Breast cancer is the most common cancer in women. Bisphenol A (BPA), as a known endocrine disrupter, is closely related to the development of breast cancer. Curcumin has been clinically used in chemopreventation and treatment of cancer; however, it remains unknown whether microRNAs are involved in curcumin-mediated protection from BPA-associated promotive effects on breast cancer. In the present study, we showed that BPA exhibited estrogenic activity by increasing the proliferation of estrogen-receptor-positive MCF-7 human breast cancer cells and triggering transition of the cells from G1 to S phase. Curcumin inhibited the proliferative effects of BPA on MCF-7 cells. Meanwhile, BPA-induced upregulation of oncogenic miR-19a and miR-19b, and the dysregulated expression of miR-19-related downstream proteins, including PTEN, p-AKT, p-MDM2, p53, and proliferating cell nuclear antigen, were reversed by curcumin. Furthermore, the important role of miR-19 in BPA-mediated MCF-7 cell proliferation was also illustrated. These results suggest for the first time that curcumin modulates miR-19/PTEN/AKT/p53 axis to exhibit its protective effects against BPA-associated breast cancer promotion. Findings from this study could provide new insights into the molecular mechanisms by which BPA exerts its breast-cancer-promoting effect as well as its target intervention.

Glycyrrhiza glabra (licorice) has been known to possess various pharmacological properties including anti-inflammatory, antioxidants, antiviral, and hepatoprotective activities. Magnesium isoglycyrrhizinate (MgIG), a magnesium salt of 18-α glycyrrhizic acid stereoisomer, is clinically used for the treatment of inflammatory liver diseases. However, the mechanism by which MgIG exerts its anti-inflammatory effects remains unknown. In the present study, we investigated the inhibitory potential of MgIG in phospholipase A2 (PLA2)/arachidonic acid (AA) pathway and release of the pathway-generated inflammatory lipid mediators in RAW264.7 macrophages. Results revealed that MgIG suppressed LPS-induced activation of PLA2 and production of AA metabolites such as prostaglandin E2 (PGE2), prostacyclin (PGI2), thromboxane 2 (TXB2), and leukotrienes (LTB4) in macrophages. Furthermore, LPS-induced AA-metabolizing enzymes including COX-2, COX-1, 5-LOX, TXB synthase, and PGI2 synthase were significantly inhibited by MgIG. Taken together, our data suggest that modulation of cyclooxygenase (COXs) and 5-lipoxygenase (LOX) pathways in AA metabolism could be a novel mechanism for the anti-inflammatory effects of MgIG.

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Curcumin is a phytochemical which exhibits significant inhibitory effect in multiple cancers including prostate cancer. MicroRNA‐34a (miR‐34a) was found to be a master tumor suppressor miRNA and regulated the growth of cancer cells. To date, however, the role of miR‐34a in the anticancer action of curcumin against prostate cancer has been rarely reported. In the present study, we showed that curcumin altered the expression of cell cycle‐related genes (cyclin D1, PCNA, and p21) and inhibited the proliferation of prostate cancer cells. Furthermore, we found that curcumin significantly upregulated the expression of miR‐34a, along with the downregulated expression of β‐catenin and c‐myc in three prostate cancer cell lines. Inhibition of miR‐34a activated β‐catenin/c‐myc axis, altered cell cycle‐related genes expression and significantly suppressed the antiproliferation effect of curcumin in prostate cancer cells. Findings from this study revealed that miR‐34a plays an important role in the antiproliferation effect of curcumin in prostate cancer.

Aluminum (Al)-induced apoptosis is considered as the major cause of its neurotoxicity. Folic acid possesses neuroprotective function by preventing neural cell apoptosis. microRNAs (miRNAs) are important regulators of gene expression participating in cellular processes. As a key component of the miR-17-92 cluster, miR-19 is implicated in regulating apoptotic process, while its role in the neuroprotective effect of folic acid has not been investigated. The present study aimed to investigate the potential involvement and function of miR-19 in the protective action of folic acid against Al-induced neural cell apoptosis. Human SH-SY5Y cells were treated with Al-maltolate (Al-malt) in the presence or absence of folic acid. Results showed that Al-malt-induced apoptosis of SH-SY5Y cells was effectively prevented by folic acid. Al-malt suppressed the expression of miR-19a/19b, along with alterations of miR-19 related apoptotic proteins including PTEN, p-AKT, p53, Bax, Bcl-2, caspase 9 and caspase 3; and these effects were ameliorated by folic acid. miR-19 inhibitor alone induced apoptosis of SH-SY5Y cells. Combination treatment of folic acid and miR-19 inhibitor diminished the neuroprotective effect of folic acid. These findings demonstrated that folic acid protected neuronal cells against Al-malt-induced apoptosis by preventing the downregulation of miR-19 and modulation of miR-19 related downstream PTEN/AKT/p53 pathway.