Overexpression of lncRNA SLC16A1-AS1 Suppresses the Growth and Metastasis of Breast Cancer via the miR-552-5p/WIF1 Signaling Pathway

BACKGROUND: Breast cancer (BC) is the most common cancer and the fifth leading cause of cancer mortality with 685,000 deaths worldwide in 2020. Long non-coding RNAs (lncRNAs) are critical in BC carcinogenesis and progression. However, the functional roles and mechanisms of SLC16A1-AS1 in BC are unknown. METHODS: The expression profile of SLC16A1-AS1 in BC patients was investigated using data from The Cancer Genome Atlas (TCGA) database and checked in 80 BC patients, followed by analyzing the prognostic value of SLC16A1-AS1 in the 80 BC patients. The biological functions of SLC16A1-AS1 were further examined in vivo and in vitro after overexpression of SLC16A1-AS1 in BC cells. Possible binding sites between SLC16A1-AS1 and miR-552-5p were predicted by miRDB and those between miR-552-5p and Wnt inhibitory factor-1 (WIF1) were predicted by miRanda, which were confirmed using dual-luciferase reporter assay with mutation. Spearman correlation assay was applied to evaluate the association between genes. Rescue experiments were further applied to investigate the molecular mechanisms involved. RESULTS: Lower SLC16A1-AS1 expression in BC tissues was related to poor prognosis of BC patients. Upregulation of SLC16A1-AS1 suppressed BC cell viability, colony formation, invasion, and migration in vitro and growth in vivo via sponging miR-552-5p to release WIF1. CONCLUSION: SLC16A1-AS1 is a tumor suppressor in BC, and lower SLC16A1-AS1 expression is an indicator of poor prognosis in BC patients. SLC16A1-AS1 inhibits BC carcinogenesis and progression via the SLC16A1-AS1/miR-552-5p/WIF1 pathway. SLC16A1-AS1 represents a novel diagnostic, therapeutic, and prognostic target for BC management.