• YAKHAK HOEJI
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• v.43 no.3
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• pp.378-384
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• 1999

Retinoic acid (RA) and dibutyryl cyclic AMP (dbcAMP) induce the differentiation of the multipotent embryonic carcinoma cell line, F9 cells, into parietal endoderm like cell. The F9 cells are highly proliferative doubling approximately 12 hourse. S Phase is predominant, lasting 10 hours and G2/M phase occupies most of the remaining cycle (2 hours) and G1 phase is nearly non-existent. In this study, we showed the effect of RA and dbcAMPon the cell cycle associated molecules (especially around G1 phase) during F9 cell differentiation. Differentiation of F9 cells was induced by the combined addition of RA ($10^{-7}M$) and dbcAMP (0.5mM), and cells were harvested daily up to 4 days. Flow cytometric analysis showed the prolongation of G1 phase around 30 hours after induction. Western blot analysis revealed that the amount of cyclin D1 and cdk2 were increased at day 4. However, histone H1 kinase activity of cdk2 was decreased. These data strongly suggest that RA and dbcAMP induce the growth arrest of F9 cells at G1 phase by decreasing the activity of cdk2, although they have increased the protein contents of cyclin D1 and cdk2. The reason for the discrepancy between the H1 kinase activity and protein contents are not clear yet.

• Journal of Life Science
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• v.23 no.9
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• pp.1109-1117
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• 2013

Induction of G1 Arrest by Methanol Extract of Lycopus lucidus in Human Lung Adenocarcinoma A549 Cells Lycopus lucidus, a herbaceous perennial, is used as a traditional remedy in East Asia, including China and Korea. It has been reported that L. lucidus has anti-allergic effects, inhibitory effects on cholesterol acyltransferase in high glucose-induced vascular inflammation, and anti-proliferative effects in human breast cancer cells. However, the molecular mechanisms of the anti-cancer effects of L. lucidus have not yet been fully determined. In this study, we evaluated the anti-cancer effect and the mechanism of action of L. lucidus in human lung adenocarcinoma A549 cells using methanol extracts of L. lucidus (MELL). MELL treatment showed cytotoxic activity in a dose-dependent manner and induced G1 arrest in A549 cells. The induction of G1 arrest by MELL was associated with the up-regulation of phospho-CHK2 and the down-regulation of Cdc25A phosphatase. In addition, MELL treatment induced decreased expression of G1/S transition-related proteins, including CDK2, CDK4, CDK6, cyclin D1 and cyclin E. MELL also regulated the mRNA expression of CDK2 and cyclin E. On the other hand, the expression of p53 and the cyclin-dependent kinase inhibitor p21 was not induced by MELL. Collectively, these results suggest that MELL may exert an anti-cancer effect by cell cycle arrest at G1 phase through the ATM/CHK2/Cdc25A/CDK2 pathway in A549 cells.

• Journal of Life Science
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• v.28 no.11
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• pp.1316-1320
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• 2018

The effects of a green tea extract (GTE) were examined using the MCF-7 human breast cancer cell line. Cell viability assays using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays revealed that GTE had a significant cytotoxic effect on MCF-7 cells, depending on the concentration of GTE. Western blotting of p53 and its related proteins, p21/cip1 and CDK2, after GTE treatment revealed that a significant and concentration dependent increase in p53 protein in response to GTE. The levels of p21/cip1 proteins were also increased at low GTE concentrations were significantly increased even at the highest GTE concentrations. However, the level of CDK2 was significantly decreased by treatment with high concentrations of GTE. These results indicate that treatment with GTE increased the p53 level in MCF-7 cells, and this activation of p53 markedly elevated the levels of p21/cip1proteins, which, in turn, inhibited CDK2 expression in the MCF-7 cells. The inhibition of CDK2 expression might then affect cell cycle progression. Subsequent FACS analysis indicated that GTE treatment the gradually increased progression of the MCF-7 to the G1 phase. These results clearly demonstrate that the anti-tumor effect of GTE in MCF-7 cells is regulated by p53 arrest of the MCF-7 cells at the G1 stage of cell cycle.

