Circular RNA (circRNA) is a key regulator in the development and progression of 
human cancers, however its role in breast cancer tumorigenesis is not well 
understood. The present study aims to investigate the expression profiles and 
potential modulation of circRNA on breast cancer carcinogenesis. Human circRNA 
microarray was performed to screen for abnormally expressed circRNA in breast 
cancer tissue. Results found circ-ABCB10, was significantly up-regulated in 
breast cancer tissue. And results were replicated in a larger sample size. In 
vitro, loss-of-function experiments showed circ-ABCB10 knockdown suppressed the 
proliferation and increased apoptosis of breast cancer cells. Bioinformatics 
prediction program predicted the complementary sequence within circ-ABCB10 and 
miR-1271, which was validated by luciferase reporter assay. Finally, miR-1271 
rescued the function of circ-ABCB10 on breast cancer cells, confirming the 
sponge effect of circ-ABCB10 on miR-1271. Overall, results identified a new 
functional circ-ABCB10 in breast cancer tumorigenesis, and reveal the important 
regulatory role of circ-ABCB10 through sponging miR-1271, providing a novel 
insight for breast cancer pathogenesis.