Expression of transcription factor Sp1 in human gastric cancer tissue and its correlation with prognosis

OBJECTIVE: To investigate the expression of transcription factor Sp1 in gastric cancer tissue and its correlation with prognosis. METHODS: Sp1 expression patterns in specimens of 86 gastric cancers, 57 normal gastric tissues and 53 metastatic lymph nodes were detected by immunohistochemical method. The activity of Sp1 in the tumor and normal tissues was examined by electrophoretic mobility shift analysis (EMSA). The correlation between transcription factor Sp1 expression of tumors and patients' prognosis were statistically analyzed using Cox proportional hazard model. RESULTS: In normal gastric tissue, Sp1 protein was predominantly expressed in the nuclei of cell located in the mucous neck region, but neither in the gastric pit cells with foveolar differentiation, nor in cells of the glandular epithelium with glandular differentiation. Strong Sp1 expression was also detected in tumor cells, but very weak or even no Sp1 expression in stromal cells or normal glandular cells surrounding the tumor. The median survival time of patients with negative, weak, and strong Sp1 expression was 43, 37, and 8 months, respectively (P < 0.01). Spl expression (P < 0.01) and stage (P < 0.001) were demonstrated as independent prognostic factor by multivariate analysis. CONCLUSION: Normal and malignant gastric tissue are found to have its own unique Sp1 expression patterns. Sp1 expression may be used as an important survival predictor in human gastric cancer.