Expression of Oncostatin M in Early Gastric Cancer and Precancerous Lesions

OBJECTIVE: To detect the expression of the Oncostatin M (OSM) gene and encoded protein in the mucosal epithelium of chronic gastritis, intestinal metaplasia (IM), low-grade intraepithelial neoplasia (LGIN), high-grade intraepithelial neoplasia (HGIN), early gastric cancer (EGC), and advanced gastric cancer (AGC) samples and to explore the correlation and clinicopathological significance of OSM expression in the process of gastric carcinogenesis. METHODS: The expression levels of OSM in chronic gastritis, IM, LGIN, HGIN, EGC, and AGC samples were detected by gene chip, real-time quantitative PCR, and immunohistochemical methods. The expression levels of OSM in the gastric mucosa were analyzed, and its correlation with clinical pathology was studied. RESULTS: The expression level of OSM in gastric HGIN and EGC tissues was significantly higher than that in LGIN tissues based on expression profiling (P < 0.001). The expression of the OSM gene in EGC was higher than that in HGIN (unpaired t test, P < 0.05) and LGIN (unpaired t test, P < 0.01) by qPCR. The expression of OSM in LGIN was significantly lower than that in HGIN (P = 0.008) and EGC (P = 0.044) by immunohistochemical staining. The expression of OSM in HGIN tissues was significantly higher than that in AGC (P = 0.007). CONCLUSION: Alterations in the expression of the OSM gene may be involved in the malignant transformation of the gastric mucosal epithelium. Because of the significant difference in the cancerization rate and clinical management between LGIN and HGIN, the difference in the staining intensity of OSM between LGIN and HGIN may be one of the early markers of gastric intraepithelial neoplasia.