Peripheral blood cells from children with RASopathies show enhanced spontaneous colonies growth in vitro and...

Area of Science:

• Genetics and Molecular Biology
• Hematology
• Pediatric Oncology

Background:

• RASopathies are genetic disorders caused by mutations in the RAS/RAF/MEK/ERK pathway.
• Noonan syndrome (NS) is a common RASopathy associated with potential complications like juvenile myelomonocytic leukemia (a myeloproliferative disorder, MPD).
• Hematological alterations in RASopathies are not fully understood.

Purpose of the Study:

• To investigate in vitro hematological differences in children with RASopathies compared to healthy controls.
• To explore potential early markers for myeloproliferative disorders (MPDs) in children with RASopathies.

Main Methods:

• Studied peripheral blood (PB) cells from 27 children with RASopathies (including NS) and 35 age-matched controls.
• Assessed in vitro colony-forming units (CFUs) activity, specifically burst-forming units-erythroid (BFU-E) and CFU-granulocyte/macrophage (CFU-GM).
• Analyzed intracellular phosphosignaling, including GM-colony-stimulating factor-induced p-ERK.

Main Results:

• Patients with RASopathies exhibited higher spontaneous growth of BFU-E and CFU-GM colonies compared to controls.
• Children with RASopathies showed significantly increased GM-colony-stimulating factor-induced p-ERK levels.
• Peripheral blood cells from RASopathy patients without MPD displayed enhanced in vitro colony formation.

Conclusions:

• Children with RASopathies, even without diagnosed MPDs, show enhanced in vitro blood cell formation.
• These findings suggest potential novel hematological markers for monitoring RASopathy patients.
• Further research is needed to understand the clinical significance and implications for MPD progression.