Nf1-Mutant Tumors Undergo Transcriptome and Kinome Remodeling after Inhibition of either mTOR or MEK

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Loss of the NF1 tumor suppressor gene activates RAS effector pathways.
• Targeted therapies like mTOR inhibitors (mTORi) and MEK inhibitors (MEKi) are used to inhibit these pathways.
• Acquired drug resistance and disease progression limit the efficacy of these treatments.

Purpose of the Study:

• To investigate molecular signatures associated with NF1 loss and acquired drug resistance.
• To compare the biochemical profiles and responses to kinase inhibition in NF1-mutant tumor cells.
• To characterize the stability of resistance phenotypes to MEKi and mTORi.

Main Methods:

• Analysis of exomes, transcriptomes, and kinomes of NF1-mutant mouse tumor cell lines.
• Generation and analysis of cell lines with acquired resistance to MEKi or mTORi.
• Biochemical comparisons of tumor cell panels derived from Nf1 mice.

Main Results:

• NF1 loss of heterozygosity does not confer a common biochemical signature or response to kinase inhibition.
• Acquired drug resistance in NF1-mutant cells involves altered kinomes and transcriptomes.
• MEK inhibitor resistance is a stable phenotype, while mTOR inhibitor resistance is reversible in multiple NF1-mutant cell lines.

Conclusions:

• NF1-mutant tumors exhibit significant biochemical heterogeneity.
• Targeted kinase inhibition induces broad remodeling of kinome activity and gene expression.
• Understanding these molecular changes is crucial for developing effective therapeutic strategies for NF1-related cancers.