• BMB Reports
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• v.36 no.2
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• pp.223-229
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• 2003

The product of a tree (Tabebuia avellanedae) from South America, $\beta$-lapachone, is known to exhibit various pharmacological properties, the mechanisms of which are poorly understood. The aim of the present study was to further elucidate the possible mechanisms by which $\beta$-lapachone exerts its anti-proliferative action in cultured human prostate cancer cells. We observed that the proliferation-inhibitory effect of $\beta$-lapachone was due to the induction of apoptosis, which was confirmed by observing the morphological changes and cleavage of the poly(ADP-ribose) polymerase protein. A DNA flow cytometric analysis also revealed that $\beta$-lapachone arrested the cell cycle progression at the G1 phase. The effects were associated with the down-regulation of the phosphorylation of the retinoblastoma protein (pRB) as well as the enhanced binding of pRB and the transcription factor E2F-1. Also, $\beta$-lapachone suppressed the cyclindependent kinases (Cdks) and cyclin E-associated kinase activity without changing their expressions. Furthermore, this compound induced the levels of the Cdk inhibitor $p21^{WAF1/CIP1}$ expression in a p53-independent manner, and the p21 proteins that were induced by $\beta$-lapachone were associated with Cdk2. $\beta$-lapachone also activated the reporter construct of a p21 promoter. Overall, our results demonstrate a combined mechanism that involves the inhibition of pRB phosphorylation and induction of p21 as targets for $\beta$-lapachone. This may explain some of its anticancer effects.

• Journal of Food Hygiene and Safety
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• v.26 no.4
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• pp.398-402
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• 2011

Cruciferous vegetables including diindolylmethane (DIM) have been shown to have anticancer activity. Especially, DIM-pPhBr and DIM-pPhF used in this study was reported to have more effective and less toxic effects than DIM. However, there is no report presenting their anti-tumorigenic activity in oral cancer. In the present study, we examined the effects of DIM-pPhBr and DIM-pPhF on the cell proliferation and apoptosis in KB human oral cancer cells. DIM-pPhBr and DIM-pPhF decreased cell proliferation and induced apoptosis evidenced by western blot analysis, DAPI staining and sub-$G_1$ population. This provides the first evidence that DIM-pPhBr and DIM-pPhF originating from Cruciferous vegetables induce apoptotic cell death in human oral cancer cells to inhibit cancer cell proliferation.

• Journal of Life Science
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• v.19 no.2
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• pp.163-168
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• 2009

To understand cytotoxic activity of Rubia cordifolia L. (Rubiaceae), which has been used as a traditional oriental medicine, the mechanism underlying cytotoxic effect of its extract on human acute Jurkat T cells was investigated. The methanol extract of roots (3 kg) of R. codifolia was evaporated, dissolved in water, and then extracted by dichloromethane. The substances in the chloroform extract showing the most cytotoxic activity were further purified by a series of preparative HPLC. The extracted active substance (65 mg) was designated as CCH1. When Jurkat T cells were treated with CCH1 at concentration ranging from 0.5 to 2.0 ${\mu}g$/ml, apoptotic phenomena of cells companying several subsequent biochemical reactions such as mitochondria cytochrome c release, activation of casapase-8, -9, and caspase- 3, degradation of PARP and DNA fragmentation occurred via mitochondria-dependent pathway. However, abrogation of apoptosis was observed in an ectopic expression of Bcl-xL, which is a suppressor for mitochondrial cytochrome c release. These results demonstrate that the cytotoxicity of CCH1 against Jurkat T cells is attributable to apoptosis mediated by mitochodria-dependent death-signaling regulated by Bcl-xL. In addition, the CCH1 is more potent to leukemia Jurkat T cell than to human peripheral blood monocyte cells (PBMC).

