[Venetoclax resistance and molecular abnormalities in AML]

Area of Science:

• Hematology
• Oncology
• Molecular Biology

Background:

• Venetoclax (BCL-2 inhibitor) has improved outcomes for acute myeloid leukemia (AML) patients.
• Resistance to venetoclax is a significant clinical challenge, affecting approximately 30% of patients initially and leading to relapse.
• Understanding the complex mechanisms of venetoclax resistance is critical for optimizing AML treatment.

Purpose of the Study:

• To elucidate the multifaceted mechanisms underlying venetoclax resistance in acute myeloid leukemia.
• To investigate the role of metabolic adaptation and compensatory signaling pathways in conferring resistance.
• To explore the correlation between specific genetic mutations and venetoclax sensitivity or resistance in AML.

Main Methods:

• Analysis of AML stem cell metabolism, focusing on oxidative phosphorylation (OXPHOS) and compensatory pathways.
• Investigation of altered expression of anti-apoptotic proteins (MCL-1, BCL-XL) in resistant cells.
• Correlation of venetoclax response with specific molecular abnormalities, including TP53, RAS, FLT3, IDH1/2, and NPM1 mutations.

Main Results:

• Venetoclax disrupts mitochondrial function, but resistant AML cells activate alternative metabolic pathways (fatty acid oxidation, amino acid metabolism) and signaling (MEK-ERK).
• Upregulation of MCL-1 and BCL-XL, along with rare BCL2 mutations, contributes to resistance by circumventing BCL-2 inhibition.
• Specific genetic mutations strongly predict venetoclax response: TP53 mutations indicate poor outcomes, RAS/FLT3 mutations confer moderate resistance, while IDH1/2 and NPM1 mutations are associated with high sensitivity.

Conclusions:

• Venetoclax resistance in AML is driven by metabolic adaptation, compensatory signaling, altered anti-apoptotic protein expression, and genetic mutations.
• Genetic profiling is essential for predicting venetoclax response and tailoring treatment strategies.
• Combination therapies targeting metabolic pathways or resistance mechanisms, guided by genetic profiles, offer a promising approach to overcome resistance and improve AML patient survival.