Tae-Wook Chung

Novel and therapeutic effect of caffeic acid and caffeic acid phenyl ester on hepatocarcinoma cells: complete regression of hepatoma growth and metastasis by dual mechanism

Our previous studies have clearly shown that the angiogenic enzymes, matrix metalloproteinase (MMP) ‐2/9, are directly involved in human hepatic tumorigenesis and metastasis and suggest that the MMP‐2/9 inhibitors, which have dual inhibitory activi¬ties on enzyme activity and transcription, represent the best candidates for achieving tumor regression. Many anti‐cancer drugs have strong cellular cytotoxicity and side effects, indicating that strong anti‐cancer drugs that have no or minimal cytotoxicity and side effects need to be developed. The specific aim of the present study was to develop powerful anti‐cancer drugs with specific tumor regression and anti‐metastatic potential having the dual inhibitory activities of specific MMP‐2 and ‐9 enzyme activities and gene transcription at the molecular level. Caffeic acid (CA), a strong and selective MMP‐9 activity and transcription inhibitor, was isolated from the plant Euonymus alatus and its derivative, caffeic acid phenethyl ester (CAPE), was synthesized. CA and CAPE selectively inhibited MMP‐2 and ‐9 but not ‐1, ‐3, ‐7, or cathepsin K. Treatment of HepG2 cells with CA (100 μg/mL) and CAPE (5 μg/mL) suppressed phorbol 12‐myristate 13‐acetate (PMA) ‐in¬duced MMP‐9 expression by inhibiting the function of NF‐κB, but not AP‐1. We confirmed that CA and CAPE suppressed the growth of HepG2 tumor xenografts in nude mice in vivo. The subcutaneous and oral administrations of CA and CAPE significantly reduced the liver metastasis. These results confirm the therapeutic potential of the compounds and suggest that the antimetastatic and anti‐tumor effects of CA and CAPE are mediated through the selective suppression of MMP‐9 enzyme activity and transcriptional down‐regulation by the dual inhibition of NF‐κB as well as MMP‐9 catalytic activity.—Chung, T.‐W., Moon, S.‐K., Chang, Y.‐C., Ko, J.‐H., Lee, Y.‐C., Cho, G., Kim, S.‐H., Kim, J.‐G., Kim, C.‐H. Novel and therapeutic effect of caffeic acid and caffeic acid phenyl ester on hepatocarcinoma cells: complete regression of hepatoma growth and metastasis by dual mechanism. FASEBJ. 18, 1670–1681 (2004)

Hepatitis B viral HBx induces matrix metalloproteinase-9 gene expression through activation of ERK and PI-3K/AKT pathways: Involvement of invasive potential

Hepatitis B virus (HBV) X protein (HBx) has been shown to be essential for the development of hepatocellular carcinoma (HCC). Recently, we have found that HBx causes the progression of liver cancer through down‐expression of PTEN, known as a tumor suppressor gene (1). The prognosis for HCC depends mainly on the clinicopathological characteristic regarding invasion and metastasis. The expression of matrix metalloproteinase (MMP)‐9 has been implicated as playing an important role in HCC invasion and metastasis. We previously reported that HBV infection increased the invasiveness of hepatocytes and HCC cells through the transcriptional activation of MMP‐9 (2). The HBx was shown to activate the mitogen‐activated protein (MAP) kinase and phosphatidylinositol 3‐kinase (PI‐3K) signal cascade, which is essential for activation of transcription factors such as activating protein (AP)‐1 and nuclear factor (NF)‐κB. In this study, we show that the HBx protein stimulates the activities of the PI‐3K‐Akt/ protein kinase B (PKB) as well as extracellular signal‐regulated kinase 1/2 (ERK 1/2) in HBx‐transfected cells. Furthermore, we have shown that enhanced expression of MMP‐9 in HBx‐transfected cells mediated by not only activation of AP‐1 transcriptional activity through ERKs pathway but also activation of NF‐κB transcriptional activity through PI‐3K‐AKT/PKB pathway, and was associated with the invasive potential. However, treatment with U0126 (known as the ERKs inhibitor) or wortmannin (known as the PI‐3K inhibitor), but not SB203580 (known as the p38 MAPK inhibitor), markedly inhibited the expression of MMP‐9 induced by HBx in HBx‐ transfected cells. Seemingly, the invasiveness of HBx‐transfected cells was decreased by treating with U0126 or wortmannin, but not SB203580. These results clearly suggest that the HBx contributed to the transcriptional regulation of MMP‐9 through the ERKs and PI‐3K‐AKT/PKB pathway, and increased an invasive potential of cells.

