• Journal of Life Science
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• v.15 no.3 s.70
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• pp.397-405
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• 2005

Sulforaphane, an isothiocyanate derived from hydrolysis of glucoraphanin in broccoli and other cruciferous vegetables, was shown to induce phase II detoxification enzymes and inhibit chemically induced mammary tumors in rodents. Recently, sulforaphane is known to induce cell cycle arrest and apoptosis in human cancer cells, however its molecular mechanisms are poorly understood. In the present study, we demonstrated that sulforaphane acted to inhibit proliferation and induce morphological changes of human cervical carcinoma HeLa cells. Treatment of HeLa cells with $10{\mu}M\;or\;15{\mu}M$ sulforaphane resulted in significant G2/M cell cycle arrest as determined by flow cytometry. Moreover, $20{\mu}M$ sulforaphane significantly induced the population of sub-G1 cells (9.83 fold of control). This anti-proliferative effect of sulforaphane was accompanied by a marked inhibition of cyclin A and cyclin-dependent kinase (Cdk)4 protein and concomitant induction of Cdc2, Cdk inhibitor p16 and p21. However, sulforaphane did not affect the levels of cyelooxygenases and telomere-regulatory gene products. Although further studies are needed, the present work suggests that sulforaphane may be a potential chemoprevetive/ chemotherapeutic agent for the treatment of human cancer cells.

• Journal of Haehwa Medicine
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• v.14 no.1
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• pp.201-211
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• 2005

Cdc2 kinase is a prototypical cyclin-dependent kinase critical for G2 to M phase cell cycle transition. Yet, its function in the nervous system is largely unknown. Here, we investigated possible role of Cdc2 in axonal regeneration using sciatic nerve system in rat. Cdc2 protein levels and activity were increased in the injured sciatic nerves 3 and 7 days after crush injury and then decreased to basal level 14 days later. Administration of Cdc2 kinase inhibitor roscovitine in vivo at the time of crush injury significantly inhibited axonal regeneration when regrowing axons were analyzed using retrograde tracers. Cdc2 protein levels in cultured Schwann cells which were prepared from sciatic nerves 7 days after crush injury were much higher compared with those from uninjured sciatic nerves, suggesting that Cdc2 protein expression was primarily induced in the Schwann cells. To further investigate Cdc2 function in Schwann cell, we examined changes in cultured Schwann cell proliferation and migration in culture system. Both the number of proliferating Schwann cells and the extent of neurite outgrowth from co-cultured DRG neurons were significantly decreased by Cdc2 inhibitor roscovitine treatment in DRG culture which was prepared from animals with sciatic nerve injury for 7 days. Also, Schwann cell migration in the injured sciatic nerve explant was significantly inhibited by roscovitine treatment. Taken together, the present data suggest that Cdc2 may be involved in peripheral nerve regeneration via Schwann cell proliferation and migration.

• Journal of Life Science
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• v.17 no.7 s.87
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• pp.976-982
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• 2007

The purpose of this study was to determine the modulating effects of histone deacetylase inhibitor, trichostatin A, on the differentiation of mouse C2C12 myoblasts. We demonstrated that trichostatin A induced morphological changes of C2C12 myoblasts into smooth muscles and significantly increased the gene expression of smooth muscle markers including smooth muscle ${\alpha}-actin$ and transgelin. These results were due to the change in the expression level of cell cycle regulators in trichostatin A-treated C2C12 cells. Real-time PCR data revealed that cyclin dependent kinase inhibitor, p21, mRNA expression was significantly increased in trichostatin A-treated C2C12 cells. However, trichostaDn A rapidly decreased cyclin Dl mRNA expression necessary for cell cycle progression in 24hr after treatment. In conclusion, the strong inhibitory effects of trichostatin A on histone deacetylation induced transdifferentiation of C2C12 myoblasts into smooth muscle cells and these results are partly due to the changes in the expression of cell cycle regulators such as p21 and cyclin D1.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.4
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• pp.417-425
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• 2017

Cnidium monnieri (L.) Cusson is distributed in China and Korea, and the fruit of C. monnieri is used as traditional Chinese medicine to treat carbuncle and pain in female genitalia. In this study, we examined the anti-proliferation and cell cycle arrest effects of ethanol extracts from C. monnieri (CME) in AGS gastric cancer cells. Our results show that CME suppressed cell proliferation and induced release of lactate dehydrogenase (LDH) in AGS cells by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay and LDH assay. Cell morphology was altered by CME in a dose-dependent manner. In order to identify the cell cycle arrest effects of CME, we investigated cell cycle analysis after CME treatment. In our results, CME induced cell cycle arrest at G1 phase. Protein kinase B (Akt) plays a major role in cell survival mechanisms such as growth, division, and metastasis. Akt protein regulates various downstream proteins such as glycogen synthase kinase-$3{\beta}$ (GSK-$3{\beta}$) and tumor protein p53 (p53). Expression levels of p-Akt, p-GSK-$3{\beta}$, p53, p21, cyclin E, and cyclin-dependent kinase 2 (CDK2) were determined by Western blot analysis. Protein levels of p-Akt, p-GSK-$3{\beta}$, and cyclin E were reduced while those of p53, p21, and p-CDK2 (T14/Y15) were elevated by CME. Moreover, treatment with CME, LY294002 (phosphoinositide 3-kinase/Akt inhibitor), BIO (GSK-$3{\beta}$ inhibitor), and Pifithrin-${\alpha}$ (p53 inhibitor) showed that cell cycle arrest effects were mediated through regulation of the Akt/GSK-$3{\beta}$/p53 signaling pathway. These results suggest that CME induces cell cycle arrest at G1 phase via the Akt/GSK-$3{\beta}$/p53 signaling pathway in AGS gastric cancer cells.

