Dataset Information

Glucocorticoid-resistant B cell acute lymphoblastic leukemia displays receptor tyrosine kinase activation.

ABSTRACT: The response of childhood acute lymphoblastic leukemia (ALL) to dexamethasone predicts the long-term remission outcome. To explore the mechanisms of dexamethasone resistance in B cell ALL (B-ALL), we generated dexamethasone-resistant clones by prolonged treatment with dexamethasone. Using RNA-sequencing and high-throughput screening, we found that dexamethasone-resistant cells are dependent on receptor tyrosine kinases. Further analysis with phosphokinase arrays showed that the type III receptor tyrosine kinase FLT3 is constitutively active in resistant cells. Targeted next-generation and Sanger sequencing identified an internal tandem duplication mutation and a point mutation (R845G) in FLT3 in dexamethasone-resistant cells, which were not present in the corresponding sensitive clones. Finally, we showed that resistant cells displayed sensitivity to second-generation FLT3 inhibitors both in vitro and in vivo. Collectively, our data suggest that long-term dexamethasone treatment selects cells with a distinct genetic background, in this case oncogenic FLT3, and therefore therapies targeting FLT3 might be useful for the treatment of relapsed B-ALL patients.

SUBMITTER: Chougule RA

PROVIDER: S-EPMC6449402 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Glucocorticoid-resistant B cell acute lymphoblastic leukemia displays receptor tyrosine kinase activation.

Chougule Rohit A RA Shah Kinjal K Moharram Sausan A SA Vallon-Christersson Johan J Kazi Julhash U JU

NPJ genomic medicine 20190404

The response of childhood acute lymphoblastic leukemia (ALL) to dexamethasone predicts the long-term remission outcome. To explore the mechanisms of dexamethasone resistance in B cell ALL (B-ALL), we generated dexamethasone-resistant clones by prolonged treatment with dexamethasone. Using RNA-sequencing and high-throughput screening, we found that dexamethasone-resistant cells are dependent on receptor tyrosine kinases. Further analysis with phosphokinase arrays showed that the type III receptor ...[more]

PMID: 30962949

Similar Datasets

Project description:BACKGROUND:Drug-resistant cell lines, established from drug-sensitive cell lines by drug exposure in vitro, are the most useful cancer models in studies on the mechanism of chemoresistance. However, the success rate of the traditional approaches to construct such cell lines is low because a long time is required for the addition of drugs. METHODS:A cell culture technique was used to establish the drug-resistant cell lines from their parental cells. Molecular and cellular biological techniques including flow cytometry, MTT assay, western blotting, and DNA fingerprinting analysis were used to characterize the drug-resistant cell lines. Nude mice were used for xenograft studies. RESULTS:We established novel glucocorticoid (GC)-resistant cell lines from 3 GC-sensitive acute lymphoblastic leukemia (ALL) cell lines. First, we established a novel GC-resistant T-ALL cell line, CEM-C7/HDR, by mimicking the microenvironment of the bone marrow and culturing GC-sensitive CEM-C7-14 cells under hypoxia for 5?weeks with a single dexamethasone (Dex) treatment. The CEM-C7/HDR cells had been cultured continuously in drug-free medium under normoxia for 1?year. The IC50 and resistance index (RI) to Dex were maintained at 60~70??M and 1500~1800, respectively, which is in consistent with the IC50 and RI of GC-resistant CEM-C1-15 cells. To clarify the reliability of the method, we subcloned CEM-C7-14 cells, and obtained Dex-resistant cell lines, CEM-C7-SC2/HDR and CEM-C7-SC14/HDR, from 2 monoclonal cells of CEM-C7-14 by the same method. Moreover, we obtained two additional Dex-resistant B-ALL cell lines, NALM-6/HDR and HXEX-ALL1/HDR, from NALM-6 and HXEX-ALL1 cells with the same approach. CONCLUSIONS:CEM-C7/HDR, NALM-6/HDR and HXEX-ALL1/HDR cell lines may serve as useful GC-resistant ALL models for both in vitro and in vivo studies. Culturing under hypoxic condition with a single Dex treatment is a novel and convenient approach for generating stable GC resistant cell lines.

Dataset Information

Glucocorticoid-resistant B cell acute lymphoblastic leukemia displays receptor tyrosine kinase activation.

Publications

Glucocorticoid-resistant B cell acute lymphoblastic leukemia displays receptor tyrosine kinase activation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets