• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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• pp.627-633
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• 2015

Background: To study the effect of parecoxib, a novel cyclooxygenase-2 selective inhibitor, on the radiation response of colorectal cancer (CRC) cells and its underlying mechanisms. Materials and Methods: Both in vitro colony formation and apoptosis assays as well as in vivo mouse xenograft experiments were used to explore the radiosensitizing effects of parecoxib in human HCT116 and HT29 CRC cells. Results: Parecoxib sensitized CRC cells to radiation in vitro with a sensitivity enhancement ratio of 1.32 for HCT116 cells and 1.15 for HT29 cells at a surviving fraction of 0.37. This effect was partially attributable to enhanced apoptosis induction by parecoxib combined with radiation, as illustrated using an in vitro apoptosis assays. Parecoxib augmented the tumor response of HCT116 xenografts to radiation, achieving growth delay more than 20 days and an enhancement factor of 1.53. In accordance with the in vitro results, parecoxib combined with radiation resulted in less proliferation and more apoptosis in tumors than radiation alone. Radiation monotherapy decreased microvessel density (MVD) and microvessel intensity (MVI), but increased the hypoxia level in xenografts. Parecoxib did not affect MVD, but it increased MVI and attenuated hypoxia. Conclusions: Parecoxib can effectively enhance radiation sensitivity in CRC cells through direct effects on tumor cells and indirect effects on tumor vasculature.

• Journal of Pharmacopuncture
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• v.19 no.1
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• pp.51-58
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• 2016

Objectives: Oldenlandia diffusa is traditionally used to relieve the symptoms of and to treat various diseases, but its anti-cancer activity has not been well studied. In the present study, the authors investigated the anti-cancer effects of an ethanol extract of Oldenlandia diffusa (EOD) on HT-29 human adenocarcinoma cells. Methods: Cells were treated with different concentrations of an EOD, and cell death was assessed by using a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Analyses of the sub G1 peak, the caspase-3 and -9 activities, and the mitochondrial membrane depolarizations were conducted to confirm cell death by apoptosis. Also, intracellular reactive oxygen species (ROS) generation was determined using carboxy-H2DCFDA (5-(and-6)-carboxy-20,70-dichlorodihydrofluorescein diacetate). Results: EOD inhibited the proliferation of HT-29 cells for 24 hours by $78.6%{\pm}8.1%$ at $50{\mu}g/mL$, $74.4%{\pm}4.6%$ at $100{\mu}g/mL$, $65.9%{\pm}5.2%$ at $200{\mu}g/mL$, $51.4%{\pm}6.2%$ at $300{\mu}g/mL$, and by $41.7%{\pm}8.9%$ at $400{\mu}g/mL$, and treatment for 72 hours reduced the proliferation at the corresponding concentrations by $43.3%{\pm}8.8%$, $24.3{\pm}5.1mV$, $13.5{\pm}3.2mV$, $6.5{\pm}2.3mV$, and by $2.6{\pm}2.3mV$. EOD increased the number of cells in the sub-G1 peak in a dose-dependent manner. The mitochondrial membrane depolarization was elevated by EOD. Also, caspase activities were dose-dependently elevated in the presence of EOD, and these activities were repressed by a pan-caspase inhibitor (zVAD-fmk). The ROS generation was significantly increased by EOD and N-acetyl-L-cysteine (NAC; a ROS scavenger) remarkably abolished EOD-induced cell death. In addition, a combination of sub-optimal doses of EOD and chemotherapeutic agents noticeably suppressed the growth of HT-29 cancer cells. Conclusion: These results indicate that EOD might be an effective chemotherapeutic for the treatment of human colorectal cancer.

• YAKHAK HOEJI
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• v.53 no.4
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• pp.184-188
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• 2009

Fluorouracil (5-FU) is one of the most widely used chemotherapeutic drugs in the treatment of advanced colorectal cancer patients. Capsaicin (N-vanillyl-8-methyl-alpha-nonenamide), a spicy component of hot pepper, is a homovanillic acid derivative that preferentially induces cancer cells to undergo apoptosis. The purpose of the present study is to examine whether capsaicin enhances the anticancer effect of 5-fluorouracil in HT-29 human colon cancer cells by inducing apoptosis, and whether PPARgamma is involved in the capsaicin action in combination treatment with 5-FU. Treatment of the cells with either 5-FU or capsaicin alone for 48 h had little effect on the cell viability up to $50{\mu}M$ concentration, whereas co-treatment of the cells with capsaicin in the presence of 5-FU for 48 h significantly decreased the cell viability in a concentration-dependent manner. In addition, caspase-3 activity, a marker enzyme for apoptosis, was significantly increased by the combined treatment with 5-FU and capsaicin compared to the 5-FU or capsaicin alone treatment. Also, treatment with troglitazone, a peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$) agonist, further enhanced the effect of the combination treatment on the cell viability and caspase-3 activity, and bisphenol A diglycidyl ether (BADGE), a $PPAR{\gamma}$ antagonist, blocked the effect of the combination treatment. These results suggest that the combination treatment of HT-29 cells with 5-FU and capsaicin induces apoptotic cell death at relatively low concentration than each drug alone, and the combination treatment may be associated with the $PPAR{\gamma}$ pathway activation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.4
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• pp.635-640
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• 2015

