Down regulation of a novel proliferation responded gene in human breast cancer

Abstract

Using RNA differential display we have recently cloned a gene(SERG)expressed at earlier stage of serum stimulation from human colon cancer line WiDr. The level of expression of SERG gene was elevated 30 minutes after serum was introduced to the starved cells. SERG gene was expressed differently in various human tissues. The higher expression was found in tissues of spleen,colon,liver,prostate,skeletal muscle,liver,lung and peripheral blood leukocyte, while very low expression in that of brain,ovary and testis. Interestingly among 15 human breast cancer cell lines, only three cell lines with low malignancy(MCF-10,AIN-4,HBL-100) differently expressed SERG gene, while others(MDA-231, MDA-463, MCF-7, T47-D, U-1180, BL-2, ZR-75, MDA-231Ewa, CTLL, Chang, V937, HDF) had no detectable expression. Since SERG is a serum stimulation responded gene,it might mean that during breast malignancy, breast cancer cells become less growth factor dependent and SERG gene is down regulated. The question whether this gene is also down regulated in other tnmors is now under investigation.