Imidazolium trans-imidazoledimethylsulphoxidetrachlororuthenate (
NAMI-A) was tested in vitro on the pro-adhesive properties, evaluated as resistance to
trypsin treatment, which is a bona fide measure of adhesion strength, of KB and HeLa
carcinoma cell lines and on human polymorphonuclear neutrophils (
HPMN).
NAMI-A increased the pro-adhesive activity of KB cells at 0.001 mM concentration, after few minutes incubation and this effect was not influenced by the vehicle used for cell challenge, neither did it depend on
NAMI-A concentration or on temperature. The same effect occurred on HeLa cells at 0.01 mM
NAMI-A. This effect, detected at concentrations up to 100 times lower than those necessary to block cells at the G(2)-M premitotic phase of cell cycle, or to inhibit
matrix metalloproteinase release or cell invasion, was not related to
ruthenium uptake by tumour cells. HeLa cells and healthy
HPMN, following short exposure to 0.1 mM
NAMI-A, assumed a different shape, with the extrusion of filopodia (HeLa) and of large lamellopodia (
HPMN), which increased their interactions with the substrate. This effect was attributed to stabilisation, altered turnover and sensitivity to
cytochalasin D of actin filaments. Provided that adhesion is associated with cell motility and invasion, these data suggest that
NAMI-A may exert antimetastatic properties at concentrations lower than those observed in the lungs at the end of a conventional intraperitoneal treatment in vivo.