• KSBB Journal
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• v.30 no.5
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• pp.223-229
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• 2015

In this study, extract from Artemisia annua in L. (AAE) is known as a medicinal herb that is effective against cancer. The cell cycle is regulated by the activation of cyclin-dependent kinase (CDK)/cyclin complex. We will focus on regulation of CDK2 by cyclin E. cyclin E is associated with CDK2 to regulate progression from G1 into S phase. Akt is known to play an important role in cell proliferation and cell survival. Activation of Akt increases mTOR activity that promotes cell proliferation and cancer growth. In this study, we investigated that AAE-induced cell cycle arrest at G1/S phase in HCT116 colon cancer. Treatment of AAE shows that reduced activation of Akt decreases mTOR/Mdm2 activity and then leads to increase the activation of p53. The active p53 promotes activation of p21. p21 induces inactivation of CDK2/cyclin E complex and occurs cell cycle arrest at G1/S phase. We treated LY294002 (Akt inhibitor) and Rapamycin (mTOR inhibitor) to know the relationship between the signal transduction of proteins associated with cell cycle arrest. These results suggest that AAE induces cell cycle arrest at G1/S phase by Akt/mTOR pathway in HCT116 colon cancer cell.

• 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.

• Herbal Formula Science
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• v.23 no.2
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• pp.199-208
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• 2015

Objectives : In the present study, we investigated the effects of ethanol extract of Scutellaria baicalensis (EESB) on the progression of cell cycle in human renal cell carcinoma Caki-1 cells. Methods : The effects of EESB on cell growth and apoptosis induction were evaluated by trypan blue dye exclusion assay and flow cytometry, respectively. The mRNA and protein levels were determined by Western blot analysis and reverse transcription-polymerase chain reaction, respectively. Results : It was found that EESB treatment on Caki-1 cells resulted in a dose-dependent inhibition of cell growth and induced apoptotic cell death as detected by Annexin V-FITC staining. The flow cytometric analysis indicated that EESB resulted in G2/M arrest in cell cycle progression which was associated with the down-regulation of cyclin A expression. Our results also revealed that treatment with EESB increased the mRNA and proteins expression of tumor suppressor p53 and cyclin-dependent kinase (Cdk) inhibitor p21(WAF1/CIP1), without any noticeable changes in cyclin B1, Cdk2 and Cdc2. In addition, the incubation of cells with EESB resulted in a significant increase in the binding of p21 and Cdk2 and Cdc2. These findings suggest that EESB-induced G2/M arrest and apoptosis in Caki-1 cells is mediated through the p53-mediated upregulation of Cdk inhibitor p21. Conclusions : Taken together, these findings suggest that EESB may be a potential chemotherapeutic agent and further studies will be needed to identify the biological active compounds that confer the anti-cancer activity of S. baicalensis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.1-6
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• 2004

$\beta$-Sitosterol is the major phytosterol in higher plants, including fruits and vegetables. The molecule has been shown to have the potential for prevention and therapy for human cancer. We investigated the effects of $\beta$-sitosterol on the cell proliferation of HCT116 human colon cancer cells in order to understand its anti-proliferative mechanism. $\beta$-Sitosterol treatment resulted in the inhibition of cell proliferation in a concentration-dependent manner. The anti-proliferative effect of HCT116 cells by $\beta$-sitosterol was associated with formation of apoptotic bodies and degradation of $\beta$-catenin protein. In addition, $\beta$-sitosterol-treatment induced a marked accumulation of tumor suppressor p53 and a concomitant induction of cyclin-dependent kinase (Cdk) inhibitor p21 without alteration in the levels of cyclins and Cdks. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of $\beta$-sitosterol.

