HUMAN LIPOSARCOMA CELL-LINE, SW872, SECRETES CHOLESTERYL ESTER TRANSFER PROTEIN IN RESPONSE TO CHOLESTEROL

Cholesteryl ester transfer protein (CETP) mediates the exchange of pho spholipids and neutral lipids between the plasma lipoproteins, and pla ys an important role in high density lipoprotein (HDL) metabolism. Whi le there are reports of low-level CETP secretion from cultured cells, the lack of a good model cell line has hampered the detailed study of CETP regulation and secretion. In this study, we have found that the h uman liposarcoma cell line, SW872, secretes cholesteryl ester transfer protein at levels substantially higher than observed from other cell lines. The secretion of CETP from this adipose-derived cell was up-reg ulated by 25-OH cholesterol and by low density lipoprotein (LDL) chole sterol in a concentration-dependent manner. Analysis of both full leng th and exon 9-deleted CETP mRNA demonstrated increases in response to LDL and 25-OH cholesterol, providing evidence for regulation at the me ssage level. Our results suggest that the CETP-producing SW872 fell li ne may provide a model in which to study the regulation of this import ant modulator of lipoprotein metabolism.