• 한국지역사회생활과학회지
• /
• 제26권2호
• /
• pp.405-414
• /
• 2015

This study examines the effects of purple Kohlrabi fresh and peel ethanol extracts on the antioxidative activity and antiproliferation of human cancer cells (Hep G2 human liver, HCT-116 human colon, and A549 human lung cancer cells.) The total flavonoid and anthocyanin content of purple Kohlrabi ethanol extracts were much greater in the peel than in the flesh. The DPPH radical scavenging activity and antioxidative index of purple Kohlrabi peel extracts were similar to those of the BHA and the BHT. Antiproliferation effects of purple Kohlrabi peel extracts on human cancer cells (Hep G2, HCT-116, and A549) strengthened in a dose-dependent manner. In particular, the antiproliferation activity of purple Kohlrabi peel extracts exceeded 40% in colon cancer cells. These results indicate that the purple Kohlrabi peel may contain bioactive compounds such as flavonoids as well as anthocyanin and that these compounds may facilitate cancer prevention.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권4호
• /
• pp.2201-2205
• /
• 2013

Colorectal cancer (CRC) is one of the most common cancers in many parts of the world. Its development is a multi-step process involving three distinct stages, initiation that alters the molecular message of a normal cell, followed by promotion and progression that ultimately generates a phenotypically altered transformed malignant cell. Reports have suggested an association of the phosphoinositide-3-kinase (PI3K)/Akt pathway with colon tumorigenesis. Activation of Akt signaling and impaired expression of phosphatase and tensin homolog (PTEN) (a negative regulator of Akt) has been reported in 60-70% of human colon cancers and inhibitors of PI3K/Akt signaling have been suggested as potential therapeutic agents. Around 80% of human colon tumors possess mutations in the APC gene and half of the remainder feature ${\beta}$-catenin gene mutations which affect downstream signaling of the PI3K/Akt pathway. In recent years, there has been a great focus in targeting these signaling pathways, with natural and synthetic drugs reducing the tumor burden in different experiment models. In this review we survey the role of PI3K/Akt/mTOR and Wnt signaling in CRC.

• BMB Reports
• /
• 제44권3호
• /
• pp.211-216
• /
• 2011

Vitamin C (VC) is an important antioxidant and enzyme co-factor that works by stimulating the immune system and protecting against infections. It is well known that melanoma cells are more susceptible to VC than any other tumor cells. However, the role of VC in the treatment of colon cancer has not been studied. Cisplatin (CDDP) is a DNA damaging agent and is widely used for treating cancer, while the role of p53 in CDDP-induced cell death has been stressed. Using cell growth assays, morphological methods, Western blotting, flow cytometry, and DNA fragmentation analysis, we measured the expression of p53 level involved in the effect of VC on CDDP-induced apoptosis of HCT116, a human colon cancer cell line. CDDP plus VC treatment resulted in significantly increased apoptosis along with upregulation of p53 compared to untreated cells and/or CDDP-treated cells. These results suggest that VC enhanced CDDP sensitivity and apoptosis via upregulation of p53.

