Wntless (GPR177) expression correlates with poor prognosis in B-cell precursor acute lymphoblastic leukemia via Wnt signaling.

B-cell precursor acute lymphoblastic leukemia (BCP ALL) is the most common childhood leukemia, with a cure rate of 80%. Nevertheless, disease relapse is the most important prognostic factor for the disease outcome. We aimed to elucidate the role of Wnt secretion-regulating protein, Wntless (Wls)/GPR177, on disease outcome in pediatric patients with BCP ALL, and assess its pathogenetic role in the regulation of the disease. Wls expression was characterized and correlated with Wnt pathway signaling in the bone marrow leukemia cells isolated from 44 pediatric patients with BCP ALL. The overexpression of Wls was detected in leukemia cells and was significantly correlated with the disease relapse and poor survival in the patients. The high expression of Wls also correlated with the Wnt expression and consequent downstream signaling activation, which was shown to provide essential proliferation, transformation and anti-apoptotic activity during leukemogenesis. These results indicated that Wls played an essential role in disease relapse and poor survival in patients with BCP ALL. Therefore, Wls may provide a potential future therapeutic target, particularly for patients who do not respond to existing therapies and suffer relapse.