LINC00221 suppresses the malignancy of children acute lymphoblastic leukemia.

As the most common malignant disease in childhood, children acute lymphoblastic leukemia (ALL) is a heterogeneous disease caused by the accumulated genetic alterations. Long non-coding RNAs (lncRNAs) are reported as critical regulators in diseases. GEPIA database indicated that long intergenic non-protein coding RNA 221 (LINC00221) was conspicuously down-regulated in acute myeloid leukemia. However, its expression pattern in ALL has not been revealed. This work was carried out to study the role of LINC00221 in ALL cells. Quantitative real-time PCR (qRT-PCR) quantified LINC00221 expression in ALL cells. The function of LINC00221 in ALL was determined by ki-67 immunofluorescence staining, EdU, TUNEL, JC-1, and caspase-3/8/9 activity assays. RNA pull down and Ago2-RNA immunoprecipitation (RIP) assays investigated the interaction between miR-152-3p and LINC00221 or ATPase sarcoplasmic/endoplasmic reticulum Ca2+ transporting 2 (ATP2A2). Our study revealed the low expression of LINC00221 in ALL cells. Subsequently, LINC00221 was verified to bind with miR-152-3p. Moreover, functional assays pointed out that LINC00221 overexpression posed anti-proliferation and pro-apoptosis effects in ALL cells, and these effects could be separately reversed by miR-152-3p up-regulation. Afterward, LINC00221 was revealed to regulate ATP2A2 expression via sponging miR-152-3p. Additionally, ATP2A2 was verified to involve in regulating LINC00221-mediated ALL cell proliferation and apoptosis. In conclusion, LINC00221 suppressed ALL cell proliferation and boosted ALL cell apoptosis via sponging miR-152-3p to up-regulate ATP2A2.