Abstract:

Objective To discuss the effect of cell division cycle protein 20 （CDC20） on the proliferation and cell cycle of endometrial carcinoma （EC） cells， and to clarify its mechanism. Methods Real-time fluorescence quantitative PCR（RT-qPCR） and Western blotting methods were used to detect the expression levels of CDC20 mRNA and protein in human endometrial stromal T-HESC cell and EC cells （KLE， RL95-2， ZJB-ENC1， and ECC-1 cells）. The RL95-2 cells were selected for the subsequent experiments. CDC20 shRNA interference lentivirus was transfected into the RL95-2 cells and the cells were divided into control group， sh-NC group （infected with negative control lentivirus）， sh-CDC20 group （infected with CDC20 shRNA interference lentivirus）， sh-NC+SM04690 group （infected with negative control lentivirus followed by treatment with 64 nmol·L?1 Wnt/β-catenin signaling pathway inhibitor SM04690 for 48 h）， and sh-CDC20+SM04690 group （infected with CDC20 shRNA interference lentivirus followed by treatment with 64 nmol·L?1 SM04690 for 48 h）. RT-qPCR and Western blotting methods were used to detect the expression levels of CDC20 mRNA and proteins in the cells in various groups； CCK-8 method was used to detect the proliferation activities of the RL95-2 cells in various groups； BrdU assay was used to detect the percentages of BrdU positive cells in various groups； flow cytometry was used to detect the percentages of the cells at G₂/M stage in various groups； Western blotting method was used to detect the expression levels of β-catenin， oncogene c-Myc， and cyclin D1 proteins in the cells in various groups. Results Compared with T-HESC cells， the expression levels of CDC20 mRNA and protein in the KLE， RL95-2， ZJB-ENC1， and ECC-1 cells were significantly increased（P<0.05）， and the highest expression levels of CDC20 mRNA and protein were observed in RL95-2 cells. Compared with sh-NC group， the proliferation activities and percentages of the BrdU positive cells in sh-CDC20 group and sh-NC+SM04690 group were significantly decreased （P<0.05）， the percentages of the cells at G₂/M phase were significantly increased （P<0.05）， and the expression levels of β-catenin， c-Myc， and cyclin D1 proteins were significantly decreased （P<0.05）. Compared with sh-CDC20 group， the proliferation activity and percentage of BrdU positive cells in sh-CDC20+SM04690 group were significantly decreased （P<0.05）， the percentage of the cells at G₂/M phase was significantly increased （P<0.05）， and the expression levels of β-catenin， c-Myc， and cyclin D1 proteins in the cells were significantly decreased （P<0.05）. Conclusion CDC20 is highly expressed in the EC cells. Silencing CDC20 may inhibit the cell proliferation by inducing G₂/M phase arrest in the RL95-2 cells through the regulation of Wnt/β-catenin signal transduction.KEYWODS Endometrial cancer； Cell division cycle protein 20； Cell cycle； Cell proliferation； Wnt/β-catenin signaling pathway