• Molecules and Cells
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• v.41 no.2
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• pp.73-82
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• 2018

Cancer preventive activities of green tea and its main constituent, (-)-epigallocatechin gallate (EGCG) have been extensively studied by scientists all over the world. Since 1983, we have studied the cancer chemopreventive effects of EGCG as well as green tea extract and underlying molecular mechanisms. The first part of this review summarizes groundbreaking topics with EGCG and green tea extract: 1) Delayed cancer onset as revealed by a 10-year prospective cohort study, 2) Prevention of colorectal adenoma recurrence by a double-blind randomized clinical phase II trial, 3) Inhibition of metastasis of B16 melanoma cells to the lungs of mice, 4) Increase in the average value of Young's moduli, i.e., cell stiffness, for human lung cancer cell lines and inhibition of cell motility and 5) Synergistic enhancement of anticancer activity against human cancer cell lines with the combination of EGCG and anticancer compounds. In the second part, we became interested in cancer stem cells (CSCs). 1) Cancer stem cells in mouse skin carcinogenesis by way of introduction, after which we discuss two subjects from our review on human CSCs reported by other investigators gathered from a search of PubMed, 2) Expression of stemness markers of human CSCs compared with their parental cells, and 3) EGCG decreases or increases the expression of mRNA and protein in human CSCs. On this point, EGCG inhibited self-renewal and expression of pluripotency-maintaining transcription factors in human CSCs. Human CSCs are thus a target for cancer prevention and treatment with EGCG and green tea catechins.

• BMB Reports
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• v.39 no.6
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• pp.730-736
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• 2006

To evaluated the effect of recombinant adenovirus Ad-ODC-AdoMetDCas which can simultaneously express both antisense ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (AdoMetDC) on cell cycle distribution in colorectal cancer cell and investigated underlying regulatory responses, human colorectal cancer cells HT-29 were cultured in RPMI 1640 medium and infected with Ad-ODC-AdoMetDCas. Cell cycle progression was detected by flow cytometry analysis. The expression levels of cell cycle regulated proteins were measured by Western blot analysis. The mRNA level of cyclin D1 was measured by RT-PCR. And a luciferase reporter plasmid of cyclin D1 promoter was constructed to observe the effect of Ad-ODC-AdoMetDCas on cyclin D1 promoter activity. The results showed that recombinant adenovirus Ad-ODC-AdoMetDCas significantly induced $G_1$ arrest, decreased levels of cyclin D1 protein and mRNA and suppressed the promoter activity. Ad-ODC-AdoMetDCas also inhibited nuclear translocation of $\beta$-catenin. In conclusion, downregulation of ODC and AdoMetDC mediated by Ad-ODC-AdoMetDCas transfection induces $G_1$ arrest in HT-29 cells and the arrest was associated with suppression of cyclin D1 expression and inhibition of $\beta$-catenin nuclear translocation. As a new anticancer reagent, the recombinant adenovirus Ad-ODC-AdoMetDCas holds promising hope for the therapy of colorectal cancers.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.1
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• pp.367-372
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• 2015

Background: Human adiponectin (ApN), a 30 kDa glycoprotein of 244-amino acids which is predominantly produced by adipocytes, exerts its effects via two receptors, namely adiponectin receptor-1 (adipo-R1) and adiponectin receptor-2 (adipo-R2) with differential binding affinity to globular adiponectin. Adiponectin receptor expression has been studied in several cancer tissues. However, there are no studies of colorectal adenomas which are considered to be precursors for colorectal carcinoma (CRC). Objectives: In the present study, the expression of adipo-R1 and adipo-R2 was investigated immunohistochemically in colorectal adenomas and colorectal carcinoma tissues in an attempt to determine associations with these tumors. Materials and Methods: The study enrolled 50 CRC patients with tumor resection and 82 patients who were diagnosed with adenomatous polyps, classified as negative for neoplasia, low-grade dysplasia (L-GD) or high- grade dysplasia (H-GD). Results: Expression of both adipo-R1 and adipo-R2 was found to be significantly lower in the CRCs than in colorectal adenomas (tubular and tubulovillous, p=0.009 and p<0.001, respectively). Adipo-R1 and adipo-R2 expression was also significantly lower in the CRC group when compared with the groups of patients with low grade dysplasia, high-grade dysplasia or no neoplasia (p=0.012 and p<0.001, respectively). In addition, it was observed that adipo-R2 expression was generally positive in the non-neoplastic group irrespective of the adipo-R2 expression. In the L-GD, H-GD and CRC groups, the adipo-R2 result was positive whenever adipo-R1 result was positive but some patients with negative adipo-R1 had positive adipo-R2 (p<0.001, p=0.004, p<0.001, respectively). Conclusions: This study indicated that ApN may play a role in the progression of colorectal adenomatous polyps to carcinoma through actions on adipo-R1 and adipo-R2 receptors.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7583-7586
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• 2013

