Inhibitory effect of CDCA5-siRNA on proliferation of breast cancer and its mechanism

Objective To study the effect of CDCA5 silencing on the growth of human breast cancer cell line MDA-MB-435s in vitro and its mechanism. Methods The expression of CDCA5 in breast cancer tissue, the adjacent normal tissue and human breast cancer cell lines MCF-7, MDA-MB-231 and MDA-MB-435s was tested by Western blot. The target sequences of CDCA5 small interfering RNA (siRNA) , control siRNA (siRNA-NC) and blank groups were designed. PCR was used to observe the gene silencing effect on CDCA5. The cell viability was measured by MTT assay in siRNA, siRNA-NC and Blank groups. Cell cycle was determined by flow cytometry. Plk1, SA2 and pSA2 protein expression was tested by Western blot. Rssults The expression of CDCA5 was higher in breast cancer tissue than in the adjacent normal tissue. The expression of CDCA5 was higher in human breast cancer cell line MDA-MB-435s than in MCF-7 or MDA-MB-231 cell line. The expression level of CDCA5 was downregulated significantly in siRNA group than other groups. The cell viability was decreased and the cell percentage of G2/M phase was elevated in siRNA group compared with those in siRNA-NC and Blank groups. Inhibition of the CDCA5 gene can suppress the expression of Plk1 and pSA2. Conclusion Silencing CDCA5 expression can effectively inhibit the proliferation of breast cancer cells, whose mechanism may lie in arresting cell cycle in G2/M phase by suppressing CDCA5/Plk1/SA2 signaling pathway. Key words: Breast cancer; CDCA5; Small interfering RNA