Cell density and oestrogen both stimulate alpha 2-macroglobulin receptor expression in breast cancer cell T-47D.

Background: Oestrogen is an important hormone supporting the growth and evolution of breast cancer. alpha 2-Macroglobulin receptor/low density lipoprotein receptor-related protein (alpha 2MR/LRP) is a multifunctional membrane receptor for endocytosis of various ligands involved in protease and cytokine activity regulation. The effects of oestrogen on the level of expression of this receptor may be important in breast tumour progression.

Materials And Methods: T-47D breast cancer cells were grown in media with controlled oestrogen levels, and flow cytometry and Western blotting were used to compare their alpha 2MR/LRP expression levels.

Results: Addition of oestrogen to T-47D cells caused a marked increase in alpha 2MR/LRP expression, coinciding with a trippling of cell proliferation. T-47D cells at high cell culture densities had similarly raised alpha 2MR/LRP expression levels.

Conclusions: Regulation of alpha 2MR/LRP expression in the oestrogen receptor-positive breast cancer cell line T-47D can be effected by both cell culture density alone and by oestrogen.