• Journal of Periodontal and Implant Science
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• v.33 no.3
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• pp.415-437
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• 2003

Ginseng Radix(GR) had been used widely from oriental medicine and the effects of it have been investigated by many researchers. The purpose of present study was to investigate the effects of GR on the cell cycle progression and its molecular mechanism in human fetal osteoblast. The results were as follows. Increased cell proliferation was observed in cells exposed to 100 ng/ml, 10 ng/ml of GR-1 at 12 hours and 24 hours, 1 ${\mu}g$/ml of GR-1 at 48 hours, and 100 ${\mu}g$/ml, 10 ${\mu}g$/ml of GK-2 at 12 hours, all treatment groups of GR-2 at 24 hours(p<0.05). S phase and G1 phase was increased in the group of treated with 100 ng/ml of GR-1, with 10 ${\mu}g$/ml and 1 ${\mu}g$/ml of GR-2, with 100 ${\mu}g$/ ml and 10 ${\mu}g$/ml of GR-3 in the cell cycle analysis. The cell cycle regulation protein levels of Cyclin D1, Cyclin E, CDK 2. CDK 4 and CDK 6 were increased in the group of treated with 1 ${\mu}g$/ml and 100 ng/ml of GR-1, with 10 ${\mu}g$/ml and 1 ${\mu}g$/ml of GR-2, with 100 ${\mu}g$/ ml and 10 ${\mu}g$/ml of GR-3. On the other hand, p21 was decreased in the treatment group with 1 ${\mu}g$/ml and 100 ng/ml of GR-1, with 10 ${\mu}g$/ml and 1 ${\mu}g$/ml of GR-2, 10 ${\mu}g$/ml of GR-3, and p53 and p16 was decreased in the treatment group with 100 ng/ml of GR-1, 100 ${\mu}g$/ml and GR-3 and pRb was decreased in the all treatment groups except 1 ${\mu}g$/ml of GR-1. These results suggested that GR increases the cell proliferation and the cell cycle progression in human fetal osteoblast, which is linked to increased cell cycle regulation protein levels of Cyclin D1 , Cyclin E, CDK 2, CDK 4, CDK 6 and decreased cell cycle regulation protein levels of p21, pRb.

• Journal of Microbiology and Biotechnology
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• v.32 no.10
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• pp.1262-1274
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• 2022

Cholangiocarcinoma (CCA) is a complex and refractor type of cancer with global prevalence. Several barriers remain in CCA diagnosis, treatment, and prognosis. Therefore, exploring more biomarkers and therapeutic drugs for CCA management is necessary. CCA gene expression data was downloaded from the TCGA and GEO databases. KEGG enrichment, GO analysis, and protein-protein interaction network were used for hub gene identification. miRNA were predicted using Targetscan and validated according to several GEO databases. The relative RNA and miRNA expression levels and prognostic information were obtained from the GEPIA. The candidate drug was screened using pharmacophore-based virtual screening and validated by molecular modeling and through several in vitro studies. 301 differentially expressed genes (DEGs) were screened out. Complement and coagulation cascades-related genes (including AHSG, F2, TTR, and KNG1), and cell cycle-related genes (including CDK1, CCNB1, and KIAA0101) were considered as the hub genes in CCA progression. AHSG, F2, TTR, and KNG1 were found to be significantly decreased and the eight predicted miRNA targeting AHSG, F2, and TTR were increased in CCA patients. CDK1, CCNB1, and KIAA0101 were found to be significantly abundant in CCA patients. In addition, Molport-003-703-800, which is a compound that is derived from pharmacophores-based virtual screening, could directly bind to CDK1 and exhibited anti-tumor activity in cholangiocarcinoma cells. AHSG, F2, TTR, and KNG1 could be novel biomarkers for CCA. Molport-003-703-800 targets CDK1 and work as potential cell cycle inhibitors, thereby having potential for consideration for new chemotherapeutics for CCA.

