MiR-129-5p suppresses breast cancer proliferation by targeting CBX4

Deregulation of microRNA (miRNA) is closely related to cancer development and progression. Our previous study identified that miR-129-5p suppresses proliferation and metastasis in breast cancer cells. Herein, we determined that CBX4 is a miR-129-5p target gene. CBX4 is up-regulated in breast cancer tissues and while its over-expression promotes cell proliferation, its knockdown suppresses cell proliferation in breast cancer cells. Furthermore, CBX4 mediates miR-129-5p-induced inhibition of cell proliferation and negatively correlates with the expression of miR-129-5p expression. These combined results suggest that CBX4 is an oncogene in breast cancer cells, and that it may provide a novel therapeutic strategy for breast cancer treatment.