Cell surface phenotype and increased penetration of human multidrug-resistant ovarian carcinoma cells into in vitro collagen-fibroblasts matrix.

Human multidrug resistant ovarian carcinoma cells (A2780/ADR) exhibited increased in vitro penetration into the collagen-normal human fibroblasts matrix, increased cell surface expression of alpha 6 integrin (CD49f antigen) and slightly increased expression of alpha 2 (CD49b) integrin compared with that of parental drug-sensitive A2780 cells. Both, multidrug-resistant and parental, drug-sensitive, cell lines did not express the 67 kDa non-integrin high affinity laminin receptor on their cell surfaces. As there were no marked differences between metalloproteinase activity of both A2780 cell sublines (with similar intensity of 72 kDa and 92 kDa lysis bands in zymograms), the increased penetration of the drug-resistant subline into the collagen-fibroblast gel matrix might be associated with the increased expression of adhesion proteins (including collagen-binding alpha 2 integrin), or cell surface-associated collagenase-stimulating protein(s). This multidrug resistant ovarian carcinoma cell line might serve as an in vitro model of neoplastic cells with increased biological aggressiveness, molecular mechanisms of which require further analysis.