| Abstract: | Mouse embryo Mus musculus castaneous epithelial cells, transformed with Moloney murine sarcoma virus (MSV) or with ecotropic murine leukemia virus (MuLV), were analyzed for production of pericellular matrix glycoproteins. The nontransformed, MSV-transformed, and MuLV-transformed cells produced fibronectin, laminin, type I collagen, and small amounts of type III collagen when studied by immunofluorescence using specific antibodies. The virus-transformed epithelial cells produced enhanced amounts of fibronectin into their growth media. Nontransformed M. musculus castaneous epithelial cells mainly produced type I collagen, as shown by metabolic labeling and polypeptide analysis. A significant increase in the glycoprotein production was seen by the MuLV-transformed cells, whereas small changes in the collagen production were apparent after MSV transformation. MuLV-transformed cells produced increased amounts of type I collagen and also some collagenous polypeptides that comigrated with procollagen type IV chains. The ratio of the procollagen type I chains deposited in the matrix was altered in transformed cells. Radioactive surface labeling of the cells revealed changes of the high-molecular-weight glycoproteins in both the MSV- and the MuLV-transformed cells. Unlike virus-transformed fibroblastic cells, these transformed epithelial cells deposited and retained connective tissue glycoproteins in their pericellular matrices. The results indicate that viral transformation modulates the pericellular matrix and surface glycoproteins of cultured mouse epithelial cels. The ability of virus-transformed epithelial cells to deposit pericellular matrices is a major difference between them and virus-transformed fibroblastic cells. |