Background: Suppressor of cytokine signaling (SOCS)-1 acts as a key regulator of many cytokine signaling pathways and its abnormal expression has been identified in several human malignancies, suggesting potential roles in carcinogenesis. The aim of this study was to investigate any association between the functional SOCS-1 -1478CA>del polymorphism and colorectal cancer (CC) as well as age at onset in a Turkish clinical sample. Materials and Methods: A total of 122 subjects were enrolled in this case-control study (70 CC cases and 52 controls). The SOCS-1 -1478CA>del polymorphism was genotyped using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Results: The odds ratio of the del allele for CC relative to the CA allele was not significantly different between the groups (OR=0.71, 95% CI=0.41-1.22, p=0.27). This result did not change after adjustment for age and sex on multivariable regression analysis (OR=0.84, 95% CI=0.59-1.34, p=0.53). When the SOCS-1 -1478CA>del polymorphism was analyzed among CC patients in relation to the age at disease onset, we found no significant differences between subjects with the del/del, CA/del, and CA/CA genotypes. Conclusions: The results of our study did not point towards a major role of the SOCS-1 -1478CA>del polymorphism in the pathogenesis of CC in Turkish subjects.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6221-6225
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• 2012

Background: To determine the frequency of HER-2 overexpression in colorectal cancer (CRC) patients, and to explore the relationship between clinicopathological prognostic factors and their effects on survival, based on immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH) analysis. Materials and Methods: The study included 80 patients with a histologically proven diagnosis of CRC that received adjuvant FOLFOX-4 chemotherapy at our department between March 2006 and September 2010. Patient data were analyzed retrospectively. Results: The median follow-up period and age of the patients were 24 months and 59 years, respectively. In immunohistochemical staining, 3+ staining was found in 2 patients (2.5%) while 2+ was in 13 (16%). FISH for HER-2 was performed for all of these 15 patients; samples which were 3+ showed positivity but the ones with 2+ were negative. There was no significant correlation between HER-2 expression and age, gender, tumor localization, histological subtype, grade, lymphovascular and perineural invasion, or pTN stage (P>0.05), even when the patients with HER-2 overexpression were analyzed separately. There was also no significant relationship between progression-free survival (PFS) and overall survival (OS), and HER-2 expression, gender, tumor localization, obstruction-perforation, bleeding, histological type, grade, lymphovascular and perineural invasion, or pT staging (P>0.05); however, there was a significant relationship between lymph node involvement, and PFS and OS (P<0.05). Conclusions: Evaluation of HER-2 overexpression in a more comprehensive, multi-center, prospective trial with standardized methods will be an appropriate approach.

• 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.

• The Korea Journal of Herbology
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• v.28 no.6
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• pp.155-160
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• 2013

Objectives : Gastric cancer is a leading cause of cancer-related deaths, worldwide. Houttuynia cordata Thunberg (H. cordata) has been used as a medicinal plants and it has an anti-cancer activity in human colorectal cancer and leukemic cancer. However, the potential anti-cancer activity and mechanisms of H. cordata for human gastric cancer cells have not been tested so far. Thus, this study examined the biological effects of H. cordata on the human gastric cancer cell line SNU-1 and AGS. Methods : Inhibition of cell proliferation and cell cycle by H. cordata was carried out by MTT assay and Muse cell cycle analysis and the expressions of protein associated with apoptosis and cell cycle regulation were investigated with Western blot analysis. Results : In MTT assay, the proliferation of SNU-1 and AGS cells was significantly inhibited by H. cordata in a time and dose dependent manner, Inhibition of cell proliferation by H. cordata was in part associated with apoptotic cell death, as shown by changes in the expression ratio of Bax to Bcl-2 by H. cordata. Also, H. cordata regulated the expression of cell cycle regulatory proteins such as pRb, cyclin D1, cyclin E, CDK4, CDK2, p21 and p15. Conclusion : The antiproliferative effect of H. cordata on SNU-1 and AGS gastric cancer cells revealed in this study suggests that H. cordata has intriguing potential as a chemopreventive or chemotherapeutic agent.

