• Parasites, Hosts and Diseases
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• 제51권1호
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• pp.61-68
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• 2013

Entamoeba histolytica, which causes amoebic colitis and occasionally liver abscess in humans, is able to induce host cell death. However, signaling mechanisms of colon cell death induced by E. histolytica are not fully elucidated. In this study, we investigated the signaling role of NOX in cell death of HT29 colonic epithelial cells induced by E. histolytica. Incubation of HT29 cells with amoebic trophozoites resulted in DNA fragmentation that is a hallmark of apoptotic cell death. In addition, E. histolytica generate intracellular reactive oxygen species (ROS) in a contact-dependent manner. Inhibition of intracellular ROS level with treatment with DPI, an inhibitor of NADPH oxidases (NOXs), decreased Entamoebainduced ROS generation and cell death in HT29 cells. However, pan-caspase inhibitor did not affect E. histolytica-induced HT29 cell death. In HT29 cells, catalytic subunit NOX1 and regulatory subunit Rac1 for NOX1 activation were highly expressed. We next investigated whether NADPH oxidase 1 (NOX1)-derived ROS is closely associated with HT29 cell death induced by E. histolytica. Suppression of Rac1 by siRNA significantly inhibited Entamoeba-induced cell death. Moreover, knockdown of NOX1 by siRNA, effectively inhibited E. histolytica-triggered DNA fragmentation in HT29 cells. These results suggest that NOX1-derived ROS is required for apoptotic cell death in HT29 colon epithelial cells induced by E. histolytica.

• 동국한의학연구소논문집
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• 제11권
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• pp.52-57
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• 2008

Objectives. In this study, we investigate that methanol extract of Euphorbiae lathyridis Semen contributes to growth inhibitory effect on the HT-29 human colon cancer cells. Methods. Euphorbiae lathyridis Semen (ELS) was extracted with 80% methanol. HT-29 cells were treated with different concentrations of ELS extract for 24-72 hrs. Growth inhibitory effect was determined by MTT assay. Cell apoptosis was determined by surveying caspases cascades activation using Western blot. Cell cycle arrest was analyzed by flow cytometry with PI staining. Results. Exposure to ELS extract showed in inhibitory effects on HT-29 cell growth as a dose-dependent manner. Cell growth inhibition by ELS extract was related with induction of cell apoptosis with DNA fragmentation through the activation of caspases-3, caspase-9 and PARP cleavage. Conclusion. ELS extract significantly inhibited cell growth and induced cell apoptosis in HT-29 human colon cancer cells, therefore, These results suggest that ELS extract can be used as chemoprevention agent of colon cancers.

• Journal of Nutrition and Health
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• 제33권1호
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• pp.80-85
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• 2000

This study was undertaken to investigate the inhibitory effects of propolis on the in vitro proliferation of human colon(HT-29) and hepatoma(HepG2) cancer cell lines. The growth of the HT-29 and HepG2 cells was respectively inhibited by the administration of propolis in a concentration response-dependent manner. The distributions of HT-29 and HepG2 cells cultured in the medium containing propolis were shifted to the smaller sizes, and then HT-29 and HepG2 cells were shrunken under microscopic observations. The progression of cell cycle from G1 to S phase was significantly inhibited by propolis in the HT-29 and HepG2 cell lines, respectively. Those observations suggest that propolis has anticancer effect against some of cancer cell lines in vitro. (Korean J Nutrition 33(1) : 80-85, 2000)

• Food Science and Biotechnology
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• 제14권6호
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• pp.866-870
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• 2005

The 14 lactic acid bacteria (LAB) have been evaluated to determine the binding capacity to HT29 cell and Aflatoxin $B_1$ ($AFB_1$). The interaction of LAB to HT29 cells has been further investigated to identify the possibility of competing the binding sites with $AFB_1$. Of 14 LAB strains, Lactobacillus casei KCTC 3260 demonstrated the higher adhesiveness to HT29 and $AFB_1$ with the rate of 19.6% and 46.3%, respectively. In competitive analysis for binding sites, the adhesion of L. casei KCTC 3260 to HT29 cells was reduced with 100 nmol $AFB_1$ by 31.2%. The protoplast of L. casei KCTC 3260 showed no binding capacity to HT29 cells with increment of $AFB_1$ concentration, indicating that cell wall components might serve as a critical factor for the binding. To discriminate the major component influencing on L. casei KCTC 3260 binding to HT29 cells and $AFB_1$, four different pre-treatments (lipase, pronase E, sodium m-periodate, and urea) were employed. Of those, sodium m-periodate treatment caused the lower adhesion of L. casei KCTC 3260 to HT29 cells with the increment of $AFB_1$ concentration. These results indicated that carbohydrate moiety on the cell wall of L. casei KCTC 3260 might be the most critical component in binding to both HT29 cells and $AFB_1$.

