Expression Pattern of Long Non-Coding RNA Growth Arrest-Specific 5 in the Remission Induction Therapy in Childhood Acute Lymphoblastic Leukemia

Background: Long non-coding RNA growth arrest-specific 5 (GAS5) is deregulated in many cancers because of its role in cell growth arrest and apoptosis. Additionally, GAS5 interacts with glucocorticoid receptor, making it a potential pharmacotranscription marker of glucocorticoid (GC) therapy. In this study, we aimed at analysing GAS5 expression in the remission induction therapy phase of childhood acute lymphoblastic leukemia (ALL), in which GCs are mandatorily used, and to correlate it with therapy response. Methods: GAS5 expression was measured in peripheral blood mononuclear cells taken from 29 childhood ALL patients at diagnosis, on day 15 and day 33 ofremission induction therapy using RT-qPCR methodology. Results: Our results have shown interindividual differences in GAS5 expression at all time points. For each ALL patient, GAS5 expression was higher on day 15 in comparison to its level at diagnosis (p<0.0005). On day 33, the level of GAS5 expression decreased in comparison with day 15 (p<0.0005), but it was still significantly higher than at diagnosis for the majority of patients (p=0.001). Patients whose number of blasts on day 8 was below 100 per mL of peripheral blood had a higherGAS5 expression at diagnosis (p=0.016), and lower ratio day 15/diagnosis (p=0.009). Conclusions: Our results suggest that the expression level of GAS5 could be a potential marker of therapy response in remission induction therapy of childhood ALL.