It has been suggested that fibronectin (FN) and syndecan play an important role in many aspects of cell-substrate interactions including cell adhesion. We hypothesized that oncofetal FN (onfFN) and syndecan play an important role in the process of adhesion of several human lung cancer cell lines. To test this, levels of onfFN in the culture supernatant were measured by an enzyme-linked immunosorbent assay in 18 human lung cancer cell lines. In addition, expressions of onfFN and syndecan-1 mRNA were analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR). Of 18 lung cancer cell lines, 3 cell lines (all adenocarcinoma) released a significant amount of onfFN in culture supernatants. Of the 18 cell lines tested, 6 cell lines expressed a significant amount of mRNA for onfFN and 4 expressed a significant amount of mRNA for syndecan-1. Levels of onfFN and expressions of mRNA for onfFN and syndecan-1 were consistently higher in non-small cell lung cancer cell lines than in small cell lung cancer cell lines. In addition, cell lines that expressed mRNA for onfFN and syndecan-1 tended to adhere to culture dishes. Syndecan-1 expression was significantly higher in attached cells compared with nonattached cells within the same cell line. Differences in onfFN and syndecan synthesis may explain some in vitro and in vivo characteristics of lung cancer.
Copyright 2001 S. Karger AG, Basel