• 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.

• The Korean Journal of Food And Nutrition
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• v.35 no.3
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• pp.204-212
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• 2022

The purpose of this study was to investigate the biological activity of fucoidan, a sulfur-containing polysaccharide, on cytotoxicity and apoptosis in the human HT-29 colorectal cancer cell line using cell viability, Flow cytometry, Western blot, and RT-PCR analyses. Fucoidan inhibited the proliferation of HT-29 cells by 39.6% at a concentration of 100 ㎍/mL for 72 h. The inhibition was dose-dependent and accompanied by apoptosis. Flow cytometric analysis showed that fucoidan increased early apoptosis and late apoptosis by 65.84% and 72.09% at concentrations of 25 and 100 ㎍/mL, respectively. Analysis of the mechanism of these events indicated that fucoidan-treated cells exhibited increases in the activation of caspase-3, caspase-8, and PARP in a dose-dependent manner. These results suggest that fucoidan may inhibit the growth of human colorectal cancer cells by various apoptosis-promoting effects, as well as by apoptosis itself.

• Korean Journal of Plant Resources
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• v.30 no.6
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• pp.640-646
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• 2017

In this study, we elucidated anti-cancer activity and potential molecular mechanism of 70% ethanol extracts from Taxilli Ramulus (Taxillus chinensis (DC.) Danser) (TR-E70) against human colorectal cancer cells. Anti-cell proliferative effect of TR-E70 was evaluated by MTT assay. The effect of TR-E70 on the expression of cyclin D1 in the protein and mRNA level was evaluated by Western blot and RT-PCR, respectively. TR-E70 suppressed the proliferation of human colorectal cancer cell lines, HCT116 and SW480. Although TR-E70 decreased cyclin D1 expression in protein and mRNA level, decreased level of cyclin D1 protein by TR-E70 more dramatically occurred than that of cyclin D1 mRNA. Cyclin D1 downregulation by TR-E70 was attenuated in presence of MG132. In addition, TR-E70 phosphorylated threonine-286 (T286) of cyclin D1. TR-E70-mediated cyclin D1 degradation was blocked in presence of LiCl as an inhibitor $GSK3{\beta}$ but not PD98059 as an ERK1/2 inhibitor and SB203580 as a p38 inhibitor. Our results suggest that TR-E70 may downregulate cyclin D1 as one of the potential anti-cancer targets through $GSK3{\beta}$-dependent cyclin D1 degradation. From these findings, TR-E70 has potential to be a candidate for the development of chemoprevention or therapeutic agents for human colorectal cancer.

• YAKHAK HOEJI
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• v.54 no.3
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• pp.192-199
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• 2010

Colorectal cancer is one of the most common alimentary malignancies. In this study, the antitumor activity of activated human natural killer (NK) cells against human colorectal cancer was evaluated in vivo. Human NK cells are the key contributors of innate immune response and the effective functions of these cells are enhanced by cytokines. Human peripheral blood mononuclear cells (PBMC) were cultured with interleukin-2 (IL-2)-containing medium for 14 days and resulted in enriched NK cell population. The resulting populations of the cells comprised 7% $CD3^+CD4^+$ cells, 25% $CD3^+CD8^+$ cells, 13% $CD3^-CD8^+$ cells, 4% $CD3^+$CD16/$CD56^+$ cells, 39% $CD3^+$CD16/$CD56^-$ cells, and 52% $CD3^-$CD16/$CD56^+$ cells. Tumor necrosis factor alpha (TNF-$\alpha$), interferon gamma (IFN-$\gamma$), IL-2, IL-4, and IL-5 transcripts of the activated NK cells were confirmed by RT-PCR. In addition, activated NK cells at doses of 2.5, 5 and 10 million cells per mouse inhibited 10%, 34% and 47% of SW620-induced tumor growth in nude mouse xenograft assays, respectively. This study suggests that NK cell-based immunotherapy may be used as an adoptive immunotherapy for colorectal cancer patients.

