BIOSYNTHESIS AND SECRETION OF LAMININ AND S-LAMININ BY HUMAN PROSTATECARCINOMA CELL-LINES

Laminin has been previously shown to participate in tumor invasion and metastasis. Tumorigenesis by human prostate cell lines can be influen ced by exogenous laminin. We have found that the human prostate tumor cell lines DU145, LNCaP, and PC-3 produce a variant form of the B1 cha in of laminin, known as S-laminin. DU145 cells produce laminin contain ing a ratio of A:B1:B2:S of 1.8:1.0:2.5:1.0, respectively, compared to LNCaP cells, which have a ratio of A:B1:B2:S of 1.0:0:10.0:2.5. Kinet ic analysis of laminin production showed that LNCaP cells retained mos t of their laminin production and secreted laminin forms characterized by decreased levels of n-acetyl glucosamine and sialic acid. In contr ast, DU145 cells secreted most of their laminin in mature forms. LNCaP cells bound very little laminin to their surface. These features of L NCaP cells could contribute to their documented low adhesivity in vitr o and its nontumorigenic phenotype. (C) 1994 Wiley-Liss, Inc.