• Fisheries and Aquatic Sciences
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• v.24 no.1
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• pp.1-9
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• 2021

Human prostate cancer is the second most frequently diagnosed cancer worldwide, and its incidence rate continues to increase. Advanced prostate cancer is more difficult to treat than early forms due to its chemotherapy resistance. There is need for more effective agents that can inhibit the progression of advanced prostate cancer. Demethoxyfumitremorgin C (DMFTC) was isolated from the fermentation extract of the marine fungus Aspergillus fumigatus. Antiproliferative activity of DMFTC against human prostate cancer PC3 cells was examined through cell cycle analysis by flow cytometry, the fluorescent nuclear imaging analysis with propidium iodide (PI), and proteins expression related to cell cycle arrest and apoptosis were investigated via Western blotting. DMFTC inhibited PC3 cells growth through G1 phase cell cycle arrest and apoptosis induction. It activated the tumor suppressor p53 and the Cdk inhibitor p21, which regulate the cell progression into the G1 phase. Additionally, PI-positive late apoptotic non-viable cells were increased and the expression levels of the G1-positive downstream regulators cyclin D, cyclin E, Cdk2, and Cdk4 were decreased by DMFTC treatment. These results suggest that DMFTC induces G1 arrest and apoptosis induction through regulation of p53/p21-dependent cyclin-Cdk complexes, and it may be a useful therapeutic agent for the treatment of human advanced prostate cancer.

• Journal of Periodontal and Implant Science
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• v.35 no.1
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• pp.87-98
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• 2005

The purpose of present study was to investigate the effects of physiologically active compound (SD62-122) from Phlomidis Radix on the cell cycle progression and its molecular mechanism in human gingival fibroblasts(HGFs). For this purpose, fibroblasts were isolated and cultured from excisioned gingiva during crown lengthening procedure in healthy adult. The following parameter were evaluated that there are cell number counting, MIT assay, cell cycle progression, western blot analysis. The cell number and MIT assay of primary cultured fibroblast was not increased at 2 days but significant increased compare to negative control at 3days(p<0.05). S phase was increased and G1 phase decreased in both $10^{-8}M$ and $10^{-9}M$ of SD62-122 in cell cycle analysis. The cell cycle regulation protein levels of Cyclin $D_1$, Cyclin E, cdk 2, cdk 4 and cdk 6 were increased compare to control in both $10^{-8}M$ and $10^{-9}M$ of SD62-122. The protein levels of p21 and p53 were decreased compare to control, but the level of pRb was not changed compare to control in $10^{-9}M$ of SD2-122. These results suggested that physiologically active compound (SD62-122) isolated from Phlomidis Radix increases the cell proliferation and cell cycle progression in HGFs, which is linked to increased cell cycle regulation protein levels of Cyclin $D_1$, Cyclin E, cdk 2, cdk 4 and cdk 6, and decreased the levels of p21, p53.

• Molecules and Cells
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• v.45 no.4
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• pp.216-230
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• 2022

SERTA domain-containing protein 1 (Sertad1) is upregulated in the models of DNA damage and Alzheimer's disease, contributing to neuronal death. However, the role and mechanism of Sertad1 in ischemic/hypoxic neurological injury remain unclear. In the present study, our results showed that the expression of Sertad1 was upregulated in a mouse middle cerebral artery occlusion and reperfusion model and in HT22 cells after oxygen-glucose deprivation/reoxygenation (OGD/R). Sertad1 knockdown significantly ameliorated ischemia-induced brain infarct volume, neurological deficits and neuronal apoptosis. In addition, it significantly ameliorated the OGD/R-induced inhibition of cell viability and apoptotic cell death in HT22 cells. Sertad1 knockdown significantly inhibited the ischemic/hypoxic-induced expression of p-Rb, B-Myb, and Bim in vivo and in vitro. However, Sertad1 overexpression significantly exacerbated the OGD/R-induced inhibition of cell viability and apoptotic cell death and p-Rb, B-Myb, and Bim expression in HT22 cells. In further studies, we demonstrated that Sertad1 directly binds to CDK4 and the CDK4 inhibitor ON123300 restores the effects of Sertad1 overexpression on OGD/R-induced apoptotic cell death and p-Rb, B-Myb, and Bim expression in HT22 cells. These results suggested that Sertad1 contributed to ischemic/hypoxic neurological injury by activating the CDK4/p-Rb pathway.

