• The Korean Journal of Physiology and Pharmacology
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• v.13 no.4
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• pp.309-313
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• 2009

Spontaneous hypertensive rats (SHR) are an established model of genetic hypertension. Vascular smooth muscle cells (VSMC) from SHR proliferate faster than those of control rats (Wistar-Kyoto rats; WKY). We tested the hypothesis that induction of heme oxygenase (HO)-1 induced by aprotinin inhibits VSMC proliferation through cell cycle arrest in hypertensive rats. Aprotinin treatment inhibited VSMC proliferation in SHR more than in normotensive rats. These inhibitory effects were associated with cell cycle arrest in the G1 phase. Tin protoporphyrin IX (SnPPIX) reversed the anti-proliferative effect of aprotinin in VSMC from SHR. The level of cyclin D was higher in VSMC of SHR than those of WKY. Aprotinin treatment downregulated the cell cycle regulator, cyclin D, but upregulated the cyclin-dependent kinase inhibitor, p21, in VSMC of SHR. Aprotinin induced HO-1 in VSMC of SHR, but not in those of control rats. Furthermore, aprotinin-induced HO-1 inhibited VSMC proliferation of SHR. Consistently, VSMC proliferation in SHR was significantly inhibited by transfection with the HO-1 gene. These results indicate that induction of HO-1 by aprotinin inhibits VSMC proliferation through cell cycle arrest in hypertensive rats.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.4
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• pp.241-244
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• 2011

A lectin from the hemolymph of purse crab, Philyra pisum, was found to have anti-proliferative activity on human lung cancer cells by our laboratory. In this study, P. pisum lectin (PPL) was molecularly characterized including molecular mass, amino acid sequences, amino acid composition, and the effects of metal ions, temperature, and pH on the activity. We found that PPL showed mitogenic activity on human lymphocytes and BALB/c mouse splenocytes. The mitogenic activity (maximum stimulation index, $SI=9.57{\pm}0.59$) of PPL on human lymphocytes was higher than that of a standard well-known plant mitogen, concanavalin A (maximum $SI=8.80{\pm}0.59$). The mitogenic activity mediated by PPL is required for optimum dosing, and higher or lower concentrations caused decreases in mitogenic response. PPL also induced mitogenic activity on mouse splenocytes, however, the maximum SI ($1.77{\pm}0.09$) on mouse splenocytes of PPL was lower than that ($2.14{\pm}0.15$) of concanavalin A. In conclusion, PPL is a metal ion-dependent monomer lectin with mitogenic activity, and could be used as a lymphocyte or splenocyte stimulator.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.244.2-245
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• 2002

4-Hydroxy nonenal (HNE) is a lipid peroxidation product derived from oxidized $\omega$-6 polyunsaturated fatty acids, such as arachidonic acid. HNE is widely used as a marker of lipid peroxidation. To study the hypothesis that HNE may induce apoptosis and cell cycle arrest, we estimated cytotoxicity of HNE in BAE (bovine aortic endothelial) cells. Anti-proliferative effects were examined by morphological changes and MTT assay after exposure to different time (0-3 hr) and concentration (3-7 ${\mu}$M of HNE. (omitted)

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.12
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• pp.5185-5188
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• 2016

Objective: Targeted-drug-delivery based lipid nanoparticles has emerged as a new and effective approach in cancer chemotherapy. Here, we investigated the ability of folate-modified nanostructured lipid carriers (NLCs) to enhance letrozol (LTZ) efficacy in MCF-7 breast cancer cells. Methods: New formulations were evaluated regarding to particle size and scanning electron microscope (SEM) features. Anti-proliferative effects of LTZ loaded nanoparticles were examined by MTT assay. To understand molecular mechanisms of apoptosis and cell cycle progression, flow cytometric assays were applied. Results: Optimum size of nanoparticles was obtained in mean average of $98{\pm}7nm$ with a poly dispersity index (PDI) of 0.165. The IC50 value was achieved for LTZ was $2.2{\pm}0.2{\mu}M$. Folate-NLC-LTZ increased the percentage of apoptotic cells from 24.6% to 42.2% compared LTZ alone (p<0.05). Furthermore, LTZ loaded folate targeted NLCs caused marked accumulation of cells in the subG1 phase. Conclusion: Taken together, our results concluded that folate targeted LTZ can be considered as potential delivery system which may overcome limitations of clinical application of LTZ and improve drug efficacy in tumor tissue.

