• Nutrition Research and Practice
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• v.9 no.2
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• pp.111-116
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• 2015

BACKGROUND/OBJECTIVES: Inonotus obliquus (I. obliquus, Chaga mushroom) has long been used as a folk medicine to treat cancer. In the present study, we examined whether or not ethanol extract of I. obliquus (EEIO) inhibits cell cycle progression in HT-29 human colon cancer cells, in addition to its mechanism of action. MATERIALS/METHODS: To examine the effects of Inonotus obliquus on the cell cycle progression and the molecular mechanism in colon cancer cells, HT-29 human colon cancer cells were cultured in the presence of $2.5-10{\mu}g/mL$ of EEIO, and analyzed the cell cycle arrest by flow cytometry and the cell cycle controlling protein expression by Western blotting. RESULTS: Treatment cells with $2.5-10{\mu}g/mL$ of EEIO reduced viable HT-29 cell numbers and DNA synthesis, increased the percentage of cells in $G_1$ phase, decreased protein expression of CDK2, CDK4, and cyclin D1, increased expression of p21, p27, and p53, and inhibited phosphorylation of Rb and E2F1 expression. Among I. obliquus fractions, fraction 2 (fractionated by dichloromethane from EEIO) showed the same effect as EEIO treatment on cell proliferation and cell cycle-related protein levels. CONCLUSIONS: These results demonstrate that fraction 2 is the major fraction that induces $G_1$ arrest and inhibits cell proliferation, suggesting I. obliquus could be used as a natural anti-cancer ingredient in the food and/or pharmaceutical industry.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.3
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• pp.153-158
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• 2012

Cellular effects of ethanol in YD-15 tongue carcinoma cells were assessed by MTT assay, caspase activity assay, Western blotting and flow cytometry. Ethanol inhibited the growth and proliferation of YD-15 cells in a dose- and time-dependent manner in an MTT assay. The effects of ethanol on cell cycle control at low percent range of ethanol concentration (0 to 1.5%), the condition not inducing YD-15 cell death, was investigated after exposing cells to alcohol for a certain period of time. Western blotting on the expression of cell cycle inhibitors showed that p21 and p27 was up-regulated as ethanol concentration increases from 0 to 1.5% whilst the cell cycle regulators, cdk1, cdk2, and cdk4 as well as Cyclin A, Cyclin B1 and Cyclin E1, were gradually down-regulated. Flow cytometric analysis of cell cycle distribution revealed that YD-15 cells exposed to 1.5% ethanol for 24 h was mainly arrested at G2/M phase. However, ethanol induced apoptosis in YD-15 cells exposed to 2.5% or higher percent of ethanol. The cleaved PARP, a marker of caspase-3 mediated apoptosis, and the activation of caspase-3 and -7 were detected by caspase activity assay or Western blotting. Our results suggest that ethanol elicits inhibitory effect on the growth and proliferation of YD-15 tongue carcinoma cells by mediating cell cycle arrest at G2/M at low concentration range and ultimately induces apoptosis under the condition of high concentration.

• Biomolecules & Therapeutics
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• v.31 no.5
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• pp.526-535
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• 2023

Breast cancer is the most common cancer and a frequent cause of cancer-related deaths among women wordlwide. As therapeutic strategies for breast cancer have limitations, novel chemotherapeutic reagents and treatment strategies are needed. In this study, we investigated the anti-cancer effect of synthetic homoisoflavane derivatives of cremastranone on breast cancer cells. Homoisoflavane derivatives, SH-17059 and SH-19021, reduced cell proliferation through G2/M cell cycle arrest and induced caspase-independent cell death. These compounds increased heme oxygenase-1 (HO-1) and 5-aminolevulinic acid synthase 1 (ALAS1), suggesting downregulation of heme. They also induced reactive oxygen species (ROS) generation and lipid peroxidation. Furthermore, they reduced expression of glutathione peroxidase 4 (GPX4). Therefore, we suggest that the SH-17059 and SH-19021 induced the caspase-independent cell death through the accumulation of iron from heme degradation, and the ferroptosis might be one of the potential candidates for caspase-independent cell death.

