Cancer cells acquire invasive ability to degrade and adhere to extracellular matrix (ECM) and migrate to adjacent tissues. This ultimately results metastasis. Hence, the present study investigated the in vitro effects of cyclopeptide glycoside, RA-XII on cell adhesion, invasion, proliferation and matrix degradation, and its underlying mechanism in murine breast tumour cells, 4T1. The effect of RA-XII on tumour growth and metastasis in 4T1-bearing mice was also investigated. Our results showed that RA-XII inhibited tumour cell adhesion to collagen, fibronectin and laminin, RA-XII also reduced the expressions of vascular cell adhesion molecule, intracellular adhesion molecule and integrins, and integrin binding. In addition, RA-XII significantly inhibited breast tumour cell migration via interfering cofilin signaling and chemokine receptors. The activities of matrix metalloproteinase-9 and urokinase-type of plasminogen activator, and the expressions of ECM-associated proteinases were attenuated significantly by RA-XII. Furthermore, RA-XII induced G1 phase arrest and inhibited the expressions of cyclins and cyclin-dependent kinases. RA-XII inhibited the expressions of molecules in PI3K/AKT, NF-kappaB, FAK/pSRC, MAPK and EGFR signaling. RA-XII was also shown to have anti-tumour, anti-angiogenic and anti-metastatic activities in metastatic breast tumour-bearing mice. These findings strongly suggested that RA-XII is a potential anti-metastatic agent for breast cancer.

Cyclopeptide RA-V has potent anti-tumor and anti-angiogenic activities, but its potential anti-metastatic activity is unknown. Cancer cells acquire invasive ability to degrade and adhere to extracellular matrix (ECM), allowing them to migrate to adjacent tissues and ultimately metastasize. Hence, the present study aimed to investigate the effects of RA-V on cell adhesion, migration, invasion and matrix degradation, and its underlying mechanism in two human breast cancer cell lines MCF-7 (ER-positive) and MDA-MB-231 (ER-negative). Our results demonstrated that RA-V (12.5 nM) can significantly inhibit breast cancer cell adhesion and migration via interfering cofilin signaling and chemokine receptors involved in cell migration. RA-V reduced the expressions of vascular intracellular adhesion molecule (VCAM), intracellular adhesion molecule (ICAM), focal adhesion kinase (FAK) and integrins. The activities and expressions of matrix metalloproteinases (MMPs), tissue inhibitors of matrix metalloproteinases (TIMPs) and urokinase-type of plasminogen activator (uPA) were also inhibited by RA-V. Furthermore, RA-V inhibits the expressions of EGFR, PI3K/AKT and NF-κB signaling molecules, and reduces the binding of β-estradiol to ER via affecting binding ability of ER in MCF-7 cells. RA-V inhibits breast cancer cell migration, adhesion and ECM degradation in vitro, implying that RA-V is a potential anti-metastatic agent in breast cancer, and likely acts via PI3K/AKT and NF-κB signaling pathways in both ER-positive and ER-negative breast cancer cells.