Breast cancer (BC) is one of the most prevalent and mortal malignancies in women worldwide, and tamoxifen is the mainstay treatment of breast cancer and the development of resistance represents a major obstacle for a cure. Long non-coding RNAs (LncRNAs) LINC00261 have been identified
to serve a key role in the development of several tumors. However, the role of LINC00261 in breast cancer and chemotherapy resistance remains largely unknown. To investigate the role of LINC00261 in BC cells, LINC00261 was upregulated in MCF-7-TAM cells by transfecting with LINC00261 plasmid
(pcDNA-LINCC00261). Subsequently, cell viability and drug sensitivity were measured using the CCK-8 assay. Reverse transcription-quantitative polymerase chain reaction (qRT-PCR) was performed to detect the level of LINC00261 in BC cells. Cell migration, invasion, and apoptosis were detected
by Transwell, Scratch Test and Flow cytometry, respectively. Additionally, the associated protein expression was detected using Western blot. The results demonstrated that LINC00261 was significantly down-regulated in BC cells, especially in MCF-7-TAM cells. Overexpression of LINC00261 inhibited
cell proliferation, migration, and invasion in MCF-7-TAM cells. Further, an abundant of LINC00261 sensitized breast cancer cells to tamoxifen and reduced tamoxifen-induced apoptosis in MCF-7-TAM cells. Finally, LINC00261 significantly regulated the protein expression of drug-resistant genes
and the protein expression related to tumor metastasis and cell apoptosis. Therefore, this study revealed that LINC00261 induces chemosensitization to tamoxifen in human breast cancer, it may be a useful biomarker and potential therapeutic target.
c-erbB-4 protein expression in human breast cancer
