Reversal of acquired drug resistance in FLT3-mutated acute myeloid leukemia cells via distinct drug combination strategies.

Abstract

PURPOSE:

FMS-like tyrosine kinase-3 (FLT3) internal tandem duplication (FLT3-ITD) mutations are common in patients with acute myeloid leukemia (AML). These patients regularly develop resistance to FLT3 inhibitors suggesting that targeted combination drug strategies are needed to enhance AML therapy efficacy.

EXPERIMENTAL DESIGN:

Acquired point mutations of FLT3-ITD gene were screened using cDNA-based sequencing approach in vitro sorafenib-resistant cells, which were developed by long-term exposure of Ba/F3-ITD to increasing doses of sorafenib, and in FLT3-ITD mutated AML patients, who developed relapse following sorafenib therapy. Drug effects (e.g., proliferation inhibition, apoptosis induction, and changes in signal transduction protein expression) were assessed in AML cells harboring the point mutations in vitro and in FLT3-ITD-mutated AML patient samples.

RESULTS:

We identified several acquired point mutations in the tyrosine kinase domains (TKD) of the FLT3 gene in sorafenib-resistant murine leukemia cell line carrying human FLT3-ITD mutations, which were also detected in two of four sorafenib-resistant patient samples. Engineering these point mutations into Ba/F3-ITD cells generated sublines that demonstrated varying degrees of sorafenib [a type II tyrosine kinase inhibitor (TKI)] resistance. A similar pattern of resistance could be observed by exposing these sublines to the other type II TKIs AC220 and MLN518. However, these sublines retained sensitivity to the type I TKIs PKC412 or crenolanib. The combination of crenolanib with sorafenib demonstrated marked cytotoxic effects in all of the sorafenib-resistant sublines.

CONCLUSIONS:

These combination strategies could be clinically important in reversing acquired resistance to FLT3 inhibition in AML.

• Authors: Weiguo Zhang, Chen Gao, Marina Konopleva, Ye Chen, Rodrigo O Jacamo, Gautam Borthakur, Jorge E Cortes, Farhad Ravandi, Abhijit Ramachandran, Michael Andreeff
• Journal: Clinical cancer research : an official journal of the American Association for Cancer Research (Clin Cancer Res) Vol. 20 Issue 9 Pg. 2363-74 (May 01 2014) ISSN: 1557-3265 [Electronic] United States
• PMID: 24619500 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)
• Copyright: ©2014 AACR.

Chemical References

• Antineoplastic Agents
• Membrane Proteins
• Phenylurea Compounds
• Protein Kinase Inhibitors
• flt3 ligand protein
• Niacinamide
• Sorafenib
• fms-Like Tyrosine Kinase 3

Topics

• Animals
• Antineoplastic Agents (pharmacology)
• Apoptosis (drug effects, genetics)
• Cell Line, Tumor
• Cell Survival (drug effects, genetics)
• DNA Mutational Analysis
• Dose-Response Relationship, Drug
• Drug Resistance, Neoplasm (genetics)
• Drug Synergism
• Gene Duplication
• Humans
• Leukemia, Myeloid, Acute (drug therapy, genetics, metabolism)
• Membrane Proteins (metabolism)
• Mice
• Mutation
• Niacinamide (analogs & derivatives, pharmacology)
• Phenylurea Compounds (pharmacology)
• Point Mutation
• Protein Interaction Domains and Motifs (genetics)
• Protein Kinase Inhibitors (pharmacology)
• Signal Transduction (drug effects)
• Sorafenib
• Tandem Repeat Sequences
• fms-Like Tyrosine Kinase 3 (chemistry, genetics, metabolism)