Targeting Aurora-A Inhibition Modulates MDA-MB-231 Breast Cancer Cell Proliferation Andangiogenesis

Objective:To verify whether inhibition of Aurora-A expression could inhibit cell proliferation and angiogenesis of human breast cancer cell line MDA-MB-231, and to explore the related mechanisms.Method:Human breast cancer cell line MDA-MB-231 was used as experimental subjects, the specific siRNA was used to tranfect the cell to inhibit the expression of Aurora-A. The expression level of Aurora-A protein was detected by Western Blot. The inhibition of breast cancer cells proliferation was determined by CCK-8 assay. Transwell assay was used to detect the invasiveness of cells, Human umbilical vein endothelial cells (HUVECs) were used to assess angiogenesis. ELIS A and Real time-PCR were used to determine VEGF secretion and transcription, respectively. All results were expressed as means±standard deviation(x±s), SPSS20 was used to statistical analysis, The results between the two groups were compared with independent t-test. A P value of <0.05 was considered significant.Results:1. After silencing Aurora-A by specific siRNA, Western blot analysis showed that the protein levels of Aurora-A and p-Aurora-A were respectively reduced by 32%, 72%, compared with normol MDA-MB-231 cell group. The difference was statistically significant (p<0.05).2. After 24 hours, compared with normal MDA-MB-231 cells, the inhibition rate of silencing Aurora-A cells was 17.9±2.7%. Transwell experiments showed that after silencing Aurora-A, the number of cells into the chamber was 85.8±10.6, significantly lower than the number of control group 119.2±10.9, reducing 28.0± 14.1%(p<0.05). It indicated that silencing Aurora-A significantly reduced proliferation and invasiveness of MDA-MB-231 cells.3. After silencing Aurora-A, compared with normal MDA-MB-231 cells,Tube formation showed that the morphological structure of blood vessels was incomplete and HUVECs arranged irregularly. The number of blood vessels in the Aurora-A silence group was 6.4±1.3, significantly lower than the control group 15.2±1.3 (p<0.05). It indicated that silencing Aurora-A of MDA-MB-231 cells significantly inhibited angiogenesis.4. After silencing Aurora-A, compared with normal MDA-MB-231 cells, q-PCR showed that VEGF mRNA level significantly reduce to 14.3±0.9%(P<0.01). An Elisa was performed to detect levels of VEGF protein from MDA-MB-231 cells, The concentration of VEGF secreted from cells where Aurora-A was silenced was 555.9±18.4 pg/ml, significantly less than in control cells, which was 911.1±7.0pg/ml, reduced to 61.0%(P<0.001). These results demonstrated that Aurora-A inhibition decreased VEGF transcription and secretion.Conclusion:1. The silence of Aurora-A of MDA-MB-231 cells were successfully constructed, and the protein levels of Aurora-A andpAurora-A were reduced.2. Silencing Aurora-A effectively reduced proliferation and invasiveness of MDA-MB-231 cells.3. Silencing Aurora-A effectively inhibited the angiogenesis of MDA-MB-231 cells, the mechanisms may be related to inhibit the VEGF transcription and secretion directly or indirectly. Aurora-A have potential to be a new target of treating breast cancer and it's worthy of further study in the future.