• 한국식품영양과학회지
• /
• 제44권3호
• /
• pp.338-346
• /
• 2015

본 연구에서는 최근 식생활의 서구화로 인해 발병률이 급증하고 있는 대장암의 진행을 억제하거나 감소시키고 인체 대장암 세포인 HT-29의 증식을 억제하며, 세포사멸을 유도하는 천연소재를 알아보기 위해서 flavonoid가 HT-29 인체 대장암 세포의 apoptosis 유도 및 기전에 미치는 영향을 알아보았다. MTT assay 결과 apigenin, rutin, naringenin, myricetin을 $100{\mu}M$ 농도로 처리하였을 때 62.71, 75.78, 74.24, 77.61%로 이 중 naringenin이 대장암 세포 성장에 억제 효과가 가장 높은 실험 결과를 나타내었다. Caspase-3 activity에서는 naringenin이 241.46%로 가장 높은 활성을 나타내었다. 이를 바탕으로 세포사멸과 관련된 유전자를 확인하고자 대장암 세포에 flavonoid인 apigenin, rutin, naringenin, myricetin에 $100{\mu}M$ 농도로 처리한 후 RTPCR을 실시한 결과, 세포사멸의 주요한 조절인자인 Bcl-2 family 단백질 중 Bcl-2는 rutin에 의해 감소되었고 Bax는 myricetin에 의해 증가하였으며, p53은 naringenin이 높게 발현되었다. 또한 western blotting을 통해 flavonoid인 apigenin, rutin, naringenin, myricetin에 $100{\mu}M$ 농도로 처리한 결과, Bcl-2 family 단백질과 더불어 세포사멸 조절에 중요한 역할을 하는 활성형인 cleaved caspase-3은 모두 증가하였고, 그중 myricetin이, PARP은 naringenin, E-cadherin은 rutin이 각각 높은 발현 양상을 나타내었다. 이번 실험 결과를 통해 flavonoid가 세포사멸의 주요한 조절 인자인 Bcl-2 family 단백질의 발현이나 caspase의 활성 등을 조절하여 암세포 사멸인자인 Bcl-2의 발현은 감소시키고 Bax, p53, PARP의 발현을 증가시키는 것을 통해 대장암 세포의 apoptosis를 유도하였다. 또한 암세포의 전이와 관련된 E-cadherin의 발현도 조절하는 것을 관찰하였다. 이상의 연구를 통해 flavonoid가 대장암 세포의 증식을 억제하는 효과가 있음을 확인하였으며, 세포사멸과 관련된 기전을 규명하였다. 이를 기초자료로 일상에서 쉽게 섭취할 수 있는 식품에 많이 존재하며 비교적 독성과 부작용이 적은 flavonoid를 이용한 천연 항암제 개발 가능성을 제시하였고, 추후 대장암의 암예방제 및 암치료제로 개발될 수 있도록 추가 연구 수행이 필요할 것으로 사료된다.

• 대한의생명과학회지
• /
• 제17권1호
• /
• pp.85-88
• /
• 2011

Tumor angiogenesis, which is essential for tumor growth and tumor metastasis, depends on angiogenic factors produced by tumor cells and/or infiltrating cells such as endothelial cells and immune cells in tumor tissue. Previously, we reported that licochalcone A (LicA), an important bioactive compound of Glycyrrhiza inflate, suppresses angiogenesis, tumor growth and metastasis. In this study, we evaluated the effect of LicA on angiogenin production in colon cancer cells because angiogenin is an essential factor to regulate angiogenesis and tumor progression. When we examined the angiogenin levels in three human colon cancer cells, HT-29, SW480 and Caco-2, LicA treatment significantly reduced the amounts of angiogenin among three cancer cell lines. In an in vivo study in which mice were implanted with HT-29 cells, oral administration of LicA reduced angiogenin in tumor tissues when compared with vehicle-administered mice. These results suggest that reduced angiogenin in response to LicA treatment may play essential role to inhibit tumor growth, angiogenesis as well as metastasis.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권2호
• /
• pp.1017-1021
• /
• 2013

The cellular apoptosis susceptibility (CSE1L) gene has been demonstrated to regulate multiple cellular mechanisms including the mitotic spindle check point as well as proliferation and apoptosis. However, the importance of CSE1L in human colon cancer is largely unknown. In the present study, we examined expression levels of CSE1L mRNA by semiquantitative RT-PCR. A lentivirus-mediated small interfering RNA (siRNA) was used to knock down CSE1L expression in the human colon cancer cell line RKO. Changes in CSE1L target gene expression were determined by RT-PCR. Cell proliferation was examined by a high content screening assay. In vitro tumorigenesis was measured by colony-formation assay. Cell cycle distribution and apoptosis were detected by flow cytometric analysis. We found CSE1L mRNA to be expressed in human colon cancer cells. Using a lentivirus based RNAi approach, CSE1L expression was significantly inhibited in RKO cells, causing cell cycle arrest in the G2/M and S phases and a delay in cell proliferation, as well as induction of apoptosis and an inhibition of colony growth capacity. Collectively, the results suggest that silencing of CSE1L may be a potential therapeutic approach for colon cancer.

