Downregulated parafibromin expression is a promising marker for pathogenesis, invasion, metastasis and prognosis of gastric carcinomas

Abstract

Parafibromin is a protein encoded by the hyperparathyroidism 2 oncosuppressor gene and its downregulated expression is involved in pathogenesis of parathyroid carcinomas. To clarify the roles of parafibromin expression in tumourigenesis and progression of gastric carcinomas, it was examined by immunohistochemistry (IHC) on tissue microarray containing gastric carcinomas (n∈=∈508), adenomas (n∈=∈45) and gastritis (n∈=∈49) with a comparison of its expression with clinicopathological parametres of carcinomas. Gastric carcinoma cell lines (MKN28, AGS, MKN45, KATO-III and HGC-27) were studied for parafibromin expression by IHC and western blot. Parafibromin expression was localised in the nucleus of gastric epithelial cells, adenoma, carcinoma cells and cell lines. Its expression was gradually decreased from gastritis to gastric carcinoma, through gastric adenomas (p∈ ∈0.05). Parafibromin was strongly expressed in older carcinoma patients compared with younger ones (p∈