THE EXPRESSIONS AND LOCALIZATIONS OF B7-H1 IN DIFFERENT GASTRIC CANCER CELL LINES / 解剖学报

ABSTRACT

Objective B7-H1 is a recently identified co-stimulatory molecule expressed on APCs and can inhibit the activation and function of T lymphocytes.This research is to study if B7-H1 has a relationship with carcinogenesis and MDR of gastric carcinoma by examining the expressions of B7-H1 in human gastric carcinoma cell lines SGC7901/VCR,SGC7901,BGC-823 and in the permanent gastric epithelial cell line GES-1. Methods Cells were cultured in RPMI-1640 supplemented with 10% fetal calf serum.The B7-H1 mRNA was detected by RT-PCR and the protein of B7-H1 was detected by cytoimmunochemistry staining,cytoimmunofluorescence staining and flow cytometric analysis.The expression levels of B7-H1 mRNA and the protein of B7-H1 in the above mentioned four kinds of cell lines were compared. Results All the four cell lines express B7-H1 mRNA at different levels.And B7-H1 expression level increased in the order of from GES-1 to SGC7901/VCR cell line,BGC-823 and then to SGC7901 cell line.The protein of B7-H1 was found to be distributed in the cell membrane and in a little cytoplasm in all the four cell lines through techniques of cytoimmunochemistry staining and cytoimmunochemistry staining.Further more with the result of flow cytometric analysis,the protein expression level of B7-H1 in all these cell lines was found to be consistent with B7-H1 transcript level expression.Conclusion The results suggest that B7-H1 expression on gastric epithelial cells may promote the growth of gastric carcinoma cells and the expression of MDR gene through inhibiting host immune responses.