• 한국식품영양과학회지
• /
• 제33권4호
• /
• pp.633-640
• /
• 2004

녹차분말을 포함하는 차가버섯 조성물의 수용성 추출물에 의한 인체 위암 세포 AGS 및 대장암 세포 HCT-15, 그리고 마우스 정상세포 NIH3T3 fibroblast의 세포생육에 미치는 효과를 세포 수 측정방법과 MTT assay 방법으로 측정하였다. 차가버섯 조성물의 수용성 추출물은 인체 대장암 세포주 HCT-15와 위암 세포주 AGS의 생육을 억제하였다. 그러나 동일한 실험조건 하에서 마우스 정상 세포주 NIH3T3은 80% 이상의 생존율을 나타내었다. 본 연구의 결과로 차가버섯 조성물의 수용성 추출물은 정상세포에는 독성을 나타내지 않으면서 위암 및 대장암 세포에는 높은 생육억제 효과를 나타냄을 알 수 있었다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권6호
• /
• pp.2569-2574
• /
• 2015

Necroptosis, also known as "programmed necrosis", has emerged as a critical factor in a variety of pathological and physiological processes and is considered a cell type-specific tightly regulated process with mechanisms that may vary rather greatly due to the change of cell line. Here we used HT-29, a human colon cancer cell line, to establish a necroptosis model and elucidate associated mechanisms. We discovered that cobalt chloride, a reagent that could induce hypoxia-inducible $factor-1{\alpha}(HIF1{\alpha})$ expression and therefore mimic the hypoxic microenvironment of tumor tissue in some aspects induces necroptosis in HT-29 cells when caspase activity is compromised. On the other hand, apoptosis appears to be the predominant death form when caspases are functioning normally. HT-29 cells demonstrated significantly increased RIPK1, RIPK3 and MLKL expression in response to cobalt chloride plus z-VAD treatment, which was accompanied by drastically increased $IL1{\alpha}$ and IL6 expression, substantiating the notion that necrosis can induce profound immune reactions. The RIPK1 kinase inhibitor necrostatin-1 and the ROS scavenger NAC each could prevent necrosis in HT-29 cells and the efficiency was enhanced by combined treatment. Thus by building up a necroptosis model in human colon cancer cells, we uncovered that mechanically RIP kinases collaborate with ROS during necrosis promoted by cobalt chloride plus z-VAD, which leads to inflammation. Necroptosis may present a new target for therapeutic intervention in cancer cells that are resistant to apoptotic cell death.

• 대한한방내과학회지
• /
• 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.

• Biomolecules & Therapeutics
• /
• 제17권3호
• /
• pp.282-287
• /
• 2009

Ochnaflavone is a natural biflavonoid and mainly found in the caulis of Lonicera japonica (Caprifoliaceae). Biological activities such as anti-inflammatory and anti-atherogenic effects have been previously reported. The anticancer activity of ochnaflavone, however, has been poorly elucidated yet. In the present study, we investigated the effect of ochnaflavone on the growth inhibitory activity in cultured human colon cancer cell line HCT-15. Ochnaflavone inhibited the proliferation of the cancer cells with an $IC_{50}$ value of $4.1{\mu}M$. Flow cytometric analysis showed that ochnaflavone arrested cell cycle progression in the G2/M phase, and induced the increase of sub-G1 peak in a concentration-dependent manner. Induction of cell cycle arrest was correlated with the modulation of the expression of cell cycle regulating proteins including cdc2 (Tyr15), cyclin A, cyclin B1 and cyclin E. The increase of sub-G1 peak by the higher concentrations of ochnaflavone (over $20{\mu}M$) was closely related to the induction of apoptosis, which was evidenced by the induction of DNA fragmentation, activation of caspase-3, -8 and -9, and cleavage of poly-(ADP-ribose) polymerase. These findings suggest that the cell cycle arrest and induction of apoptosis might be one possible mechanism of actions for the anti-proliferative activity of ochnaflavone in human colon cancer cells.