Targeting heterochromatin eliminates chronic myelomonocytic leukemia malignant stem cells through reactivation of...

Area of Science:

• Hematology
• Cancer Biology
• Epigenetics

Background:

• Chronic myelomonocytic leukemia (CMML) is a severe myeloid malignancy with limited treatment options.
• Current DNA hypomethylating agents (HMAs) offer only temporary responses in CMML patients.
• HSC aging involves heterochromatin changes, including altered H3K9me2 and H3K9me3 marks, crucial for suppressing transposable elements (TEs).

Purpose of the Study:

• To investigate the role of heterochromatin disorganization in CMML hematopoietic stem and progenitor cells (HSPCs).
• To explore the potential of combining HMAs with G9A/GLP inhibitors as a novel therapeutic strategy for CMML.

Main Methods:

• Analysis of heterochromatin organization and histone marks (H3K9me2) in CMML HSPCs.
• Assessment of TE derepression and immune/age-associated transcript reactivation.
• Evaluation of combination therapy with HMAs and G9A/GLP inhibitors in targeting mutated cells.

Main Results:

• Significant heterochromatin disorganization observed in CMML HSPCs, with increased H3K9me2 at TEs.
• Repression of immune and age-associated transcripts in CMML HSPCs.
• Combination therapy reactivated these pathways, selectively targeting mutated cells while sparing wild-type HSCs.

Conclusions:

• Heterochromatin disorganization and TE repression are key features of CMML HSPCs.
• Combining HMAs with G9A/GLP inhibitors represents a promising therapeutic strategy for CMML.
• This approach offers selective targeting of malignant cells and preservation of healthy stem cells.