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. 2012 Dec 3;109(51):21046–21051. doi: 10.1073/pnas.1218750110

Fig. 5.

Fig. 5.

Immune-mediated killing of CRC cell lines in the presence of cetuximab and trastuzumab. (A) Cells with different levels of ERBB1 were used as targets. Unfractionated PBMC cells were used at an effector:target ratio of 40:1. Cetuximab caused ADCC in a concentration dependent manner (0.001–1μg/mL), particularly in ERBB1 high (SW48, CAR1, COLO678, and SKCO1) cell lines. This was also seen in ERBB1 intermediate (HT29, HCT116, CCK81, and HCA46) cell lines but to a lesser degree. The effect was negligible in negative cell lines (COLO320DM and RKO). (B) ADCC strongly correlated with the ERBB1 expression levels. (C) Trastuzumab is able to mediate ADCC of ERBB2+ CRC cell lines (COLO678, HCA46, and SW48) but not in lines that lacked ERBB2-expression (CCO7 and SW620). The y axis represents percentage of specific lysis and the x axis represents log (antibody) concentration (μg/mL). (D) There was no significant (NS) difference in the level of ADCC (1μg/mL cetuximab) measured in KRAS/BRAF/PIK3CA WT and mutant cell lines (Mann–Whitney test, P = 0.69).