Preliminary in vitro comparison of 111In and 131I labeled nimotuzumabs

The anti-tumor cell proliferative effect of [111In] In-DOTA-nimotuzumab and [131I] I-ATE-nimotuzumab was systematically investigated. Both indium-111 and iodine-131 were labeled onto nimotuzumab targeting EGFR which was over expressed in various tumors, with high radiochemical purity of 95% and 97%, respectively. [111In] In-DOTA-nimotuzumab exhibited higher stability and cell binding rate, and it could inhibit cell viability more effectively than [131I] I-ATE-nimotuzumab. Further investigations suggested that the better cell apoptosis induction of [111In] In-DOTA-nimotuzumab might be attributed to its higher stability and suitable nuclide feature, which can block the proliferation of cancer cells by breaking DNA chains directly or through reactive oxygen species approach.