LyP-1 Modification To Enhance Delivery of Artemisinin or Fluorescent Probe Loaded Polymeric Micelles to Highly Metastatic Tumor and Its Lymphatics
Metastatic cancers are prone to form metastasis at a distance and acquire drug resistance, which are very common clinically and major obstacles to successful chemotherapy. Besides the tumor itself, the lymphatic system is increasingly emerging as a new target for anticancer therapy because it is an important route of tumor metastasis. To specifically deliver drug to both highly metastatic tumor and its lymphatics, tumor- and tumor lymphatics-homing peptide (LyP-1) conjugated PEG-PCL micelles (LyP-1-PM) were first constructed. Artemisinin (ART), a natural product with potential anticancer and antilymphangiogenesis effects, was chosen as the model drug and associated into the micelles. Both PM and LyP-1-PM had similar physiochemical properties, about 30 nm in size with uniform distribution. Highly metastatic breast cancer MDA-MB-435S cells and lymphatic endothelial cells (LEC) were applied as cell models. Flow cytometry and confocal microscopy studies showed that LyP-1-PM exhibited its specificity to both cell lines evidenced by its higher cellular uptake than PM. LyP-1-PM-ART demonstrated higher inhibition effect than PM-ART against these two cell lines in cell apoptosis, cell cycle and cytotoxicity tests. Near-infrared imaging showed that LyP-1-PM was distributed more in orthotopic MDA-MB-435S tumor than PM. Further study by colocalization indicated that PM accumulated near blood vessels, while LyP-1-PM further homed to tumor lymphatic vessels. LyP-1-PM achieved higher antitumor efficacy than other ART formulations in vivo with low toxicity. Both in vitro and in vivo studies here proved that LyP-1 modification enhanced the specific delivery of ART or fluorescent probe loaded polymeric micelles to MDA-MB-435S and LEC. Therefore, LyP-1-PM might be promising in terms of specific delivery of therapeutic or imaging agents to both highly metastatic breast tumor and its lymphatics.
[Show abstract] [Hide abstract] ABSTRACT: The aim of the present study was to investigate the inhibitory effects of dihydroartemisinin (DHA) on the primary tumor growth and metastasis of the human breast cancer cell line, MDA-MB-231, in vitro. The expression levels of urokinase-type plasminogen activator (uPA) were detected by immunocytochemistry in two cell lines (MCF-7 and MDA-MB-231). The MDA-MB-231 cell activity was inhibited by various concentration gradients of DHA. The inhibitory rate, cell growth curve and apoptotic morphological observations were obtained using the MTT assay at 0, 24, 48 and 72 h. Cell scratch migration was performed at various time-points to test the cell proliferation and migration capacity. Reverse transcription-polymerase chain reaction was used to analyze the effect of DHA on uPA mRNA expression in breast cancer cells. The human breast cancer cell line, MDA-MB-231, possesses higher metastatic potential and relatively higher expression of uPA when compared with the MCF-7 cell line. DHA was found to inhibit the proliferation and migration capacity of the cell line, MDA-MB-231, in vitro. The growth inhibition occurred in a time- and dose-dependent manner, with IC50 values of 117.76±0.04, 60.26±0.12 and 52.96±0.07 μmol/l following 24, 48 and 72 h, respectively. The inhibition of uPA was observed to decrease breast cancer cell growth and migration. Thus, results of the present study indicate that DHA may be used for further studies with regard to breast cancer therapy.0Comments 4Citations
- "Thus, these cells are prone to the intracellular production of reactive oxygen. The anticancer properties of ART have been extensively investigated and characterized in various experimental settings, including oxidative damage, apoptotic induction, cell cycle arrest, angiogenesis inhibition, aborted lymphatic metastasis and enhanced radiosensitivity (8–13). Dihydroartemisinin (DHA) is the main active metabolite of ART and its antimalarial and antitumor activities are stronger than those of the other ART derivatives. "
- [Show abstract] [Hide abstract] ABSTRACT: Peptide ligands have played an important role in tumor-targeted drug delivery as targeting moieties. The in vivo fate of peptide-mediated drug delivery systems and the following antitumor effects may greatly depend on the stability of the peptide ligand. In the current study, a tumor-targeting cyclic peptide screened by phage display, Lyp-1 (a peptide that specifically binds to tumor and endothelial cells of tumor lymphatics in certain tumors), was structurally modified by replacement of the original intramolecular disulfide bond with a diseleno bond. The produced analog Syp-1 (seleno derivative of Lyp-1) maintained specific binding ability to the target protein p32 (Kd = 18.54 nM), which is similar to that of Lyp-1 (Kd = 10.59 nM), indicated by surface plasmon resonance assay. Compared with Lyp-1, Syp-1 showed significantly improved stability against serum. After the peptide attached onto the surface of fluorophore-encapsulating liposomes, the more efficient tumor uptake of liposomal fluorophore mediated by Syp-1 was observed. Furthermore, Syp-1 modified liposomal doxorubicin presented the most potent tumor growth inhibitory ability among all the therapeutic groups, with a low half maximal inhibitory concentration of 588 nM against MDA-MB-435 cells in vitro and a high tumor inhibition rate of 73.5% in vivo. These findings clearly indicated that Syp-1 was a stable and effective tumor targeting ligand and suggest that the sulfur-to-selenium replacement strategy may help stabilize the phage-displayed cyclic peptide containing disulfide-bond under physiological conditions and strongly support the validity of peptide-mediated drug targeting.0Comments 18Citations
- [Show abstract] [Hide abstract] ABSTRACT: As versatile drug delivery systems, polymeric micelles have demonstrated particular strength in solubilizing hydrophobic anticancer drugs while eliminating the use of toxic organic solvents and surfactants. However, the true promise of polymeric micelles as drug carriers for cancer therapy resides in their potential ability to preferentially elevate drug exposure in the tumor and achieve enhanced anticancer efficacy, which still remains to be fully exploited. Here, we review various micellar constructs that exhibit the enhanced permeation and retention effect in the tumor, the targeting ligands that potentiate the anticancer efficacy of micellar drugs, and the polyplex micelle systems suitable for the delivery of plasmid DNA and small interference RNA. Together, these preclinical studies in animal models help us further explore polymeric micelles as emerging drug carriers for targeted cancer therapy.0Comments 20Citations