Phenotypic-screening generates active novel fetal globin-inducers that downregulate Bcl11a in a monkey model

Area of Science:

• Genetics and Molecular Biology
• Hematology
• Drug Discovery

Background:

• Heritable hemoglobin disorders, including β-thalassemia and sickle cell disease, are common monogenic conditions.
• Increasing fetal hemoglobin (HbF) levels can alleviate the clinical severity of these β-hemoglobinopathies.

Purpose of the Study:

• To identify novel compounds that enhance γ-globin expression, a component of HbF, using high-throughput phenotypic screening.
• To investigate the mechanism of action of identified compounds on epigenetic enzymes and transcriptional factors.
• To evaluate the efficacy of a lead compound in vivo.

Main Methods:

• High-throughput phenotypic screening of approximately 18,000 compounds.
• Testing selected compounds for HbF induction in human erythroid cell lines and primary erythroid progenitors (CD34+ cells).
• In vivo evaluation of a lead compound in monkey models, including assessment of its effect on transcriptional regulators (Bcl11a, LRF).

Main Results:

• Eighteen compounds were selected from the initial screen, with one 3-phenyl-isoxazole derivative showing significant promise.
• This compound demonstrated the potential to induce HbF in monkey bone marrow cells following oral administration.
• The compound downregulated negative transcriptional regulators of HbF (Bcl11a and LRF) without affecting known epigenetic enzymes.

Conclusions:

• Phenotypic screening is an effective approach for discovering novel therapeutic agents for hemoglobinopathies.
• A novel 3-phenyl-isoxazole derivative was identified as a potent inducer of fetal hemoglobin.
• This compound represents a promising therapeutic candidate for treating β-hemoglobinopathies by modulating key transcriptional regulators.