• 생약학회지
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• 제42권3호
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• pp.282-287
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• 2011

This study was presented to the anti-cancer activity from different fraction of Zanthoxylum schnifolium fruits. The values for human colon cancer cell(HT-29) survival rate of 0.3 mg/mL of 70% EtOH and 70% MeOH ethyl acetate fraction extracts were 7.62${\pm}$0.173%, 7.66${\pm}$0.037%, respectively. It was shown that human colon cancer cell(HT-29) survival rate was in a dose-dependent manner. The percentages of cells were increased in the sub-G0 and G0/G1 phase region, meaning that cell proliferation was decreased. The RT-PCR demonstrated that 70% EtOH and 70% MeOH ethyl acetate fraction extracts were down-regulated the expression of Bcl-2 and survivin genes in HT-29 cells. We examined that 70% EtOH and 70% MeOH ethyl acetate fraction extracts anti-cancer activities initiated through ROS generation suggesting that HT-29 cells treated with ethyl acetate fraction extracts induced ROS generation. Our results revealed that the Zanthoxylum schnifolium fruit may expect for anti-cancer activities in HT-29 cells.

• 대한본초학회지
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• 제22권2호
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• pp.65-72
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• 2007

Objectives : In this study, we investigate that Euphorbiae lathyridis Semen extract contributes to growth inhibitory effect and anti-cancer activity on the HT-29 human colon cancer cells. Methods : Euphorbiae lathyridis Semen was extracted from the Semen of the plant using 80% Methanol. The Euphorbiae lathyridis Semen extract was treated to different concentrations for 24 hr, 4Shr or 72hr. Growth inhibitory effect was analyzed by measuring FACS study and MTT assay. Cell apoptosis was confirmed by surveying caspases cascades activation using Westem blot. Results : Exposure to Euphorbiae lathyridis Semen extract (0.4mg/ml) results in an inhibitory effect on cell growth in HT-29 cells. Growth inhibition by Euphorbiae lathyridis Semen extract in HT-29 cells was related with the inhibition of proliferation and induction of apoptosis. The Euphorbiae lathyridis Semen extract induces DNA fragmentation in HT-29 cells. Furthermore, Euphorbiae lathyridis Semen extract induces cell apoptosis through the activation of caspases-3, caspase-9 and PARP cleavage. Conclusion : Euphorbiae lathyridis Semen extract induces apoptosis in human colon cancer cells, therefore, we suggest that Euphorbiae lathyridis Semen extract can be used as a novel class of anti-cancer drugs.

• Journal of Nutrition and Health
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• 제41권1호
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• pp.13-21
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• 2008

본 실험은 인돌의 인체 대장암세포의 경과 및 전이억제와 TJ 활성 조절에 미치는 영향을 알아보기 위해 실험하였다. 인돌은 십자화 야채류인 양배추, 컬리플라워, 브로클리 등에 존재하는 glucosinolate, glucobrassicin의 대사산물 이다. 본 연구의 결과는 인돌이 대장암 세포 HT-29에서 농도 의존적으로 세포증식 저해를 나타내었다. 상처회복 실험을 통한 세포이동성과 세포 침윤성 실험결과 인돌이 암세포의 이동과 침윤성을 억제하였고 투과성상피세포의 전기적 저항성 측정치는 인돌 처리 세포에서 증가하였다. HT-29 세포에서 과발현을 나타내는 밀착결합 단백질인 claudin-1, claudin-5 발현은 인돌 처리로 유전자의 전사수준과 단백질 수준에서 유의적인 감소를 나타내었다. 이상의 결과에서 인돌이 HT-29 세포의 밀착결합과 그 구성 단백질 중 claudin 발현 현상을 회복시키므로 암 경과와 전이 억제를 나타내었다. 결론적으로, 천연 항암화합물인 인돌은 대장암 세포 HT-29에서 밀착결합 단백질인 claudin-1, -5을 억제하여 밀착결합을 활성화하므로 암 진행과 전이를 억제할 수 있는 인돌에 의한 새로운 기전을 보고합니다.

