• Journal of Ginseng Research
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• v.40 no.4
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• pp.431-436
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• 2016

Background: Although numerous studies of the anticancer activities of Korean Red Ginseng (KRG) have been performed, the therapeutic effect of KRG on leukemia has not been fully elucidated. In this study, we investigated the antileukemia activities of KRG and its cellular and molecular mechanisms. Methods: An established leukemia tumor model induced by xenografted T cell lymphoma (RMA cells) was used to test the therapeutic activity of KRG water extract (KRG-WE). Direct cytotoxic activity of KRG-WE was confirmed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The immunomodulatory activities of KRG-WE were verified by immunohistochemistry, nitric oxide production assay. The inhibitory effect of KRG-WE on cell survival signaling was also examined. Results: Orally administered KRG-WE reduced the sizes of tumor masses. Levels of apoptosis regulatory enzymes and cleaved forms of caspases-3 and -8 were increased by this extract. In addition, expression of matrix metalloproteinase-9, a metastasis regulatory enzyme, was decreased by KRG-WE treatment. The proportion of CD11c+ cells was remarkably increased in the KRG-treated group compared to the control group. However, KRG-WE did not show significant direct cytotoxicity against RMA cells. Conclusion: Our results strongly suggest that the KRG might have antileukemia activity through CD11c+ cell-mediated antitumor immunity.

• 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.

• 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.

• The Journal of Korean Obstetrics and Gynecology
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• v.22 no.2
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• pp.94-118
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• 2009

Purpose: Gleditsiae spina (GS) has been used to treat patients with several diseases such as carbuncle, swelling and parasites. Recently GS is known to have anticancer activity in abdominal solid tumor, but the effects of GS on breast cancers is not clarified. For these reasons, we investigated effects of Gleditsiae spina (GS) on gene expression of human breast cancer cells. Methods: We investigated the effects of GS on proliferation of breast cancer cell line, MDA-MB-231. In addition, the genetic profile for the effect of GS on breast cancer cells was measured using microarray technique, and the functional analysis on these genes was conducted. Results: Total 1,434 genes were up-regulated and 2,483 genes down-regulated in the cells treated with GS. Genes induced or suppressed by GS were all mainly concerned with metabolic process, regulation of biological process and protein binding. The network of total protein interactions was measured using cytoscape program, and some key molecules that can be used for elucidation of therapeutical mechanism of medicine in future were identified. Conclusion: These results suggest possibility of GS as anti-cancer drug for breast cancer, and also suggest that related mechanisms are involved in regulation of intra-cellular metabolism in breast cancer cells.

• Journal of Microbiology and Biotechnology
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• v.33 no.4
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• pp.449-462
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• 2023

Previously, we confirmed that Mychonastes sp. 246 methanolic extract (ME) markedly reduced the viability of BxPC-3 human pancreatic cancer cells. However, the underlying mechanism ME remained unclear. Hence, we attempted to elucidate the anticancer effect of ME on BxPC-3 human pancreatic cancer cells. First, we investigated the components of ME and their cytotoxicity in normal cells. Then, we confirmed the G1 phase arrest mediated growth inhibitory effect of ME using a cell counting assay and cell cycle analysis. Moreover, we found that the migration-inhibitory effect of ME using a Transwell migration assay. Through RNA sequencing, Gene Ontology-based network analysis, and western blotting, we explored the intracellular mechanisms of ME in BxPC-3 cells. ME modulated the intracellular energy metabolism-related pathway by altering the mRNA levels of IGFBP3 and PPARGC1A in BxPC-3 cells and reduced PI3K and mTOR phosphorylation by upregulating IGFBP3 and 4E-BP1 expression. Finally, we verified that ME reduced the growth of three-dimensional (3D) pancreatic cancer spheroids. Our study demonstrates that ME suppresses pancreatic cancer proliferation through the IGFBP3-PI3K-mTOR signaling pathway. This is the first study on the anticancer effect of the ME against pancreatic cancer, suggesting therapeutic possibilities and the underlying mechanism of ME action.

• IMMUNE NETWORK
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• v.22 no.1
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• pp.3.1-3.21
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• 2022

Cancer is one of the leading causes of death worldwide and the number of cancer patients is expected to continuously increase in the future. Traditional cancer therapies focus on inhibiting cancer growth while largely ignoring the contribution of the immune system in eliminating cancer cells. Recently, better understanding of immunological mechanisms pertaining to cancer progress has led to development of several immunotherapies, which revolutionized cancer treatment. Nonetheless, only a small proportion of cancer patients respond to immunotherapy and maintain a durable response. Among multiple factors contributing to the variability of immunotherapy response rates, commensal microbiota inhabiting patients have been identified as one of the most critical factors determining the success of immunotherapy. The functional diversity of microbiota differentially affects the host immune system and controls the efficacy of immunotherapy in individual cancer patients. Moreover, clinical studies have demonstrated that changing the gut microbiota composition by fecal microbiota transplantation in patients who failed a previous immunotherapy converts them to responders of the same therapy. Consequently, both academic and industrial researchers are putting extensive efforts to identify and develop specific bacteria or bacteria mixtures for cancer immunotherapy. In this review, we will summarize the immunological roles of commensal microbiota in cancer treatment and give specific examples of bacteria that show anticancer effect when administered as a monotherapy or as an adjuvant agent for immunotherapy. We will also list ongoing clinical trials testing the anticancer effect of commensal bacteria.