Various medicinal plants were collected, air-dried, and subjected to extraction with ethanol. Ethanol extracts were screened for their efficacies as antioxidative and antiproliferative agents against cancer cells. Among the 15 species, extract of Lindera glauca Blume stem with a total polyphenolic content of $70.99{\pm}1.88{\mu}g/TAE\;{\mu}g$, was found to possess high DPPH radical scavenging ($IC_{50}=30.54{\pm}0.62{\mu}g/mL$), nitrite scavenging ($IC_{50}=787.94{\pm}89.28{\mu}g/mL$), and reducing power activities ($595.76{\pm}1.90{\mu}g/mL$). The antiproliferative activities of plant extracts were determined using MTT assay in human colorectal cancer cells. Extracts of stems and roots from L. glauca Blume were found to possess high anti-proliferative activities in HT-29 and HCT116 cells ($IC_{50}=711.52{\pm}40.27{\mu}g/mL$ and $IC_{50}=85.07{\pm}4.06{\mu}g/mL$, respectively). These results suggest that L. glauca Blume extract could be a useful natural antioxidant and anticancer resource.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.1
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• pp.126-130
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• 2008

Water extract from Prunella vulgaris L. (PVW) was tested for colon cancer chemopreventive activity by measuring the activities of cytochrome P450 1A1, phase Ⅱ detoxification enzyme [quinone reductase (QR) and glutathione S-transferase (GST)] and ornithine decarboxylase (ODC) and glutathione (GSH) levels in cultured human colorectal adenocarcinoma HT-29 cells. PVW significantly inhibited 7,12-dimethylbenz[a]anthracene (DMBA)-induced cytochrome P450 1A1 activity at 10 and 50 ${\mu}g/ml$. PVW induced QR activity in a dose-dependent manner over a concentration range of $1{\sim}50\;{\mu}g/ml$. GST activity was also induced with the treatment of PVW in HT-29 cells. In addition GSH levels were increased with PVW. PVW inhibited ODC activity, a key enzyme of polyamine biosynthesis, which is enhanced in tumor promotion. These results suggest that Prunella vulgaris L. has colon cancer chemopreventive activity by inhibiting cytochrome P450 1A1 and ODC activities and by increasing phase Ⅱ enzyme activity and GSH levels.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3767-3772
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• 2014

Introduction: MicroRNAs have emerged as post-transcriptional regulators that are critically involved in tumorigenesis. This study was designed to explore the effect of miRNA 133b on the proliferation and expression of TBPL1 in colon cancer cells. Methods: Human colon cancer SW-620 cells and human colon adenocarcinoma HT-29 cells were cultured. MiRNA 133b mimcs, miRNA 133b inhibitors, siRNA for TBPL1 and scrambled control were synthesized and transfected into cells. MiR-133b levels in cells and CRC tumor tissue was measured by real-time PCR. TBPL1 mRNA was detected by RT-PCR. Cell proliferation was studied with MTT assay. Western blotting was applied to detect TBPL1 protein levels. Luciferase assays were conducted using a pGL3-promoter vector cloned with full length of 3'UTR of human TBPL1 or 3'UTR with mutant sequence of miR-133b target site in order to confirm if the putative binding site is responsible for the negative regulation of TBPL1 by miR-133b. Results: Real time PCR results showed that miRNA 133b was lower in CRC tissue than that in adjacent tissue. After miR-133b transfection, its level was elevated till 48h, accompanied by lower proliferation in both SW-620 and HT-29 cells. According to that listed in http://www.targetscan.org, the 3'-UTR of TBPL1 mRNA (NM_004865) contains one putative binding site of miR-133b. This site was confirmed to be responsible for the negative regulation by miR-133b with luciferase assay. Further, Western blotting and immunohistochemistry both indicated a higher TBPL1 protein expression level in CRC tissue. Finally, a siRNA for TBPL1 transfection obviously slowed down the cell proliferation in both SW-620 and HT-29 cells. Conclusion: MiR-133b might act as a tumor suppressor and negatively regulate TBPL1 in CRC.

