Fast, In Vivo Model for Drug-Response Prediction in Patients with B-Cell Precursor Acute Lymphoblastic Leukemia

Abstract

Only half of patients with relapsed B-cell precursor (BCP) acute lymphoblastic leukemia (ALL) currently survive with standard treatment protocols. Predicting individual patient responses to defined drugs prior to application would help therapy stratification and could improve survival. With the purpose to aid personalized targeted treatment approaches, we developed a human–zebrafish xenograft (ALL-ZeFiX) assay to predict drug response in a patient in 5 days. Leukemia blast cells were pericardially engrafted into transiently immunosuppressed Danio rerio embryos, and engrafted embryos treated for the test case, venetoclax, before single-cell dissolution for quantitative whole blast cell analysis. Bone marrow blasts from patients with newly diagnosed or relapsed BCP-ALL were successfully expanded in 60% of transplants in immunosuppressed zebrafish embryos. The response of BCP-ALL cell lines to venetoclax in ALL-ZeFiX assays mirrored responses in 2D cultures. Venetoclax produced varied responses in patient-derived BCP-ALL grafts, including two results mirroring treatment responses in two refractory BCP-ALL patients treated with venetoclax. Here we demonstrate proof-of-concept for our 5-day ALL-ZeFiX assay with primary patient blasts and the test case, venetoclax, which after expanded testing for further targeted drugs could support personalized treatment decisions within the clinical time window for decision-making.

Inhibiting casein kinase 2 sensitizes acute lymphoblastic leukemia cells to venetoclax via MCL1 degradation

“…Our findings concur with similar observations made in a preclinical model of AML. 20 To validate this synergistic interaction in vivo, we used an established xenograft model in zebrafish embryos 21 , where BCP-ALL cells (SEM) are injected into the pericardium of immunosuppressed zebrafish embryos and bathed in the drug for 72h before flow cytometrically evaluating effects on BCP-ALL cells. Analyses showed an enhanced induction of apoptosis (p<0.05) after combined silmitasertib/venetoclax treatment (Figure 2F) and confirmed silmitasertib induced downregulation of MCL1 as functional underpinning of the synergistic treatment effect also in vivo (Supplementary Figure S10).…”

Systematic Roadmap for Cancer Drug Screening Using Zebrafish Embryo Xenograft Cancer Models: Melanoma Cell Line as a Case Study

“…Site of cancer cell implantation. One of the most important factors affecting engraftment potential is the site of cell implantation [32]. The yolk sac has traditionally been the most employed location because it provides a larger site for housing transplanted cells [10] (Supplementary Table S1); however, we herein demonstrated the yolk to be the worst site for implantation, as it had the lowest rates of survival, tumor engraftment and growth.…”

Effective tumor cell abrogation via Venetoclax-mediated BCL-2 inhibition in KMT2A-rearranged acute B-lymphoblastic leukemia

“…VEN in vitro incubation of KMT2A -r cell lines SEM and RS4;11 with low nanomolar and physiologically achievable concentrations resulted in severely reduced tumor cell counts, apoptosis induction, and morphological changes. Other groups conducting basic viability screenings with the same cell lines achieved comparable results [ 5 , 14 , 22 , 23 ]. In vivo application of VEN induced decelerated tumor cell growth rates and reduced blast frequencies in bone marrow and spleen in both KMT2A -r cell line-derived xenograft systems.…”

“…In vivo application of VEN induced decelerated tumor cell growth rates and reduced blast frequencies in bone marrow and spleen in both KMT2A -r cell line-derived xenograft systems. Gauert et al used SEM cells in a zebrafish xenograft model and found comparable results [ 23 ]. The fact that mice engrafted with RS4;11 cells, which were highly responsive to VEN incubation in vitro, seemed to benefit less from VEN therapy than SEM-derived models, is most likely due to the faster proliferation kinetics of SEM cells compared to RS4;11.…”