• Journal of Physiology & Pathology in Korean Medicine
• /
• v.19 no.3
• /
• pp.722-728
• /
• 2005

The DNA topoismerase I inhibitor ${\beta}-lapachone$, the product of a lapacho tree (Tabebuia avellanedae) from South America, activates a novel apoptotic response in a number of cell lines. In the present report, we investigated the effects of ${\beta}-lapachone$ on the growth of human lung in human non-small-cell-lung-cancer A549 cells. Upon treatment with ${\beta}-lapachone$, a concentration-dependent inhibition of cell viability and cell proliferation was observed as measured by hemocytometer counts and MTT assay. The ${\beta}-lapachone-treated$ cells developed many of the hallmark features of apoptosis, including membrane shrinking, condensation of chromatin and DNA fragmentation. These apoptotic effects of ${\beta}-lapachone$ in A549 cells were associated with a marked induction of pro-apoptotic Bax expression, however the levels of anti-apoptotic Bcl-2 expression were decreased in a dose-dependent manner. Accordingly, elevated amount of cyclin-dependent kinase inhibitor p21 expression accompanied by up-regulation of tumor suppressor p53 was observed. By RT-PCR analyses, decrease in gene expression level of telomerase reverse transcriptase and telomeric repeat binding factor were also observed. Thus, these findings suggest that ${\beta}-lapachone$ may be a potential anti-cancer therapeutics for the control of human lung cancer cell model.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.20 no.3
• /
• pp.690-696
• /
• 2006

Houttuynia cordata Thunb, well known as 'E-Sung-Cho' in Korea, is a traditional medicinal plant generally used in Oriental medicine therapy. In the present study, we investigated the effect of water extract of H. cordafa (WEHC) on the growth of human breast carcinoma MCF-7 cells. Exposure of MCF-7 cells to WEHC resulted in growth inhibition and apoptosis in a dose-dependent manner as measured by MTT assay and fluorescent microscope. The anti-proliferative effect of WEHC was associated with a dose-dependent up-regulation of cyclin-dependent kinase inhibitor p21 in a p53-independent fashion. We found WEHC decreased the levels of cyclooxygenase (COX)-2 and inducible nitric oxide synthease (iNOS) expression without significant changes in the expression of COX-1 , which was correlated with a decrease in prostaglandin $E_2{\;}(PGE_2)$ synthesis. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of H. cordata.

• Environmental Analysis Health and Toxicology
• /
• v.27
• /
• pp.10.1-10.7
• /
• 2012

Objectives: In recent years, a number of structurally diverse Histone deacetylase (HDAC) inhibitors have been identified and these HDAC inhibitors induce growth arrest, differentiation and/or apoptosis of cancer cells in vitro and in vivo. This study aimed at investigating the antitumor activity of newly synthesized HDAC inhibitor, 3-(4-dimethylamino phenyl)-N-hydroxy-2-propenamide (IN-2001) using human breast cancer cells. Methods: We have synthesized a new HDAC inhibitor, IN-2001, and cell proliferation inhibition assay with this chemical in estrogen receptor-positive human breast cancer MCF-7 cells. Cell cycle analysis on MCF-7 cells treated with IN-2001 was carried out by flow cytometry and gene expression was measured by RT-PCR. Results: In MCF-7 cells IN-2001 showed remarkable anti-proliferative effects in a dose- and time-dependent manner. In MCF-7 cells, IN-2001 showed a more potent growth inhibitory effect than that of suberoylanilide hydroxamic acid. These growth inhibitory effects were related to the cell cycle arrest and induction of apoptosis. IN-2001 showed accumulation of cells at $G_2$/M phase and of the sub-$G_1$ population in a time-dependent manner, representing apoptotic cells. IN-2001-mediated cell cycle arrest was associated with HDAC inhibitor-mediated induction of CDK inhibitor expression. In MCF-7 cells, IN-2001 significantly increased $p21^{WAF1}$ expression. Conclusions: In summary, cyclin-dependent kinase (CDK) induced growth inhibition, possibly through modulation of cell cycle and apoptosis regulatory proteins, such as CDK inhibitors, and cyclins. Taken together, these results provide an insight into the utility of HDAC inhibitors as a novel chemotherapeutic regime for hormone-sensitive and insensitive breast cancer.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.19 no.2
• /
• pp.452-458
• /
• 2005

