• Nutrition Research and Practice
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• 제13권1호
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• pp.58-63
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• 2019

BACKGROUND/OBJECTIVES: Telomeres are located at the chromosomal ends and progressively shortened during each cell cycle. Telomerase, which is regulated by hTERT and c-MYC, maintains telomeric DNA sequences. Especially, telomerase is active in cancer and stem cells to maintain telomere length for replicative immortality. Recently we reported that walnut phenolic extract (WPE) can reduce cell viability in a colon cancer stem cell (CSC) model. We, therefore, investigated the effect of WPE on telomere maintenance in the same model. MATERIALS AND METHODS: $CD133^+CD44^+$ cells from HCT116, a human colon cancer cell line, were sorted by Fluorescence-activated cell sorting (FACS) and treated with WPE at the concentrations of 0, 10, 20, and $40{\mu}g/mL$ for 6 days. Telomere lengths were assessed by quantitative real-time PCR (qRT-PCR) using telomere specific primers and DNA extracted from the cells, which was further adjusted with single-copy gene and reference DNA ($ddC_t$). Telomerase activity was also measured by qRT-PCR after incubating the PCR mixture with cell protein extracts, which was adjusted with reference DNA ($dC_t$). Transcriptions of hTERT and c-MYC were determined using conventional RT-PCR. RESULTS: Telomere length of WPE-treated cells was significantly decreased in a dose-dependent manner ($5.16{\pm}0.13$ at $0{\mu}g/mL$, $4.79{\pm}0.12$ at $10{\mu}g/mL$, $3.24{\pm}0.08$ at $20{\mu}g/mL$ and $3.99{\pm}0.09$ at $40{\mu}g/mL$; P = 0.0276). Telomerase activities concurrently decreased with telomere length ($1.47{\pm}0.04$, $1.09{\pm}0.01$, $0.76{\pm}0.08$, and $0.88{\pm}0.06$; P = 0.0067). There was a positive correlation between telomere length and telomerase activity (r = 0.9090; P < 0.0001). Transcriptions of both hTERT and c-MYC were also significantly decreased in the same manner. CONCLUSION: In the present cell culture model, WPE reduced telomere maintenance, which may provide a mechanistic link to the effect of walnuts on the viability of colon CSCs.

• Asian Pacific Journal of Cancer Prevention
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• 제16권5호
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• pp.2061-2068
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• 2015

Background: Tumors are largely unable to metabolize ketone bodies for energy due to various deficiencies in one or both of the key mitochondrial enzymes, which may provide a rationale for therapeutic strategies that inhibit tumor growth by administration of a ketogenic diet with average protein but low in carbohydrates and high in fat. Materials and Methods: Thirty-six male BALB/C nude mice were injected subcutaneously with tumor cells of the colon cancer cell line HCT116. The animals were then randomly split into three feeding groups and fed either a ketogenic diet rich in omega-3 fatty acids and MCT (MKD group; n=12) or lard only (LKD group; n=12) or a standard diet (SD group; n=12) ad libitum. Experiments were ended upon attainment of the target tumor volume of $600mm^3$ to $700mm^3$. The three diets were compared for tumor growth and survival time (interval between tumor cell injection and attainment of target tumor volume). Results: The tumor growth in the MKD and LKD groups was significantly delayed compared to that in the SD group. Conclusions: Application of an unrestricted ketogenic diet delayed tumor growth in a mouse xenograft model. Further studies are needed to address the mechanism of this diet intervention and the impact on other tumor-relevant parameters such as invasion and metastasis.

• Molecules and Cells
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• 제42권12호
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• pp.869-883
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• 2019

Interleukin (IL)-15 is an essential immune-modulator with high potential for use in cancer treatment. Natural IL-15 has a low biological potency because of its short half-life and difficulties in mass-production. IL-15Rα, a member of the IL-15 receptor complex, is famous for its high affinity to IL-15 and its ability to lengthen the half-life of IL-15. We have double-transfected IL-15 and its truncated receptor IL-15Rα into CT26 colon cancer cells to target them for intracellular assembly. The secreted IL-15:IL-15Rα complexes were confirmed in ELISA and Co-IP experiments. IL-15:IL-15Rα secreting clones showed a higher anti-tumor effect than IL-15 secreting clones. Furthermore, we also evaluated the vaccine and therapeutic efficacy of the whole cancer-cell vaccine using mitomycin C (MMC)-treated IL-15:IL-15Rα secreting CT26 clones. Three sets of experiments were evaluated; (1) therapeutics, (2) vaccination, and (3) long-term protection. Wild-type CT26-bearing mice treated with a single dose of MMC-inactivated secreted IL-15:IL-15Rα clones prolonged survival compared to the control group. Survival of MMC-inactivated IL-15:IL-15Rα clone-vaccinated mice (without any further adjuvant) exceeded up to 100%. This protection effect even lasted for at least three months after the immunization. Secreted IL-15:IL-15Rα clones challenging trigger anti-tumor response via CD4⁺ T, CD8⁺ T, and natural killer (NK) cell-dependent cytotoxicity. Our result suggested that cell-based vaccine secreting IL-15:IL-15Rα, may offer the new tools for immunotherapy to treat cancer.