• Journal of Life Science
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• v.24 no.1
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• pp.92-97
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• 2014

Cordycepin, an active component originally isolated from the traditional medicine Cordyceps militaris, is a derivative of the nucleoside adenosine, which has been shown to possess a number of pharmacological properties, including antioxidant and anti-inflammatory activities, immunological stimulation, and antitumor effects. This study was conducted on cultured human prostate carcinoma LNCap cells to elucidate the possible mechanisms by which cordycepin exerts its anticancer activity, which, until now, has remained poorly understood. Cordycepin treatment of LNCap cells resulted in dose-dependent inhibition of cell growth and the induction of apoptotic cell death as detected by an MTT assay, cleavage of poly ADP-ribose polymerase, and annexin V-FITC staining. Flow cytometric analysis revealed that cordycepin resulted in G2/M arrest in cell cycle progression and downregulation of cyclin B1 and cyclin A expression in a concentration-dependent manner. Moreover, the incubation of cells with cordycepin caused a striking induction in the expression of the cyclin-dependent kinase (CDK) inhibitor p21Waf1/Cip1 without affecting the expression of the tumor suppressor p53. It also resulted in a significant increase in the binding of CDK2 and CDC2 to p21. These findings suggest that cordycepin-induced G2/M arrest and apoptosis in human prostate carcinoma cells is mediated through p53-independent upregulation of the CDK inhibitor p21.

• Journal of Periodontal and Implant Science
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• v.49 no.3
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• pp.138-147
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• 2019

Purpose: Several studies have shown that the oral cavity is a secondary location for Helicobacter pylori colonization and that H. pylori is associated with the severity of periodontitis. This study investigated whether H. pylori had an effect on the periodontium. We established an invasion model of a standard strain of H. pylori in human periodontal ligament fibroblasts (hPDLFs), and evaluated the effects of H. pylori on cell proliferation and cell cycle progression. Methods: Different concentrations of H. pylori were used to infect hPDLFs, with 6 hours of co-culture. The multiplicity of infection in the low- and high-concentration groups was 10:1 and 100:1, respectively. The Cell Counting Kit-8 method and Ki-67 immunofluorescence were used to detect cell proliferation. Flow cytometry, quantitative real-time polymerase chain reaction, and western blots were used to detect cell cycle progression. In the high-concentration group, the invasion of H. pylori was observed by transmission electron microscopy. Results: It was found that H. pylori invaded the fibroblasts, with cytoplasmic localization. Analyses of cell proliferation and flow cytometry showed that H. pylori inhibited the proliferation of periodontal fibroblasts by causing G2 phase arrest. The inhibition of proliferation and G2 phase arrest were more obvious in the high-concentration group. In the low-concentration group, the G2 phase regulatory factors cyclin dependent kinase 1 (CDK1) and cell division cycle 25C (Cdc25C) were upregulated, while cyclin B1 was inhibited. However, in the high-concentration group, cyclin B1 was upregulated and CDK1 was inhibited. Furthermore, the deactivated states of tyrosine phosphorylation of CDK1 (CDK1-Y15) and serine phosphorylation of Cdc25C (Cdc25C-S216) were upregulated after H. pylori infection. Conclusions: In our model, H. pylori inhibited the proliferation of hPDLFs and exerted an invasive effect, causing G2 phase arrest via the Cdc25C/CDK1/cyclin B1 signaling cascade. Its inhibitory effect on proliferation was stronger in the high-concentration group.