• Journal of Nutrition and Health
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• 제33권6호
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• pp.660-667
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• 2000

Previous studies on the effect of age on intestinal taurine transport in animals have invariably shown a decline in the activity of the transport system with increasing age. In the present study changes in taurine transporter activity were observed during cell differentiation in the human colon carcinoma cell line HT-29 This cell line exhibits various enterocytic characteristics when differentiated and therefore has frequently been used to study the characteristcs and regulation of nutrient and drug absorption in the small intestine at the cellular level. Pre-treatment of the cells with $\beta$-alanine(10mM) reduced the taurine transport activity to 33% of the value for the control cells(p<0.05) which implies that taurine and $\beta$-alanine share a common $\beta$-amino acid transport system for their celluar uptake in the HI-29 was continued until 21 days post seeding. Kinetic studies of the taurine transporter were conducted in the HT-29 cell line with varying taurine concentration(5-60$\mu$M) in the uptake medium Both Vmax and the Michaelis-Menten constant(Km) of taurine transporter were decreased as differentiation of the HT-29 cell line was progressed ; Vmax of the taurine transporter in cells incubated for 4, 14 and 21 days post seeding was 2.79$\pm$3.4m 16.89$\pm$1.74, and 0.85$\pm$0.08 and 0.32$\pm$0.01nmol.mg protein-1 .30min-1 respectively(p<0.001) and Km was 42.3$\pm$3.4, 16.89$\pm$1.74, and 11.2$\pm$3.0$\mu$M respectively (p<0.01) These results indicate that the activity of sodium dependent active taurine transport system in the HT-29 cell line is decreased as confluent cells are differentiated. This phenomenon in cell culture system corresponds well with the earlier observation of lower intestinal taurine transport activity in suckling rats compared to that in adult animals although direct relationship of cell differentiation with in vivo aging process needs further verification.

• Asian Pacific Journal of Cancer Prevention
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• 제15권4호
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• pp.1871-1877
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• 2014

Enhancing of radioresponsiveness of tumors by using radiosensitizers is a promising approach to increase the efficacy of radiation therapy. Recently, the ethanolic extract of the medicinal plant, Derris scandens Benth has been identified as a potent radiosensitizer of human colon cancer HT29 cells. However, cell death mechanisms underlying radiosensitization activity of D scandens extract have not been identified. Here, we show that treatment of HT-29 cells with D scandens extract in combination with gamma irradiation synergistically sensitizes HT-29 cells to cell lethality by apoptosis and mitotic catastrophe. Furthermore, the extract was found to decrease Erk1/2 activation. These findings suggest that D scandens extract mediates radiosensitization via at least two distinct modes of cell death and silences pro-survival signaling in HT-29 cells.

• 대한본초학회지
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• 제21권4호
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• pp.51-58
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• 2006

Objectives : In this study, we investigate that Ulmi cortex extract contributes to growth inhibitory effect and anti-cancer activity on the HT-29 human colon cancer cells. Methods : Ulmi cortex was extracted from the leaves of the plant using water. The Ulmi cortex extract was treated to different concentrations for 24 hr. Growth inhibitory effect was analyzed by measuring FACS study and MTT assay. Cell cycle inhibition was confirmed by kinases assay. Cell apoptosis was confirmed by surveying caspases cascades activation using Western blot. Results : Exposure to Ulmi cortex extract (0.4mg/ml) results in an inhibitory effect on cell growth in HT-29 cells. Growth inhibition by Ulmi cortex extract in HT-29 cells was related with the inhibition of proliferation and induction of apoptosis. The Ulmi cortex extract induces G1-cell cycle arrest and DNA fragmentation in HT-29 cells. Furthermore, Ulmi cortex extract induces cell apoptosis through the activation of caspases-3 and PARP cleavage. Conclusion : Ulmi cortex extract induces apoptosis in human colon cancer cells, therefore, we suggest that Ulmi cortex extract can be used as a novel class of anti-cancer drugs.