PTTG promotes invasion in human breast cancer cell line by upregulating EMMPRIN via FAK/Akt/mTOR signaling.

Pituitary tumor transforming gene (PTTG) is a novel oncogene that is expressed at higher level in most of the tumors. PTTG overexpression correlates with lymph node infiltration and a higher degree of tumor recurrence in breast cancer. However, the cellular functions and precise signals elicited by PTTG in breast cancer are not fully understood. Here, we established a breast cancer cell line which stably overexpressed PTTG. In vitro experiments showed that overexpression of PTTG in MCF-7 cells was associated with enhanced cell migration and invasion as well as EMT. Our results also demonstrated that PTTG overexpression correlated with elevated EMMPRIN level, which mediated the enhanced cell migration, invasion and EMT. Moreover, our findings suggested that PTTG enhances metastatic potential of breast cancer cells by inducing EMMPRIN through activating FAK/Akt/mTOR pathway. Our findings may lead to a better understanding of the biological effect of PTTG and provide mechanistic insights for developing potential therapeutic strategies for inhibiting the invasion and metastasis of breast cancer.