• Microbiology and Biotechnology Letters
• /
• 제50권3호
• /
• pp.387-394
• /
• 2022

Verotoxin-1 (VT-1) or Shiga-like toxin 1 (Stx-1) is produced by enterohemorrhagic Escherichia coli (EHEC) and is an AB5 holotoxin with a strong inhibitor of protein synthesis. VT-1 is a type 2 ribosome-inactivating protein (RIP) that has been shown to have cytotoxic and anticancer potential by inducing necrosis, apoptosis, and cell cycle arrest, making it a promising antitumor candidate. Here, we tested the cytotoxicity of VT-1 on CaCo2 and NCM425 cell lines and the results showed that VT-1 was more potent on CaCo2. Morphological changes were also evaluated on the cellular level and the results showed that VT-1 caused a decrease in viable cell count, altered cell membrane permeability, and an increase in total nuclear intensity. On the other hand, VT-1 displayed a lesser impact on mitochondrial membrane potential (MMP) and cytochrome c release. On the expression of caspases 3 and 9, VT-1 exhibited an insignificant effect on both which alongside the mitochondrial membrane potential (MMP) and cytochrome c results, might indicate that CaCo2 suffered from the necrosis process as a mechanism of cell death after exposure to VT-1.

• 한국약용작물학회:학술대회논문집
• /
• 한국약용작물학회 2011년도 춘계학술발표회
• /
• pp.316-317
• /
• 2011

• Proceedings of the Zoological Society Korea Conference
• /
• 한국동물학회 2003년도 한국생물과학협회 학술발표대회
• /
• pp.213.2-213
• /
• 2003

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
• /
• 한국동물학회 1999년도 한국생물과학협회 학술발표대회
• /
• pp.254.2-254
• /
• 1999

No Abstract, See Full Text

• Proceedings of the PSK Conference
• /
• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
• /
• pp.256.3-257
• /
• 2003

The bioactivity-guided fractionation of an active methylene chloride extract of the sclerotium of Poria cocos led to the isolation of compounds 1-5. These compounds were tested in the human colon carcinoma and human breast carcinoma cell lines, compounds 3, 4, and 5 exhibited IC50 values of 10.8, 15.4, and 5.1 $\mu\textrm{g}$/$m\ell$ against human colon carcinoma cell line. In addition, compounds 3, 4 and 5 showed moderate activities as inhibitors of Topoisomerase I and all compounds were inactive in the Topoisomerase II inhibition.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권12호
• /
• pp.6017-6022
• /
• 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.

• Biomolecules & Therapeutics
• /
• 제30권2호
• /
• pp.137-144
• /
• 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.

• The Journal of Internal Korean Medicine
• /
• 제31권2호
• /
• pp.273-289
• /
• 2010

Objectives : To investigate the anti-cancer effect of Baekduong-tang(BDOT) against cancer cells, the signaling pathway of apoptosis was explored in human colon cancer cells. Materials and Methods : Human colon cancer cell lines, including HT-29 and HCT-116 cells, were used. Cell viability was measured by MTT assay. Apoptosis was determined by DAPI nuclei staining and flow cytometry in HCT-116 cells treated with 0.25 mg/$m{\ell}$ Baekduong-tang for 48 hrs. Results : Baekduong-tang induced the apoptosis of p53 positive HCT-116 cells with G2/M phase arrest. Treatment with Baekduong-tang led to increased expression and phosphorylation of p53 and decreased expression of CDK2 and CDK6 in HCT-116 cells. It also activated caspase-3 through caspase-10 and caspase-9 activation. Finally, Baekduong-tang induced production $H_2O_2$, superoxide anion ($O_2^-$) and NO and modulated proteins expression including SOD, NOS, Bax and Bcl-2. Conclusions : These results indicate Baekduong-tang induces apoptotic death of HCT-116 cells through G2/M phase arrest and disturbance of intracellular redox status in a p53-dependent manner.

• Korean Journal of Medicinal Crop Science
• /
• 제15권5호
• /
• pp.329-334
• /
• 2007

The potential antioxidant and anticancer activities of Hexane, EtOAc (Ethyl acetate), BuOH (n-Buthanol) and water fractions from methanolic (MeOH) extract of Picrasma quassioides (D. Don) Benn. were evaluated in vitro. Tested fractions showed strong antioxidant activity, especially EtOAc fraction had the highest activity ($IC_{50}\;=\;114.01\;{\mu}g/mL$), containing high total phenolics and total flavonoids contents, showed $67.59\;Tan\;{\mu}g/mg$ and $64.95\;Que\;{\mu}g/mg$ respectively. Anticancer activity of these fractions was tested by MTT assay on HT-29 (the human colon carcinoma cells) cell line. BuOH fraction not only showed very high anticancer activity, but also had no cytotoxic effect on 293 (the human normal kidney cells) cell line. Considering these results, we used BuOH fraction of MeOH crude extract from P. quassioides (D.Don) Benn. to do assessment of apoptosis by flow cytometry and the mRNA expression levels of widely established apoptotic-related genes on HT-29 cell line. All the experiments showed that BuOH fraction can induce apoptosis on HT-29 cell line strongly. Taken together, methanolic extract of P. quassioides has potential for antioxidant and anticancer activities products.

• Journal of Nutrition and Health
• /
• 제34권2호
• /
• pp.150-157
• /
• 2001

Intestinal absorption of dietary taurine is one of the regulatory component maintaining taurine homeostasis along with renal reabsorption, bile acid conjugation and secretion, and de nobo synthesis of taurine in mammals. Recent observations of decreased enterocytic levels of taurine in response to trauma, infection and surgical insults, postulate the possibility that intestinal taurine absorption might be impaired in such stressed conditions. The aim of the present study was to evaluate changes in enterocytic taurine transporter activity using the human intestinal colon carcinoma cell line, HT-29, in various stress-induced conditions. Pretreatment of the HT-29 cells with dexamethasone, a stress hormone(0.1,1,10 or 100$\mu$M) for 3 hrs, or with E coli heat-stable enterotoxin(10, 100, or 200nM) for 30 minutes in order to induce the condition of enterotoxigenic infection did not influence taurine uptake as compared to the value found in control cells. In contrast, pretreatment of the cells with cholera toxin(10, 100, 500, or 1000ng/ml)for 3hr or 24hr significantly decreased taurine uptake by HT-29 cells to 40~50% of the value found in untreated control cells. Kinetic studies of the taurine transporter activity were conducted in control and cholera toxin treated HT-29 cells with varying taurine concentrations(2~60$\mu$M) in the uptake medium. Pretreatment of the cells with cholera toxin(100ng/ml) for 3hr did not influence the Vmax, but resulted in a 55% increase in the Michaelis-Menten constant(Km) of the taurine transporter compared to those in control cells. These results suggest that cholera toxin-induced reduction in taurine transporter activity in HT-29 cells is associated with decreased affinity of the taurine transporter without altering the amount of transporter protein. Intestinal taurine absorption appears to be reduced in the condition of water-borne diseases caused by bacteria such as V. cholerae. This might influence the taurine status of infants and young children more readily, an age group in which the prevalence of intestinal infection is high and the role of intestinal absorption is crucial for maintaining the body taurine pool. (Korean J Nutrition 34(2) : 150-157, 2001)