Figure 1.

Gal-1 stimulates anoikis in HepG2 cells. (a) HepG2 cells were cultured overnight either adherent or suspended on poly-HEMA-coated plates and received Gal-1 (125 μg/ml) as indicated. The pre-G₁ fractions were quantitated by flow cytometry to determine apoptosis (adherent) and anoikis (suspended). (b) Adherent HepG2 cells were pretreated with either vehicle or Gal-1 (125 μg/ml) and subsequently transferred to poly-HEMA-coated plates. Anoikis was then determined following overnight incubation in the presence or absence of Gal-1. Control cells received vehicle throughout the experiment, for the other samples conditions were as indicated (pretreatment/treatment). Pretreatment with Gal-1 was sufficient to sensitize HepG2 cells to anoikis (^*P<0.05). (c) Functional modulation of Gal-1-stimulated cell death by addition of the indicated concentrations of soluble fibronectin or 2 μg/ml of an α₅β₁-integrin-blocking antibody. Cells received the treatment immediately after detachment and were then kept in suspension for 24 h before cell death rates were determined. Data represent mean±S.E.M. of at least three independent experiments (^**P<0.01, ^***P<0.001 versus. Gal-1-treated cells)