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Objective: To determine expression of brain-derived neurotrophic factor antisense (BDNF-AS) long non-coding RNA (ln-cRNA) in breast cancer, and to investigate its effects on proliferation, apoptosis, migration and invasion. Methods: Between 2016 and 2018, samples from 88 cases of breast cancer were collected at the First Hospital of Lanzhou University. RT-qPCR was used to deter-mine expression of lncRNA BDNF-AS in breast cancer tissue and cells. A pcDNA3.1 plasmid was used to overexpress BDNF-AS in MDA-MB-231 cells. Cell viability was quantified using an MTT assay, proliferative capacity was determined using an EdU assay and a colori-metric assay was used to measure the Caspase-3 activity. Moreover, the protein levels of Bax, Bcl-2, MMP-9, E-cadherin, and BDNF were quantified by Western blot. Scratch and transwell assays were used to determine cell migration and invasion. Results: Lower ln-cRNA BDNF-AS expression was observed in breast cancer tissue and cells compared with normal paracancerous tissues (P<0.05), and with normal, HBL-100 breast cells (P<0.01). BDNF-AS expression negatively correlated with tumor-node-metastasis (TNM) stage (P<0.05) and lymphatic metastasis (P<0.05) of breast cancer. Overexpression of BDNF-AS with the pcDNA3.1 plasmid decreased viability of MDA-MB-231 cells (P<0.01), EdU-positive cells (P<0.01), and Caspase-3 activity (P<0.01). Additionally, Bcl-2, MMP-9, and BDNF ex-pression was downregulated (P<0.01), while Bax and E-cadherin expression was upregulated (P<0.01). Overexpression of BDNF-AS al-so inhibited cell healing and invasion which were determined by scratch assays (P<0.01). Conclusions: LncRNA BDNF-AS expression is downregulated in breast cancer, which inhibits breast cancer cell proliferation, migration, invasion, and promotes apoptosis.
RESUMO
Background and purpose:Multiple microRNAs (miRNAs) are abnormally expressed in breast cancer and play an important role in the regulation of breast cancer. miRNAs may be a new target for the treatment of breast cancer. This study aimed to investigate the expression of miR-199a-3p in breast cancer and the effect of miR-199a-3p on proliferation and apoptosis of breast cancer.Methods:Real-time PCR was used to test the expression of miR-199a-3p in breast cancer tissues, normal breast tissues, breast cancer cells and normal breast cells. Overexpression (or silencing the expression) of miR-199a-3p was conducted by transfecting MDA-MB-231 with miR-199a-3p mimics (or inhibitors). The proliferation of MDA-MB-231 was detected by MTT method. The apoptosis of MDA-MB-231 was investigated by Hoechst staining and caspase-3 activity assay kit.Results:Compared to corresponding non-tumor breast tissues (or normal breast cell HBL-100), lower levels of miR-199a-3p were expressed in breast cancer tissues or breast cancer cells. Overexpression of miR-199a-3p induced by miR-199a-3p mimic inhibited the proliferation and promoted the apoptosis of MDA-MB-231, while silencing the expression of miR-199a-3p induced by miR-199a-3p in-hibitor increased the proliferation and suppressed the apoptosis of MDA-MB-231.Conclusion:The expression of miR-199a-3p is lower in breast cancer, which shows its tumor suppression effect by regulating the proliferation and apoptosis of breast cancer cells.