• BMB Reports
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• v.46 no.1
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• pp.25-30
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• 2013

Gap junctions and their structural proteins, connexins (Cxs), have been implicated in carcinogenesis. To explore the involvement of Cx32 in gastric carcinogenesis, immunochemical analysis of Cx32 and proliferation marker Ki67 using tissue-microarrayed human gastric cancer and normal tissues was performed. In addition, after Cx32 overexpression in the human gastric cancer cell line AGS, cell proliferation, cell cycle analyses, and $p21^{Cip1}$ and $p27^{Kip1}$ expression levels were examined by bromodeoxyuridine assay, flow cytometry, real-time RT-PCR, and western blotting. Immunohistochemical study noted a strong inverse correlation between Cx32 and Ki67 expression pattern as well as their location. In vitro, overexpression of Cx32 in AGS cells inhibited cell proliferation significantly. $G^1$ arrest, up-regulation of cell cycle-regulatory proteins $p21^{Cip1}$ and $p27^{Kip1}$ was also found at both mRNA and protein levels. Taken together, Cx32 plays some roles in gastric cancer development by inhibiting gastric cancer cell proliferation through cell cycle arrest and cell cycle regulatory proteins.

• The Journal of Internal Korean Medicine
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• v.36 no.1
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• pp.13-21
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• 2015

Objectives : In Korea, Rhus verniciflua Stokes (RVS) has been used in traditional medicine for various diseases such as back pain, syndromes of the blood system in women, gastrointestinal disease, and cancer. However, the molecular mechanisms of its anti-cancer activity have not been clearly elucidated yet. Methods : This study investigated the possible mechanisms by which RVS extract (RVE) exerts its anti-proliferative action in cultured human breast carcinoma MCF-7 cells. Results : Treatment with RVE in MCF-7 cells resulted in inhibition of cell viability through G1 arrest of the cell cycle and induction of apoptosis in a time- and concentration-dependent manner, as determined by MTT assay and flow cytometry analysis. The induction of G1 arrest by RVE treatment was associated with the inhibition of cyclin D1, cyclin-dependent kinase (Cdk) 2, retinoblastoma protein (pRB), and mouse double minute 2 (MDM2) expression. Moreover, RVE treatment concentration dependently increased the levels of tumor suppressor p53, which was associated with the marked induction of Cdk inhibitors such as p21 (Waf1/Cip1) and p27 (Kip1). However, the inhibition of p53 function by the wild-type p53-specific inhibitor, pifithrin-α, abolished the above-mentioned effects of RVE, showing that p53 was responsible for the cytotoxicity of RVE Conclusions : These data indicate that a molecular pathway involving p53-dependent G1 cell cycle arrest plays a pivotal role in the cellular response to RVE, and demonstrate the potential applications of RVE as an anti-cancer drug for breast cancer treatment.

• Archives of Pharmacal Research
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• v.27 no.5
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• pp.554-561
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• 2004

Trichostatin A, an antifungal antibiotics, and HC-toxin are potent and specific inhibitors of histone deacetylase activity. Histone deacetylase inhibitors are new class of chemotherapeutic drugs able to induce tumor cell apoptosis and/or cell cycle arrest. In this study, the antiproliferative activities of trichostatin A and HC-toxin were compared between estrogen receptor positive human breast cancer cell MCF-7 and estrogen receptor negative human breast cancer cell MDA-MB-468. Trichostatin A and HC-toxin showed potent antiproliferative activity in both MCF-7 and MDA-MB-468 cells. In MCF-7 cells that contain high level estrogen receptor, trichostatin A and HC-toxin brought about three-times more potent cell growth inhibitory effect than estrogen receptor negative MDA-MB-468 cells. Both trichostatin A and HC-toxin showed cell cycle arrest at G$_2$/M phases of MCF-7 and MDA-MB-468 cells in a dose- and time- depen- dent manner. Trichostatin A and HC-toxin also induced apoptosis from MCF-7 and MDA-MB-468 cells in a dose- and time-dependent manner. Results of this study suggested that antipro-liferative effects of trichostatin A and HC-toxin might be involved in estrogen receptor signaling pathway, but cell cycle arrest and apoptosis of trichostatin A and HC-toxin might not be involved in estrogen receptor system of human breast cancer cells.

• Journal of Ginseng Research
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• v.39 no.2
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• pp.125-134
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• 2015

