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Background: Interleukin-8 (IL-8) expression is associated with metastasis in a variety of cancer cells.Purpose: Here, we investigated the regulatory mechanism of IL-8 expression as well as the pharmacological effect of berberine (BBR) on IL-8 expression in triple-negative breast cancer (TNBC) cells.Methods: The clinical value of IL-8 was analyzed by from a public database [Kaplan‑Meier plotter database. IL-8 mRNA and protein expression was analyzed by real-time PCR and ELISA, respectively. Cell invasion was analyzed by Boyden chamber assay. Tumor cell growth was analyzed by colony forming assay.Results: Clinically, we observed that breast cancer patients with highly expressed IL-8 are associated with poor outcomes in areas such as relapse-free, overall, and distant metastasis-free survival. We showed that IL-8 expression is higher in TNBC cells than in non-TNBC cells. In addition, the rates of cell invasion were significantly increased by IL-8 treatment. These IL-8 levels were decreased by EGFR (Neratinib and Afatinib) and MEK (PD98059) inhibitors in TNBC cells. Finally, we observed that BBR dramatically suppresses IL-8 expression. In addition, BBR also inhibited cell invasiveness and anchorage-independent growth. Interestingly, our results showed that BBR down-regulates EGFR protein expression and dose-dependently inhibits MEK and ERK phosphorylation.Conclusion: Here, we demonstrate that BBR may be a promising drug to suppress cell invasiveness and growth of TNBC through IL-8-related mechanisms. [ABSTRACT FROM AUTHOR]

Interleukin-8 (IL-8) serves as a prognostic marker for breast cancer, and its expression level correlates with metastatic breast cancer and poor prognosis. Here, we investigated the levels of IL-8 expression in a variety of breast cancer cells and the regulatory mechanism of IL-8 in triple-negative breast cancer (TNBC) cells. Our results showed that IL-8 expression correlated positively with overall survival in basal-type breast cancer patients. The levels of IL-8 mRNA expression and protein secretion were significantly increased in TNBC cells compared with non-TNBC cells. In addition, the invasiveness of the TNBC cells was dramatically increased by IL-8 treatment and then augmented invasion-related proteins such as matrix metalloproteinase (MMP)-2 or MMP-9. We observed that elevated IL-8 mRNA expression and protein secretion were suppressed by a specific MEK1/2 inhibitor, UO126. In contrast, the overexpression of constitutively active MEK significantly increased the level of IL-8 mRNA expression in BT474 non-TNBC cells. Finally, we investigated the effect of UO126 on the tumorigenecity of TNBC cells. Our results showed that anchorage-independent growth, cell invasion, and cell migration were also decreased by UO126 in TNBC cells. As such, we demonstrated that IL-8 expression is regulated through MEK/ERK-dependent pathways in TNBC cells. A diversity of MEK blockers, including UO126, may be promising for treating TNBC patients. [ABSTRACT FROM AUTHOR]

The epithelial–mesenchymal transition (EMT) is a key process in tumor invasion and migration. Transforming growth factor-βs (TGF-βs) are multifunctional growth factors and powerful modulators of the EMT. Here, we investigated the relationship between TGF-β expression and invasion by treated triple-negative breast cancer (TNBC) cells. Our results show that invasion capacity of TNBC cells was markedly higher than that of non-TNBC cells. In addition, EMT-related gene signatures, including vimentin (vim), fibronectin (FN), snail, and slug were highly expressed in TNBC cells. Interestingly, our results show that TGF-β1 and β2 mRNA expression levels were higher in TNBC cells than those in non-TNBC cells. Thus, we examined the effect of the TGF-β receptor I/II inhibitor LY2109761 on EMT-related gene expression and cell motility. Our data show that vim, FN, and slug mRNA expression levels dose-dependently decreased in response to LY2109761. TNBC cell motility also decreased in response to LY2109761. Finally, we investigated the effect of LY2109761 on TGF-β1 or TGF-β2-induced E-cadherin (E-cad), vim, and FN mRNA and protein expression. The reduction in E-cad and induction of vim and FN expression by TGF-β1 or TGF-β2 were completely reversed by LY2109761 treatment in HCC1806 TNBC cells. Taken together, we demonstrated that elevated TGF-β expression triggers invasion and migration by TNBCs through the EMT process. Inhibiting the TGF-β signaling pathway is considered a promising therapeutic strategy for treating TNBC. [ABSTRACT FROM AUTHOR]

WNT5A is abnormally increased in a variety of cancers including breast cancer and has an adverse effect on the prognosis. However, the biological function of WNT5A is not fully known in HER2-positive (HER2+) breast cancer. Using public clinical data, we analyzed disease-free survival (DFS) and distant metastasis-free survival (DMFS). Here, we found that abnormal WNT5A induction is a correlation with the poor prognosis of HER2+ breast cancer. WNT5A expression was also decreased by pan-HER inhibitor neratinib but not by trastuzumab. In addition, WNT5A augmented cell invasiveness of HER2+ breast-cancer cells. To find WNT5A-induced metastatic-related factors, we did a human cytokine array. The levels of GM-CSF and CXCL8 were significantly increased by WNT5A. CXCL8 also accelerated cell invasiveness in HCC1954 breast-cancer cells. The expression of CXCL8 induced by WNT5A has been significantly reduced by MEK inhibitor, binimetinib. Finally, we studied the effect of CXCR2 antagonist, SB225002, to verify the relevance of CXCL8 in WNT5A-induced cell invasion. As expected, we found that WNT5A-induced cell invasion is completely inhibited by SB225002. Taken together, we have demonstrated that WNT5A directly mediates cell invasion through the induction of CXCL8 and ultimately affects the survival rate of HER2+ breast cancer. [ABSTRACT FROM AUTHOR]

Aberrant interleukin-1 beta (IL-1β) expression is associated with cancer development, metastasis, and poor prognosis. Here, we have investigated the regulatory mechanism of IL-1β expression, and the inhibitory effect of zerumbone (ZER) on IL-1β expression and IL-1β-induced signatures, including cell invasion and signaling activation in triple negative breast cancer (TNBC) cells. The basal IL-1β and cell invasiveness levels were significantly higher in TNBC cells, compared with non-TNBC cells. The invasiveness of TNBC cells was also increased following IL-1β treatment. In contrast, the invasiveness of TNBC cells was decreased following IL-1 receptor antagonist (IL-1RA) treatment. Additionally, the basal IL-1β level and the invasiveness of TNBC cells were decreased by Bay11-7085. In contrast, overexpression of NF-κB (p65) caused an increase in IL-1β expression in TNBC cells. Our results showed that treatment with ZER decreased the basal IL-1β expression level, and the phosphorylation level of NF-κB, in TNBC cells. Furthermore, we found that ZER completely suppressed IL-1β-induced NF-κB phosphorylation, but did not suppress IL-1β-induced Akt phosphorylation, in TNBC cells. Our results also demonstrate that IL-1β-induced cell invasion is suppressed by ZER in TNBC cells. Taken together, we demonstrated that IL-1β expression is regulated by the NF-κB-dependent pathway, and that elevated IL-1β is directly influencing the invasiveness of TNBC cells. ZER down-regulates IL-1β expression through the inhibition of NF-κB activity, and then suppresses cell invasiveness of TNBC. [ABSTRACT FROM AUTHOR]