ObjectiveTo investigate the differences of Glutathione Stransferase A1 (GSTA1) expression on mRNA and protein level between nasopharyngeal carcinoma (NPC) tissues and normal nasopharyngeal epithelial tissues and assess the association between the expression level of GSTA1 and clinical characteristics of NPC patients.MethodsThe expression difference of GSTA1 gene at the transcription level between NPC tissues and normal control tissues was explored via analysis of cDNA microarray data (GSE12452, GSE64634) from GEO by GCBI (GeneCloud of Biotechnology Information) platform. The relative mRNA and protein level of GSTA1 was determined in NPC tissues and normal control tissues by realtime RTPCR and immunohistochemistry (IHC), respectively. In addition, the correlation between the transcription level of GSTA1 and the clinical stage of head and neck tumors was analyzed using data from TCGA (The Cancer Genome Atlas) database.ResultsThe transcription and expression of GSTA1 gene were significantly downregulated in NPC. The mRNA levels of GSTA1 were significantly different among different stages of head and neck tumors.ConclusionDownregulation of GSTA1 is a noteworthy molecular feature of NPC, which indicates that GSTA1 may be involved in the occurrence and progression of NPC by affecting tumor metabolism.