• BMB Reports
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• v.36 no.1
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• pp.82-94
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• 2003

Although debates still exist whether Helicobacter pylori infection is really class I carcinogen or not, H. pylori has been known to provoke precancerous lesions like gastric adenoma and chronic atrophic gastritis with intestinal metaplasia as well as gastric cancer. Chronic persistent, uncontrolled gastric inflammations are possible basis for ensuing gastric carcinogenesis and H. pylori infection increased COX-2 expressions, which might be the one of the mechanisms leading to gastric cancer. To know the implication of long-term treatment of antiinflammatory drugs, rebamipide or nimesulide, on H. pylori-associated gastric carcinogenesis, we infected C57BL/6 mice with H. pylori, especially after MNU administration to promote carcinogenesis and the effects of the long-term administration of rebamipide or nimesulide were evaluated. C57BL/6 mice were sacrificed 50 weeks after H. pylori infection. Colonization rates of H. pylori, degree of gastric inflammation and other pathological changes including atrophic gastritis and metaplasia, serum levels and mRNA transcripts of various mouse cytokines and chemokines, and NF-${\kappa}B$ binding activities, and finally the presence of gastric adenocarcinoma were compared between H. pylori infected group (HP), and H. pylori infected group administered with long-term rebamipide containing pellet diets (HPR) or nimesulide mixed pellets (HPN). Gastric mucosal expressions of ICAM-1, HCAM, MMP, and transcriptional regulations of NF-${\kappa}B$ binding were all significantly decreased in HPR group than in HP group. Multi-probe RNase protection assay showed the significantly decreased mRNA levels of apoptosis related genes and various cytokines genes like IFN-$\gamma$, RANTES, TNF-$\alpha$, TNFR p75, IL-$1{\beta}$ in HPR group. In the experiment designed to provoke gastric cancer through MNU treatment with H. pylori infection, the incidence of gastric carcinoma was not changed between HP and HPR group, but significantly decreased in HPN group, suggesting the chemoprevention of H. pylori-associated gastric carcinogenesis by COX-2 inhibition. Long-term administration of antiinflammatory drugs should be considered in the treatment of H. pylori since they showed the molecular and biologic advantages with possible chemopreventive effect against H. pylori-associated gastric carcinogenesis. If the final concrete proof showing the causal relationship between H. pylori infection and gastric carcinogenesis could be obtained, that will shed new light on chemoprevention of gastric cancer, that is, that gastric/cancer could be prevented through either the eradication of H. pylori or lessening the inflammation provoked by H. pylori infection in high risk group.

• BMB Reports
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• v.41 no.4
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• pp.328-333
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• 2008

A variety of anti-inflammatory agents have been shown to exert chemopreventive activity via targeting of transcription factors such as NF-${\kappa}B$ and AP-1. Lithospermum erythrorhizon (LE) has long been used in traditional oriental medicine. In this study, we demonstrated the inhibitory effects of LE extracts on lipopolysaccharide (LPS)-stimulated production of inflammatory cytokines. As an underlying mechanism of inhibition, LE extracts reduced LPS-induced transactivation of AP-1 as well as NF-${\kappa}B$ in mouse macrophage cells. Electrophoretic mobility shift assays indicated that LE extracts inhibited the DNA binding activities of AP-1 and NF-${\kappa}B$. In addition, phosphorylation of $I{\kappa}B-{\alpha}$ protein was suppressed by LE extracts. Moreover, LE extracts inhibited c-Jun N-terminal kinase and extracellular signal-regulated signaling pathways. Our results suggest that the anti-inflammatory activity of LE extracts may be mediated by the inhibition of signal transduction pathways that normally lead to the activation of AP-1and NF-${\kappa}B$. These inhibitory effects may be useful for chemoprevention of cancer or other chronic inflammatory diseases.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2201-2205
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• 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.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.12
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• pp.5047-5056
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• 2016

