H/ACA box small nucleolar RNA 7B acts as an oncogene and a potential prognostic biomarker in breast cancer.

ABSTRACT

BACKGROUND: Breast cancer (BC) is the most frequent malignancy occurring in women worldwide. Emerging evidence indicates that small nucleolar RNAs (snoRNAs) play a role in tumor development. In the current study, we evaluated expression profiles and functions of snoRNAs associated with BC. METHODS: We analyzed the expression levels of snoRNAs between breast cancer and normal tissues in TCGA database and found that SNORA7B is upregulated in BC. We confirmed this result in clinical cancer tissues and BC cell lines via qRT-PCR. Then, we investigated clinical significance in public datasets and biological function of SNORA7B using a series of in vitro gain- and loss-of-function experiments. RESULTS: SNORA7B expression was significantly upregulated in samples from patients with BC in both public database and our clinical tissues compared to its expression in normal tissues. Meanwhile, patients with high SNORA7B expression have worse prognosis. Inhibition of SNORA7B expression impaired cell growth, proliferation, migration, and invasion via inducing apoptosis. CONCLUSIONS: SNORA7B functions as an important oncogenic snoRNA in BC and may serve as a potential prognosis biomarker for BC.