Cordyceps militaris is a medicinal fungus, which has been used for patient suffering from cancer in Oriental medicine. It was reported previously that C. militaris extracts are capable of inhibiting tumor growth, however, the anti-poliferative effects of human cancer cells have not been poorly understood. In this study, to elucidate the growth inhibitory mechanisms of human cancer cells by treatment of aqueous extract of C. militaris (AECM) we investigated the anti-proliferative effects of AECM in human leukemia U937 cell line. AECM treatment inhibited the growth of U937 cells and induced the apoptotic cell death in a concentration-dependent manner, which was associated with morphological changes. We observed the up-regulation of cyclin-dependent kinase (Cdk) inhibitor p21(WAF1/CIP1) by p53-independent manner and activation of caspase-3 in AECM-treated U937 cells, however, the activity of caspase-9 was remained unchanged. Additionally, AECM treatment caused a dose-dependent inhibition of the expression of telomere regulatory gene products such as human telomere reverse transcriptase (hTERT) and telomerase-associated protein-1 (TEP-1). Taken together, these findings suggest that AECM-induced inhibition of human leukemic cell proliferation is associated with the induction of apoptotic cell death via modulation of several major growth regulatory gene products, and C. militaris may have therapeutic potential in human lung cancer.

• Biomolecules & Therapeutics
• /
• v.15 no.4
• /
• pp.218-223
• /
• 2007

T cell proliferation is a pivotal to an effective immune response. Cyclin-dependent kinase (cdk) inhibitor, $p27^{kip1}$ is degraded to initiate T cell expansion. In this study, we show that although the expression of $p27^{kip1}$ protein was down-regulated, that of $p21^{cip1}$, another cdk inhibitor, was up-regulated in $CD8^+$ T cells following in vitro stimulation. Ex vivo gB antigen-stimulation following HSV immunization increased $p21^{cip1}$ positive cells that co-expressed IFN-$\gamma$. Moreover, $p21^{cip1}$ was co-expressed with IFN-${\gamma}$ in E7 antigen-stimulated $CD8^+$ T cells, whereas $p27^{kip1}$ was not. Our findings imply a role of $p21^{cip1}$ proteins in antigen-induced effector $CD8^+$ T cells differentiation in vivo.

• Biomedical Science Letters
• /
• v.16 no.2
• /
• pp.71-74
• /
• 2010

Cell proliferation is governed by precise and orderly process the regulation of which involves many different proteins. The key enzyme for cell growth and arrest is cyclin dependent kinases (cdks). In human cells, several cdks orchestrate four distinct cell cycle phases (M, $G_1$, S and $G_2$ ) and they sequentially operate in an order of cdc1, cdk4, cdk6 and cdk2. The regulatory components of cdks consist of cyclins and two family of cdk inhibitors, INK4 (inhibitors of cdk4) and KIP (kinase inhibitor protein). $G_1$ regulatory molecules for cdk mainly respond to environmental cues of mitogenic and anti-mitogenic stimuli and therefore influence activities of $G_1$ cdks, namely, cdk4/6 and cdk2. $G_1$ inhibitors include $p21^{CIP}$ and $p27^{KIP1}$. Between them, $p27^{KIP1}$ has attracted attentions of many researchers because of its characteristic regulatory features and diverse functions. Besides, the role of $p27^{KIP1}$ in cancer development warrants further studies in the future. Therefore, this review will focus on the recent findings and especially on the complexity of regulatory mechanisms of $p27^{KIP1}$.

