The Prognostic Value of RASGEF1A RNA Expression and DNA Methylation in Cytogenetically Normal Acute Myeloid Leukemia
Authors: He Xue , Zhang Weilong , Fu Wei , Liu Xiaoni , Yang Ping , Wang Jing , Li Shaoxiang , Zhang Xiuru , Dong Gehong , Yan Changjian , Zhao Yali , Jing Hongmei 
Published: July 2021

Abstract
Background

Acute myeloid leukemia (AML) is a significantly heterogeneous malignancy of the blood. Cytogenetic abnormalities are crucial for the prognosis of AML. However, since more than half of patients with AML are cytogenetically normal AML (CN-AML), new markers are badly required for predicting prognosis. In recent years, gene abnormalities are considered to be strong prognostic factors of CN-AML, already having clinical significance for treatment. In addition, the relationship of methylation in some genes and AML prognosis predicting has been discovered. RASGEF1A is a guanine nucleotide exchange factors of Ras, and has been reported to relate to malignancy. However, there is no research about the relationship of RASGEF1A gene and CN-AML.
Methods

By integrating the Cancer Genome Atlas (TCGA) database 75 patients with CN-AML and 240 Gene Expression Omnibus (GEO) database CN-AML samples, we examined the association between RASGEF1A ’s RNA expression level and DNA methylation of and AML patients’ prognosis. Then, we investigated the RASGEF1A RNA expression and DNA methylation’s prognostic value in 77 patients with AML after allogeneic hematopoietic stem cell transplantation (Allo-HSCT) as well as 101 AML patients after chemotherapy respectively. We investigated the association between sensitivity to Crenolanib and expression level of RASGED1A in patients by integrating 191 CN-AML patients from BeatAML dadataset. Finally, we integrated the expression and methylation of RASGEF1A to predict the CN-AML patients’ prognosis.
Results

We found that RASGEF1A gene high expression group predicted poorer event-free survival (EFS) (P < 0.0001) as well as overall survival (OS) (P < 0.0001) in CN-AML samples, and the identical results were found in AML patients receiving chemotherapy (P < 0.0001) and Allo-HSCT (P < 0.0001). RASGEF1A RNA expression level is an CN-AML patients’ independent prognostic factor (EFS: HR = 5.5534, 95% CI: 1.2982–23.756, P = 0.0208; OS: HR = 5.3615, 95% CI: 1.1014–26.099, P = 0.0376). The IC50 (half maximal inhibitory concentration) of Crenolanib of CN-AML samples with RASGEF1A high expression level is lower. In addition, patients with high RASGEF1A methylation level had significant favorable prognosis (EPS: P < 0.0001, OS: P < 0.0001). Furthermore, the integrative analysis of expression and methylation of RASGEF1A could classify CN-AML patients into subgroups with different prognosis (EFS: P < 0.0001, OS: P < 0.0001).
Conclusion

Higher RASGEF1A RNA expression and lower DNA methylation predicts CN-AML patients’ poorer prognosis. The RASGEF1A high expression level from patients with CN-AML have better sensitivity to Crenolanib. The integrative analysis of RASGEF1A RNA expression and DNA methylation can provide a more accurate classification for prognosis. Lower RASGEF1A expression is a favorable prognostic factor for AML patients receiving chemotherapy or Allo-HSCT.