Objective     To characterize the radioimmunoimaging and metabolic dynamics of anti-ATP-binding cassette subfamily G member 2 (ABCG2) single-chain antibody of lung adenocarcinoma in nude mice and its anti-tumor capacity. Methods     Human lung adenocarcinoma A549 cells were treated with different concentrations of anti-ABCG2 antibody

a self-constructed single-chain variable fragment (scFv) antibody. Western blotting was performed to evaluate the expression of ABCG2 protein. Cell proliferation rate was detected by CCK-8 assay. Cell apoptosis and changes of cell cycle were analyzed by flow cytometry. Xenograft models were generated to determine the anti-tumor capacity of this antibody. 131I-labelled scFv antibody was then prepared and used for the biodistribution study and SPECT/CT imaging in tumorbearing mice. Results     The scFv antibody resulted in antibody-mediated down-regulation of ABCG2 protein

proliferation inhibition

apoptosis

and cell cycle arrest in lung adenocarcinoma cells. The biodistribution and radioimmunoimaging analyses showed favorable effects of scFv antibody in fast penetration

specific binding to target tissue and rapid blood clearance

indicating its superior pharmacokinetic properties. Conclusion     The specific single-chain antibody against ABCG2 of lung adenocarcinoma exhibits satisfactory radioimmunoimaging effect

better pharmacokinetics

tumoraffin and anti-tumor activity. This may provide a strong basis for subsequent body visualization of lung adenocarcinoma and to explore its potential as a delivery vehicle in immunotherapy.