• Journal of Nutrition and Health
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• 제36권3호
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• pp.270-279
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• 2003

Conjugated linoleic acid (CLA) is a group of positional and geometric isomers of linoleic acid (LA) and exhibits anticarcinogenic activity in a variety of animal models. We have previously observed that CLA inhibited the growth of Caco-2 cells, a human colon adenocarcinoma cell line. The present study was performed to determine whether the growth inhibitory effect of CLA is related to change in secretion of IGF- II and/or IGF-binding proteins (IGFBPs) that have been shown to regulate Caco-2 cell proliferation by an autocrine mechanism. Cells were incubated in serum-free medium with various concentrations of CLA or linoleic acid (LA). Immunoblot analysis of 24-hours, serum-free, conditioned medium using a monoclonal anti-IGF-IIantibody revealed that Caco-2 cells secreted both mature 6,500 Mr and higher Mr forms of pro IGF-II. The levels of pro IGF-II and mature IGF-IIwere decreased by 43 $\pm$ 2% and 53 $\pm$ 6%, respectively by treatment with 50 $\mu$ M CLA. LA slightly increased pro IGF- II levels. Results from Northern blot analysis showed that CLA decreased IGF-II mRNA levels at 50 $\mu$ M concentration suggesting that CLA regulation of IGF-II protein expression occurs partly at the transcriptional level. Ligand blot analysis of conditioned media using 1251-IGF-II revealed that CLA slightly decreased IGFBP-2 levels and increased IGFBP-4 levels. We confirmed our previous results that CLA inhibited cell growth in a dose-dependent manner but LA slightly increased cell growth. Exogenous IGF-II mitigated the growth inhibitory effect of CLA. These results indicate that the growth inhibitory effect of CLA may be at least in part mediated by decreasing IGF-II and IGFBP-2 secretion and increasing IGFBP-4 secretion in Caco-2 cells.

• International Journal of Internet, Broadcasting and Communication
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• 제12권2호
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• pp.98-112
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• 2020

There is a strong connection between the diet rich in antioxidants and the decreased incidence of inflammatory bowel disease and cancerous diseases. Diets that are rich in anti-oxidants particularly include fruits and vegetables containing the high amounts of vitamin A-E, carotenoids, and minerals. The supercritical heat-treated radish extracts of the research result had an inhibitory effect on the development of aberrant crypt foci (ACF), namely, preneoplastic lesions having a potential to become cancer cells and reduced the number of the aberrant crypt foci (ACF) consisting of four or more aberrant crypts (AC) having high risk to become tumors by about half. The supercritical heat-treated radish extracts can reduce the incidence of preneoplastic lesions having a high risk of developing cancer by about 28 %. DSS-treated mice developed symptoms similar to those of human UC, such as severe bloody diarrhea and weight loss. Supercritical heat-treated radish extracts, as well as sulfasalazine, suppressed colonic length and mucosal inflammatory infiltration. In addition, supercritical heat-treated radish extracts treatment significantly reduced the expression of pro-inflammatory signaling molecules through suppression both mitogen-activated protein kinases (MAPK) and nuclear factor-kappa B (NF-kB) signaling pathways, and prevented the apoptosis of colon. Moreover, supercritical heat-treated radish extracts administration significantly led to the up-regulation of anti-oxidant enzyme including SOD and Catalase.

• 생약학회지
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• 제37권4호
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• pp.283-289
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• 2006

Ethanol extracts of the whole herb of Agastachis Herba (A) and of Pueraria Radix (P) alone and of their mixture (A+P) downregulated the cell growth, cyclooxygenase-2 (COX-2) expression, prostaglandin $E_2\;(PGE_2)$, and cGMP production. A, P, and A + P inhibited the cell growth of HT-29 colon cancer cells in a concentration- and time-dependent manner but not the growth of normal colon cell, CCD-112CoN. In addition, they markedly inhibited the productions of $PGE_2$ and cGMP as well as the mRNA expression of COX-2. These data suggest that non-toxic concentration of A, P, and A + P have a significant effect on the in vitro growth of HT-29 cells, specifically through the inhibition of the $PGE_2$ production via COX-2.

