Background: Acute myeloid leukemia (AML) is one of the most common hematological diseases in adults. The overall survival rate remains unsatisfactory. It is urgent to identify potential prognostic biomarkers and develop new molecular therapeutic strategies for AML. Signal transducer and activator of transcription (STAT) is a family of genes that encode intracellular transcription factors. STATs are associated with leukemogenesis, cellular transformation, and cell cycle in AML.
Methods: We used sequencing data and clinical data from The Cancer Genome Atlas (TCGA) and ONCOMINE to identify expression difference, gene variability and correlation as well as prognostic effects of STAT genes in AML patients. Then, we verified the expression difference of STAT6  between healthy control and AML patients and its prognostic impact in Gene Expression Omnibus (GEO) database and our own recruited cohort.
Results: The mRNA level of STAT6  was increased in AML patients among TCGA, GEO and ONCOMINE public datasets and was found to be an independent risk factor of overall survival in all AML patients and patients who only received chemotherapy by multivariate analysis. In our study, STAT6  mRNA level was markedly up-regulated in AML patients (n=105) compared to healthy donor (n=39) (P=0.0435) as a validated cohort. Patients that only received chemotherapy in high STAT6 group showed significantly lower overall survival (OS) (P=0.0055).
Conclusion: STAT6  expression was increased in AML patients. STAT6 was found to be an adverse prognosis factor in AML patients, especially those who only received chemotherapy treatments.
Keywords: acute myeloid leukemia, STAT, prognosis, TCGA, GEO