PCAT18, as a novel differentially regulated long noncoding RNA in adult acute myeloid leukemia patients revealed by next-generation sequencing.

INTRODUCTION Long noncoding RNAs (lncRNAs) play significant roles in the carcinogenesis and progression of human tumors. The aim of this work was to evaluate the expression level of lncRNAs in adult acute myeloid leukemia (AML) patients and to explore the function of candidate lncRNA PCAT18 in clinical diagnosis and prognosis of AML. METHODS Noncoding RNA screening was performed by second-generation sequencing on adult newly diagnosed AML patients and healthy controls. GO and KEGG pathway analysis were performed for functional analysis of differentially regulated lncRNAs. The expression of candidate lncRNA PCAT18 was detected by real-time PCR. In K-562 and THP-1 cells, proliferation, and cell cycle analysis were performed using CCK-8 assay and Cell Cycle Assay Kit. RESULTS The lncRNA expression profile of AML patients and healthy controls showed that six upregulated (>5-fold) and eight downregulated (<0.2-fold) lncRNAs. The candidate lncRNA PCAT18 showed higher expression in AML patients with NPM1 mutation and favorable-risk. RT-PCR revealed a significant increase of PCAT18 expression comparing to control cells. PCAT18 overexpression obviously promoted cell proliferation and PCAT18 knockdown decreased cell proliferation. The fraction of the S phases was increased in the PCAT18 overexpression group and decreased in the PCAT18 knockdown group. CONCLUSIONS The candidate lncRNA PCAT18 in our study was firstly found upregulated in AML samples, that its overexpression promoted cell proliferation and G1/S transition. Further study of PCAT18 and its target mRNAs are needed to confirm the mechanism of PCAT18 in AML. PCAT18 may act as diagnostic and prognosis biomarker for AML.