Premium
99m Tc‐labeled tetramer and pentamer of single‐domain antibody for targeting epidermal growth factor receptor in xenografted tumors
Author(s) -
Li Chongjiao,
Feng Hongyan,
Xia Xiaotian,
Wang Lifei,
Gao Bin,
Zhang Yongxue,
Lan Xiaoli
Publication year - 2016
Publication title -
journal of labelled compounds and radiopharmaceuticals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 47
eISSN - 1099-1344
pISSN - 0362-4803
DOI - 10.1002/jlcr.3399
Subject(s) - chemistry , tetramer , pentamer , epidermal growth factor receptor , antibody , cancer research , epidermal growth factor , receptor , microbiology and biotechnology , biochemistry , immunology , enzyme , biology
The single‐domain antibody EG2 can be fused with right‐handed coiled‐coil (RHCC) and human cartilage oligomeric matrix protein (COMP), to form the multivalent antibodies EG2‐RHCC and EG2‐COMP. We labeled these two antibodies with 99m Tc and assessed their targeting efficiency for epidermal growth factor receptor (EGFR). Cell binding, uptake, efflux, and blocking studies were performed with EGFR high‐ and/or low‐expressing cells with 99m Tc‐labeled EG2‐RHCC or EG2‐COMP. Single photon‐emission computed tomography (SPECT) imaging and biodistribution studies were further carried out. Both 99m Tc‐EG2‐RHCC and 99m Tc‐EG2‐COMP can specially bind to EGFR in vitro . SPECT imaging showed that A431, which expresses high levels of EGFR, was clearly visible 6 h after 99m Tc‐EG2‐COMP injection; however, it was not detectable after administration of 99m Tc‐EG2‐RHCC. Uptake of both antibodies by the non‐EGFR‐secreting OCM‐1 tumors was low. EG2‐COMP shows promise in identifying EGFR over‐expression in tumors; however, EG2‐RHCC may not be suitable for targeting EGFR in vivo .