lncRNA GHET1 knockdown suppresses breast cancer activity in vitro and in vivo.

Long non-coding RNA gastric carcinoma high-expressed transcript 1 (lncRNA GHET1) is highly expressed in many tumors. The aim of the present study was to determine whether GHET1 inhibition decreases growth and metastasis of MCF-7 breast cancer cells by modulating epidermal growth factor receptor (EGFR) expression. In vitro， lncRNA GHET1 knockdown suppressed cell proliferation， migration， and invasion and enhanced cell apoptosis by maintaining MCF-7 cells in the G1 phase of the cell cycle. Furthermore， lncRNA GHET1 knockdown reduced the expression of EGFR and related proteins. Treatment of mice with a GHET1 inhibitor prevented tumor growth in vivo. The results indicate that lncRNA GHET1 inhibition directly suppresses EGFR expression， significantly inhibiting the downstream PI3K/AKT/Cyclin D1/MMP2/9 pathway. This mechanism may underlie the suppression of breast cancer cell activities including proliferation， migration， and invasion. In conclusion， lncRNA GHET1 knockdown suppresses tumor growth and metastasis by suppressing the activity of EGFR and downstream pathways.