Abstract. Breast cancer is one of the most common malignant tumors in women. Cell division cycle-associated 5 (CDCAS) is closely associated with the behavior of various cancer types.

The aim of the present study was to explore the effect of CDCAS on breast cancer. Western blot analysis and reverse transcrip-tion-quantitative PCR were used to detect the expression level of CDCAS in human normal mammary cells and human breast cancer cell lines. To determine its function in MDA-MB-231 cells, CDCA5 was silenced in MDA-MB-231 cells by transient short hairpin RNA transfection. Cell Counting Kit-8 and clono-genicity assays were used to evaluate cell proliferation. Wound healing and Transwell assays were used to detect cell invasion and migration. Western blot analysis was used to detect the protein expressions of Ki67 and PCNA associated with prolif-eration, MMP2 and MMP9 associated with migration. CDCAS was found to be markedly increased in breast cancer cell lines.

CDCAS knockdown was able to suppress cell proliferation, invasion and migration. CDCAS inhibition downregulated PDS5 cohesin-associated factor A (PDS5A) expression in breast cancer cells. PDS5A overexpression was found to reverse the effect of CDCAS inhibition on breast cancer cell proliferation and migration. CDCAS knockdown was shown to suppress the malignant progression of breast cancer cells by regulating PDS5A. The present findings may provide new potential targets for breast cancer therapy.