Inhibiting H3K27 Demethylases Downregulates CREB-CREBBP, Overcoming Resistance in Relapsed Acute Lymphoblastic...

Area of Science:

• Epigenetics
• Cancer Biology
• Hematology

Background:

• CREB binding protein (CREBBP) is a crucial epigenetic regulator implicated in relapsed acute lymphoblastic leukemia (ALL).
• Targeting epigenetic signaling offers a novel strategy to combat drug resistance in ALL.
• GSK-J4, an H3K27 histone demethylase inhibitor, has demonstrated anti-tumor effects in preclinical cancer models.

Purpose of the Study:

• To investigate the therapeutic potential of GSK-J4 in ALL.
• To characterize the molecular mechanisms underlying GSK-J4's anti-leukemic effects.
• To identify biomarkers for predicting response to GSK-J4 treatment.

Main Methods:

• Drug response profiling, CRISPR-Dropout Screening, BH3 profiling, and immunoblotting were employed.
• Experiments were conducted on ALL cell lines and patient-derived samples.
• Analysis focused on the effects of GSK-J4 on CREB, CREBBP, and apoptosis-related proteins.

Main Results:

• GSK-J4 was found to downregulate CREB and CREBBP in B-cell precursor-ALL (BCP-ALL).
• High CREBBP expression correlated with increased sensitivity to GSK-J4 and decreased sensitivity to dexamethasone.
• GSK-J4 treatment induced dependency on Bcl-2 and Bcl-XL, leading to apoptosis.

Conclusions:

• H3K27 demethylase inhibition represents a promising treatment strategy for refractory ALL.
• CREBBP serves as a potential biomarker for predicting patient response to GSK-J4.
• Combination therapy with GSK-J4, venetoclax, and navitoclax demonstrated synergistic effects.