Upregulation of SPHK1 in esophageal carcinoma and correlation with clinical outcome. SPHK1 protein expression was assessed in esophageal carcinoma tissues. (A) Twelve sample pairs, each consisting of esophageal carcinoma tissue and normal esophageal tissue from the same patient, were analyzed by Western blotting. SPHK1 was overexpressed in seven of twelve esophageal carcinoma tissues (58%) compared to the companion normal tissue. (B) The expression SPHK1 in 30 pairs of esophageal-carcinoma and normal tissues were also analyzed by IHC. In 23 of 30 cases (76%), SPHK1 expression appeared to be upregulated in the tumors when compared to the companion normal tissue with the following immunostaining scores: normal: 0.93 ± 0.173; tumor: 2.06 ± 0.46, P < 0.01. (C-D) SPHK1 protein expression in an esophageal carcinoma tissue microarray (n = 274 tissue microarray elements from 124 cases of esophageal squamous carcinoma). By Kaplan-Meier analysis, strong SPHK1 expression (staining intensity equal to, or greater than, 2) was significantly associated with clinical failure, whereas the weak SPHK1staining (staining intensity less than 2) was found in individuals with delayed clinical failure, P < 0.01.