Histone demethylase GASC1, a potential prognostic and predictive marker in esophageal squamous cell carcinoma.

Gene amplified in squamous cell carcinoma 1 (GASC1) is a member of Jumonji C-domain containing histone demethylases that play an essential role in affecting chromatin architecture and gene expression. The purpose of this study was to determine the expression features and the clinical significance of GASC1 in esophageal squamous cell carcinoma (ESCC). GASC1 expression was detected on tissue microarrays of ESCC samples in 185 cases using immunohistochemical staining. Strong nuclear staining for GASC1 was observed in a subset of ESCC samples. The nuclear expression of GASC1 was significantly associated with lymph node metastasis (P=0.030) and tumor-node metastasis stages (P=0.013). Kaplan-Meier survival analysis showed a tendency that high expression of GASC1 in the nucleus was associated with poor survival of ESCC patients, with a 5-year survival rate of 26.5%, as compared to 43.7% for patients with GASC1-negative/low expression. Furthermore, multivariate analysis revealed that high expression of GASC1 likely acts as a predictive factor for overall survival of ESCC patients, despite the P-value failing to reach significance (P=0.059). The findings indicate that histone demethylase GASC1 may play an important role in promoting cancer metastasis, and shed new light on the importance of targeting GASC1 to suppress metastatic disease in various tumor types, including ESCC.