Expression of the long noncoding RNA CASC2 in acute myeloid leukemia and its prognostic significance.

Background: Cancer susceptibility candidate 2 (CASC2) was found underexpressed in multiple types of human malignancies. However, the specific role of CASC2 in AML remains uncertain. The purpose of this study is to explore the expression of CASC2 in patients with AML and healthy donors and its prognostic significance in AML.

Methods: Total RNA was isolated from bone marrow samples or peripheral blood samples of 87 patients with AML and 26 healthy adult donors. The expression of long noncoding RNA CASC2 was detected by quantitative real-time polymerase chain reaction. The association between CASC2 expression and other clinicopathological factors as well as its prognosis significance were analyzed.

Results: The peripheral blood mononuclear cell (PBMC) expression level of CASC2 in AML was significantly lower than that in the healthy control cohort (P = 0.0048), and in the bone marrow samples, CASC2 was significantly upregulated in patients with AML after the achievement of CR (median value: 0.041, range: 0.015-0.064) compared with that at newly diagnosis (median value: 0.017, range: 0.008-0.041) (P = 0.002). The expression of CASC2 had a significant relationship with complete remission (P = 0.019). Survival data assessed by Kaplan-Meier curves showed that patients with lower CASC2 expression had shorter overall survival and disease-free survival than patients with higher CASC2 expression. Finally, Cox proportional hazards analysis demonstrated that CASC2 was an independent prognostic indicator for both OS (P = 0.013) and DFS (P = 0.001) of AML.

Conclusions: LncRNA CASC2 may serve as a new molecular biomarker for the early diagnosis and of AML, and may be an independent prognostic factor affecting the survival of patients with AML.