Long non-coding RNA ZEB2-AS1 promotes the proliferation, metastasis and epithelial mesenchymal transition in triple-negative breast cancer by epigenetically activating ZEB2.

The triple-negative breast cancer is the most malignant type of breast cancer. Its pathogenesis and prognosis remain poor despite the significant advances in breast cancer diagnosis and therapy. Meanwhile, long noncoding RNAs (LncRNAs) play a pivotal role in the progression of malignant tumors. In this study, we found that LncRNA-ZEB2-AS1 was dramatically up-regulated in our breast cancer specimens and cells (MDA231), especially in metastatic tumor specimens and highly invasive cells, and high lncRNA-ZEB2-AS1 expression is associated with clinicopathologic features and short survival of breast cancer patients. LncRNA-ZEB2-AS1 promotes the proliferation and metastasis of MDA231 cells in SCID mice. Thus, it is regarded as an oncogene in triple-negative breast cancer. It is mainly endo-nuclear and situated near ZEB2, positively regulating ZEB2 expression and activating the epithelial mesenchymal transition via the PI3K/Akt/GSK3ß/Zeb2 signaling pathway. Meanwhile, EGF-induced F-actin polymerization in MDA231 cells can be suppressed by reducing lncRNA-ZEB2-AS1 expression. The migration and invasion of triple-negative breast cancer can be altered through cytoskeleton rearrangement. In summary, we demonstrated that lncRNA-ZEB2-AS1 is an important factor affecting the development of triple-negative breast cancer and thus a potential oncogene target.