Rottlerin Exerts Its Anti-tumor Activity Through Inhibition Of Skp2 In Breast Cancer Cells

Objective:Studies have investigated the tumor suppressive role of Rottlerin in carcinogenesis.However,the molecular mechanisms of Rottlerin-induced anti-tumor activity are largely unclear.Skp2(S-phase kinase associated protein 2)has been validated to play an oncogenic role in a variety of human malignancies.Therefore,inactivation of Skp2 could be helpful for the treatment of human cancers.Methods:1.The cell proliferation was analyzed by CTG assay and colony formation assay in breast cancer cells after Rottlerin treatment and overexpression or down-regulation of Skp2.2.The cell apoptosis and cell cycle were performed by flow cytometry in breast cancer cells which were treated with Rottlerin and then overexpressed or down-regulated of Skp2.3.The ability of migration and invasion was exerted by wound-healing assay and Transwell assay in breast cancer cells after Rottlerin treatment.4.The mRNA levels of key oncogenic gene Skp2 were analyzed by real time PCR in breast cancer cells after Rottlerin treatment.5.The expression of Skp2 proteins was detected by Western blot in breast cancer cells after curcumin treatment or transfection.6.Transfection of Skp2 plasmid or small interfering RNA(siRNA)was used to regulate the expression of Skp2,and then to explored the molecular mechanisms of Skp2 in breast cancer cells.Results:We found that Rottlerin treatment inhibited cell growth,induced apoptosis and cell cycle arrest.We also revealed that Rottlerin suppressed cell migration and invasion in breast cancer cells.Mechanically,we observed that Rottlerin significantly down-regulated the expression of Skp2 in breast cancer cells.Conclusions:Overexpression of Skp2 abrogated Rottlerin-mediated tumor suppressive activity,whereas down-regulation of Skp2 enhanced Rottlerin-triggered anti-tumor function.Strikingly,we identified that Rottlerin exhibited its anti-tumor potential partly through inactivation of Skp2 in breast cancer.Our findings indicate that Rottlerin could be a potential safe agent for the treatment of breast cancer.