Background: Black ginseng (Ginseng Radix nigra, BG) refers to the ginseng steamed for nine times and fine roots (hairy roots) of that is called fine black ginseng (FBG). It is known that the content of saponin of FBG is higher than that of BG. Therefore, in this study, we examined antitumor effects against MCF-7 breast cancer cells to target the FBG extract and its main component, ginsenoside Rg5 (Rg5). Methods: Action mechanism was determined by MTT assay, cell cycle assay and western blot analysis. Results: The results from MTT assay showed that MCF-7 cell proliferation was inhibited by Rg5 treatment for 24, 48 and 72 h in a dose-dependent manner. Rg5 at different concentrations (0, 25, 50 and $100{\mu}M$), induced cell cycle arrest in G0/G1 phase through regulation of cell cycle-related proteins in MCF-7 cells. As shown in the results from western blot analysis, Rg5 increased expression of p53, $p21^{WAF1/CIP1}$ and $p15^{INK4B}$ and decreased expression of Cyclin D1, Cyclin E2 and CDK4. Expression of apoptosiserelated proteins including Bax, PARP and Cytochrome c was also regulated by Rg5. These results indicate that Rg5 stimulated cell apoptosis and cell cycle arrest at G0/G1 phase via regulation of cell cycle-associated proteins in MCF-7 cells. Conclusion: Rg5 promotes breast cancer cell apoptosis in a multi-path manner with higher potency compared to 20(S)-ginsenoside Rg3 (Rg3) in MCF-7 (HER2/ER+) and MDA-MB-453 (HER2+/ER) human breast cancer cell lines, and this suggests that Rg5 might be an effective natural new material in improving breast cancer.

• Imaging Science in Dentistry
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• v.30 no.3
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• pp.189-198
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• 2000

Purpose: The study was aimed to detect the induction of apoptosis, cell cycle arrest and calcified nodule formation after irradiation on primarily cultured osteoblasts. Materials and Methods: Using rat calvarial osteoblasts, the effects of irradiation on apoptosis, cell cycle arrest, and calcified nodule formation were studied. The single irradiation of 10 and 20 Gy was done with 5.38 Gy/min dose rate using the l37Cs cell irradiator at 4th and 14th day of culture. Apoptosis induction and cell cycle arrest were assayed by the flowcytometry at 1, 2, 3, and 4 days after irradiation. The formation of calcified nodules was observed by alizarin red staining at 1, 3, 10, 14 days after irradiation at 4th day of culture, and at 1, 4, 5 days after irradiation at 14th day of culture. Results: Apoptosis was not induced by 10 or 20 Gy independent of irradiation and culture period. Irradiation did not induced G1 arrest in post-irradiated ostedblasts. After irradiation at 4th-day of culture, G2 arrest was induced but it was not statistically significant after irradiation at 14th-day of culture. In the case of irradiated cells at 4th day of culture, calcified nodules were not formed and at 14th-day of culture after irradiation, calcified nodule formation did not affected. Conclusion: Taken together, these results suggest that irradiation at the dose of 10-20 Gy would not affect apoptosis induction of osteoblasts. Cell cycle and calcified nodule formation were influenced by the level of differentiation of osteblasts.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.103.3-104
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• 2003

Activation of hepatic stellate cell has been identified as a critical step in hepatic fibrogenesis and is regulated by several factors including cytokines and oxidative stress. In this study, we assayed effects of saponin (CKS), inulin (CKI) and oligo-sugars (CKO) isolated from Platycodon grandiflorum A. DC, changkil (CK) on experimental cell cycle arrest and apoptosis in hepatic stellate cell line (HSC-T6). CKS induced cell arrest at G$_1$. CKS also reduced intercellular reactive oxygen species and collagen synthesis in hydrogen peroxide-induced oxidative stress and acetaldehyde-stimulated collagen synthesis, respectively, in HSC-T6 cells. (omitted)

• BMB Reports
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• v.43 no.11
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• pp.750-755
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• 2010

Crude Orostachys japonicus polysaccharide extract (OJP) was prepared by hot steam extraction. Polysaccharides (OJPI) were separated from OJP by gel filtration chromatography and phenol-sulfuric acid assay. The average molecular weight of the OJPI was 30-50 kDa. The anti-proliferative effect of OJPI on HT-29 human colon cancer cells was investigated via morphology study, cell viability assay, apoptosis assay, cell cycle analysis, and cDNA microarray. OJPI inhibited proliferation and growth of HT29 cells and also stimulated apoptosis in a dose- and time-dependent manner. In cell cycle analysis, treatment with OJPI resulted in a marked increase of cells in the G0 (sub G1) and G2/M phases. To screen for genes involved in the induction of cell cycle arrest and apoptosis, the gene expression profiles of HT-29 cells treated with OJPI were examined by cDNA microarray, revealing that a number of genes were up- or down-regulated by OJPI. Whereas several genes involved in anti-apoptosis, cell proliferation and growth, and cell cycle regulation were down-regulated, expression levels of several genes involved in apoptosis, tumor suppression, and other signal transduction events were up-regulated. These results suggest that OJPI inhibits the growth of HT-29 human colon cancer cells by various apoptosis-aiding activities as well as apoptosis itself. Therefore, OJPI deserve further development as an effective agent exhibiting anticancer activity.