Related Experiment Video
Updated: Aug 13, 2026
Pre-clinical Evaluation of Tyrosine Kinase Inhibitors for Treatment of Acute Leukemia
Published on: September 18, 2013
Quantitative phosphotyrosine profiling of patient-derived xenografts identifies therapeutic targets in pediatric
Sibasish Dolai1, Keith C S Sia2, Alissa K Robbins3
1Leukemia Biology, Childrens Cancer Institute.
Abstract:
Activating mutations in tyrosine kinases (TKs) drive pediatric high-risk acute lymphoblastic leukemia (ALL) and confer resistance to standard chemotherapy. Therefore, there is urgent need to characterize dysregulated TK signaling axes in patients with ALL and identify actionable kinase targets for the development of therapeutic strategies. Here, we present the first study to quantitatively profile TK activity in xenografted patient biopsies of high-risk pediatric ALL. We integrated a quantitative phosphotyrosine profiling method with 'spike-in' stable isotope labeling with amino acids in cell culture (SILAC) and quantified 1394 class I phosphorylation sites in 16 ALL xenografts. Moreover, hierarchical clustering of phosphotyrosine sites could accurately classify these leukemias into either B or T-cell lineages with the high-risk early T-cell precursor (ETP) and Ph-like ALL clustering as a distinct group. Furthermore, we validated this approach by using specific kinase pathway inhibitors to perturb ABL1, FLT3, and JAK TK signaling in four xenografted patient samples. By quantitatively assessing the tyrosine phosphorylation status of activated kinases in xenograft models of ALL, we were able to identify and validate clinically relevant targets. Therefore, this study highlights the application and potential of phosphotyrosine profiling for identifying clinically relevant kinase targets in leukemia.
Insights
This study quantitatively profiles tyrosine kinase (TK) activity in pediatric high-risk acute lymphoblastic leukemia (ALL) xenografts. Findings identify actionable TK targets for novel therapeutic strategies against ALL.
Area of Science:
- Oncology
- Biochemistry
- Molecular Biology
Background:
- Activating mutations in tyrosine kinases (TKs) are key drivers of pediatric high-risk acute lymphoblastic leukemia (ALL).
- TK dysregulation confers resistance to conventional chemotherapy, necessitating new therapeutic targets.
- Characterizing TK signaling is crucial for developing effective treatments for ALL.
Purpose of the Study:
- To quantitatively profile TK activity in xenografted patient biopsies of high-risk pediatric ALL.
- To identify and validate clinically relevant kinase targets for ALL therapy.
- To explore the utility of phosphotyrosine profiling in leukemia research.
Main Methods:
- Quantitative phosphotyrosine profiling integrated with stable isotope labeling with amino acids in cell culture (SILAC).
- Analysis of 1394 class I phosphorylation sites across 16 ALL xenografts.
- Hierarchical clustering of phosphotyrosine sites for leukemia classification and kinase pathway inhibitor validation.
Main Results:
- Accurate classification of ALL subtypes (B-cell, T-cell, ETP, Ph-like ALL) based on phosphotyrosine profiles.
- Identification of dysregulated TK signaling axes in high-risk pediatric ALL.
- Validation of ABL1, FLT3, and JAK as potential therapeutic targets through inhibitor studies.
Conclusions:
- Phosphotyrosine profiling is a powerful tool for identifying clinically relevant kinase targets in ALL.
- This approach enables the characterization of TK signaling in patient-derived xenografts.
- The study provides a foundation for developing targeted therapies for pediatric ALL.