• Food Science and Biotechnology
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• v.17 no.6
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• pp.1265-1271
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• 2008

Adlay bran is a waste product previously thought to have no commercial value, Its methanolic extract was fractionated using n-hexane (ABM-Hex), ethyl acetate (ABM-EtOAc), 1-butanol (ABM-BuOH), and water (ABM-$H_2O$). The ABM-EtOAc fraction exhibited a strongest inhibition against growth of human lung cancer cell A549 and human colorectal carcinoma cells HT-29 and COLO 205. Inhibition of cell cycle progression at $G_0/G_1$ transition, increase of cells at the sub-$G_1$ phase, and DNA ladders were observed in cells treated with ABM-EtOAc. The ABM-BuOH fraction showed the strongest inhibition of proinflammatory cytokines tumor necrosis factor (TNF)-$\alpha$ and interlukin (IL)-$1{\beta}$ in stimulated RAW 264.7 macrophages. Further, ABM-EtOAc and ABM-BuOH inhibited cyclooxygenase (COX)-2 expression in A549 and HT-29 carcinoma cells, while COX-l expression was not affected. These results reveal that both ABM-EtOAc and ABM-BuOH may aid the prevention of cancers and the applications in cancer chemotherapy.

• Biomolecules & Therapeutics
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• v.23 no.3
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• pp.225-232
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• 2015

We identified a novel Akt signaling mechanism that mediates fucoidan-induced suppression of human colon cancer cell (HT29) proliferation and anticancer effects. Fucoidan treatment significantly inhibited growth, induced G1-phase-associated upregulation of p21WAF1 expression, and suppressed cyclin and cyclin-dependent kinase expression in HT29 colon cancer cells. Additionally, fucoidan treatment activated the Akt signaling pathway, which was inhibited by treatment with an Akt inhibitor. The inhibition of Akt activation reversed the fucoidan-induced decrease in cell proliferation, the induction of G1-phase-associated p21WAF1 expression, and the reduction in cell cycle regulatory protein expression. Intraperitoneal injection of fucoidan reduced tumor volume; this enhanced antitumor efficacy was associated with induction of apoptosis and decreased angiogenesis. These data suggest that the activation of Akt signaling is involved in the growth inhibition of colon cancer cells treated with fucoidan. Thus, fucoidan may serve as a potential therapeutic agent for colon cancer.

• Biomolecules & Therapeutics
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• v.23 no.2
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• pp.128-133
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• 2015

Although coffee is known to have antioxidant, anti-inflammatory, and antitumor properties, there have been few reports about the effect and mechanism of coffee compounds in colorectal cancer. Heat shock proteins (HSPs) are molecular chaperones that prevent cell death. Their expression is significantly elevated in many tumors and is accompanied by increased cell proliferation, metastasis and poor response to chemotherapy. In this study, we investigated the cytotoxicity of four bioactive compounds in coffee, namely, caffeine, caffeic acid, chlorogenic acid, and kahweol, in HT-29 human colon adenocarcinoma cells. Only kahweol showed significant cytotoxicity. Specifically, kahweol increased the expression of caspase-3, a pro-apoptotic factor, and decreased the expression of anti-apoptotic factors, such as Bcl-2 and phosphorylated Akt. In addition, kahweol significantly attenuated the expression of HSP70. Inhibition of HSP70 activity with triptolide increased kahweol-induced cytotoxicity. In contrast, overexpression of HSP70 significantly reduced kahweol-induced cell death. Taken together, these results demonstrate that kahweol inhibits colorectal tumor cell growth by promoting apoptosis and suppressing HSP70 expression.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.6
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• pp.1572-1575
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• 2006

Water extract from Cnidii Rhizoma (CRW) was tested for colon cancer chemopreventive activity by measuring the induction of phase II detoxification enzyme activity [quinone reductase (QR) and glutathione S-transferase (GST)] and glutathion (GSH) levels and ornithine decarboxylase (ODC) activity in cultured human colorectal adenocarcinoma HT-29 cells. CRW inhibited cell proliferation in cultured HT-29 cells. CRW induced QR activity in a dose-dependent manner in a concentration range of 0.1${\sim}$5.0 $mg/m{\ell}$. GST activity was also induced with the treatment of CRW in HT-29 cells. In addition GSH levels was increased with CRW. CRW inhibited ODC activity, a key enzyme of polyamine biosynthesis, which is enhanced in tumor promotion. These results suggest that CRW has colon cancer chemopreventive activity by increasing phase II enzyme activity and GSH levels and inhibiting ODC activity in vitro.