Low Expression of Long Noncoding RNA IRAIN Is Associated with Poor Prognosis in Non-M3 Acute Myeloid Leukemia Patients

Aims: Deregulation of the long noncoding RNA IRAIN has been identified in several cancers. However, the expression pattern of IRAIN and its clinical implication in acute myeloid leukemia (AML) is unknown. The purpose of this study was to investigate the expression status of IRAIN and its clinical significance in non-M3 AML patients. Methods: Quantitative reverse transcription-polymerase chain reaction was performed to examine IRAIN transcript levels in 64 de novo non-M3 AML patients and 51 healthy controls. The association of IRAIN expression with clinicopathological factors was statistically analyzed. Results: Compared with the controls, IRAIN was significantly downregulated in non-M3 AML patients (p<0.001). The median of IRAIN expression divided the non-M3 AML patients into IRAIN low-expressing (IRAIN(low)) and IRAIN high-expressing (IRAIN(high)) groups. The IRAIN(low) group tended to have higher white blood cell count and blast counts and had markedly shorter overall survival (OS) and relapse-free survival (RFS) (p=0.044 and 0.009, respectively). In addition, patients with refractory response to chemotherapies and those with subsequent relapse had lower initial IRAIN expression. Multivariate analysis further identified IRAIN transcript levels as an independent prognostic factor for both RFS and OS. Conclusions: Our finding suggests that IRAIN transcript levels may be used as a potential diagnostic and prognostic marker for non-M3 AML patients.