RGD-Modified Endostatin Peptide 30 Derived from Endostatin Suppresses Invasion and Migration of HepG2 Cells Through the αvβ3 Pathway

Abstract

The nucleotide sequence encoding amino acids 1-30 of endostatin (peptide 30, with amino acids 25-31 mutated from RGIRGAD to RGDRGD) was artificially synthesized and cloned into the plasmid pTYB2 and expressed in Escherichia coli (DE3). Peptide 30 was purified by chitin affinity chromatography followed by dithiothreitol removal by gel filtration and protein identification using Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Similarly, peptide 27, corresponding to amino acids 1-27 of endostatin, was produced as control. The effects of peptide 30 on the metastatic potential of HepG2 cells were then investigated. Peptide 30 was found to effectively suppress the adhesion, invasion, and migration of HepG2 cells. Flow cytometry demonstrated that peptide 30 did not alter the expression of membrane integrin αvβ3, although immunofluorescent staining revealed that these integrins formed clusters on the cell surface. Therefore, the effects of peptide 30 on cancer cell invasion may involve the αvβ3 pathway. Moreover, peptide 30 inactivated metalloproteinase-2 (MMP-2) and MMP-9 and downregulated the expression of COX-2 (cyclooxygenase 2), MMP-2, and MMP-9 at both mRNA and protein levels. Peptide 30 also upregulated the expression of tissue inhibitor of metalloproteinase-1 and tissue inhibitor of metalloproteinase-2 at mRNA and protein levels. Lastly, an antibody against αvβ3 enhanced the biological effects of peptide 30.

Inhibition of T‐type Ca2+ channels by endostatin attenuates human glioblastoma cell proliferation and migration

“…In contrast, growing evidences have recently shown that ES could play a direct role in inhibiting tumour cells (Yang et al ., 2011). Also, it has been reported recently that peptide 30 derived from ES suppresses the proliferation and migration of HepG2 cells in vitro (Li et al ., 2011). In the present study, we revealed that, besides its antiangiogenesis effects, ES played a direct role in inhibition of U87 human glioblastoma cell proliferation and migration in vitro by targeting T‐type Ca 2+ channels.…”

“…Interestingly, there is growing evidence that ES can elicit a direct effect in tumour cells (Yang et al ., 2011). It has been reported recently that peptide 30 derived from ES suppresses the proliferation and migration of HepG2 cells in vitro (Li et al ., 2011). However, whether and how ES directly affects tumour cells, especially glioblastoma cells, is less clear.…”

Effect of integrin receptor-targeted liposomal paclitaxel for hepatocellular carcinoma targeting and therapy

“…Clinically, these modifications are able to increase targeting efficiency and reduce toxicity. The cyclic arginine-glycine-aspartic acid-phenylalanine-lysine (cRGDFK/RGD) peptide has been widely used with various anticancer agents and nanocarriers to facilitate specific tumor targeting (22,23). The RGD motif, comprised of extracellular matrix proteins, functions as a cell adhesion site for various types of integrin, particularly αvβ3 and αvβ5.…”

RGD-conjugated mesoporous silica-encapsulated gold nanorods enhance the sensitization of triple-negative breast cancer to megavoltage radiation therapy

“…Soluble cRGD peptides, integrin α v β 3 receptor-specific ligands, have been reported to block the adhesion, invasion, and metastasis of breast cancer cells. 43,44 GNRs serve as cRGD peptide carriers that not only promote specific binding to tumor cells but also increase the absorption of RT energy and the preferential accumulation in tumor tissues. 12 Our findings showed that pGNRs@ mSiO 2 -RGD nanoprobes could downregulate the expression of integrin α v β 3 induced by RT and under control conditions, presumably leading to the dose enhancement effect.…”