The long non-coding RNA SUMO1P3 facilitates breast cancer progression by negatively regulating miR-320a.

Although the long non-coding RNA (lncRNA) SUMO1P3, small ubiquitin-like modifier 1 pseudogene 3, has been shown to play a role in human cancer, the biological function and mechanism of SUMO1P3 in breast cancer remained unclear. In this study, we showed that SUMO1P3 expression was higher in breast cancer tissues when compared to adjacent normal tissues and we found that high levels of SUMO1P3 expression associated significantly with tumor progression and poor survival of breast cancer patients. Moreover, we found that knockdown of SUMO1P3 suppressed proliferation, migration, and invasion of breast cancer cells. Bioinformatics analysis and luciferase reporter assays confirmed that SUMO1P3 binds to miR-320a, which has been identified as a tumor suppressor in various cancers, including breast cancer. We also confirmed that the tumor-promoting effects of SUMO1P3 in breast cancer are partly mediated by negative regulation of miR-320a. Our data indicates that SUMO1P3 functions as an oncogenic lncRNA in breast cancer and may serve as a novel diagnostic and biological target for breast cancer diagnosis and treatment.