α-Tomatine suppresses invasion and migration of human non-small cell lung cancer NCI-H460 cells through inactivating FAK/PI3K/Akt signaling pathway and reducing binding activity of NF-κB.

α-Tomatine, isolated from Lycopersicon esculentum Linn., is a naturally occurring steroidal glycoalkaloid in immature green tomatoes. Some reports demonstrated that α-tomatine had various anticarcinogenic properties. The purpose of this study is to investigate the anti-metastatic effect of α-tomatine in NCI-H460 human non-small cell lung cancer cells. First, the results showed that α-tomatine significantly suppressed the abilities of the adhesion, invasion, and migration of NCI-H460 cells under non-cytotoxic concentrations. Molecular data also showed α-tomatine could inhibit the activation of focal adhesion kinase (FAK) and phosphatidylinositol 3-kinase (PI3K)/Akt signal involve in the downregulation the enzyme activities, protein and messenger RNA levels of matrix metalloproteinase-7 (MMP-7). Next, α-tomatine also strongly inhibited the degradation of inhibitor of kappaBα (IκBα) and the nuclear levels of nuclear factor kappa B (NF-κB). Also, a dose-dependent inhibition on the binding ability of NF-κB by α-tomatine treatment was further observed. Furthermore, α-tomatine significantly decreased the levels of phospho-Akt and MMP-7 in Akt1-cDNA-transfected cells concomitantly with a marked reduction on cell invasion and migration. Presented results indicated α-tomatine might be further application for treating cancer metastasis.