Hockney, S. | Search bioRxiv

bioRxiv2023

A bone marrow ECM mimicking, animal-component free hydrogel identifies TNTs as key mediators of druggable cell-cell and cell-ECM crosstalk in an animal replacement organoid model.

Treatment resistance, conferred onto cancer cells largely by the oncogenic niche, remains a clinically unmet need in leukaemia. Tractable and clinically translatable models that mimic cancer-niche crosstalk remain limited, consequently means of clinically drugging microenvironment-driven cancer treatment resistance remain underexplored. Here we develop a prototype bone marrow (BM) like extracellular matrix (ECM), Vitronectin-Alginate-Laminin (VAL), which comprises animal-free components, displays viscoelastic properties like the human BM, and engrafts a range of patient-derived-xenograft acute lymphoblastic leukaemia (PDX-ALL) samples. We discover that following treatment with oxidative stress-inducing apoptotic therapies, such as dexamethasone, ABT-199 and dexamethasone-ABT-199 combination, PDX-ALL cells reach out to MSC via the formation of tunnelling nanotubes (TNT). Nevertheless, we reveal that ALL-VAL-MSC-TNTs are clinically druggable, as they are absent following treatment with CDH2 antagonist ADH-1, a compound well-tolerated in solid cancer Phase I trials. We ultimately expose a triple drug combination of dexamethasone-ABT-199 and ADH-1, with most synergy area (MSA) scores of >30, that shows high efficacy and disrupts functional cancer-niche-TNTs in 4 different high risk PDX-ALL samples. In summary, here we develop prototype cancer-ECM-niche organoids and using leukaemia as a disease paradigm, we provide proof-of-concept insights enabling the beginning of research into drugging functional cancer cell crosstalk with its surrounding cellular and ECM niche.

cancer biology↗

bioRxiv2022

A human mesenchymal spheroid prototype to replace moderate severity animal procedures in leukaemia drug testing

Patient derived xenograft (PDX) models are regarded as gold standard preclinical models in leukaemia research, especially in testing new drug combinations where typically 45-50 animals are used per assay. 9000 animal experiments are performed annually in leukaemia research with these expensive procedures being described as moderate severity, meaning they cause significant pain, suffering and visible distress to animals state. Furthermore, not all clinical leukaemia samples engraft and when they do data turnaround time can be between 6-12 months. Heavy dependence on animal models is because clinical leukaemia samples do not proliferate in vitro. Alternative cell line models though popular for drug testing are not biomimetic - they are not dependent on the microenvironment for survival, growth and treatment response and being derived from relapse samples they do not capture the molecular complexity observed at disease presentation. Here we have developed an in vitro platform to rapidly establish co-cultures of patient-derived leukaemia cells with 3D bone marrow mesenchyme spheroids, BM-MSC-spheroids. We optimise protocols for developing MSC-spheroid leukaemia co-culture using clinical samples and deliver drug response data within a week. Using three patient samples representing distinct cytogenetics we show that patient-derived-leukaemia cells show enhanced proliferation when co-cultured with MSC-spheroids. In addition, MSC-spheroids provided improved protection against treatment. This makes our spheroids suitable to model treatment resistance - a major hurdle in current day cancer management Given this 3Rs approach is 12 months faster (in delivering clinical data), is a human cell-based biomimetic model and 45-50 animals/drug-response assay cheaper the anticipated target end-users would include academia and pharmaceutical industry. This animal replacement prototype would facilitate clinically translatable research to be performed with greater ethical, social and financial sustainability. Research HighlightsO_ST_ABSScientific BenefitC_ST_ABSA 3D spheroid-based approach for ex vivo co-culture of clinical leukaemia samples for further investigation into cancer biology such as blast-niche interactions, blast proliferation and treatment resistance 3Rs BenefitTo replace moderate severity animal procedures in leukaemia research and drug testing Practical Benefit3Rs approach that yields drug response data quickly and is more ethically, socially and financially sustainable than its in vivo counterparts Current applicationsExploration of leukaemia biology such as blasts proliferation, blast-niche interactions, niche-impacted treatment resistance and obtain drug response data Potential applicationsExtend the approach to include other haematological cancers as well as bone cancers.

cancer biology↗