Abstract:

Objective To explore the expression of pololike kinase 1 （PLK1） and cell-division cycle protein 20 （CDC20） in breast cancer as well as the relationship of their expression with clinicopathological features and prognosis. Methods The expression datasets of PLK1 and CDC20 from cBioPortal database were collected to analyze the co-expressions of these two genes. The clinical data and mRNA microarray data of 1092 patients with breast cancer obtained from the Cancer Genome Atlas（TCGA） database were collected and analyzed for expression of PLK1 and CDC20. The KaplanMeier method and Cox proportional-hazards regression model was used to analyze the relationship between the expressions of PLK1 or CDC20 and the survival of patients with breast cancer. The relationships between PLK1 or CDC20 and age， gender and ER， PR or HER-2 genes expression levels were further analyzed by χ2 test. Results The expression levels of PLK1 and CDC20 in breast cancer were significantly correlated （r=0.88，P＜0.001）. Also， the expressions of PLK1 and CDC20 significantly was related to the disease free survival （DFS） of patients with breast cancer（P＜0.05）. Patients with high expression of PLK1 and CDC20 had short DFS compared with patients with low expression of both （P=0.007）. At the same time， the expression levels of PLK1 and CDC20 in ER negative and PR negative patients were significantly higher than those in ER positive and PR positive patients （P＜0.001）. Conclusion PLK1 and CDC20 may play a role in promoting tumorigenesis in breast cancer， and may serve as potential tumor diagnostic markers and individual therapeutic targets.