Caffeic Acid Phenethyl Ester Inhibits Alpha-Melanocyte Stimulating Hormone-Induced Melanin Synthesis through Suppressing Transactivation Activity of Microphthalmia-Associated Transcription Factor

Caffeic acid phenethyl ester (1), a natural compound found in various plants and propolis, is a well-known anti-inflammatory, immunomodulatory, and cytotoxic agent. The present study aimed to investigate the molecular events underlying the antimelanogenic activity of 1 in alpha-melanocyte stimulating hormone (α-MSH)-stimulated B16-F10 melanoma cells. In this investigation, 1 effectively reduced α-MSH-stimulated melanin synthesis by suppressing expression of melanogenic enzymes such as tyrosinase, tyrosinase-related protein-1 (TRP-1), and tyrosinase-related protein-2 (TRP-2), although this compound did not directly inhibit tyrosinase enzyme activity. On the other hand, the expression and nuclear translocation of microphthalmia-associated transcription factor (MITF) as a key transcription factor for tyrosinase expression regulating melanogenesis were not affected by treatment with 1. The upstream signaling pathways including cAMP response element-binding protein (CREB), glycogen synthase kinase-3β (GSK-3β), and Akt for activation and expression of MITF were also not influenced by 1. Interestingly, 1 inhibited transcriptional activity of a tyrosinase promoter by suppressing the interaction of MITF protein with an M-box containing a CATGTG motif on the tyrosinase promoter. Given the important role of MITF in melanogenesis, suppression of 1 on the function of MITF to transactivate tyrosinase promoter may present a novel therapeutic approach to treat hyperpigmentation disorders.

Correlation between plasma levels of matrix metalloproteinase (MMP)-9 /MMP-2 ratio and α-fetoproteins in chronic hepatitis carrying hepatitis B virus

Background:  Matrix metalloproteases (MMP) and α‐fetoproteins (AFP) are involved in hepatitis B virus (HBV)‐induced chronic hepatitis. In the present study, we have determined the correlation between the MMP‐9/MMP‐9 ratio and AFP levels in the serum of patients during chronic viral B hepatitis.

Anti-Inflammatory Effect of Ascochlorin in LPS-Stimulated RAW 264.7 Macrophage Cells Is Accompanied With the Down-Regulation of iNOS, COX-2 and Proinflammatory Cytokines Through NF-κB, ERK1/2, and p38 Signaling Pathway

A natural compound C23H32O4Cl, ascochlorin (ASC) isolated from an incomplete fungus, Ascochyta viciae has been known to have several biological activities as an antibiotic, antifungal, anti‐cancer, anti‐hypolipidemic, and anti‐hypertension agent. In this study, anti‐inflammatory activity has been investigated in lipopolysaccharide (LPS)‐induced murine macrophage RAW 264.7 cells, since ASC has not been observed on the inflammatory events. The present study has clearly shown that ASC (1–50 μM) significantly suppressed the production of nitric oxide (NO) and prostaglandin E2 (PGE2) and decreased the gene expression of inducible NO synthase (iNOS) and cyclooxygenase‐2 (COX‐2) in a dose‐dependent manner. Moreover, ASC inhibited the mRNA expression and the protein secretion of interleukin (IL)‐1β and IL‐6 but not tumor necrosis factor (TNF)‐α in LPS‐stimulated RAW 264.7 macrophage cells. In addition, ASC suppressed nuclear translocation and DNA binding affinity of nuclear factor‐κB (NF‐κB). Furthermore, ASC down‐regulated phospho‐extracellular signal‐regulated kinase 1/2 (p‐ERK1/2) and p‐p38. These results demonstrate that ASC exhibits anti‐inflammatory effects in RAW 264.7 macrophage cells. J. Cell. Biochem. 117: 978–987, 2016.

Catalpol suppresses advanced glycation end-products-induced inflammatory responses through inhibition of reactive oxygen species in human monocytic THP-1 cells.

Advanced glycation end-products (AGEs) play a pivotal role in the development of diabetic complications by inducing inflammation. We previously reported that the fresh roots of Rehmannia glutinosa Libosch., which have been used for the treatment of diabetes in traditional Korean medicine, also have the potential to suppress AGE-mediated inflammatory response in THP-1 cells. In the present study, we isolated catalpol from R. glutinosa, and examined whether it has anti-inflammatory effects on AGE-stimulated THP-1 cells. Catalpol reduced the expression of pro-inflammatory mediates, such as monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor-α (TNF-α), inducible NO synthase (iNOS), and receptor for AGE (RAGE). Promoter and electromobility shift assays showed that transcriptional activation of NF-κB was significantly reduced by catalpol treatment, while AP-1 was not. Catalpol also suppressed AGE-induced phosphorylation of mitogen activated protein (MAP) kinases, degradation of IκBα and the nuclear localization of NF-κB. Moreover, the production of intracellular reactive oxygen species (ROS) elicited by AGE was also suppressed by catalpol treatment, through dual action of reducing ROS itself and inhibiting NADPH oxidase activity. Our findings indicate that catalpol suppresses AGE-mediated inflammation by inhibiting ROS production and NF-κB activity. We suggest that catalpol, a major constituent of the fresh roots of R. glutinosa, contributes to the prevention of AGE-mediated diabetic complications.

