2D difference gel electrophoresis of prepubertal and pubertal rat mammary gland proteomes.

Rat mammary gland proteomes at day 21 (prepubertal) and day 50 (late puberty) were compared by 2D difference gel electrophoresis. Two-hundred fifty-one spots were significantly different ( p < 0.05) in abundance. Peptide mass fingerprint analysis of a subset of these proteins identified two significantly over-represented classes including structural and blood proteins (increased), and metabolism-relevant proteins (reduced) in day 50 relative to day 21 glands. This is a first report of mammary gland proteome differences at these important breast cancer-relevant time-points.