High expression of CD52 predicts poor prognosis of cytogenetic normal acute myeloid leukemia

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 play 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 validate these results with 345 CN-AML patients from Gene Expression Omnibus (GEO) dataset. Results: CN-AML patients with high CD52 mRNA expression have 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=0.0197; log-rank test) and GSE71014 (OS, P=0.0197; log-rank test). Hematopoietic stem cell transplantation (HSCT) may improve prognosis of patients with CD52 high . Multivariate cox regression analysis show that the expression level of CD52 (HR=1.503; 95%CI:1.158-1.949 ; P=0.002) was 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 show 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 . CD52 DNA demethylation may responsible for the high level of CD52 mRNA. Functional enrichment analysis of differentially expressed genes in CD52 high and CD52 low suggests that leukemia cell adhesion-related pathways may be associated with poor prognosis in CD52 high patients . Conclusions: CD52 gene mRNA overexpression is an independent adverse prognostic factor for CN-AML, which could be reversed by HSCT. CD52 DNA demethylation may responsible for the high level of CD52 mRNA. The poor prognosis of patients with CD52 high may involves in leukemia cell adhesion-related pathways. Whether CD52 monoclonal antibodies play a role in high risk patients need further research.