Laminin-5 suppresses chondrogenic differentiation of murine teratocarcinoma cell line ATDC5

Here, the authors examined the possible role of laminin 332 in chondrogenesis. The murine teratocarcinoma cell line ATDC5 transiently and weakly expressing laminin 332 were stimulated for differentiation. Exogenous laminin 332 in either insoluble or soluble form strongly inhibited the differentiation phenotypes, i.e. formation of cartilaginous cell aggregates and production of chondrogenic marker proteins through its integrin-binding domain LG3 in the a3 chain. Laminin 332 had no effect on cell growth. In addition, they found that the laminin 332 with the 105-kDa, processed g2 chain suppressed differentiation more strongly than one with the 150-kDa g2 chain. This indicated that the proteolytic processing of g2 chain regulated the activity of laminin 332. However, a g2 chain short arm fragment had no effect on the chondrogenesis, and it rather suppressed the differentiation at excessive concentrations. These results suggest that laminin 332 and its processing modulate chondrogenic differentiation during development.