• Biomolecules & Therapeutics
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• 제27권1호
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• pp.41-47
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• 2019

The apoptotic effects of shikonin (5,8-dihydroxy-2-[(1R)-1-hydroxy-4-methylpent-3-enyl]naphthalene-1,4-dione) on the human colon cancer cell line SNU-407 were investigated in this study. Shikonin showed dose-dependent cytotoxic activity against SNU-407 cells, with an estimated $IC_{50}$ value of $3{\mu}M$ after 48 h of treatment. Shikonin induced apoptosis, as evidenced by apoptotic body formation, sub-G_1$ phase cells, and DNA fragmentation. Shikonin induced apoptotic cell death by activating mitogen-activated protein kinase family members, and the apoptotic process was mediated by the activation of endoplasmic reticulum (ER) stress, leading to activation of the $PERK/elF2{\alpha}/CHOP$ apoptotic pathway, and mitochondrial $Ca^{2+}$ accumulation. Shikonin increased mitochondrial membrane depolarization and altered the levels of apoptosis-related proteins, with a decrease in B cell lymphoma (Bcl)-2 and an increase in Bcl-2-associated X protein, and subsequently, increased expression of cleaved forms of caspase-9 and -3. Taken together, we suggest that these mechanisms, including MAPK signaling and the ER- and mitochondria-mediated pathways, may underlie shikonin-induced apoptosis related to its anticancer effect.

• Food Science and Biotechnology
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• 제16권1호
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• pp.163-166
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• 2007

The cytotoxic effects of partially purified substances from Bacillus polylfermenticus SCD toward a variety tumor cell lines were studied. Cytotoxic activity was determined with regard to the A549 (human lung carcinoma), AGS (human stomach adenocarcinoma), DLD-1 (human colon adenocarcinoma), HEC-1-B (human uterus adenocarcinoma), SW-156 (human kidney carcinoma), and NIH/3T3 (murine normal fibroblast) cell lines using the MTT assay. Cytotoxic substances were partially purified through Diaion HP-20 columns and extracted with methanol or other organic solvents (n-hexane, chloroform, ethylacetate, and butanol). B. polyfermenticus SCD supernatant showed up to 60% inhibition of cell viability fer all five human cancer cell lines tested. When treated with 10 mg/mL of n-hexane, chloroform, ethylacetate, and butanol extract, HEC-1-B cells showed a 25,62,35, and 63% rate of inhibition respectively, and AGS cells showed a 72, 61, 44, and 67% rate of inhibition, respectively. At a concentration of 10 mg/mL, 100% methanol Diaion HP-20 extracts showed inhibition rates of 97.0% toward A-549 cells, 98.1% toward AGS cells, 81.6% toward DLD-1 cells, 83.5% toward HEC-1-B cells, and 92.7% toward SW-156 cells. These results indicate that partially purified fractions from B. polyfermenticus SCD have the potential to inhibit not only colon cancer cells, but also lung, stomach uterus, and kidney cancer cells. Further studies are needed to characterize the cytotoxic substances released in B. polyfermenticus SCD cultures.

• 대한약침학회지
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• 제10권1호통권22호
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• pp.5-16
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• 2007

Objectives : The aim of this study was to verify anti-cancer and anti-oxidant efficacies of Korean wild ginseng and cultivated wild ginseng of Korea and China. Methods : For the measurement of anti-oxidation, SOD-like activity was evaluated using xanthine oxidase reduction method under in vitro environment. Subcutaneous and abdominal cancer were induced using CT-26 human colon cancer cells for the measurement of growth inhibition of cancer cells and differences in survival rate. Results : 1. Measurement of anti-oxidant activity of ginseng, Chinese and Korean cultivated wild ginseng, and natural wild ginseng samples showed concentration dependent anti-oxidant activity in HX/XOD system. Anti-oxidant activity showed drastic increase at 1mg/ml in all samples. 2. For the evaluation of growth inhibition of cancer cells after hypodermic implantation of CT-26 cancer cells in the peritoneal cavity of mice, Chinese and Korean cultivated wild ginseng and natural wild ginseng groups showed significant inhibition of tumor growth from the 12th day compared to the control group. Similar inhibitory effects were also shown on the 15th and 18th days. But there was no significant difference between the experiment groups. 3. For the observation of increase in survival rate of the natural wild ginseng group, CT-26 cancer cells were implanted in the peritoneal cavity of mice.

• BMB Reports
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• 제57권2호
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• pp.104-109
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• 2024

Gefitinib exerts anticancer effects on various types of cancer, such as lung, ovarian, breast, and colon cancers. However, the therapeutic effects of gefitinib on cervical cancer and the underlying mechanisms remain unclear. Thus, this study aimed to explore whether gefitinib can be used to treat cervical cancer and elucidate the underlying mechanisms. Results showed that gefitinib induced a caspase-dependent apoptosis of HeLa cells, which consequently became round and detached from the surface of the culture plate. Gefitinib induced the reorganization of actin cytoskeleton and downregulated the expression of p-FAK, integrin β1 and E-cadherin, which are important in cell-extracellular matrix adhesion and cell-cell interaction, respectively. Moreover, gefitinib hindered cell reattachment and spreading and suppressed interactions between detached cells in suspension, leading to poly (ADP-ribose) polymerase cleavage, a hallmark of apoptosis. It also induced detachment-induced apoptosis (anoikis) in C33A cells, another cervical cancer cell line. Taken together, these results suggest that gefitinib triggers anoikis in cervical cancer cells. Our findings may serve as a basis for broadening the range of anticancer drugs used to treat cervical cancer.