Application of reproductive hormone peptides for tumor targeting.

Targeted therapy may be a promising approach against cancer because its focus of attention is to enhance the efficacy and to reduce the side effects of antitumor agents through high selectivity. One of targeted strategies is to use tumor-specific ligands as targeting moieties to carry drugs into tumor cells, and use the receptors that expressed on tumor cells as target sites to bind with peptide ligands. The fact that the distributions of reproductive hormone receptors are relatively limited in normal tissues makes it possible to use them as targeted sites and use hormone peptides as targeting moieties for cancer treatment. Until now many tumor targeting approaches with reproductive hormone peptides have been developed, and some of them have been introduced into clinical trials. Here a review is given to discuss the targeted antitumor therapeutic strategies based on gonadotropin-releasing hormone, follicle-stimulating hormones, luteinizing hormone, human chorionic gonadotropin and their receptors.