Colorectal cancer (CRC) is a major worldwide health problem owing to its high prevalence and mortality rates. Carcinogenesis in the colon is a multistage and multifactorial process. An imbalance between free radical exposure and anti-oxidant defense systems may leads to oxidative stress and attack of macromolecules which can alter signal transduction pathways and gene expression. Consequently, oxidative damage can lead to cellular dysfunction and contribute to pathophysiological processes in a variety of diseases including CRC. One factor tightly associated with CRC is chronic inflammation, which can be present from the earliest stage of tumor onset. Unpolished rice is an attractive chemoprevention in CRC due to their anti-oxidant and anti-inflammatory activities. The aim of this paper is to review evidence linking oxidative stress and inflammation to CRC and to provide essential background information for understanding future research on oxidative stress and inflammation on CRC. Mechanisms of action of unpolished rice in CRC carcinogenesis are also discussed.

• Korean Journal of Plant Resources
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• v.30 no.3
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• pp.265-271
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• 2017

In this study, we elucidated the molecular mechanism of silymarin by which silymarin may inhibits cell proliferation in human colorectal cancer cells in order to search the new potential anti-cancer target associated with the cell growth arrest. Silymarin reduced the level of c-Myc protein but not mRNA level indicating that silymarin-mediated downregulation of c-Myc may result from the proteasomal degradation. In the confirmation of silymarin-mediated c-Myc degradation, MG132 as a proteasome inhibitor attenuated c-Myc degradation by silymarin. In addition, silymarin phosphorylated the threonine-58 (Thr58) of c-Myc and the point mutation of Thr58 to alanine blocked its degradation by silymarin, which indicates that Thr58 phosphorylation may be an important modification for silymarin-mediated c-Myc degradation. We observed that the inhibition of ERK1/2, p38 and $GSK3{\beta}$ blocked the Thr58 phosphorylation and subsequent c-Myc degradation by silymarin. Finally, the point mutation of Thr58 to alanine attenuated silymarin-mediated inhibition of the cell growth. The results suggest that silymarin induces the cell growth arrest through c-Myc proteasomal degradation via ERK1/2, p38 and $GSK3{\beta}-dependent$ Thr58 phosphorylation.

• Proceedings of the Ginseng society Conference
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• 2002.10a
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• pp.277-287
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• 2002

The chemopreventive effects of ginseng on rat carcinogenesis models were investigated, In the present study, the inhibitory effects of white and red ginseng on tumor development were examined using medium-term liver, initiation and medium-term multi-organ carcinogenicity bioassay systems. No modifying potential of the ginsengs was evident in terms of the numbers or areas of glutathione S-transferase placental form (GST -P)-positive foci, which is a marker of preneoplastic lesion in rat livers. However, white ginseng, but not red ginseng was found to decrease the incidences of adenocarcinoma of the small intestine and colon in the medium-term multi-organ carcinogenesis model. These results indicate that white ginseng may have inhibitory effects on progression stage of rat intestinal carcinogenesis, but the influence is not strong. Ginseng is unlikely to have promoting or inhibitory effects in other organs under the present type of experimental conditions. Possible application on ginseng for chemoprevention of colon cancer in humans, can be concluded given the lack of obvious adverse effects.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.21
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• pp.9423-9426
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• 2014

Objective: Hapatitis B visus (CHB)-induced fibrosis is a precancerous condition of liver. To explore the influence of Chongcao Preparation (Chongcao Yigan Capsule) on the function of intestinal flora and chemoprevention for patients with CHB-induced liver fibrosis. Methods: A total of 136 patients with CHB-induced liver fibrosis were randomly divided into control group treated with lamivudine (LAM) and research group added with Chongcao Yigan Capsule for totally 48 weeks. The changes of intestinal flora, secretory immunoglobin A (SIgA), serum albumin (ALB), prealbumin (PALB), IgA and IgG at different time points in both groups were observed. Results: Before treatment, there was no significant difference between two groups in each index (P>0.05). After treatment, the intestinal flora were evidently optimized in research group than treatment before (P<0.05 or P<0.01), and were apparently better than those in control group (P<0.05 or P<0.01); SIgA was obviously increased and ALB, PALB, IgA and IgG were markedly improved in research group than treatment before (P<0.05 or P<0.01), and were significantly better than those in control group (P<0.05 or P<0.01). Conclusions: Chongcao Yigan Capsule could regulate the intestinal flora, increase SIgA, serum ALB and PALB concentrations and significantly improve serum IgA and IgG as well as strengthen the immunological function and autologous repair capacity of patients with CHB-induced liver fibrosis.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6685-6690
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• 2015