• Biomolecules & Therapeutics
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• v.29 no.5
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• pp.562-570
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• 2021

Topoisomerase IIα has been a representative anti-cancer target for decades thanks to its functional necessity in highly proliferative cancer cells. As type of topoisomerase IIα targeting drugs, topoisomerase II poisons are frequently in clinical usage. However, topoisomerase II poisons result in crucial consequences resulted from mechanistically induced DNA toxicity. For this reason, it is needed to develop catalytic inhibitors of topoisomerase IIα through the alternative mechanism of enzymatic regulation. As a catalytic inhibitor of topoisomerase IIα, AK-I-191 was previously reported for its enzyme inhibitory activity. In this study, we clarified the mechanism of AK-I-191 and conducted various types of spectroscopic and biological evaluations for deeper understanding of its mechanism of action. Conclusively, AK-I-191 represented potent topoisomerase IIα inhibitory activity through binding to minor groove of DNA double helix and showed synergistic effects with tamoxifen in antiproliferative activity.

• Biomolecules & Therapeutics
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• v.30 no.2
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• pp.137-144
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• 2022

Radiation resistance represents an imperative obstacle in the treatment of patients with colorectal cancer, which remains difficult to overcome. Here, we explored the anti-proliferative and migration-inhibiting properties of the natural product shikonin on a radiation-resistant human colon carcinoma cell line (SNU-C5RR). Shikonin reduced the viability of these cells in a dose-dependent manner; 38 µM of shikonin was determined as the half-maximal inhibitory concentration. Shikonin induced apoptotic cell death, as demonstrated by increased apoptotic body formation and the number of TUNEL-positive cells. Moreover, shikonin enhanced mitochondrial membrane depolarization and Bax expression and also decreased Bcl-2 expression with translocation of cytochrome c from mitochondria into the cytosol. In addition, shikonin activated mitogen-activated protein kinases, and their specific inhibitors reduced the cytotoxic effects of shikonin. Additionally, shikonin decreased the migration of SNU-C5RR cells via the upregulation of E-cadherin and downregulation of N-cadherin. Taken together, these results suggest that shikonin induces mitochondria-mediated apoptosis and attenuates epithelial-mesenchymal transition in SNU-C5RR cells.

• Journal of Life Science
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• v.19 no.4
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• pp.502-507
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• 2009

In modern oriental medicine, bee venom therapy is being used for aqua-acupuncture to relieve pain and to cure inflammatory diseases such as rheumatoid arthritis, osteoarthritis, and gout. Bee venom therapy has been processed and reported in many experimental studies, with regard to its effects on pain alleviation, anti-inflammation, removal of fever, anti-convulsion, suppression of tumor and immunity strengthening, etc., however, its mechanism of action, molecular targeting on prostaglandin $E_2$ ($PGE_2$) production and telomere length regulation in human cancer remains unclear. In this study, we investigated the effect of bee venom on the levels of cyclooxygenases (COXs) and telomere regulatory components of A549 human lung cancer cells. Bee venom-induced anti-proliferative effects of A549 cells were associated with the inhibition of human telomerase reverse transcriptase (hTERT) as well as human telomerase RNA (hTR), transcription factor c-myc and the activity of telomerase. In addition, bee venom treatment markedly decreased the levels of COX-2 mRNA and protein expression without significant changes in the expression of COX-1, which was correlated with a decrease in $PGE_2$ synthesis. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of bee venom.

