Long noncoding RNA SNHG1 promotes TERT expression by sponging miR-18b-5p in breast cancer

Long noncoding RNA (lncRNA) small nucleolar RNA host gene 1 (SNHG1) plays a positive role in the progression of human malignant tumors. However, the molecular mechanism of SNHG1 remains elusive in breast cancer.

LncRNA SNHG1 was upregulated and had a positive relationship with poor prognosis according to bioinformatics analysis in pan-cancer including breast cancer. Silencing SNHG1 inhibited tumorigenesis in breast cancer both in vitro and in vivo. Mechanistically, SNHG1 functioned as a competing endogenous RNA (ceRNA) to promote TERT expression by sponging miR-18b-5p in breast cancer. miR-18b-5p acted as a tumor repressor in breast cancer. Moreover, the combination of SNHG1 knockdown and TERT inhibitor administration showed a synergistic inhibitory effect on breast cancer growth in vivo. Finally, E2F1 as a transcription factor, binding to SNHG1 promoter and enhanced SNHG1 transcription in breast cancer.

Our results provide a comprehensive understanding of the oncogenic mechanism of lncRNA SNHG1 in breast cancer. Importantly, we identified a novel E2F1-SNHG1-miR-18b-5p-TERT axis, which may be a potential therapeutic target for breast cancer. Our results also provided a potential treatment for breast cancer when knockdown SNHG1 and TERT inhibitor administration simultaneously.