RESUMO
p21-activated kinase 5 (PAK5), a kind of the PAK family of serine / threonine kinases, modulates various cellular processes, including cytoskeletal remodeling, cell proliferation, migration and metastasis. Although studies have suggested that PAK5 is a key regulator of breast cancer progression, the link of PAK5 to senescence has not been reported yet. In this study, the CRISPR/ Cas9 lentivirus infection method was used to construct two PAK5 stably knockdown cell lines of human breast cancer (MDA-MB-231 and BT474). The effect of PAK5 knockdown on the proliferation of breast cancer cells was detected by CCK-8 and clone formation assays. The effect of PAK5 knockdown on cell cycle was detected by flow cytometry. The effect of PAK5 knockdown on cell senescence was observed by β-galactosidase staining. Western blotting was performed to detect the expression of senescence-related proteins including p53, p21 and p16 in breast cancer cells. Cells were treated by CHX and MG132 to explore the possible mechanism of PAK5 regulating p53 protein expression. The results showed that knockdown of PAK5 inhibited cell proliferation and blocked cells in the G