Fig. 8

Importance of the type I IGF receptor in IGF protection from anoikis. Cells were trypsinised, resuspended in serum-free medium alone or with the indicated concentrations of IGF-1 (a) or in the presence of IgG2 (−figit.) or figitumumab (+figit.) (c) or in serum-containing medium in the absence or presence of figitumumab (d) and then placed in 35-mm-diameter poly-HEMA-coated wells and cultured for 24 h (MCF-7 and ZR-75) or 5 h (EFM-19). MCF-7 cells were left untransfected or transfected with a scrambled non-silencing siRNA duplex oligonucleotide sequence or an siRNA against type I IGF receptor mRNA and incubated in maintenance medium for 48 h. Cells were trypsinised, resuspended in serum-free medium alone or with 10 ng/ml IGF-1, placed in 35-mm-diameter poly-HEMA-coated wells and cultured for 24 h (b). Cells were lysed and aliquots of 10 μg of protein analysed by western transfer for cleaved PARP, type I IGF receptor, phosphorylated Akt, total Akt and GAPDH as described above. Asterisks show PARP cleavage that is statistically significantly less in the presence of IGF-1 than in its absence (a) or significantly more in the presence of figitumumab than in its absence (c and d) (ANOVA, p < 0.01)