Background: Genetic studies have shown a possible relationship between the rs16969968 polymorphism in CHRNA5 and the risk of lung cancer. However, the results have been conflicting. Thus we rigorously conducted a meta-analysis to clarify any association. Materials and Methods: A total of 10 case-control studies involving 17,962 lung cancer cases and 77,216 control subjects were analysed. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to measure the strength of the association. Results: We found the CHRNA5 rs16969968 polymorphism to be associated with the risk of lung cancer (AA vs GG: OR=1.60, 95%CI=1.51-1.71). On stratified analysis by smoking status, a statistically significant increased risk was observed in the smoking group (AA vs GG: OR=1.80, 95%CI=1.61-2.01). However, this polymorphism was not associated with lung cancer risk in Asians (AA vs GG: OR=0.95, 95%CI=0.35-2.59), whereas it was linked to increased risk of lung cancer among Caucasians (AA vs GG: OR=1.65, 95%CI=1.55-1.76). Conclusions: Our meta-analysis provided statistical evidence for a strong association between rs16969968 polymorphism and the risk of lung cancer, especially in smokers and Caucasians. Application of this relationship may contribute to identification of individuals at high risk of lung cancer and indicate a chemoprevention target.

• Journal of Life Science
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• v.17 no.7 s.87
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• pp.996-1001
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• 2007

To investigate whether sulindac, sulindac sulfone, and sulindac sulfide could affect cancer cell viabilities, human colorectal HCTl16 cells were treated with 10 ${\mu}M$ of each NSAID. Among treated NSAms, sulindac sulfide dramatically decreased the cell viabilities detected by MTS and the cytotoxic effect showed dose-dependent manner. To understand the molecular mechanism of cell death in response to sulindac sulfide treatment, we performed oligo DNA microarray analysis. We found that 23 genes were up-regulated more than 2 folds, whereas 33 genes were down-regulated more than 2 folds by treatment of 10 ${\mu}M$ sulindac sulfide. Among the up-regulated genes, we selected 3 genes (NAG-1, DDIT3, PCK2) and performed RT-PCR and quantitative real-time PCR to cofirm microarray data. The results of RT-PCR and real-time PCR were highly accorded with those of microarray experiment. As NAG-1 is well-known gene as tumor suppressor, we detected changes of NAG-1 expression by 10 ${\mu}M$ of sulindac, sulindac sulfone, and sulindac sulfide. The results of RT-PCR and quantitacve real-time PCR indicated that sulindac sulfide was the strongest inducer of NAG-1 among treated NSAIDS. This result implies that induction of NAG-1 by sulindac sulfide plays important role in cell death of colorectal cancer. Overall, we speculate that these results may be helpful in understanding the molecular mechanism of the cancer chemoprevention by sulindac sulfide in human colorectal cancer.

• Korean Journal of Pharmacognosy
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• v.35 no.2 s.137
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• pp.147-151
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• 2004

Water extracts from Thesium chinense Tunczaninov (TCTW) and Prunella vulgaris L. (PVW) were tested for aromatase and cyclooxygenase activities. TCTW and PVW were capable of suppressing aromatase in a human placenta microsomal assay. PVW was shown to be more effective than TCTW in the suppression of aromatase activity. TCTW significantly inhibited cyclooxygenase-2 (COX-2) activity at the concentration of 0.25 (p<0.05), 0.5 (p<0.01) and 2.5 mg/ml (p<0.005). PVW also inhibited COX-2 activity in a dose-dependent manner in a concentration range of $0.05{\sim}2.5\;mg/ml$. The expression of COX-2 was inhibitied by TCTW and PVW in western blot analysis. These results suggest that TCTW and PVW may have breast cancer chemopreventive potentials by inhibiting aromatase and cyclooxygenase activities.