Brazilein suppresses migration and invasion of MDA-MB-231 breast cancer cells.

Brazilein, a bioactive compound isolated from Caesalpinia sappan L., has long been used in oriental folk medicines. Cancer metastasis is a primary cause of cancer death. However, the anti-metastatic effects of brazilein remain elusive. In this study, we found that brazilein inhibited human breast cancer MDA-MB-231 cell migration and invasion using wound-healing assay and Boyden chamber assay. The results of Western blot, gelatin zymography and reversed transcription-PCR analysis showed that brazilein suppressed matrix metalloproteinase-2 (MMP-2) expression in a concentration-dependent manner. Brazilein also decreased the nuclear protein level of nuclear factor kappaB (NF-κB). Brazilein potently suppressed the phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK), phosphatidylinositide-3-kinase (PI3K) and Akt, but did not affect phosphorylation of extracellular signal regulating kinase (ERK)1/2 and c-Jun N-terminal kinase (JNK). Additionally, treatment of SB203580 (p38 MAPK inhibitor) or wortmannin (PI3K inhibitor) resulted in a reduced activity and expression of MMP-2 as well as inhibition on cell migration and invasion in MDA-MB-231 cells. Taken together, these results suggest that brazilein inhibition of MDA-MB-231 cells may be mediated through inactivation of both PI3K/Akt and p38 MAPK signaling pathways, leading to inhibitory effect on NF-κB activation. Consequently, brazilein suppresses MMP-2 expression, and thus confers anti-migration and anti-invasion of MDA-MB-231 cells.

Hsieh CY ，Tsai PC ，Chu CL ，Chang FR ，Chang LS ，Wu YC ，Lin SR ... -  《-》

Antimetastatic effect and mechanism of ovatodiolide in MDA-MB-231 human breast cancer cells.

Cancer metastasis is a primary cause of cancer death. Ovatodiolide, a bioactive cembrane-type diterpenoid isolated from Anisomeles indica (L.) Kuntze (Labiatae), has been shown to inhibit the growth and proliferation of cancer cells. However, the anti-metastatic effects of ovatodiolide on highly metastatic human breast cancer MDA-MB-231 cells remain unclear. In this study, we first noted that ovatodiolide inhibited MDA-MB-231 cell migration and invasion by wound-healing assay and Boyden chamber assay. Western blot, gelatin zymography and reversed transcription-PCR analysis showed that ovatodiolide significantly and selectively suppressed the expression, activation, and mRNA of matrix metalloproteinase-9 (MMP-9) in a concentration-dependent manner. Ovatodiolide significantly decreased the nuclear level of nuclear factor kappaB (NF-κB), increased inhibitor of kappaBα (IκBα) through preventing phosphorylation of upstream signal IκB kinase (IKK). Pretreatment with a specific NF-κB inhibitor (PDTC) and an IκB protease inhibitor (TPCK) also reduced MMP-9 activity, cell migration and cell invasion. Moreover, ovatodiolide can suppress activation of c-Jun N-terminal kinase, p38 mitogen-activated protein kinase, phosphatidylinositol 3-kinase and Akt, while it did not affect phosphorylation of extracellular signal regulating kinases (ERK)1/2. Additionally, the treatment of inhibitors specific for PI3K (wortmannin), JNK (SP600125) or p38 MAPK (SB203580) to MDA-MB-231 cells could result in a reduced activation of MMP-9, concomitantly with a marked inhibition on cell migration and invasion. Taken together, these results demonstrate that ovatodiolide inhibits the metastatic ability of MDA-MB-231 cells by reducing MMP-9 activity through suppressing JNK, p38 MAPK and PI3K/Akt signaling pathways and inhibiting NF-κB activity. These results are the first to reveal the function of ovatodiolide in tumor metastasis and its underlying molecular mechanism, thus suggesting ovatodiolide to be a promising antimetastatic agent.

Lin KL ，Tsai PC ，Hsieh CY ，Chang LS ，Lin SR ... -  《-》

Platycodin D inhibits migration, invasion, and growth of MDA-MB-231 human breast cancer cells via suppression of EGFR-mediated Akt and MAPK pathways.

