Skip to Content
Merck
  • High-throughput screening of human leukemia xenografts to identify dexamethasone sensitizers.

High-throughput screening of human leukemia xenografts to identify dexamethasone sensitizers.

Journal of biomolecular screening (2014-08-12)
Cara E Toscan, Tim Failes, Greg M Arndt, Richard B Lock
ABSTRACT

Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy. Glucocorticoids (e.g., dexamethasone) form a critical component of chemotherapy regimens for pediatric ALL, and the initial response to glucocorticoid therapy is a major prognostic factor, where resistance is predictive of poor outcome. We have previously established a clinically relevant ALL xenograft model, consisting of primary pediatric ALL biopsies engrafted into immune-deficient mice, in which in vitro and in vivo dexamethasone sensitivity significantly correlated with patient outcome. In this study, we used high-throughput screening (HTS) to identify novel compounds that reverse dexamethasone resistance in a xenograft (ALL-19) derived from a chemoresistant pediatric ALL patient that is representative of the most common pediatric ALL subtype (B-cell precursor [BCP-ALL]). The compound 2-(4-chlorophenoxy)-2-methyl-N-(2-(piperidin-1-yl)phenyl)propanamide showed little cytotoxic activity alone (IC50 = 31 µM), but when combined with dexamethasone, it caused a marked decrease in cell viability. Fixed-ratio combination assays were performed against a broad panel of dexamethasone-resistant and -sensitive xenografts representative of BCP-ALL, T-cell ALL, and Mixed Lineage Leukemia-rearranged ALL, and synergy was observed in six of seven xenografts. We describe here the development of a novel 384-well cell-based high-throughput screening assay for identifying potential dexamethasone sensitizers using a clinically relevant ALL xenograft model.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Trypan Blue, powder, BioReagent, suitable for cell culture
SKU
Pack Size
Availability
Price
Quantity
Sigma-Aldrich
Trypan Blue, Vetec, reagent grade
SKU
Pack Size
Availability
Price
Quantity
Dexamethasone for peak identification, European Pharmacopoeia (EP) Reference Standard
SKU
Pack Size
Availability
Price
Quantity
Sigma-Aldrich
Trypan Blue, Dye content 60 %, ≥80% (HPLC)
SKU
Pack Size
Availability
Price
Quantity
Supelco
Dexamethasone, Pharmaceutical Secondary Standard; Certified Reference Material
SKU
Pack Size
Availability
Price
Quantity
Supelco
Dexamethasone, VETRANAL®, analytical standard
SKU
Pack Size
Availability
Price
Quantity
Sigma-Aldrich
Dexamethasone, powder, γ-irradiated, BioXtra, suitable for cell culture, ≥80% (HPLC)
SKU
Pack Size
Availability
Price
Quantity
Sigma-Aldrich
Dexamethasone, ≥98% (HPLC), powder
SKU
Pack Size
Availability
Price
Quantity
Sigma-Aldrich
Dexamethasone, powder, BioReagent, suitable for cell culture, ≥97%
SKU
Pack Size
Availability
Price
Quantity
Sigma-Aldrich
Dexamethasone, meets USP testing specifications
SKU
Pack Size
Availability
Price
Quantity
Sigma-Aldrich
Trypan Blue solution, 0.4%, liquid, sterile-filtered, suitable for cell culture
SKU
Pack Size
Availability
Price
Quantity
Sigma-Aldrich
Dexamethasone, tested according to Ph. Eur.
SKU
Pack Size
Availability
Price
Quantity
Sigma-Aldrich
Trypan Blue solution, 0.4%, for microscopy
SKU
Pack Size
Availability
Price
Quantity
Dexamethasone, European Pharmacopoeia (EP) Reference Standard
SKU
Pack Size
Availability
Price
Quantity
USP
Dexamethasone, United States Pharmacopeia (USP) Reference Standard
SKU
Pack Size
Availability
Price
Quantity
Dexamethasone for system suitability, European Pharmacopoeia (EP) Reference Standard
SKU
Pack Size
Availability
Price
Quantity