RESUMEN
OBJECTIVE To investigate the effects of aucubin （Auc） on the malignant biological behavior of breast cancer cells by regulating cyclin-dependent kinase 1（CDK1）/cyclin B1（CCNB1）/Polo-like kinase 1 （PLK1） signaling pathway. METHODS Human breast cancer cells MCF-7 were divided into control group， Auc low-， medium- and high-concentration groups （AUC-L， AUC-M， AUC-H groups， 20， 40 and 80 μmol/L Auc）， Auc-H+pcDNA-NC group （80 μmol/L Auc+transfected pcDNA- NC plasmid）， and Auc-H+pcDNA-CDK1 group （80 μmol/L Auc+transfected pcDNA-CDK1 plasmid）. Cell proliferation， clonal formation， invasion and migration abilities， apoptosis and cycle distribution， and the expressions of related proteins of apoptosis， epithelial-mesenchymal transformation （EMT） and CDK1/CCNB1/PLK1 signaling pathway were detected in each group. The transplanted tumor model of BALB/c nude mice was established by subcutaneous inoculation of MCF-7 cell suspension， and the mice were divided into control group and Auc group （12 mice in each group）. The tumor volume， mass and the expressions of related proteins of CDK1/CCNB1/PLK1 signaling pathway in tumor tissues were detected. RESULTS Compared with control group， the number of clonal formation， proliferation rate， cell invasion number， scar healing rate， G1/G0 phase and S phase cell proportions， and the expressions of B cell lymphoma-2 （Bcl-2）， N-cadherin， fibronectin， CDK1， CCNB1 and PLK1 were decreased significantly （P＜0.05）. The apoptotic rate， G2/M phase cell proportion and the expressions of Bcl-2 associated X protein and E-cadherin were significantly increased， in a dose-dependent manner （P＜0.05）. Compared with the Auc-H+pcDNA-NC group， there was no statistical significance in the above indexes in the Auc-H group （P＞0.05）， while the above indexes in the Auc-H+ pcDNA-CDK1 group were significantly reversed （P＜0.05）. Compared with the control group， the tumor volume and mass， and the expressions of CDK1， CCNB1 and PLK1 in tumor tissue of Auc group were significantly decreased （P＜0.05）. CONCLUSIONS Auc can inhibit the proliferation， invasion and migration of breast cancer cells， induce cell cycle arrest， and inhibit the progression of EMT， which may be related to inhibiting the activation of the CDK1/CCNB1/PLK1 signaling pathway.