• Biomolecules & Therapeutics
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• v.32 no.1
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• pp.104-114
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• 2024

Licochalcone C (LCC; PubChem CID:9840805), a chalcone compound originating from the root of Glycyrrhiza inflata, has shown anticancer activity against skin cancer, esophageal squamous cell carcinoma, and oral squamous cell carcinoma. However, the therapeutic potential of LCC in treating colorectal cancer (CRC) and its underlying molecular mechanisms remain unclear. Chemotherapy for CRC is challenging because of the development of drug resistance. In this study, we examined the antiproliferative activity of LCC in human colorectal carcinoma HCT116 cells, oxaliplatin (Ox) sensitive and Ox-resistant HCT116 cells (HCT116-OxR). LCC significantly and selectively inhibited the growth of HCT116 and HCT116-OxR cells. An in vitro kinase assay showed that LCC inhibited the kinase activities of EGFR and AKT. Molecular docking simulations using AutoDock Vina indicated that LCC could be in ATP-binding pockets. Decreased phosphorylation of EGFR and AKT was observed in the LCC-treated cells. In addition, LCC induced cell cycle arrest by modulating the expression of cell cycle regulators p21, p27, cyclin B1, and cdc2. LCC treatment induced ROS generation in CRC cells, and the ROS induction was accompanied by the phosphorylation of JNK and p38 kinases. Moreover, LCC dysregulated mitochondrial membrane potential (MMP), and the disruption of MMP resulted in the release of cytochrome c into the cytoplasm and activation of caspases to execute apoptosis. Overall, LCC showed anticancer activity against both Ox-sensitive and Ox-resistant CRC cells by targeting EGFR and AKT, inducing ROS generation and disrupting MMP. Thus, LCC may be potential therapeutic agents for the treatment of Ox-resistant CRC cells.

• Journal of Life Science
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• v.26 no.6
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• pp.705-710
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• 2016

Colorectal cancer (CRC) is the third most common cancer and a leading cause of cancer-related death worldwide. Although several diagnostic and therapeutic tools have been available, CRC remains difficult to complete cure because of insufficient understanding of the molecular mechanisms underlying this disease progression. MicroRNAs (miRNAs) are small non-coding RNA molecules that strongly regulate gene expression via transcriptional and translational control mechanisms. Many crucial cellular pathways are frequently disrupted in cancer development process due to dysregulation of several miRNAs. Mir-31 functions as an oncogene that modulate expression of multiple cancer related genes. Thus, we aimed to demonstrate clinical relevance of miR-31 in human CRC. Quantitative RT-PCR analysis of miR-31 expression was performed in 175 CRC tissues and 16 normal colonic mucosa (NM). Next, we investigated clinical significances of miR-31 expression in various clinicopathologic features in CRC patients cohort. Mir-31 was significantly up-regulated in CRC tissues compared to NM. In CRC tissues, miR-31 expression level was significantly elevated in a stage-dependent manner, which was associated with poor survival in patients with CRC. High miR-31 levels in CRC tissues significantly correlated with poor prognosis (hazard ratio [HR]=2.4) as well as distant metastasis (odds ratio [OR]=2.3). In conclusion, we identified clinical significance of miR-31 expression in CRC. High miR-31 expression may be clinically able to use as a biomarker for CRC prognosis and predicting metastasis.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.1719-1722
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• 2012

The Wiskott-Aldrich Syndrome Protein family Verprolin - homologous proteins (WAVEs), encoded by a metastasis promoter gene, play considerable roles in adhesion of immune cells, cell proliferation, migration and destruction of foreign agents by reactive oxygen species. These diverse functions have lead to the hypothesis that WAVE proteins have multi-functional roles in regulating cancer invasiveness, metastasis, development of tumor vasculature and angiogenesis. Differentials in expression of WAVE proteins are associated with a number of neoplasms include colorectal cancer, hepatocellular cancer, lung squamous cell carcinoma, human breast adenocarcinoma and prostate cancer. In this review we attempt to unify our knowledge regarding WAVE proteins, focusing on their potentials as diagnostic markers and molecular targets for cancer therapy.