Laminin alpha-1, alpha-3, and alpha-5 chain expression in human prepubertal [correction of prepubetal] benign prostate glands and adult benign and malignant prostate glands.

Background: Laminins (Lns) are a family of extracellular matrix glycoproteins located in the basement membrane (BM) of epithelial cells. They exist as heterotrimers composed of an alpha, beta, and gamma chain. Presently, five alpha (alpha1-5), three beta (beta1-3), and three gamma (gamma1-3) chains have been identified with different combinations of these chains resulting in 14 laminin heterotrimers thus far identified (1, 3-5).