rLj-RGD3 induces apoptosis via the mitochondrial-dependent pathway and inhibits adhesion, migration and invasion of human HeyA8 cells via FAK pathway

Ovarian carcinoma is a tumor derived from ovary, which brings relatively higher mortality rate among the fatal gynecological cancers. Recently, lots of studies have concentrated on the anti-tumor effects of Arg-Gly-Asp (RGD) motif containing peptides due to their integrin binding properties. In order to meet the criterion of genetic engineering drugs, a recombinant RGD toxin protein (rLj-RGD3) without a His-tag was cloned from the buccal glands of Lampetra japonica in the present study. After endotoxin removal, the His-tag removed rLj-RGD3 was shown to inhibit the proliferation of HeyA8 cells. According to the confocal microscope, flow cytometry and western blot analysis, rLj-RGD3 could trigger HeyA8 cells apoptosis by changing mitochondrial membrane potential, arrangement of F-actin, protein level of BCL2, BAX, caspase 3, and cleaved caspase 3, concentration of cytoplasmic calcium, as well as phosphorylation level of ERK/JNK/p38. Furthermore, rLj-RGD3 was also able to suppress the adhesion, migration, and invasion processes of HeyA8 cells by disturbing the organization of F-actin and reducing the level of p-FAK. In addition, rLj-RGD3 could inhibit the adhesion of HeyA8 cells to extracellular matrix proteins by competitively binding to integrins, indicated that rLj-RGD3 might act as an anti-tumor drug to treat ovarian carcinoma patients in the future.