Marine algal fucoxanthin inhibits the metastatic potential of cancer cells

Metastasis is major cause of malignant cancer-associated mortality. Fucoxanthin has effect on various pharmacological activities including anti-cancer activity. However, the inhibitory effect of fucoxanthin on cancer metastasis remains unclear. Here, we show that fucoxanthin isolated from brown alga Saccharina japonica has anti-metastatic activity. To check anti-metastatic properties of fucoxanthin, in vitro models including assays for invasion, migration, actin fiber organization and cancer cell-endothelial cell interaction were used. Fucoxanthin inhibited the expression and secretion of MMP-9 which plays a critical role in tumor invasion and migration, and also suppressed invasion of highly metastatic B16-F10 melanoma cells as evidenced by transwell invasion assay. In addition, fucoxanthin diminished the expressions of the cell surface glycoprotein CD44 and CXC chemokine receptor-4 (CXCR4) which play roles in migration, invasion and cancer-endothelial cell adhesion. Fucoxanthin markedly suppressed cell migration in wound healing assay and inhibited actin fiber formation. The adhesion of B16-F10 melanoma cells to the endothelial cells was significantly inhibited by fucoxanthin. Moreover, in experimental lung metastasis in vivo assay, fucoxanthin resulted in significant reduction of tumor nodules. Taken together, we demonstrate, for the first time, that fucoxanthin suppresses metastasis of highly metastatic B16-F10 melanoma cells in vitro and in vivo.

Pimaric acid from Aralia cordata has an inhibitory effect on TNF-α-induced MMP-9 production and HASMC migration via down-regulated NF-κB and AP-1.

Many studies have indicated that activation of matrix metalloproteinase (MMP)-9 and smooth muscle cell (SMC) migration are involved in neointimal formation and atherosclerosis. In this study, we revealed that pimaric acid (PiMA) purified from Aralia cordata had an inhibitory effect on MMP-9 production and migration of human aortic smooth muscle cells (HASMCs) induced by tumor necrosis factor (TNF)-α. Down-regulated MMP-9 mRNA transcription was detected in PiMA-treated cells using RT-PCR and the luciferase-tagged MMP-9 promoter assay. Results of an electrophoretic mobility shift assay indicated that PiMA-treated HASMCs showed decreased binding activity of nuclear factor (NF)-κB and activator protein-1 transcription factors. A Western-blot analysis using nuclear extract demonstrated that PiMA reduced the levels of NF-κB p65, c-Fos, p-c-Jun, Jun-D, and p-ATF2 proteins in the nucleus. In addition, TNF-α stimulated mitogen activated protein kinase (MAPK) containing extracellular signal regulated kinase 1 and 2, p38, and c-Jun N-terminal kinase was inhibited by PiMA. Using the Transwell system, we found that PiMA inhibited TNF-α stimulated HASMC migration/invasion in a dose-dependent manner. To confirm whether MAPK mediated MMP-9 expression, we used MAPK inhibitors including U0126, SB253580, and SP600125 and found that those inhibitors reduced MMP-9 expression and HASMC migration/invasion. These results suggest that PiMA has potent anti-atherosclerotic activity with inhibitory action on MMP-9 production and cell migration in TNF-α-induced HASMCs.

Linear congenital smooth muscle hamartoma with follicular spotted appearance.

Congenital smooth muscle hamartoma (CSMH) with follicular spotted appearance is a rare clinical variant of CMSH in which patients have marked perifollicular papules in the patches. A linear distribution of CSMH is also extremely rare. We report a 16‐year‐old Korean girl with this uncommon form of CSMH who had linearly arranged, hyperpigmented lesions with follicular papules extending from the right flank to the right lower leg from birth. Pathological findings, including immunohistochemical stains, were consistent with smooth muscle hamartoma. To date, there are only four reports on this rare, follicular form and one report on the linear form of CSMH in the literature. This paper describes the first combined occurrence of follicular spotted lesions and linear arrangement in CSMH.

Lipocalin-2 elicited by advanced glycation end-products promotes the migration of vascular smooth muscle cells

Advanced glycation end-products (AGEs) play key roles in the development of diabetic vascular complications by activating the proliferation and migration of vascular smooth muscle cells. Here, we identified an increase of the migratory properties of human aortic smooth muscle cells (HASMC) through AGE-induced expression of lipocalin-2 (LCN2). Because the AGE-elicited expression of LCN2 was diminished by an antibody against the AGE receptor (RAGE), diphenylene iodonium (DPI), N-acetyl cysteine, LY294002, and SP600125, we suggest that AGEs enhance the expression of LCN2 via a RAGE-NADPH oxidase-reactive oxygen species pathway, leading to the phosphorylation of PI3K-Akt and JNK in HASMCs. In addition, a chromatin immunoprecipitation assay and promoter assay revealed that CCAAT/enhancer binding protein β is crucial for AGE-induced expression of LCN2. However, any other AGE-related signaling pathway, including ERK1/2, p38, NF-κB, and AP-1, did not affect the AGE- induced expression of LCN2. Knockdown of LCN2 expression by shRNA showed that AGE-elicited LCN2 expression enhanced the invasive and migratory properties of HASMCs, but showed no effect on cell proliferation. Considering the importance of HASMC migration in the development of atherosclerosis, our study provides a novel insight into diabetic vascular complications.