Dyregulation of the lncRNA TPT1-AS1 positively regulates QKI expression and predicts a poor prognosis for patients with breast cancer.

The long noncoding RNA (lncRNA) TPT1-AS1 has been reported to be involved in the development of multiple cancers. However, its clinical value, biological function, and underlying molecular mechanism in breast cancer (BC) remain unclear. In the present study, TPT1-AS1 expression was decreased in BC tissues, based on RNA-seq data download from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases and the qRT-PCR results confirmed the above findings. Otherwise, low TPT1-AS1 expression was significantly associated with some clinical features of malignancy, such as high TNM stage, lymph node metastasis, a Her-2-negative status, and shorter overall survival. More importantly, univariate and multivariate Cox regression analyses indicated that TPT1-AS1 is an independent prognostic factor for patients with BC. Overexpression and knockdown of TPT1-AS1 in BC cell lines altered their proliferation, metastasis and invasion, as measured using the cell counting kit-8 (CCK-8) assay, wound-healing assay and transwell assay, respectively. In addition, a dual luciferase activity reporter assay validated that TPT1-AS1 and QKI shared a binding site in miR-330-3p. Based on these findings, TPT1-AS1 potentially represents a prognostic biomarker for patients with BC and participates in the development of BC through the TPT1-AS1/miR-330-3p/QKI axis.