Design, synthesis and pharmacological evaluation of a novel PEG-cRGD-conjugated irinotecan derivative as potential antitumor agent

A novel PEG-cRGD-conjugated irinotecan derivative BGC0222 was designed and synthesized as antitumor agent. Antitumor activity screening assay indicated that BGC0222 exhibited better in vitro antiproliferation activity than irinotecan and NKTR-102 against HT29, MIA PaCa-2 and MCF-7 tumor cell lines, with IC50 of 1.83 ± 0.09 μM, 3.95 ± 0.16 μM and 0.68 ± 0.04 μM, respectively, while it displayed better in vivo antiproliferation activity than irinotecan and NKTR-102 in HT-29, MIA PaCa-2, NCI-H446, U-87 MG and MDA-MB-231 xenograft models. The action mechanism of BGC0222 was then investigated by integrin-binding competition (IBC) and chick chorioallantoic membrane (CAM) angiogenesis assays, which indicated that BGC0222 may exert antitumor activity by binding to αvβ3 target and consequently inducing neovascularization effect. Pharmacokinetic analysis showed that BGC0222 could slowly and steadily release irinotecan, which was subsequently metabolized into 7-ethyl-10-hydroxycamptothecin (SN-38) in the whole blood.