Expression of REG Protein During Cell Growth and Differentiation of Two Human Colon Carcinoma Cell Lines

Abstract

SUMMARYWe localized REG protein in Paneth cells and nonmature columnar cells of the human small intestinal crypts and speculated that this protein was associated with growth and/or differentiation. The aim of this study was to determine whether REG protein is present in two human colon cancer cell lines that exhibit enterocytic differentiation after confluence and to investigate changes in the level of its expression during growth and differentiation. Results were compared to those obtained on cells that remain undifferentiated. Western immunoblotting and immunofluorescence demonstrated the presence of REG protein in the three cell lines. With the antisera against human REG protein, the staining was diffusely spread throughout the cytoplasm at Day 2, and after Days 3-4 it appeared to have migrated to cell boundaries. After confluence, we observed only a punctate staining array along cell boundaries, which disappeared at Day 15. REG mRNA expression was demonstrated by RTPCR and REG mRNA hybridization until Day 13, but not after, in the three cell types. REG protein may be involved in cellular junctions. Its presence appears to be associated with the cell growth period and the protein must be downregulated when growth is achieved and differentiation is induced. (J Histochem Cytochem 47:863-870, 1999)

Target Genes of Peroxisome Proliferator-activated Receptor γ in Colorectal Cancer Cells

“…Furthermore, RegIA levels negatively correlate with survival rates following curative surgery of patients with colorectal cancer (62). In tissue culture, RegI-levels negatively correlate with the differentiation status of colon cancer cells (63). Collectively, these data argue that excessive RegIA may act as a factor that inappropriately stimulates intestinal epithelial proliferation and regeneration in pathological settings.…”

Pancreatic Stone Protein/Regenerating Protein Family in Pancreatic and Gastrointestinal Diseases

“…They speculated that the presence of the Reg protein might be associated with growth and also differentiation (117). Reg I protein was ectopically expressed in colorectal mu-cosa at the transition zone of colorectal cancer (CRC) and occasionally within the tumor itself.…”

Expression of regenerating gene I in gastric adenocarcinomas

“…We agree that REG has a similar expression pattern in gastric carcinomas. It is interesting to note that Bernard-Perrone et al 27 demonstrated that, in colon carcinoma cells, REG expression was detected during the growth phase and almost disappeared when the growing cells came into contact with each other. The authors speculated that REG expression was associated with the cell growth period and was down-regulated when the growth was achieved and differentiation was induced.…”

“…9 Several authors have concluded that REG expression is inversely regulated with the cellular differentiation status. 9,27 . We agree that REG has a similar expression pattern in gastric carcinomas.…”