Lower expression of bone marrow miR-122 is an independent risk factor for overall survival in cytogenetically normal acute myeloid leukemia.

Background The liver-enriched microRNA-122 ( miR-122 ) plays a crucial role in pathogenesis of hepatocellular carcinoma (HCC) with prognostic value. Recently, miR-122 was also found to be related to many other cancers besides HCC. However, less study determined miR-122 expression and its clinical significance in acute myeloid leukemia (AML). Methods Real-time quantitative PCR was performed to detect the level of bone marrow (BM) miR-122 in de novo AML patients. The clinical significance of miR-122 expression in AML was further investigated. Results Among whole-cohort AML, lower expression of BM miR-122 was associated with male patients, higher hemoglobin and favorable-karyotypes ( P  = 0.038, 0.006, and 0.038, respectively). Among cytogenetically normal AML (CN-AML), lower expression of BM miR-122 was correlated with DNMT3A wild type ( P  = 0.043). Moreover, patients with lower expression of BM miR-122 presented lower complete remission (CR) rate and shorter overall survival (OS) than those with higher expression of BM miR-122 in CN-AML ( P  = 0.025 and 0.013, respectively). Cox regression analyses further confirmed the prognostic value of BM miR-122 expression in CN-AML ( P  = 0.024). In follow-up patients, BM miR-122 expression level in CR time was increased compared to diagnosis time, and was returned to primary level when in relapse time again ( P  = 0.062 and 0.049, respectively). Conclusions Our findings indicated that lower expression of BM miR-122 acted as an independent risk factor for OS in CN-AML. [ABSTRACT FROM AUTHOR]