Abstract
Breast cancer is the second most prevalent cancer in women worldwide. Long non‑coding RNAs (lncRNAs) have been identified as important regulators of tumorigenesis and tumor metastasis. lncRNA FGD5‑AS1 has been previously reported as a carcinogenic gene, however its role in breast cancer has yet to be investigated. The present study aimed to understand the function of lncRNA FGD5‑AS1 in breast cancer and examine the underlying molecular mechanisms. Sample tissues for downstream gene expression profiling were collected from patients with breast cancer (n=23). The effect of FGD5‑AS1 overexpression on cell viability, invasion and migration has been studied in breast cancer cells (MDA‑MB‑231). Changes in glycolysis were monitored by comparing glucose consumption, lactate production and ATP levels. Using StarBase and TargetScan databases a putative interaction between FGD5‑AS1, miR‑195‑5p and SNF1‑like kinase 2 (NUAK2) was predicted in silico. Expression levels of FGD5‑AS1, has‑miR‑195‑5p and NUAK2 were validated by reverse transcription‑quantitative PCR and interactions were validated using dual‑luciferase reporter assays and RNA pull‑down. High expression of lncRNA FGD5‑AS1 was detected in breast cancer tissue samples and disease model cell lines. Silencing of FGD5‑AS1 led to decreased cell proliferation, migration and invasion. It was identified that at a molecular level FGD5‑AS1 serves as a sponge of miR‑195‑5p and alters the expression of its downstream target gene NUAK2. In breast cancer lncRNA FGD5‑AS1 serve a key role in glycolysis and tumor progression via the miR‑195‑5p/NUAK2 axis. The findings of the present study indicated FGD5‑AS1 as a candidate target for intervention in patients with breast cancer.