• Biomedical Science Letters
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• v.19 no.2
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• pp.98-104
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• 2013

Radiation is one of the major therapy for the removal of cancer cells. The results of the radiation therapy depend on the radio-resistance of cancer cells. For the effective treatment in these radio-resistant cancers, the use of chemicals that act on cancer cells is known to enhance the cytotoxic effects of radiation therapy. In this study, I investigated the effect of potassium cyanate (KCN) on the irradiated-colorectal cancer cell line, HCT 116 cells. KCN induces the carbamylation of proteins and can change the biological activity of various human cells. To understand the effect of KCN on the radiosensitivity of HCT 116 cells, I examined alteration of the cell cycle, generation of reactive oxygen species (ROS), cell viability, apoptosis and intracellular signaling proteins in the irradiated cells with/without KCN treatment. Combination treatment caused significant increase in sub $G_0/G_1$ and ROS generation in HCT 116 cells. KCN inhibited the proliferation and cell viability in irradiated HCT 116 cells. KCN-induced apoptosis of irradiated cells was processed via the activation of caspase 3 and caspase 9. Apoptosis-associated signal proteins, including Bax and Bcl-2 were regulated by irradiation with KCN treatment. Taken together, these results may indicate that KCN enhances the radiosensitivity of radio-resistant cell and then has a synergistic effect on radiation therapy in colorectal cancer.

• The Korean Journal of Physiology and Pharmacology
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• v.28 no.3
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• pp.265-273
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• 2024

This study aims to explore possible effect of RNA polymerase I subunit D (POLR1D) on proliferation and angiogenesis ability of colorectal cancer (CRC) cells and mechanism herein. The correlation of POLR1D and Yin Yang 1 (YY1) expressions with prognosis of CRC patients in TCGA database was analyzed. Quantitative realtime polymerase chain reaction (qRT-PCR) and Western blot were applied to detect expression levels of POLR1D and YY1 in CRC cell lines and CRC tissues. SW480 and HT-29 cells were transfected with si-POLR1D or pcDNA3.1-POLR1D to achieve POLR1D suppression or overexpression before cell migration, angiogenesis of human umbilical vein endothelial cells were assessed. Western blot was used to detect expressions of p38 MAPK signal pathway related proteins and interaction of YY1 with POLR1D was confirmed by dual luciferase reporter gene assay and chromatin immunoprecipitation (ChIP). TCGA data showed that both POLR1D and YY1 expressions were up-regulated in CRC patients. High expression of POLR1D was associated with poor prognosis of CRC patients. The results showed that POLR1D and YY1 were highly expressed in CRC cell lines. Inhibition or overexpression of POLR1D can respectively suppress or enhance proliferation and angiogenesis of CRC cells. YY1 inhibition can suppress CRC progression and deactivate p38 MAPK signal pathway, which can be counteracted by POLR1D overexpression. JASPAR predicted YY1 can bind with POLR1D promoter, which was confirmed by dual luciferase reporter gene assay and ChIP. YY1 transcription can up-regulate POLR1D expression to activate p38 MAPK signal pathway, thus promoting proliferation and angiogenesis ability of CRC cells.

• Journal of Applied Biological Chemistry
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• v.63 no.1
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• pp.103-110
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• 2020

