Figure 2.

(A) Western analysis of p21^Waf1 expression in α-particle-irradiated AG1522 human fibroblasts in the presence or absence of lindane (40 μM), DDT, or dieldrin. At 10 cGy, by which about 50–60% of the cells' nuclei are traversed by an α-particle track, p21^Waf1 is induced in the presence or absence of the inhibitors. At 1 cGy, by which only 7% of the cells in the culture would have their nuclei traversed by an α-particle, p21^Waf1 induction is not detected in the presence of any of the inhibitors. (B). In situ immunofluorescence detection of p21^Waf1 expression in nonirradiated lindane-treated (40 μM), and irradiated AG1522 cultures exposed to 0.3 cGy α-particles in the presence or absence of lindane. The absence of induced aggregates of cells in the irradiated and lindane-pretreated cultures indicates that GJIC contributes to the bystander response. (C) In situ immunofluorescence detection of p21^Waf1 expression in AG1522 cultures exposed to 10 cGy in the presence or absence of lindane.