• BMB Reports
• /
• v.41 no.7
• /
• pp.523-528
• /
• 2008

BMI-1026 is a synthetic aminopyrimidine compound that targets cyclin dependent kinases (cdks) and was initially designed as a potential anticancer drug. Even though it has been well documented that BMI-1026 is a potent cdk inhibitor, little is known about the cellular effects of this compound. In this study, we examined the effects of BMI-1026 treatment on inducing premature senescence and then evaluated the biochemical features of BMI-1026-induced premature senescence. From these experiments we determined that BMI-1026 treatment produced several biochemical features of premature senescence and also stimulated expression of mitogen activated protein kinase (MAPK) family proteins. BMI-1026 treatment caused nuclear translocation of activated Erk1/2 and the formation of senescence associated heterochromatin foci in 5 days. The heterochromatin foci formation was perturbed by inhibition of Erk1/2 activation.

• BMB Reports
• /
• v.50 no.5
• /
• pp.269-274
• /
• 2017

The biological activities of macrophage migration inhibitory factor (MIF) might be mediated through a classical receptor-mediated or non-classical endocytic pathway. JAB1 (C-Jun activation domain-binding protein-1) promotes the degradation of the tumor suppressor, p53, and the cyclin-dependent kinase inhibitor, p27. When MIF and JAB1 are bound to each other in various intracellular sites, MIF inhibits the positive regulatory effects of JAB1 on the activity of AP-1. The intestinal parasite, Anisakis simplex, has an immunomodulatory effect. The molecular mechanism of action of As-MIF and human JAB1 are poorly understood. In this study, As-MIF and hJAB1 were expressed and purified with high solubility. The structure of As-MIF and hJAB1 interaction was modeled by homology modeling based on the structure of Ace-MIF. This study provides evidence indicating that the MIF domain of As-MIF interacts directly with the MPN domain of hJAB1, and four structure-based mutants of As-MIF and hJAB1 disrupt the As-MIF-hJAB1 interaction.

• Biomolecules & Therapeutics
• /
• v.19 no.4
• /
• pp.411-418
• /
• 2011

Ginsenoside Rp1 (G-Rp1) is a novel ginseng saponin derivative with anti-tumor activity. However, the biochemical and molecular mechanisms of G-Rp1 on anti-tumor activity are not fully understood. In the present study, we report that G-Rp1 inhibits lung cancer cell proliferation, migration and adhesion in p53 wild-type A549 and p53-defi cient H1299 cells. Anti-proliferative activity of G-Rp1 in lung cancer cells is mediated by enhanced nuclear localization of cyclin-dependent kinase inhibitors including $p27^{Kip1}$ and $p21^{WAF1/Cip1}$, and subsequent inhibition of pRb phosphorylation. We also show that these anti-tumor activities of G-Rp1 in both A549 and H1299 cells appear to be mediated by suppression of mitogenic signaling pathways such as ERK, Akt and $p70^{S6K}$. Taken together, these findings suggest further development and evaluation of G-Rp1 for the treatment of lung cancers with mutated p53 as well as wild-type p53.

• Archives of Pharmacal Research
• /
• v.25 no.4
• /
• pp.463-468
• /
• 2002

We have previously reported on the identification of the endogenous transmethylation inhibitor oligosaccharide-linked acyl carrier protein (O-ACP), In this study, the role of the transmethylation reaction on cell cycle progression was evaluated using various transmethylase inhibitors, including O-ACP. O-ACP significantly inhibited the growth of various cancer cell lines, including NIH3T3, ras-transformed NIH3T3, MDA-MB-231, HT-1376, and AGS. In addition, exposure of ras-transformed NIH3T3 to O-ACP caused cell cycle arrest at the $G_0/G_1$ phase, which led to a decrease in cells at the S phase, as determined by flow cytometry. In contrast, transmethylase inhibitors did not affect the expression of $p21^{WAF1/Cip1}$, a well known inhibitor of cyclin dependent kinase, indicating that the cell cycle arrest by transmethylase inhibitors might be mediated by a $p21^{WAF1/Cip1}$-independent mechanism. Therefore, O-ACP, a novel transmethylase inhibitor, could be a useful tool for elucidating the novel role of methylation in cell proliferation and cell cycle progression.