Clinical significance of gene expression, a novel tumor suppressor gene, in esophageal squamous cell carcinoma.

The present authors previously identified a novel candidate tumor suppressor gene, zinc finger protein 750 (), in esophageal squamous cell carcinoma (ESCC) (1). The present study aimed to clarify the clinical significance of expression in ESCC. The association between DNA mutation status and the mRNA expression was examined by whole exome sequence analysis and quantitative reverse transcription polymerase chain reaction (RT-qPCR). The expression of in 76 patients with ESCC (Kyushu University Beppu Hospital) was measured using immunohistochemistry and RT-qPCR. Using this dataset, the association between mRNA expression and clinicopathological factors was examined. Additionally, survival analysis was performed using datasets from the Kyushu University Beppu Hospital and The Cancer Genome Atlas (TCGA). The biological effects of expression were explored using gene set enrichment analysis (GSEA) and were validated using datasets from the Cancer Cell Line Encyclopedia (CCLE) and the Kyushu University Beppu Hospital. expression analyses demonstrated that mRNA expression was lower in patients with the DNA mutations compared with those without the mutations (P<0.05), and expression was downregulated in tumor tissues compared with normal tissues (P<0.00005). In the clinicopathological analysis, the low expression group exhibited a higher incidence of undifferentiated histology (P<0.05) compared with the high expression group. The low expression group exhibited a poorer prognosis in the Kyushu and TCGA datasets (P<0.0005 and P<0.05, respectively). GSEA indicated that expression was significantly correlated with epithelial differentiation in ESCC. This was confirmed using the datasets from CCLE and the Kyushu University Beppu Hospital by analyzing the levels of small proline rich protein 1A mRNA, an epithelial differentiation-associated gene. In conclusion, the results of the present study suggested that serves a role as a tumor suppressor; potentially via regulating epithelial differentiation and that it may be a promising biomarker of poor outcomes in ESCC.