Study Of The Regulation Role Of Prosaposin On Breast Cancer Progression And Estrogen Receptor Alpha

Prosaposin (PSAP), a secreted protein, is a well-known pleiotropic growth factor. Growth factors are implicated in the development and neoplastic growth of the mammary gland. Although previous reports have indicated that PSAP is overexpressed in breast cancer cells, the role that PSAP in the development of breast cancer remains to be identified. Here, we revealed that PSAP was highly expressed in human breast cancer tissue. Its expression positively correlated with tumor grade and HER2. Further statistical data indicated that PSAP expression correlated positively with Ki67in estrogen receptor α (ERα) positive tumors rather than ERα negative tumors. Consistent with these observations, PSAP promoted proliferation, migration and prevented apoptosis in estrogen receptor-α (ERα)-positive cell line:MCF-7and T47D. It has been well documented that ERa is essential for mammary gland development and is a major oncogene in breast cancer. In the present investigation, we demonstrated PSAP upregulated ERa expression and nuclear ERα content in MCF-7and T47D cells. Furthermore, our data also showed that PSAP-upregulated ERa expression through MAPK-signaling pathway. Taken together, our studies suggest that PSAP is a regulator of ERα and its overexpression might enhance ERα-mediated signaling axis and play a role in breast cancer development and progression.