Targeting eIF4F translation complex sensitizes B-ALL cells to tyrosine kinase inhibition

Area of Science:

• Oncology
• Molecular Biology
• Pharmacology

Background:

• Mechanistic target of rapamycin (mTOR) activation correlates with poor prognosis in pre-B cell acute lymphoblastic leukemia (B-ALL).
• Existing mTOR kinase inhibitors (TOR-KIs) targeting both mTORC1 and mTORC2 have shown limited efficacy in clinical trials for blood cancers.
• Selective inhibition of mTORC1 or downstream pathways like the eukaryotic initiation factor 4F (eIF4F) complex offers a potential strategy for improved leukemia cell targeting.

Purpose of the Study:

• To investigate the efficacy of selectively targeting mTORC1 kinase activity or eIF4F complex components in sensitizing B-ALL cells to tyrosine kinase inhibitors (TKIs).
• To evaluate the therapeutic potential of SBI-756, an eIF4F assembly inhibitor, in combination with TKIs for B-ALL treatment.

Main Methods:

• Utilized novel chemical and genetic approaches to selectively target mTORC1 or eIF4F in murine BCR-ABL-dependent pre-B leukemia cells.
• Assessed the impact of SBI-756 on the cytotoxicity of dasatinib in human Ph+ and Ph-like B-ALL cells.
• Evaluated the effect of SBI-756 on the survival of T lymphocytes and natural killer cells.

Main Results:

• Selective targeting of mTORC1 or eIF4F components sensitized murine leukemia cells to dasatinib.
• SBI-756 demonstrated sensitization of human Ph+ and Ph-like B-ALL cells to dasatinib-induced cytotoxicity.
• SBI-756 did not adversely affect the survival of T lymphocytes or natural killer cells.

Conclusions:

• Selective targeting of the eIF4F complex, using agents like SBI-756, is a viable strategy to enhance TKI efficacy in B-ALL.
• Combination therapy with eIF4F-targeted molecules and TKIs warrants further investigation for B-ALL and other blood cancers.