of on-going genomic evolution in PDX models are incompletely understood, particularly in the context of heterogeneous cancers such as non-small cell lung cancer (NSCLC). To investigate the depiction of intratumour heterogeneity by PDX models, we derived 47 new subcutaneous multi-region PDX models from 22 patients with primary NSCLC enrolled in the clinical longitudinal cohort study TRACERx. By analysing whole exome sequencing data from primary tumours and PDX models, we find that PDX establishment creates a genomic bottleneck, with 76% of PDX models being derived from a single primary tumour subclone. Despite this, multiple primary tumour subclones were capable of PDX establishment in regional PDX models, indicating that PDX libraries derived from multiple tumour regions can capture intratumour heterogeneity. Acquisition of somatic mutations continued during PDX model expansion, and was associated with APOBEC- or mismatch repair deficiency-induced mutational signatures in a subset of models. Overall, while NSCLC PDX models retain truncal genomic alterations, the absence of subclonal heterogeneity representative of the primary tumour is a major limitation. Our results emphasise the importance of characterising and monitoring intratumour heterogeneity in the context of pre-clinical cancer studies.

cancer biology↗