12-O-tetradecanoyl phorbol 13-acetate induces the expression of B7-DC, -H1, -H2, and -H3 in K562 cells.
ABSTRACT Induction of the B7 family molecules by 12-O-tetradecanoyl phorbol 13-acetate (TPA) has been reported, however, the mechanism by which TPA up-regulates these molecules remains poorly understood. In this study, the expression of B7-DC, -H1, -H2, and -H3 in response to TPA was markedly induced in K562 cells. TPA also induced activation of ERK, p38 mitogen-activated protein kinase (MAPK), JNK, phosphatidylinositol-3-kinase (PI-3K), or nuclear factor (NF)-kappaB. Pre-treatments with protein kinase C (PKC) inhibitors significantly inhibited TPA-induced expression of B7-DC, -H1, -H2, and -H3 mRNA as well as TPA-induced phosphorylation of ERK, p38 MAPK, JNK, and PI-3K. TPA-induced expression of B7-DC, -H1, -H2, and -H3 mRNA was abrogated by pre-treatments with inhibitors of ERK and p38 MAPK. However, inhibition of PI-3K and JNK only caused decrease of TPA-induced B7-DC mRNA and B7-H3 mRNA, respectively. TPA-induced degradation of IkappaB-alpha was markedly abrogated by treatments with PKC inhibitors, but not by treatments with inhibitors of ERK, p38 MAPK, JNK, or PI-3K. NF-kappaB inhibitors significantly attenuated the expression of B7-DC, -H1, -H2, and -H3 mRNA in response to TPA. These results suggest that TPA induces the expression of B7-DC, -H1, -H2, and -H3 mRNA in K562 cells via activation of PKC, ERK, p38 MAPK, and NF-kappaB. Distinctly, the expression of B7-DC mRNA and -H3 mRNA in response to TPA is also PI-3K- and JNK-dependent, respectively.
SourceAvailable from: Shang-Tao Chien[Show abstract] [Hide abstract]
ABSTRACT: Galangin (3,5,7-trihydroxyflavone) is a flavonoid compound found in high concentration in lesser galangal. The objective of this study was to investigate the ability of galangin to inhibit 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced the invasion and metastasis of HepG2 liver cancer cells. First, using a cell-matrix adhesion assay, immunofluorescence assay, transwell-chamber invasion/migration assay, and wound healing assay, we observed that galangin exerted an inhibitory effect on TPA-induced cell adhesion, morphology/actin cytoskeleton arrangement, invasion and migration. Furthermore, the results of gelatin zymography and reverse transcriptase polymerase chain reaction (RT-PCR) assays showed that galangin reduced the TPA-induced enzyme activity of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) in HepG2 cells; moreover, the messenger RNA level was downregulated. We also observed through a Western blotting assay that galangin strongly inhibited the TPA-induced protein expressions of protein kinase Cα (PKCα), protein kinase Cδ (PKCδ), phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2), the phospho-inhibitor of kappaBα (phospho-IκBα), c-Fos, c-Jun, and nuclear factor kappa B (NF-κB). Next, galangin dose-dependently inhibited the binding ability of NF-κB and activator protein 1 (AP-1) to MMP-2/MMP-9 promoters, respectively, resulting in the suppression of MMP-2/MMP-9 enzyme activity. The results revealed that galangin effectively inhibited the TPA-induced invasion and migration of HepG2 cells through a protein kinase C/extracellular signal-regulated kinase (PKC/ERK) pathway. Thus, galangin may have widespread applications in clinical therapy as an anti-metastatic medicament.Cancer Cell International 12/2015; 15(1). DOI:10.1186/s12935-015-0168-2 · 1.99 Impact Factor
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ABSTRACT: α-Tomatine, isolated from Lycopersicon esculentum Linn., is a naturally occurring glycoalkaloids in immature green tomatoes. Some reports demonstrated that α-tomatine had various anti-carcinogenic properties. First, the result demonstrated α-tomatine could inhibit TPA-induced the abilities of the adhesion, morphology/actin cytoskeleton arrangement, invasion, and migration by cell-matrix adhesion assay, immunofluorescence stain assay, Boyden chamber invasion assay, and wound-healing assay. Data also showed α-tomatine could inhibit the activation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) and protein kinase C-α (PKCα) involved in the downregulation of the enzyme activities and messenger RNA levels of matrix metalloproteinase-2/9 (MMP-2/MMP-9) induced by TPA. Next, α-tomatine also strongly inhibited TPA-induced the activation of nuclear factor kappa B (NF-κB) and phospho-inhibitor of kappa Bα (phospho-IκBα). In addition, TPA-induced translocation of PKC-α from cytosol to membranes, and suppression of TPA elicited the expression of PKC-α by adding the PKC-α inhibitors, GF-109203X and Gö-6983. The treatment of specific inhibitor for ERK (U0126) to MCF-7 cells could inhibit TPA-induced MMP-2/MMP-9 and phospho-ERK along with an inhibition on cell invasion and migration. Application of α-tomatine to prevent the invasion/migration of MCF-7 cells through blocking PKCα/ERK/NF-κB activation is first demonstrated herein.Cell biochemistry and biophysics 11/2012; 66(1). DOI:10.1007/s12013-012-9465-8 · 2.38 Impact Factor
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ABSTRACT: Matrix metalloproteinase-9 (MMP-9) plays a crucial role in tumor metastasis. Previous studies showed that polyunsaturated fatty acids exhibit an anti-cancer effect in various human carcinoma cells, but the effect of docosahexaenoic acid (DHA) and linoleic acid (LA) on metastasis of breast cancer cells is not fully clarified. We studied the anti-metastasis potential of DHA and LA in 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced MCF-7 cells. We found that TPA (100 ng/ml) induced MMP-9 enzyme activity both dose- and time-dependently, and 200 μM DHA and LA significantly inhibited MMP-9 mRNA and protein expression, enzyme activity, cell migration, and invasion. Treatment with PD98059 (10 μM), wortmannin (10 μM), and GF109203X (0.5 μM) decreased TPA-induced MMP-9 protein expression and enzyme activity. TPA-induced activation of ERK1, Akt, and PKCδ was attenuated by DHA, whereas LA attenuated only ERK1 activation. GF109203X also suppressed ERK1 activation. EMSA showed that DHA, LA, PD98059, and wortmannin decreased TPA-induced NF-κB and AP-1 DNA-binding activity. Furthermore, DHA rather than LA dose-dependently increased HO-1 expression. HO-1 siRNA alleviated the inhibition by DHA of TPA-induced MMP-9 protein expression and enzyme activity in MCF-7 cells, and HO-1 knockdown reversed the DHA inhibition of cell migration. These results suggest that DHA and LA have both similar and divergent signaling pathways in the suppression of TPA-induced MCF-7 metastasis.Archives of Toxicology 01/2013; DOI:10.1007/s00204-012-1003-3 · 5.08 Impact Factor