High expression of CD52 mRNA predicts poor prognosis for cytogenetic normal acute myeloid Leukemia patients

Abstract Background: The prognosis of cytogenetic normal acute myeloid leukemia (CN-AML) varies. Finding new biomarkers affecting the prognosis of these patients may bring a new strategy for precise classification and treatment. CD52 plays a significant role in chronic lymphocytic leukemia (CLL). However, the potential role of CD52 in CN-AML remains largely elusive. Methods: We analyzed the prognostic role of different expression levels of CD52 in 58 CN-AML from The Cancer Genome Atlas (TCGA) dataset and validated these results with 345 CN-AML patients from Gene Expression Omnibus (GEO) dataset. Results: CN-AML patients with high CD52 mRNA expression had a poorer prognosis compared to low CD52 expression ( event-free survival [EFS], P =0.056; overall survival [OS], P=0.043; log-rank test) and the results was verified by GSE12417 (OS, P=0.020; log-rank test) and GSE71014 (OS, P=0.020; log-rank test). Hematopoietic stem cell transplantation (HSCT) may improve prognosis of patients with CD52 high . Regression analysis shows that the expression level of CD52 (HR=1.503; 95%CI:1.158-1.949 ; P=0.002) is a prognostic factor independent of age (HR=3.045; 95%CI:1.524-6.086; P=0.002) and FLT3 mutation status (HR=2.219; 95%CI:1.123-4.382; P=0.022). CD52 gene expression shows a predictive effect on EFS (1-year survival- area under the curve [AUC]:0.685, 2-year survival-AUC:0.752) and OS (1-year survival-AUC: 0.717, 2-year survival-AUC:0.770). Besides, we also found that there is a significant negative correlation between CD52 mRNA expression and DNA methylation . Accordingly, we speculated that CD52 DNA hypomethylation may responsible for the high level of CD52 mRNA. Functional enrichment analysis of differentially expressed genes in CD52 high and CD52 low suggests that adhesion molecule deregulation maybe also the potential pathological mechanism of CD52. Conclusions: CD52 gene mRNA overexpression is an independent adverse prognostic factor for CN-AML. CD52 DNA hypomethylation may responsible for the high level of CD52 mRNA. Adhesion molecule deregulation maybe potential pathological mechanism of CD52. Whether CD52 monoclonal antibodies play a role in high risk patients need further research.