Correlation of miRNA-509 expression level with the clinical characteristics and prognosis in acute myeloid leukemia patients / 白血病·淋巴瘤

ABSTRACT

Objective:To explore the correlation of miRNA-509 (miR-509) expression level with the clinical characteristics and prognosis in acute myeloid leukemia (AML) patients.Methods:The RNA-seq expression data and clinical data of 162 newly diagnosed AML patients (non-M 3 subtype) based on the World Health Organization (WHO) classification were obtained from the Cancer Genome Atlas (TCGA) database (Project IDTCGA-LAML). The final follow-up time was April 30th, 2013. According to the different treatment methods, all cases were firstly divided into the chemotherapy group and allogeneic hematopoietic stem cell transplantation (allo-HSCT) group. Each group was subdivided into high miR-509 group and low miR-509 group according to the median relative expression of miR-509, respectively; the clinical characteristics of both groups were analyzed. The effects of miR-509 relative expression level on overall survival (OS) and event-free survival (EFS) of AML patients in chemotherapy group and allo-HSCT group were compared. On the other hand, cases were divided into two groups based on the median relative expression level of miR-509, then each group were further divided into the chemotherapy subgroup and allo-HSCT subgroup according to different treatment methods. The differences of OS and EFS of AML patients with different miR-509 expression in chemotherapy and allo-HSCT subgroups were compared. Results:All the 162 AML patients were firstly divided into chemotherapy group (90 cases) and allo-HSCT group (72 cases). Each group was subdivided into high miR-509 and low miR-509 group according to the median relative expression of miR-509 (chemotherapy group 14.07, allo-HSCT group 14.85), respectively. There were no statistically significant differences in the proportion of patients with gender, white blood cell count at initial diagnosis, bone marrow blast/naive cells ratio, peripheral blood blast/naive cells ratio and France-America-British (FAB) subtype between high miR-509 and low miR-509 subgroups in chemotherapy subgroup and allo-HSCT subgroup (all P > 0.05). In the chemotherapy group, low miR-509 group comprised more cases with intermediate prognosis compared to high miR-509 group[68.9% (31/45) vs. 42.2% (19/45), χ2 = 6.48, P = 0.011]. No significant differences in the proportion of patients with other risk stratification were found between both subgroups (all P > 0.05). Of the 90 cases in chemotherapy group, the median OS time in low miR-509 group (45 cases) and high miR-509 group (45 cases) was 10.2 months and 6.7 months, respectively. The 5-year OS rates of the two subgroups in chemotherapy group were 17.9% and 17.0%, and the 5-year EFS rates were 16.9% and 18.2%.There were no significant differences in OS and EFS of low miR-509 group and high miR-509 group ( P = 0.575, P = 0.436). In the allo-HSCT group (72 cases), longer OS and EFS were observed in low miR-509 group compared with high miR-509 group, and the differences were statistically significant ( P = 0.006, P = 0.022). All the 162 cases were divided into low miR-509 group (81 cases) and high miR-509 group (81 cases) based on the median expression level of miR-509 (14.19). In the low miR-509 expression group, cases administered allo-HSCT had a better OS in comparison with those administered chemotherapy ( P<0.001). The EFS of the allo-HSCT group was better than that of chemotherapy group, but the difference was not statistically significant ( P = 0.079). In the high miR-509 expression group, the allo-HSCT group had a better OS compared with that of the chemotherapy group ( P = 0.043). There was no significant difference in the EFS between the allo-HSCT group and chemotherapy group in high miR-509 group ( P = 0.154). Conclusions:The expression level of miR-509 may be helpful in the treatment selection of AML patients. Allo-HSCT can improve the prognosis of patients with low expression of miR-509.