• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2437-2444
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• 2012

Tumor metastasis remains the principal cause of treatment failure and poor prognosis in patients with colorectal cancer. It is a multistage process which includes proteolysis, motility and migration of cells, proliferation in a new site, and neoangiogenesis. A crucial step in the process of intra- and extra-vasation is the activation of proteolytic enzymes capable of degrading the extracellular matrix (ECM). In this stage, urokinase plasminogen activator receptor (uPAR) and matrix metalloproteinases (MMPs) are necessary. Micrometastases need the presence of growth factor and vascular growth factor so that they can form macrometastasis. In addition, cell adhesion molecules (CAMs) and guanine nucleotide exchange factors (GEFs) play important roles in the progression of colorectal cancer and metastatic migration. Further elucidation of the mechanisms of how these molecules contribute will aid in the identification of diagnostic and prognostic markers as well as therapeutic targets for patients with colorectal metastasis.

• Journal of Microbiology and Biotechnology
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• v.30 no.11
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• pp.1607-1613
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• 2020

Colorectal cancer (CRC) is regarded as one of the most common and deadly forms of cancer. Gut microbiota is vital to retain and promote several functions of intestinal. Although previous researches have shown that some gut microbiota have the abilities to inhibit tumorigenesis and prevent cancer from progressing, they have not yet clearly identified associative mechanisms. This review not only concentrates on the antitumor effects of metabolites produced by gut microbiota, for example, SCFA, ferrichrome, urolithins, equol and conjugated linoleic acids, but also the molecules which constituted the bacterial cell wall have the antitumor effect in the host, including lipopolysaccharide, lipoteichoic acid, β-glucans and peptidoglycan. The aim of our review is to develop a possible therapeutic method, which use the products of gut microbiota metabolism or gut microbiota constituents to help treat or prevent colorectal cancer.

• Korean Journal of Plant Resources
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• v.29 no.3
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• pp.297-304
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• 2016

The seed of safflower (Carthamus tinctorius L) has been reported to suppress human cancer cell proliferation. However, the mechanisms by which safflower seed inhibits cancer cell proliferation have remained nuclear. In this study, the inhibitory effect of the safflower seed (SS) on the proliferation of human colorectal cancer cells and the potential mechanism of action were examined. SS inhibited markedly the proliferation of human colorectal cancer cells (HCT116, SW480, LoVo and HT-29). In addition, SS suppressed the proliferation of human breast cancer cells (MDA-MB-231 and MCF-7). SS treatment decreased cyclin D1 protein level in human colorectal cancer cells and breast cancer cells. But, SS-mediated downregulated mRNA level of cyclin D1 was not observed. Inhibition of proteasomal degradation by MG132 attenuated cyclin D1 downregulation by SS and the half-life of cyclin D1 was decreased in SS-treated cells. In addition, SS increased cyclin D1 phosphorylation at threonine-286 and a point mutation of threonine-286 to alanine attenuated SS-mediated cyclin D1 degradation. Inhibition of ERK1/2 by PD98059 suppressed cyclin D1 phosphorylation and downregulation of cyclin D1 by SS. In conclusion, SS has anti-proliferative activity by inducing cyclin D1 proteasomal degradation through ERK1/2-dependent threonine-286 phosphorylation of cyclin D1. These findings suggest that possibly its extract could be used for treating colorectal cancer.

• Development and Reproduction
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• v.18 no.4
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• pp.225-231
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• 2014

Autophagy is a homeostatic degradation process that is involved in tumor development and normal development. Autophagy is induced in cancer cells in response to chemotherapeutic agents, and inhibition of autophagy results in enhanced cancer cell death or survival. Chloroquine (CQ), an anti-malarial drug, is a lysosomotropic agent and is currently used as a potential anticancer agent as well as an autophagy inhibitor. Here, we evaluate the characteristics of these dual activities of CQ using human colorectal cancer cell line HCT15. The results show that CQ inhibited cell viability in dose- and time-dependent manner in the range between 20 to 80 uM, while CQ did not show any antiproliferative activity at 5 and 10 uM. Cotreatment of CQ with antitumor agent NVP-BEZ235, a dual inhibitor of PI3K/mTOR, rescued the cell viability at low concentrations meaning that CQ acted as an autophagy inhibitor, but CQ induced the lethal effect at high concentrations. Acridine orange staining revealed that CQ at high doses induced lysosomal membrane permeabilization (LMP). High doses of CQ produced cellular reactive oxygen species (ROS) and cotreatment of antioxidants, such as NAC and trolox, with high doses of CQ rescued the cell viability. These results suggest that CQ may exert its dual activities, as autophagy inhibitor or LMP inducer, in concentration-dependent manner.

• Biomedical Science Letters
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• v.18 no.1
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• pp.16-21
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• 2012

Although there are many potential cytotoxic molecules released from bacteria, the role of these molecules on the apoptosis of various cancer cells is not well understood. Pseudomonas aeruginosa (P. aeruginosa) is a Gram-negative, aerobic and rod-shaped bacterium, and has a number of virulence factors. To understand the cytotoxic effect of bacterial extracts on the colorectal cancer cell line, HCT 116 cells, we examined alteration of the cell viability, proliferation, cell cycle and apoptosis of HCT 116 cells after treatment with extract of P. aeruginosa (PaE). These cytotoxicity of PaE occurred in a time- and a dose-dependent manners. In addition, PaE arrested the cell cycle of HCT 116 cell in a time-dependent manner. PaE inhibited the protein levels of Bcl-2 and induced the release of cytochrome c from mitochondria of HCT 116 cells. The decrease of procaspase-3 was induced by the treatment of PaE. These results indicate that PaE has a cytotoxicity in HCT 116 cells via the induction of apoptosis associated with mitochondrial pathway. Therefore, PaE may used as the potential target for the treatment of colorectal cancer.

