MAPK/ERK and PI3K/AKT signaling pathways are activated in adolescent and adult acute lymphoblastic leukemia

Background: The mitogen‐activated protein kinase (MAPK)/ERK signaling cascade and the phosphoinosytol‐3 phosphate/Akt (PI3K/Akt) pathways are involved in proliferation and differentiation of hematopoietic cells. The frequency of PI3K/Akt and MAPK pathway activation in adult acute lymphoblastic leukemia (ALL) still need to be elucidated. Aims: To assess the activity and prognostic implications of MAPK/ERK and PI3K/Akt pathways in adult (ALL). Methods We examined 28 precursor‐B‐cell ALL and 6 T‐cell primary ALL samples. Flow cytometry was employed to analyze the expression levels of phosphorylated ERK and phosphorylated Akt. Results Ten out of 15 (67%) ALL fresh samples (7 B‐cell, 3 T‐cell) showed constitutive p‐ERK expression. The p‐ERK mean fluorescent index ratio (MFI (R)) showed a tendency to be higher in ALL than in normal T lymphocytes (1.26 [0.74–3.10] vs. 1.08 [1.02–1.21], respectively [p = .069]) and was significantly lower than in leukemic cell lines (median MFI (R) 3.83 [3.71–5.97] [p