• Journal of Life Science
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• v.14 no.5
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• pp.800-808
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• 2004

Resveratrol, a phytoalexin found at high levels in grapes and in grape products such as red wine, has been reported to possess a wide range of biological and pharmacological activities including antioxident, anti-inflammatory, anti-mutagenic, and anti-carcinogenic effects. According to recent studies, this compound is an effective inhibitor of cell growth in general, triggers partial arrest of the cell cycle and induce apoptosis. In this study, the anti-proliferative effects of resveratrol in A549 human lung carcinoma cells were investigated. It is shown that resveratrol induced the growth inhibition in a time-dependent manner and morphological changes of A549 cells, which were associated with induction of S phase arrest of the cell cycle and apoptotic cell death. The Bcl-$X_L$levels were markedly down-regulated in resveratrol treated cells, however, Bax and Bcl-2 were remained unchanged. Resveratrol treatment induced the proteolytic degradation of Sp-l and proliferating cell nuclear antigen protein, and inhibited the expression of $\beta$-catenin protein. Resveratrol treatment also induced a marked up-regulation of cyclin-dependent kinase (Cdk) inhibitor p21 and inhibited the kinase activities of Cdk2 and Cdk4. In addition, resveratrol treatment inhibited the levels of cyclooxygenase (COX)-2 mRNA and protein, and the release of prostagladin E2 without alteration of COX-1 expression. Taken together, these findings suggest that resveratrol may be a potential chemotherapeutic agent for the control of human lung carcinorma cells.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6047-6053
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• 2012

Bracken fern [Pteridium aquilinem (L.) kuhn (Dennstaedtiaceae)] is one of the most common species on the planet. It has been consumed by humans and animals for centuries. Use by some human groups is because they believe bracken fern is good for health as plant medicine. However, it is also one of the few known plants that can cause tumors in farm animals. Many interested groups have focused their attention on bracken fern because of these interesting features. In order to evaluate the biological effects of exposure to this plant in cellular level, human cancer cell lines were treated with the fern dichloromethane extracts and the genotoxic and cytotoxic effects were studied. Anti-proliferative/cytotoxic effects were evaluated by cell count, MTT assay and flow cytometry methods with three different cancer cell lines, TCC, NTERA2, and MCF-7, and two normal cells, HDF1 and HFF3. Pro-apoptotic effects of the extracts were determined by DAPI staining and comet assay, on TCC cancer cells compared to the normal control cell lines. Cellular morphology was examined by light microscopy. Our present study showed that the extract caused DNA damage and apoptosis at high concentrations ($200{\mu}g/mL$) and also it may induce cell cycle arrest (G2/M phase) at mild concentrations (50 and $30{\mu}g/mL$) depending on the cell type and tumor origin. These results indicate that bracken fern extract is a potent source of anticancer compounds that could be utilized pharmaceutically.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6017-6022
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• 2012

Background: Resveratrol has been reported to have potential chemopreventive and apoptosis-inducing properties in a variety of tumor cell lines. Objective: In this study, to investigate the effects of resveratrol on protein kinase C (PKC) activity and apoptosis in human colon carcinoma cells, we used HT-29 cells and examined the $PKC{\alpha}$ and ERK1/2 signaling pathways. Methods: To test the effects of resveratrol on the growth of HT-29 cells, the cells were exposed to varying concentrations and assessed with the the MTT cell-viability assay. Fluorescence-activated cell sorter (FACS) analysis was applieded to determine the effects of resveratrol on cell apoptosis. Western blotting was performed to determine the protein levels of $PKC{\alpha}$ and ERK1/2. In inhibition experiments, HT-29 cells were treated with G$\ddot{o}$6976 or PD98059 for 30 min, followed by exposure to $200{\mu}M$ resveratrol for 72 h. Results: Resveratrol had a significant inhibitory effect on HT-29 cell growth. FACS revealed that resveratrol induced apoptosis. Western blotting showed that e phosphorylation of $PKC{\alpha}$ and ERK1/2 was significantly increased in response to resveratrol treatment. Pre-treatment with $PKC{\alpha}$ and ERK1/2 inhibitors (G$\ddot{o}$6976 and PD98059) promoted apoptosis. Conclusion: Resveratrol has significant anti-proliferative effects on the colon cancer cell line HT-29. The PKC-ERK1/2 signaling pathway can partially mediate resveratrol-induced apoptosis of HT-29 cells.