• 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.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.5
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• pp.518-524
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• 2008

Chromosome 18q alteration plays a key role in colorectal tumorigenesis, and loss of heterozygosity at 18q is associated with a poor prognosis in colon cancer. DCC(Deleted in Colorectal Cancer) is a putative tumor- suppressor gene at 18q21 that encodes a transmembrane protein with structural similarity to neural cell adhesion molecule that is involved in both epithelial and neuronal cell differentiation. DCC is implicated in regulation of cell growth, survival and proliferation. Thus, tumor progression in squamous cell carcinoma, stomach cancer, colorectal cancer correlates with downregulation of DCC expression. The mechanism for DCC suppression is associated with hypermethylation of the DCC gene promoter region. Hence, the goal of this study is to identify the promoter methylation responsible for the down-regulation of DCC expression in oral squamous cell carcinoma. 12 of tissue specimens for the study are excised and gathered from 12 patients who are diagnosed as SCC in department of OMS, dental hospital, dankook university. To find expression of DCC in each tissue samples, immunohistochemical staining, RT-PCR gene analysis and methylation specific PCR are processed. The results are as follows. 1. In the DCC gene RT-PCR analysis, 5(41.6%) of 12 specimens of oral squamous cell carcinoma did not expressed DCC gene. 2. In the promoter methylation specific PCR analysis, 5(41.6%) of 12 specimens showed promoter methylation of DCC gene. 3. In the immunohistochemical staining of poor differentiated and invasive oral squamous cell carcinoma, loss of DCC expression was observed. These findings suggest that methylation of the DCC gene may play a role in loss of gene expression in invasive oral squamous cell carcinoma.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.89-89
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• 2020

In this study, we evaluated the effect of the extracts from Lonicera caerulea leaves (LCLE), branches (LCBE) and fruits (LCFE) on the cell growth and migration in human colorectal cancer cells, HCT116 and SW480 cells. LCLE and LCBE dose- and time-dependently inhibited the proliferation of HCT116 and SW480 cells. However, LCFE did not affect the proliferation of HCT116 and SW480 cells. In addition, LCLE and LCBE dramatically cell migration and wound healing in HCT116 cells. LCLE and LCBE decreased β-catenin protein level but not mRNA level in HCT116 and SW480 cells. Furthermore, LCLE decreased TCF4 level in both protein and mRNA level in HCT116 and SW480 cells. However, LCBE decreased TCF4 protein level but not mRNA level in HCT116 and SW480 cells. Based on these findings, LCLE and LCBE may inhibit the cell proliferation and migration through blocking Wnt signaling activation in human colorectal cancer cells. Therefore, LCLE and LCBE may be a potential candidate for the development of chemopreventive or therapeutic agents for human colorectal cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.12
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• pp.4981-4985
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• 2015

Background: Colorectal cancer (CRC) is a leading cause of morbidity and mortality worldwide. Targeting autophagic cell death is emerging as a novel strategy in cancer chemotherapy. Aldose reductase (AR) catalyzes the rate limiting step of the polyol pathway of glucose metabolism; besides reducing glucose to sorbitol, AR reduces lipid peroxidation-derived aldehydes and their glutathione conjugates. A complex interplay between autophagic cell death and/or survival may in turn govern tumor metastasis. This exploratory study aimed to investigate the potential role of AR inhibition using a novel inhibitor Fidarestat in the regulation of autophagy in CRC cells. Materials and Methods: For glucose depletion (GD), HT-29 and SW480 CRC cells were rinsed with glucose-free RPMI-1640, followed by incubation in GD medium +/- Fidarestat ($10{\mu}M$). Proteins were extracted by a RIPA-method followed by Western blotting ($35-50{\mu}g$ of protein; n=3). Results: Autophagic regulatory markers, primarily, microtubule associated protein light chain (LC) 3, autophagy-related gene (ATG) 5, ATG 7 and Beclin-1 were expressed in CRC cells; glyceraldehyde-3 phosphate dehydrogenase (GAPDH) was used as an internal reference. LC3 II (14 kDa) expression was relatively high compared to LC3A/B I levels in both CRC cell lines, suggesting occurrence of autophagy. Expression of non-autophagic markers, high mobility group box (HMG)-1 and Bcl-2, was comparatively low. Conclusions: GD +/- ARI induced autophagy in HT-29 and SW-480 cells, thereby implicating Fidarestat as a promising therapeutic agent for colorectal cancer; future studies with more potent ARIs are warranted to fully dissect the molecular regulatory networks for autophagy in colorectal carcinoma.

• Journal of Digestive Cancer Reports
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• v.8 no.1
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• pp.56-60
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• 2020

In recent years, liquid biopsy has received immense attention. Liquid biopsy is a minimally invasive method used for obtaining biological fluids including urine, pleural fluid and, mostly, peripheral blood. Liquid biopsy involves various targets including circulating tumors cells (CTCs), circulating cell-free tumor DNA (ctDNA), and microRNA (miRNA). Colorectal cancer (CRC), like other solid tumors, shed tumor cells into the bloodstream. Analysis of these CTCs, as well as ctDNA is the primary objective of the liquid biopsy. Evaluation of CTC or ctDNA offers information about early tumor release, development of tumor metastasis and also about mechanisms involved in tumor resistance to treatment.