Breast cancer is the most common female malignancies in the world which seriously impacts the female health. In recent years, various studies have been reported to determine the relevance of miRNAs to human cancer. One of these miRNAs, miR-146a has been down-regulated in multiple human cancer types, but up-regulation showed inducing apoptosis. To determine the role of quercetin treated on breast cancer, we investigated the effect of quercetin on cell proliferation in human breast cancer cell lines MCF-7 and MDA-MB-231 with/without transfection of miR-146a mimic or anti-miR-146a. Furthermore, the expressions of bax and cleaved-caspase-3, mainly were increased in control and overexpression miR-146a groups, however, the expression of EGFR was inverse. All the results demonstrated that quercetin exhibited excellent effect on inhibiting cell proliferation in human breast cancer cells, which was performed by up-regulating miR-146a expression, then via inducing apoptosis through caspase-3 activation and mitochondrial-dependent pathways, and inhibiting invasion through down-regulating the expression of EGFR.
HOTAIR plays an important role in the regulation of cancer cell proliferation and cancer invasion in breast cancer. The up-regulation of HOTAIR has been reported in both estrogen receptor (ER) positive and triple-negative (TN) breast cancer. It has been reported that HOTAIR is regulated by estrogen (E2) via ERs in ER-positive breast cancer. However, it is unknown how HOTAIR is regulated in TN breast cancer. In this study, we found that HOTAIR was increased in the peripheral blood mononuclear cells and cancer tissues from breast cancer patients, and was especially higher in patients with metastatic breast cancer. In addition, we found that estrogen promoted HOTAIR through its receptor GPER and estrogen-induced breast cancer cell migration was reversed by deleting HOTAIR in TN breast cancer cells MDA-MB-231and BT549. Furthermore, we identified that E2-GPER induces the level of HOTAIR through the suppression of miR-148a. miR-148a level was negatively correlated with HOTAIR level in breast cancer patients. After the mutation of the predicted miR-148a binding sites in HOTAIR, miR-148a had no effect on HOTAIR. In conclusion, our findings offer important new insights into the ability of estrogenic GPER signaling to increase the HOTAIR level by inhibiting miR-148a in breast cancer.
Background
Tumor-associated macrophages (TAMs) and tumor cells are important components of the tumor microenvironment. M2 polarization of TAMs, which is a major actor in breast cancer malignancy and metastasis, can be induced by breast cancer cells. However, the potential mechanisms of the interaction between breast cancer cells and TAMs remain unclear.
Methods
The candidate breast cancer-associated long non-coding RNAs (lncRNAs) were analyzed using the GEO database. Functional assays, including MTT assay, Transwell assay, and EdU labeling detection, were performed to investigate the oncogenic role of linc00514 in breast cancer progression. The co-culture and ELISA assays were used to assess the role of linc00514 in macrophage recruitment and M2 polarization. RNA immunoprecipitation, RNA pull-down, and luciferase reporter assays were applied to determine the mechanism of linc00514 in breast cancer metastasis. Mouse xenograft models, mouse pulmonary metastatic models, and mouse primary tumor models were used to assess the role of linc00514 in M2 macrophage polarization and breast cancer tumorigenicity.
Results
Linc00514 was highly expressed in clinical breast cancer tissues and breast cancer cell lines. Overexpression of linc00514 promoted the proliferation and invasion of breast cancer cells and increased xenograft tumor volumes and pulmonary metastatic nodules. Overexpression of linc00514 also increased the percentage of macrophages expressing M2 markers CD206 and CD163. Mechanistically, linc00514 promoted Jagged1 expression in a transcriptional manner by increasing the phosphorylation of a transcription factor STAT3. Subsequently, Jagged1-mediated Notch signaling pathway promoted IL-4 and IL-6 secretions in breast cancer cells and ultimately inducing M2 polarization of macrophages.
Conclusion
Linc00514 plays an important role in regulating breast cancer tumorigenicity and M2 macrophage polarization via Jagged1-mediated Notch signaling pathway.
Nanobiotechnology plays an important role in drug delivery, and various kinds of nanoparticles have demonstrated new properties, which may provide opportunities in clinical treatment. Nanoparticle-mediated drug delivery systems have been used in anti-inflammatory therapies. Diseases, such as inflammatory bowel disease, rheumatoid arthritis, and osteoarthritis have been widely impacted by the pathogenesis of inflammation. Efficient delivery of anti-inflammatory drugs can reduce medical dosage and improve therapeutic effect. In this review, we discuss nanoparticles with potential anti-inflammatory activity, and we present a future perspective regarding the application of nanomedicine in inflammatory diseases.
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