PTX3 promotes breast cancer cell proliferation and metastasis by regulating PKCζbreast cancer, pentraxin 3, protein kinase Cζ, proliferation, metastasis.

Breast cancer (BC) is the most commonly diagnosed cancer in women, providing a leading cause of death from malignancy. Pentraxin 3 (PTX3) and protein kinase C ζ (PKCζ) are both known to exert important roles in the progression of multiple types of tumors, including BC. The present study aimed to explore both their interaction and their role in promoting the proliferation and metastasis of BC. The expression level of PTX3 was found to be elevated both in patients with BC and in BC cells; furthermore, it was found to be associated with lymph node metastasis in patients with BC. Knockdown of PTX3 decreased the rate of cell proliferation and the effects of a series of metastasis-associated cellular processes, including cell chemotaxis, migration, adhesion and invasion, as well as diminishing actin polymerization of the MDA-MB-231 and MCF7 BC cells, and decreasing tumor pulmonary metastasis . Mechanistically, PTX3 and PKCζ were found to be colocalized intracellularly, and they were co-translocated to the cell membrane upon stimulation with epidermal growth factor. Following the knockdown of PTX3, both the phosphorylation and membrane translocation of PKCζ were significantly impaired, suggesting that PTX3 regulates the activation of PKCζ. Taken together, the findings of the present study have shown that PTX3 may promote the proliferation and metastasis of BC cells through regulating PKCζ activation to enhance cell migration, cell chemotaxis, cell invasion and cell adhesion.