Objective: To investigate the effects of down-regulating the expression of ubiquitin-protein ligase E3A (UBE3A) on the biological behaviors in three negative breast cancer (TNBC) cells.
Methods: Three constructed UBE3A shRNA sequences were respectively transfected into the human TNBC MDA-MB-231 cells through lentiviral vectors, and the shRNA sequence with highest interference efficiency was selected for experiments after interference efficiency tests. In MDA-MB-231 cells after transfected with the selected UBE3A shRNA sequence, the changes in proliferation, invasion and cell cycle were determined by CCK-8 assay, Transwell invasion assay and flow cytometry respectively, using the MDA-MB-231 cells without any treatment and transfected with a scrambled sequence as blank control and negative control.
Results: The lentiviral vectors with UBE3A shRNA expression were successfully constructed and the UBE3A shRNA sequence with highest interreference efficiency was picked up (the inhibitory rate was 89.5% for UBE3A gene and 45.3% for UBE3A protein). Compared with the cells in blank control group, the proliferative and invasion abilities were significantly decreased with significant S-phase cell cycle arrest in MDA-MB-231 cells with UBE3A down-regulation (all P<0.05); all the observed indexes in cells of negative control group showed no significant changes (all P>0.05).
Conclusion: Down-regulating UBE3A expression can induce cell cycle arrest in TNBC cells and thereby inhibit their proliferation and invasion abilities, and suggests that UBE3A expression plays an important role in the malignant biological behaviors of TNBC cells.