Pharmacologic inhibition of PI3K p110δ in mutant Shp2E76K-expressing mice

Area of Science:

• Oncology
• Hematology
• Molecular Biology

Background:

• Juvenile myelomonocytic leukemia (JMML) is a rare childhood cancer with limited effective treatments.
• The PI3K p110δ pathway is implicated in the hyperproliferation of cells with the Shp2 gain-of-function mutation, a key factor in JMML.

Purpose of the Study:

• To evaluate the therapeutic efficacy of a PI3Kδ inhibitor in a mouse model of JMML.
• To assess the impact of PI3Kδ inhibition on leukemia cell burden and survival.

Main Methods:

• Treatment of mice harboring the Shp2 E76K gain-of-function mutation with a PI3Kδ inhibitor.
• Assessment of splenomegaly, bone marrow progenitor cell frequency, and peripheral blood myeloid cell differentiation.
• Survival analysis of treated versus control mice.

Main Results:

• PI3Kδ inhibitor treatment significantly reduced splenomegaly and the frequency of bone marrow progenitor cells.
• The drug increased the proportion of terminally differentiated myeloid cells in peripheral blood.
• Drug-treated mice exhibited significantly prolonged survival compared to vehicle-treated controls.

Conclusions:

• PI3Kδ inhibition demonstrates therapeutic potential for JMML by targeting key cellular pathways.
• These findings support the investigation of PI3Kδ inhibitors as a treatment strategy for JMML and other myeloid malignancies.
• Existing PI3Kδ inhibitors used for lymphoid malignancies may be repurposed for myeloid diseases.