Targeting nonclassical oncogenes for therapy in T-ALL

Area of Science:

• Oncology
• Molecular Biology
• Immunology

Background:

• Constitutive phosphoinositide 3-kinase (PI3K)/Akt pathway activation is a hallmark of T-cell acute lymphoblastic leukemia (T-ALL).
• Four class I PI3K isoforms (α, β, γ, δ) are implicated, but their specific roles in T-ALL pathogenesis remain unclear.
• PTEN phosphatase tumor suppressor loss is common in T-ALL, leading to aberrant PI3K/Akt signaling.

Purpose of the Study:

• To investigate the specific roles of PI3K isoforms in PTEN-null T-ALL.
• To evaluate the therapeutic potential of targeting PI3K isoforms in T-ALL.

Main Methods:

• Utilized mouse models of PTEN-null T-ALL.
• Assessed leukemogenesis upon individual or combined inactivation of PI3Kγ and PI3Kδ.
• Administered a dual PI3Kγ/δ inhibitor to T-ALL mouse models and human T-ALL cells.

Main Results:

• PI3Kγ or PI3Kδ alone could support leukemogenesis in PTEN-null T-ALL.
• Inactivation of both PI3Kγ and PI3Kδ suppressed tumor formation.
• Dual PI3Kγ/δ inhibition reduced disease burden, prolonged survival in mice, and inhibited proliferation of human T-ALL cells.

Conclusions:

• PTEN-null T-ALL is critically dependent on the combined activity of PI3Kγ and PI3Kδ.
• Combined inhibition of PI3Kγ/δ demonstrates therapeutic efficacy in preclinical T-ALL models.
• Targeting PI3Kγ/δ offers a promising therapeutic strategy for T-ALL.