Figure 2.

Effect of ICAM2 expression on cell growth and cell survival. (A) HSC2 cells were transfected with 100 nmol l⁻¹ ICAM2 siRNA (siICAM2), siNT, or vehicle. At the indicated time points, the cells were trypsinised and counted using a haemocytometer in triplicate samples. The results represent the mean±s.d. The asterisks indicate significant differences between siNT and ICAM2 siRNA (^**P<0.01, Student's t-test). (B) HSC3 cells were transfected with expression vector encoding ICAM2 cDNA or vehicle. At the indicated time points, the cells were trypsinised and counted using a haemocytometer in triplicate samples. The results are expressed as the mean±s.d. The asterisks indicate significant differences between the vehicle and ICAM2 transfectant (^**P<0.01, Student's t-test). (C) The effect of radiation on the clonogenic survival of HSC2 cells transfected with the vehicle, siNT, and siICAM2. At 72, 84, and 96 h after transfection; the cells were trypsinised and plated for clonogenic survival assay for siICAM2 at 96 h, siICAM2 at 108 h, and siICAM2 at 120 h, respectively. After 24 h, when the cells had attached, they were irradiated. Colonies were stained with crystal violet and counted after 8–10 days. Each experiment was repeated at least three times; the error bars represent ±s.d. The significance of the difference between siNT (open square) and siICAM2 (closed circle) is indicated by asterisks (^**P<0.01, ^*P<0.05, Student's t-test). (D) The effect of radiation on the clonogenic survival of HSC3 cells overexpressing ICAM2, vehicle treated cells, and untreated control. The clonogenic survival of HSC3 cells was calculated in the same way as for HSC2 cells. The significance of the difference between the vehicle (open triangles) and ICAM2-overexpressing cells (closed circles) is indicated by asterisks (^**P<0.01, ^*P<0.05, Student's t-test).