Platycodin D (PD), an active triterpenoid saponin from Platycodon grandiflorum, has been known to inhibit the proliferation of a variety of cancer cells, but the effect of PD on the invasiveness of cancer cells is largely unknown. In this study, we first determined the molecular mechanism by which PD inhibits the migratory and invasive abilities of the highly metastatic MDA-MB-231 breast cancer cell line. We demonstrated that a non-cytotoxic concentration of PD markedly suppressed wound healing migration, invasion through the matrigel, and adhesion to an ECM-coated substrate in a dose-dependent manner. Moreover, PD inhibited cell invasion by reducing matrix metalloproteinase (MMP)-9 enzyme activity and mRNA expression. Western blot analysis indicated that PD potently suppressed the phosphorylation of extracellular signal-regulated kinase (ERK), p38, and c-Jun N-terminal kinase (JNK) as well as blocked the phosphatidylinositol-3-kinase (PI3K)/Akt/mTOR signaling pathway. Furthermore, PD treatment inhibited the DNA binding activity of NF-κB, which is known to mediate the expression of epidermal growth factor receptor (EGFR), as observed by electrophoretic mobility shift assay. Specific mechanisms of action exerted by PD involved the downregulation of EGFR and the inhibition of EGF-induced activation of the EGFR, MAPK, and PI3K/Akt pathways. The in vivo studies showed that PD significantly inhibited the growth of MDA-MB-231 xenograft tumors in BALB/c nude mice. These results suggest that PD might be a potential therapeutic candidate for the treatment of breast cancer metastasis.

Chun J ，Kim YS 《-》

Antimetastatic potential of cardiotoxin III involves inactivation of PI3K/Akt and p38 MAPK signaling pathways in human breast cancer MDA-MB-231 cells.

The aim of this study is to determine whether cardiotoxin III (CTX III) inhibited the metastasis in MDA-MB-231 cells and to further explain its possible mechanisms. The MTT assay, wound healing assay, Boyden chamber invasion assay, zymography analysis, reverse transcriptase polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), inhibitor assay, and Western blot analysis were used to reveal molecular events of CTX III in this study. During treatment with non-toxic doses of CTX III, not only cell migration and invasion were markedly suppressed but the expression/activity of matrix metalloproteinase-9 (MMP-9) was also significantly and selectively suppressed in a concentration-dependent manner. In addition, CTX III decreased the nuclear protein level of nuclear factor kappa B (NF-κB), and pretreatment with NF-κB inhibitor (PDTC) or IκB protease inhibitor (TPCK) also reduced MMP-9 expression/activity and cell migration. Our biochemical assays indicated that CTX III potently suppressed the phosphorylation of p38 mitogen-activated protein kinase (MAPK), phosphatidylinositide-3-kinase (PI3K) and Akt. Additionally, the treatment of inhibitors specific for p38 MAPK (SB203580) or PI3K (wortmannin) to cells could result in a reduced expression of NF-κB and MMP-9 expression, concomitantly with an inhibition on cell metastasis. These results demonstrated that CTX III inhibition of MDA-MB-231 cells may occur through inactivation of both PI3K/Akt and p38 MAPK signaling pathways, exerting inhibitory effects on NF-κB transcriptional factor, thereby decreasing the activity of MMP-9 and then posing an anti-metastatic effect in the cells.

Lin KL ，Chien CM ，Hsieh CY ，Tsai PC ，Chang LS ，Lin SR ... -  《-》

Curcumol Suppresses Breast Cancer Cell Metastasis by Inhibiting MMP-9 Via JNK1/2 and Akt-Dependent NF-κB Signaling Pathways.

Curcumolhas been reported to possess antitumor activity. However, its effect and mechanisms against tumor metastasis are still unclear. This study is to investigate the inhibitory effect of curcumol on breast cancer cell metastasis and elucidate the underlying molecular mechanisms. Our results showed that noncytotoxicity was caused by curcumol within 10 to 40 µg/mL in MDA-MB-231 and 4T1 cells for 24 hours, whereas sustained treatment with curcumol for 14 days significantly suppressed the clonogenic activity of cells. Importantly, curcumol at noncytotoxic concentrations suppressed the migration ability of both MDA-MB-231 and 4T1 cells. Moreover, curcumol suppressed the migration and invasion of MDA-MB-231 cells in the Boyden chamber migration and invasion assay and inhibited the adhesion of MDA-MB-231 cells onto the matrigel. Further investigations revealed that curcumol decreased the enzyme activity and protein expression of matrix metalloproteinase (MMP-9) in MDA-MB-231 cells. Moreover, curcumol inhibited the activation of c-Jun N-terminal kinase (JNK) 1/2 and Akt (Ser473). Meanwhile, it also inhibited the nuclear translocation and transcriptional activity of nuclear factor κB (NF-κB). Furthermore, JNK inhibitor SP600125 and Akt (Ser473) inhibitor LY294002 enhanced the inhibition of curcumol on NF-κB p65 nuclear translocation. Finally, supplementation with SP600125, LY294002, or NF-κB inhibitor Ammonium pyrrolidinedithiocarbamate (PDTC) significantly enhanced the inhibitory effect of curcumol on MMP-9 expression and cell migration, invasion, and adhesion in MDA-MB-231 cells. Our findings provide evidence for the suppression of breast cancer cell metastasis by curcumol and suggest that the inhibition of MMP-9 via JNK1/2 and Akt (Ser473)-dependent NF-κB signaling pathways may be the underlying mechanisms.

Ning L ，Ma H ，Jiang Z ，Chen L ，Li L ，Chen Q ，Qi H ... -  《-》