Downregulation of RPS14 inhibits the proliferation and metastasis of estrogen receptor-positive breast cancer cells

Ribosomal protein S14 (RPS14) is a component of the 40S ribosomal subunit and is considered to be indispensable for ribosomal biogenesis. Previously, we found that RPS14 was significantly downregulated in estrogen receptor-positive (ER+) breast cancer cells following treatment with 4-hydroxytamoxifen (4-OH-TAM). However, its role in breast cancer remains poorly understood. In the present study, we sought to demonstrate, for the first time, that RPS14 is highly expressed in ER+ breast cancer tissues and its downregulation can significantly inhibit the proliferation, cycle, and metastasis of ER+ breast cancer cells, as well as induce cell apoptosis. Quantitative RT-PCR and western blotting were used to determine the expression of target genes. Herein, lentivirus-mediated small hairpin RNA (shRNA) targeting RPS14 was designed to determine the impact of RPS14 knockdown on ER+ breast cancer cells. Further, bioinformatics analysis was used to reveal the significance of differentially expressed genes in RPS14 knockdown breast cancer cells. RPS14 was highly expressed in ER+ breast cancer tissues compared to ER− tissues. The downregulation of RPS14 in two ER+ breast cancer cell lines suppressed cell proliferation, cell cycle and metastasis, and induced apoptosis. Based on bioinformatics analysis, the expression level of several significant genes, such as ASNS , Ret , and S100A4 , was altered in breast cancer cells after RPS14 downregulation. Furthermore, the BAG2 and interferon signaling pathways were identified to be significantly activated. The downregulation of RPS14 in ER+ breast cancer cells can inhibit their proliferation and metastasis.