lncRNA HEIH, an indicator of high malignancy and poor prognosis, functions as an oncogene in breast cancer.

Long non‑coding RNA high expression in hepatocellular carcinoma (lncRNA HEIH) acts as an oncogene in multiple tumors, including hepatocellular carcinoma, colorectal cancer, melanoma and non‑small cell lung cancer. However, the role of HEIH in breast cancer remains unknown. The present study focused on the clinical significance and biological function of HEIH in breast cancer. Specifically, the expression levels of HEIH in breast cancer tissues and breast cancer cell lines were investigated. The results indicated high expression levels of HEIH in human breast cancer tissues, and its expression was positively associated with malignancy status and poor disease prognosis. High expression levels of HEIH were detected in the breast cancer cell lines, including MCF‑7, SK‑BR‑3, MDA‑MB‑231 and MDA‑MB‑468. These data were consistent with those derived from the in vivo study. Therefore, small interfering RNA was used to knockdown HEIH expression in order to explore whether HEIH exhibits an oncogenic function in breast cancer. Following HEIH knockdown, the proliferative and metastatic activity of MDA‑MB‑231 cells was decreased, whereas the induction of cell apoptosis was increased. These results suggested the oncogenic role of HEIH in breast cancer and the potential application of HEIH as an index of malignancy and poor prognosis in breast cancer.