• Journal of Life Science
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• v.20 no.7
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• pp.977-982
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• 2010

We investigated the anti-cancer effects of two dibenzocyclooctadiene lignans, gomisin A and gomisin N, isolated from Schizandra chinensis Baill, in human promyelocytic U937 cells. Gomisin N, but not gomisin A, inhibited cell growth in a concentration-dependent manner, which was associated with the induction of G1 arrest of the cell cycle. G1 arrest induced by gomisin N was correlated with down-regulation of cyclin E, cyclin-dependent kinase (Cdk) 2 and Cdk4, and a concomitant up-regulation of Cdk inhibitors such as p16 (INK4A) and p21 (WAF1/CIP1). Furthermore, gomisin N inhibited phosphorylation of retinoblastoma protein (pRB) and p130, and expression of transcription factor E2Fs. The results indicated that growth inhibition by gomisin N is related to cell cycle arrest at G1 in U937 cells and these findings suggest that gomisin N may be a useful chemotherapeutic agent.

• Environmental Analysis Health and Toxicology
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• v.27
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• pp.10.1-10.7
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• 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
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• v.22 no.4
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• pp.821-828
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• 2008

Onchungeum, a herbal formula, which has been used for treatment of anemia due to bleeding, discharging blood and skin disease. In the present study, it was examined the effects of extract of Onchungeum (OCE) on the growth of human hepatocarcinoma cell lines Hep3B (p53 null type) and HepG2 (p53 wild type) in order to investigate the anti-proliferative mechanism by OCE. Treatment of Hep3B and HepG2 cells to OCE resulted in the growth inhibition in a dose-dependent manner, however Hep3B cell line exhibited a relatively strong anti-proliferative activity to OEC. Flow cytometric analysis revealed that OCE treatment in Hep3B cells caused G1 phase arrest of the cell cycle, which was associated with various morphological changes in a dose-dependent fashion. RT-PCR and immunoblotting data revealed that treatment of OCE caused the down-regulation of cyclin D1 expression, however the levels of cyclin E expression were not changed by OCE. The G1 arrest of the cell cycle was also associated with the induction of Cdk inhibitor p27 by OCE. Because the p53 gene is null in Hep3B cells, it is most likely that the induction of p21 is mediated through a p53-independent pathway. Moreover, p27 detected in anti-Cdk4 and anti-Cdk2 immunoprecipitates from the OCE-treated cells, suggesting that OCE-induced p27 protein blocks Cdk kinase activities by directing binding to the cyclin/Cdk complexes. Furthermore, OCE treatment potently suppresses the phosphorylation of retinoblastoma proteins and the levels of the transcription factor E2F-1 expression. Taken together, these results indicated that the growth inhibitory effect of OCE in Hep3B hepatoma cells was associated with the induction of G1 arrest of the cell cycle through regulation of several major growth regulatory gene products.

• 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.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.677-682
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• 2014

Resveratrol has been examined in several model systems for potential effects against cancer. Adenosine monophosphate-activated protein kinase (AMPK) is reported to suppress proliferation in most eukaryocyte cells. Whether resveratrol via AMPK inhibits proliferation of oesophageal adenocarcinoma cells (OAC) is unknown. The aim of this study was to determine the roles of AMPK in the protective effects of resveratrol in OAC proliferation and to elucidate the underlying mechanisms. Treatment of cultured OAC derived from human subjects or cell lines with resveratrol resulted in decreased cell proliferation. Further, inhibition of AMPK by pharmacological reagent or genetical approach abolished resveratrol-suppressed OAC proliferation, reduced the level of $p27^{Kip1}$, a cyclin-dependent kinase inhibitor, and increased the levels of S-phase kinase-associated protein 2 (Skp2) of $p27^{Kip1}$-E3 ubiquitin ligase and 26S proteasome activity reduced by resveratrol. Furthermore, gene silencing of $p27^{Kip1}$ reversed resveratrol-suppressed OAC proliferation. In conclusion, these findings indicate that resveratrol inhibits Skp2-mediated ubiquitylation and 26S proteasome-dependent degradation of $p27^{Kip1}$ via AMPK activation to suppress OAC proliferation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.8
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• pp.1237-1245
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• 2004

Agaricus blazei Murill is a medicinal mushroom native to Brazil. It used to be a source of antitumor and immunoactive compounds and considered a health food in many countries. In the present study, it was examined the effects of water extract of A. blazei (WEAB) on the growth of human lung carcinoma cell line A549 in order to investigate the anti-proliferative mechanism by WEAB. Treatment of A549 cells to WEAB resulted in the growth inhibition, morphological change and induction of apoptotic cell death in a dose-dependent manner as measured by MTT assay and flow cytometric analysis. Flow cytometric analysis revealed that WEAB caused G2/M phase arrest of the cell cycle, which was associated with a down-regulation of cyclin A in both transcriptional and translational levels. WEAB treatment induced a marked up-regulation of cyclin-dependent kinase (Cdk) inhibitor p21, however, the levels of Cdk2, Cdc2, Wee1, Cdc25C and p53 expression were remained unchanged in WEAB treated cells. In addition, WEAB treatment inhibited the levels of cyclooxygenase (COX)-2 mRNA and protein without alteration of COX-l expression. Taken together, these findings suggest that WEAB may be a potential chemotherapeutic agent for the control of human lung carcinorma cells and further studies will be needed to identify the active compounds that confer the anti-cancer activity of WEAB. Once such compounds are identified, the mechanisms by which they exert their effects can begin to be characterized.