Using BRAF(V600E) as a marker of autophagy dependence in pediatric brain tumors

Area of Science:

• Oncology
• Molecular Biology
• Cancer Therapeutics

Background:

• Autophagy inhibition presents a novel therapeutic avenue for central nervous system (CNS) tumors.
• The BRAF(V600E) mutation is implicated in modulating autophagy.
• Understanding the interplay between BRAF(V600E) and autophagy is crucial for developing targeted therapies.

Purpose of the Study:

• To investigate the role of BRAF(V600E) mutation in autophagy in CNS tumors.
• To evaluate the efficacy of autophagy inhibition, particularly with chloroquine, in BRAF(V600E)-mutated CNS tumors.
• To explore the synergistic effects of chloroquine with RAF kinase inhibitors and standard chemotherapeutics.

Main Methods:

• Comparative analysis of autophagy rates in BRAF(V600E) mutant versus wild-type CNS tumor cells.
• Assessment of sensitivity to autophagy inhibition (e.g., chloroquine) in these cells.
• Evaluation of drug synergy between chloroquine and vemurafenib or chemotherapeutics in preclinical models.
• Clinical case study of chloroquine's effect on vemurafenib resistance.

Main Results:

• CNS tumor cells with BRAF(V600E) mutations exhibit high induced autophagy rates, unlike wild-type cells.
• BRAF(V600E)-mutated cells are sensitive to autophagy inhibition.
• Chloroquine demonstrates synergistic effects when combined with vemurafenib or standard chemotherapeutics.
• Chloroquine enhances vemurafenib sensitivity in resistant cells and a patient.

Conclusions:

• CNS tumors harboring the BRAF(V600E) mutation are dependent on autophagy for survival.
• BRAF(V600E) status can serve as a predictive biomarker for response to autophagy inhibition therapies.
• Targeting autophagy, especially in combination therapies, offers a promising strategy for treating BRAF(V600E)-mutated CNS tumors, including those with acquired resistance.