• 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.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2001.10b
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• pp.151-152
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• 2001

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2001.10b
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• pp.150-150
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• 2001

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.4
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• pp.745-755
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• 2002

To examine the effects of Yunpyesan on the cell proliferation of A549 human lung carcinoma cell line, we performed various experiments such as dose-dependent effect of Yunpyesan on cell proliferation and viability, morphological changes, quantification of apoptotic cell death and alterations of apoptosis/cell cycle-regulatory gene products. Yunpyesan declined cell viability and proliferation in both a dose- and a time-dependent manner. The anti-proliferative effect by Yunpyesan treatment in A459 cells was associated with morphological changes such as membrane shrinking and cell rounding up. Yunpyesan Induced apoptotic cell death in a time-dependent manner, which was associated with degradation of poly-(ADP-ribose) polymerase (PARP), an apoptotic target protein, without alterations of the balance between Bcl-2 and Bax expressions. DNA flow cytometric histograms showed that population of G1 phase of the cell cycle was increased by Yunpyesan treatment in a dose-dependent manner. Western blot analysis revealed that cyclin D1 and A were reduced by Yunpyesan treatment, whereas cyclin dependent kinase (Cdk) inhibitor p27 was markedly increased in a time-dependent fashion. The level of tumor suppressor p53 proteins was also increased by Yunpyesan treatment and its increase might be linked to increase of Cdk inhibitor p27. In addition, Mdm2, negative regulator of p53, was down-regulated by Yunpyesan treatment. Since the expression of retinoblastome protein (pRB), a key regulator of G1/S progression, was reduced by Yunpyesan treatment, we supposed that phosphorylation of pRB might be also blocked. The present results indicated that Yunpyesan-induced inhibition of lung cancer cell proliferation is associated with the induction of apoptosis and the blockage of G1/S progression.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.6
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• pp.1177-1183
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• 2002

We investigated the effects of Sabaek-san (SBS) water extract on the cell proliferation of human lung carcinoma A549 cells. SBS treatment resulted in the inhibition of cell proliferation in a concentration-dependent manner. This anti-proliferative effect of A549 cells by SBS treatment was associated with morphological changes such as membrane shrinking and cell rounding up. DNA flow cytometric histograms showed that population of G1 phase of the cell cycle was increased by SBS treatment in a concentration-dependent manner. SBS treatment induced a marked accumulation of tumor suppressor p53 and a concomitant induction of cyclin-dependent kinase (Cdk) inhibitor p21WAF1/CIP, which appears to be transcriptionally upregulated and is p53 dependent. In addition, SBS treatment resulted in down-regulation of cyclooxygenase-2 (COX-2) as determined by RT-PCR analysis. The present results indicated that SBS-induced inhibition of lung cancer cell proliferation is associated with the blockage of G1/S progression the induction of apoptosis.

• Biomolecules & Therapeutics
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• v.20 no.1
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• pp.81-88
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• 2012

Histone deacetylases (HDACs) are enzymes involved in the remodelling of chromatin, and have a key role in the epigenetic regulation of gene expression. Histone deacetylase (HDAC) inhibitors are emerging as an exciting new class of potential anti-cancer agents. In recent years, a number of structurally diverse HDAC inhibitors have been identifi ed and these HDAC inhibitors induce growth arrest, differentiation and/or apoptosis of cancer cells in vitro and in vivo. However, the underlying molecular mechanisms remain unclear. This study aimed at investigating the anti-tumor activity of various HDAC inhibitors, IN-2001, using T47D human breast cancer cells. Moreover, the possible mechanism by which HDAC inhibitors exhibit anti-tumor activity was also explored. In estrogen receptor positive T47D cells, IN-2001, HDAC inhibitor showed anti-proliferative effects in dose-and time-dependent manner. In T47D human breast cancer cells showed anti-tumor activity of IN-2001 and the growth inhibitory effects of IN-2001 were related to the cell cycle arrest and induction of apoptosis. Flow cytometry studies revealed that IN-2001 showed accumulation of cells at $G_2$/M phase. At the same time, IN-2001 treatment time-dependently increased sub-$G_1$ population, representing apoptotic cells. IN-2001-mediated cell cycle arrest was associated with induction of cdk inhibitor expression. In T47D cells, IN-2001 as well as other HDAC inhibitors treatment significantly increased $p21^{WAF1}$ and $p27^{KIP1}$ expression. In addition, thymidylate synthase, an essential enzyme for DNA replication and repair, was down-regulated by IN-2001 and other HDAC inhibitors in the T47D human breast cancer cells. In summary, IN-2001 with a higher potency than other HDAC inhibitors induced growth inhibition, cell cycle arrest, and eventual apoptosis in human breast cancer possibly through modulation of cell cycle and apoptosis regulatory proteins, such as cdk inhibitors, cyclins, and thymidylate synthase.