• Journal of Ginseng Research
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• v.46 no.3
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• pp.396-407
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• 2022

Background: Colorectal cancer (CRC) has a high morbidity and mortality worldwide. 20 (S)-ginsenoside Rh2 (G-Rh2) is a natural compound extracted from ginseng, which exhibits anticancer effects in many cancer types. In this study, we demonstrated the effect and underlying molecular mechanism of G-Rh2 in CRC cells in vitro and in vivo. Methods: Cell proliferation, migration, invasion, apoptosis, cell cycle, and western blot assays were performed to evaluate the effect of G-Rh2 on CRC cells. In vitro pull-down assay was used to verify the interaction between G-Rh2 and Axl. Transfection and infection experiments were used to explore the function of Axl in CRC cells. CRC xenograft models were used to further investigate the effect of Axl knockdown and G-Rh2 on tumor growth in vivo. Results: G-Rh2 significantly inhibited proliferation, migration, and invasion, and induced apoptosis and G₀/G₁ phase cell cycle arrest in CRC cell lines. G-Rh2 directly binds to Axl and inhibits the Axl signaling pathway in CRC cells. Knockdown of Axl suppressed the growth, migration and invasion ability of CRC cells in vitro and xenograft tumor growth in vivo, whereas overexpression of Axl promoted the growth, migration, and invasion ability of CRC cells. Moreover, G-Rh2 significantly suppressed CRC xenograft tumor growth by inhibiting Axl signaling with no obvious toxicity to nude mice. Conclusion: Our results indicate that G-Rh2 exerts anticancer activity in vitro and in vivo by suppressing the Axl signaling pathway. G-Rh2 is a promising candidate for CRC prevention and treatment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.3
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• pp.338-346
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• 2015

This study was performed to elucidate the anti-proliferative and apoptotic mechanism of flavonoids in HT-29 human colon cancer cells. We investigated the anti-proliferative activity of flavonoids in HT-29 human colon cancer cells via cell viability assay (MTT assay), caspase-3 activity, RT-PCR, and western blotting. We cultured HT-29 cells in the presence of various flavonoids (apigenin, rutin, naringenin, and myricetin) at a concentration of $100{\mu}M$. In the MTT assay, naringenin showed the strongest effect on cell viability in HT-29 colon cancer cells. Caspase-3 activity, a marker of apoptosis, significantly increased upon naringenin treatment. For RT-PCR, myricetin significantly increased Bax protein levels, naringenin increased p53 protein levels, and rutin reduced expression of the anti-apoptotic protein Bcl-2. Western blotting of HT-29 colon cancer cells showed that myricetin increased cleaved caspase-3 protein levels, naringenin significantly increased poly (ADP-ribose) polymerase protein levels, and rutin increased E-cadherin protein levels. These results indicate that flavonoid exerts anticancer effects on human colon HT-29 cells through a caspase-dependent apoptotic pathway.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.409-412
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• 2013

Curcumin (Cum) has been reported to have potential chemo-preventive and chemotherapeutic activity through influencing various processes, inducing cell cycle arrest, differentiation and apoptosis in a series of cancers. However, the poor solubility of Cum limits its further applications in the treatment of cancer. We have previously reported Cum-loaded nanoparticles (Cum-NPs) prepared with amphilic methoxy poly(ethylene glycol)-polycaprolactone (mPEG-PCL) block copolymers. The current study demonstrated superior antitumor efficacy of Cum-NPs over free Cum in the treatment of lung cancer. In vivo evaluation further demonstrated superior anticancer effects of Cum-NPs by delaying tumor growth compared to free Cum in an established A549 transplanted mice model. Moreover, Cum-NPs showed little toxicity to normal tissues including bone marrow, liver and kidney at a therapeutic dose. These results suggest that Cum-NPs are effective to inhibit the growth of human lung cancer with little toxicity to normal tissues, and could provide a clinically useful therapeutic regimen. They thus merit more research to evaluate the feasibility of clinical application.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.10
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• pp.4755-4759
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• 2016

Introduction: Lung cancer is one of the most common cancers worldwide. In certain countries such as United States of America, it is the leading cause of related cancer mortality among both men and women. Natural products play an important role in overcoming the limitations of chemotherapy and radiotherapy. Objectives: In this study, we investigated the antiproliferative and apoptotic activities of Kanahia laniflora methanolic extract against human non-small cell lung cancer cells (A549). Methods: Sulforhodamine B colorimetric assays were used to determine the inhibitory effects of a leaf methanolic extract against A549 cells. Results: The extract showed strong cytotoxic activity against A549 cells with an $IC_{50}$ value of $0.13{\mu}g/ml$ compared to $0.21{\mu}g/ml$ for doxorubicin. The extract also significantly increased the percentage of apoptotic cells to 49.7% as compared to 1.4% and 47.4% for control and doxorubicin respectively. Conclusion: These results showed, for the first time, that a methanolic extract of Kanahia laniflora leaves can inhibit the proliferation of human non-small cell lung cancer cells (A549). Further attention to its potential as a new effective anticancer agent is warranted.

