title: Production of fibronectin and adherence to fibronectin by human myeloma cell lines.
abstract: In the present study we examined the production of fibronectin (FN) in 10 human myeloma cell lines (HMCL). By Northern blot analysis we could detect the presence of FN-mRNA in most of these lines. A majority of the cell lines (LP-1, OPM1, SKMM-2, EJM, JJN3 and ARH-77) hybridized with two probes recognizing total FN while the mRNA of one cell line (LB84-1) was shown to hybridize also with a probe recognizing the EDA segment of cellular FN. In one cell line (L363) FN-mRnA could only be detected after PCR amplification. Using an enzyme-linked immunosorbent assay, we could also demonstrate that HMCL secrete FN in their culture medium. Seven myeloma cell lines that produce FN showed a significant adherence to soluble FN. By blocking experiments, this adhesion was found to be mediated by the VLA-4 (alpha 4 beta 1) receptor. The production of fibronectin and the expression of a functional receptor for this protein may represent independent features of myeloma cells but may also be functionally linked. Since fibronectin has recently been identified as a crucial co-factor of IL6 in the regulation of the terminal B cell differentiation, the endogenous FN production may be part of an autocrine-line process mediating the autonomous growth of these cell lines. Alternatively, the FN production may also reflect a mechanism that myeloma cells use to communicate with their natural environment, i.e. the bone marrow stroma.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Haematology-Immunolgy, Faculty of Medicine, Free University Brussels, Belgium.
authors.forename: I
authors.initials: I
authors.lastname: van Riet
authors.forename: C
authors.initials: C
authors.lastname: de Greef
authors.forename: H
authors.initials: H
authors.lastname: del Favero
authors.forename: C
authors.initials: C
authors.lastname: Demanet
authors.forename: B
authors.initials: B
authors.lastname: Van Camp
mesh_terms: D001483:Base Sequence; D015152:Blotting, Northern; D002448:Cell Adhesion; D005353:Fibronectins / Q000096:biosynthesis*; D006801:Humans; D008969:Molecular Sequence Data; D009101:Multiple Myeloma / Q000097:blood / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics; D014407:Tumor Cells, Cultured
chemical_list: D005353:Fibronectins; D009363:Neoplasm Proteins; D012333:RNA, Messenger