RBMS3 Inhibits the Proliferation and Metastasis of Breast Cancer Cells.

RBMS3, a gene encoding a glycine-rich RNA-binding protein, belongs to the family of c-Myc gene single-strand binding proteins (MSSP). Recently, several reports have provided evidence that RBMS3 was deregulated in a diverse range of solid tumors and played a critical role in tumor progression. However, it remains unclear whether RBMS3 inhibits the progression of human breast cancer. Thus, the aim of this study was to investigate the role of RBMS3 in breast cancer and explore the underlying mechanism in breast cancer progression. Our results showed, for the first time, that the expression of RBMS3 at both the mRNA and protein levels was significantly downregulated in human breast cancer tissues and cell lines. In addition, RBMS3 overexpression dramatically suppressed the proliferation, migration, and invasion of breast cancer cells in vitro and attenuated tumor growth in vivo. Furthermore, we observed that RBMS3 greatly inhibited the protein expression of β-catenin, cyclin D1, and c-Myc in breast cancer cells. In summary, we have shown that RBMS3 inhibited the proliferation and tumorigenesis of breast cancer cells, at least in part, through inactivation of the Wnt/β-catenin signaling pathway. Thus, RBMS3 may be a potential treatment target for breast cancer.