• Biomolecules & Therapeutics
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• v.17 no.1
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• pp.25-31
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• 2009

Clusterin is a heterodimeric sulfated glycoprotein and plays a role in many different types of cancer as a cell survival factor and helps cancerous cells to evade stress-induced apoptosis. To investigate whether the regulation of clusterin expression is involved in the mechanism of anticancer agent, we studied the effect of tamoxifen on clusterin expression in human prostate cancer PC-3 cells. Treatment of PC-3 cells with tamoxifen reduced cellular proliferation. Western blot analyses showed that treatment with tamoxifen suppressed clusterin expression in a concentration-dependent manner. Transfection with clusterin siRNA plasmid showed that clusterin is required for PC-3 cell survival. We found that tamoxifen resulted in a rapid decrease in the phosphorylation of Akt on Ser473 leading to prevent kinase activity. Expression of myristoylated Akt prevented tamoxifen-mediated clusterin downregulation. Interestingly, MG132, a wellknown proteasome inhibitor also recovered clusterin expression suppressed by tamoxifen. These data indicate that clusterin expression may be regulated by activation of Akt and ubiquitin-proteasome pathway plays an important role in tamoxifen-mediated clusterin suppression.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.785-791
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• 2014

Crude extracts or phytochemicals obtained from some plants have potential anti-cancer properties. Teucrium persicum is an Iranian endemic plant belonging to the Lamiaceae family which has traditionally been used to relieve abdominal pains. However, the anti-cancer properties of this species of the Teucrium genus have not been investigated previously. In this study, we have used a highly invasive prostate cancer cell line, PC-3, which is an appropriate cell system to study anti-tumor properties of plants. A methanolic extract obtained from T persicum potently inhibited viability of PC-3 cells. The viability of SW480 colon and T47D breast cancer cells was also significantly decreased in the presence of the T persicum extract. Flow cytometry suggested that the reduction of cell viability was due to induction of apoptosis. In addition, the results of wound healing and gelatin zymography experiments supported anti-cell invasion activity of T persicum. Interestingly, sublethal concentrations of T persicum extract induced an epithelial-like morphology in a subpopulation of cells with an increase in E-Cadherin and ${\beta}$-Catenin protein levels at the cell membrane. These results strongly suggest that T persicum is a plant with very potent anti-tumor activity.

• International Journal of Oral Biology
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• v.40 no.2
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• pp.63-69
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• 2015

Curcumin (diferuloylmethane), a constituent of turmeric powder derived from the rhizome of Curcuma longa, has been shown to inhibit the growth of various types of cancer cells by regulating cell proliferation and apoptosis. However, a need exists to design more effective analogs because of curcumin's poor intestinal absorption. EF-24 (diphenyl difluoroketone), the monoketone analog of curcumin, has shown good efficacy in anticancer screens. However, the effects of curcumin and EF-24 on salivary gland epidermoid carcinoma cells are not clearly established. The main goal of this study was to investigate the effects of curcumin and EF-24 on cell growth and induction of apoptosis in human salivary gland epidermoid carcinoma cells. Our studies showed that curcumin and EF-24 inhibited the growth of HTB-41 cells in a dose- and time-dependent manner, and the potency of EF-24 was > 34-fold that of curcumin. Treatment with curcumin or EF-24 resulted in nuclear condensation and fragmentation in HTB-41 cells, whereas the control HTB-41 cell nuclei retained their normal regular and oval shape. Curcumin and EF-24 promoted proteolytic cleavages of procaspase-3/-7/-9, resulting in an increase in the amount of cleaved caspase-3/-7/-9 in the HTB-41 cells. Caspase-3 and -7 activities were detected in viable HTB-41 cells treated with curcumin or EF-24. These results suggest that the curcumin and EF-24 inhibit cell proliferation and induce apoptosis in HTB-41 human salivary gland epidermoid carcinoma cells, and that they may have potential properties as an anti-cancer drug therapy.