Objective: The objective of our study was to investigate anti-cancer effects of Danggui Liuhuang Decoction extract bioconverted by protease liquid coenzyme of Aspergillus kawachii (DLD-BE), compared to a non-bioconverted DLD extract (DLD-E) and determine the underlying mechanisms. Methods: DLD-E and DLD-BE were evaluated for their ability to modulate these signaling pathways and suppress the proliferation of human colorectal cancer (CRC) cells, HCT-116, LoVo, and HT-29. The anti-cancer effects of DLD-E and DLD-BE were measured by using proliferation and migration assays, cell cycle analysis, Western blots, and real-time PCR. Results: In this study, treatment with DLD-E and DLD-BE at concentrations of 25-100 ㎍/mL inhibited proliferation and migration in human CRC cells. DLD-BE induced apoptotic cell death and decreased COX-2 expression in HT-29 cells. The mechanisms of action included modulation of the AKT and extracellular-signal-regulated kinase signaling cascades along with inhibition of COX-2 expression. The results demonstrate novel anti-cancer mechanisms of DLD-BE against the growth of human CRC cells. Thus, we propose that DLD-BE can be developed as a more potent supplement to inhibit colorectal tumor growth and intestinal inflammation than DLD-E.

• Biomolecules & Therapeutics
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• v.23 no.4
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• pp.339-344
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• 2015

Naringenin (NAR) as one of the flavonoids observed in grapefruit has been reported to exhibit an anti-cancer activity. However, more detailed mechanism by which NAR exerts anti-cancer properties still remains unanswered. Thus, in this study, we have shown that NAR down-regulates the level of cyclin D1 in human colorectal cancer cell lines, HCT116 and SW480. NAR inhibited the cell proliferation in HCT116 and SW480 cells and decreased the level of cyclin D1 protein. Inhibition of proteasomal degradation by MG132 blocked NAR-mediated cyclin D1 downregulation and the half-life of cyclin D1 was decreased in the cells treated with NAR. In addition, NAR increased the phosphorylation of cyclin D1 at threonine-286 and a point mutation of threonine-286 to alanine blocked cyclin D1 downregulation by NAR. p38 inactivation attenuated cyclin D1 downregulation by NAR. From these results, we suggest that NAR-mediated cyclin D1 downregulation may result from proteasomal degradation through p38 activation. The current study provides new mechanistic link between NAR, cyclin D1 downregulation and cell growth in human colorectal cancer cells.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2459-2463
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• 2015

Background: To investigate the expression and clinical significance of zinc finger protein 217 (ZNF217) in human colorectal carcinoma (CRC). Materials and Methods: The expression of ZNF217 in 60 CRC tissues and matched tumor adjacent tissues, collected between January 2013 and June 2014, was assessed immunohistochemically. The relationship between the expression of ZNF217 and clinicopathlogical features was analyzed by Pearson chi-square test. In addition, siRNA was used to down-regulate the expression of ZNF217 in CRC cells. The effects of ZNF217 for cell migration and invasion were measured by wound healing assay and transwell assay, respectively. Results: The expression level of ZNF217 was significantly higher in CRC tissues than in tumor adjacent tissues (p<0.05), positively correlating with tumor size, lymphatic metastasis and advanced TNM stage (p<0.05). Down-regulation of ZNF217 in CRC cells could significantly suppress cell migration and invasion. Conclusions: ZNF217 is overexpressed in colorectal carcinoma tissues and is associated with tumor malignant clinicopathological features. ZNF217 may promote CRC progression by inducing cell migration and invasion.

• BMB Reports
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• v.48 no.4
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• pp.217-222
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• 2015

Colorectal cancer (CRC) is the third most common cancer and the fourth most common cause of cancer-related death worldwide. Distant metastasis is a major cause of mortality in CRC. MicroRNAs (miRNAs) are small non-coding RNA molecules involved in the post-transcriptional and translational regulation of gene expression. Many miRNAs are aberrantly expressed in cancer and influence tumor progression. Accumulating studies suggest that multiple miRNAs are actively involved in the CRC metastasis process. Thus, we aim to introduce the role of miRNAs in multi-steps of CRC metastasis, including cancer cell invasion, intravasation, circulation, extravasation, colonization, angiogenesis, and epithelial-mesenchymal transition (EMT). Moreover, we suggest the potential application of miRNAs as biomarkers for CRC patients with metastasis. [BMB Reports 2015; 48(4): 217-222]