Expression of alpha 2 macroglobulin receptor/low density lipoprotein receptor-related protein is cell culture density-dependent in human breast cancer cell line BT-20.
alpha 2Macroglobulin receptor/low density lipoprotein receptor-related protein (alpha 2MR/LRP) is a multifunctional cell plasma membrane receptor that binds and facilitates the endocytosis of a number of ligands involved in protease regulation and lipoprotein metabolism. In the invasive breast cancer cell line BT-20 we show that the expression of alpha 2MR/LRP can be strongly affected by cell culture density. By comparing measurements of mRNA, total cellular alpha 2MR/LRP antigen, and cell surface alpha 2MR/LRP expression we have demonstrated a marked cell density-dependent regulation of this receptor expression. Increasing the cell density results in a 3.4-fold increase in cell surface alpha 2MR/LRP expression. This corresponds to a marked increase in alpha 2MR/LRP mRNA in Northern blots of total RNA from cells cultured at high density and to consistent increases in alpha 2MR/LRP heavy chain in Western blots of cell lysates from high density cultures. These studies together demonstrate the significant up-regulation of alpha 2MR/LRP expression in BT-20 by increased cell density.
Li
Y
Y
Department of Surgery, North Queensland Clinical School, University of Queensland, Townsville, Australia.
Wood
N
N
Yellowlees
D
D
Donnelly
P
P
D015152:Blotting, Northern; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000737:chemistry / Q000378:metabolism* / Q000473:pathology*; D002452:Cell Count; D002462:Cell Membrane / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D026503:Low Density Lipoprotein Receptor-Related Protein-1; D009361:Neoplasm Invasiveness; D012333:RNA, Messenger / Q000032:analysis; D011971:Receptors, Immunologic / Q000096:biosynthesis* / Q000235:genetics; D011973:Receptors, LDL / Q000096:biosynthesis* / Q000235:genetics; D014407:Tumor Cells, Cultured; D000511:alpha-Macroglobulins / Q000378:metabolism*
D026503:Low Density Lipoprotein Receptor-Related Protein-1; D012333:RNA, Messenger; D011971:Receptors, Immunologic; D011973:Receptors, LDL; D000511:alpha-Macroglobulins