Abstract
Lanreotide is an octapeptide analog of endogenous somatostatin, specifically binding with tumors over-express somatostatin receptor 2 (SSTR2). In this study, we conjugated lanreotide to 1, 2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy (poly-(ethylene glycol))-2000] (PEG-DSPE), constructed active targeted micelles (lanreotide-PM), characterized their in vitro and in vivo targeting effect, and explored the receptor mediated transportion. The uptake of lanreotide-PM was found to be related to the expression level of SSTR2 in different cell lines and the competitive inhibition phenomenon indicated that the cellular uptake of lanreotide-PM was via a receptor meditated mechanism. In vivo, more lanreotide-PM accumulated in SSTR2 high expression tumor xenografts, endocytosed by the tumor cells, induced more apoptosis of tumor cells, and suppressed tumor growth efficiently. In conclusion, lanreotide–modified micelles containing antitumor drugs provide a promising strategy for the treatment of SSTR-expressing tumors.
Acknowledgements
We thank Dr. Zara Wang and Dr. Xuening Bai for their help in the manuscript revision.
Declaration of interest
This study was supported by National Science Foundation (No. 81130059) and Ministry of Science and Technology of China (No. 2009CB930300).
Supplementary material available online
Supplementary Figure S1.