• BMB Reports
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• v.34 no.3
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• pp.237-243
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• 2001

Taxol, a natural product extracted from the Taxus brevifolia, is known to have significant anti-tumor activities against many common cancers, including ovarian and breast cancers. Despite the pronounced anti-tumor activity of this compound, its poor solubility in aqueous solutions hampers its clinical applications. We studied the anticancer mechanisms of the water-soluble taxol diethylenetriamine pentaacetate (DTPA) used for radiolabeling, and compared it to that of taxol. In vitro cytotoxicities of taxol and taxol-DTPA conjugate were tested in HT29 human colorectal cancer cells by the MTT method. As the result, the $IC_{50}$ value of the taxol-DTPA conjugate was about three fold higher than that of taxol. When analyzed by an agarose gel electrophoresis, the DNA ladders became evident after the incubation of cells with the taxol-DTPA conjugate for 24 h. We also found morphological changes of the cells undergoing apoptosis with electron microscopy Next, we examined the signal pathway of taxol-DTPA conjugate-induced apoptosis in HT29 cells. The activation of extracellular signal-regulated protein kinase (ERK1/2) occurred at 10, 30, 60 and 120 min after 200 nM taxol-DTPA conjugate treatment. The pretreatment of the MEK inhibitor (PD98059) completely blocked the taxol-DTPA conjugate-induced ERK1/2 activation. The activated ERK1/2 translocated into the nucleus at the same time and phosphorylated its transcriptional factor, c-Jun. These results suggest that the taxol-DTPA conjugate has an apoptotic activity in HT29 cells, and that its proapoptic activity might be related with the signal transduction via ERK1/2 and c-Jun similar to that of taxol.

• Journal of Life Science
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• v.30 no.6
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• pp.501-512
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• 2020

Sasa quelpaertensis Nakai leaf has been used as a folk medicine for the treatment of gastric ulcer, dipsosis, and hematemesis based on its anti-inflammatory, antipyretic, and diuretic characteristics. We have previously reported the procedure for deriving a phytochemical-rich extract (PRE) from S. quelpaertensis and how PRE and its ethyl acetate fraction (EPRE) exhibits an anticancer effect by inducing apoptosis in various gastric cancer cells. To explore the molecular targets involved in this apoptosis, we investigated the mRNA and microRNA profiles of EPRE-treated SNU-16 human gastric cancer cells. In total, 2,875 differentially expressed genes were identified by RNA sequencing, and gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses indicated that the EPRE-modulated genes are associated with apoptosis, mitogen-activated protein kinase, inflammatory response, tumor necrosis factor signaling, and cancer pathways. Subsequently, protein-protein interaction network analysis confirmed interactions among genes associated with cell death and apoptosis, and 27 differentially expressed microRNAs were identified by further sequencing. Here, GO and KEGG pathway analysis revealed that EPRE modified the expression of microRNAs associated with the cell cycle and cell death, as well as signaling of tropomyosin-receptor-kinase receptor, transforming growth factor-b, nuclear factor kB, and cancer pathways. Taken together, these results provide insight into the mechanisms underlying the anticancer effect of EPRE.

• Journal of Life Science
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• v.23 no.4
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• pp.518-528
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• 2013

Scutellaria baicalensis, belonging to the family Labiatae, is widely distributed in Korea, China, Mongolia, and eastern Siberia. It has been used in traditional medicine for various diseases, such as dysentery, pyrexia, jaundice, and carbuncles. In addition, S. baicalensis is reported to possess various beneficial pharmacological activities, including anti-inflammatory, antidiabetic, antiviral, antihypertension, antioxidant, and anticancer effects. However, the molecular mechanisms of its anticancer activity have not been clearly elucidated. In the present study, we investigated the proapoptotic effects of ethanol extract of S. baicalensis (EESB) on human renal cell carcinoma Caki-1 cells. The anti-proliferative activity of EESB was associated with apoptosis induction, which was associated with the up-regulation of death receptor 4, the Fas ligand, and Bax and the down-regulation of Bid, XIAP, and cIAP-1 proteins. EESB treatment also induced mitochondrial dysfunction, proteolytic activation of caspase-3, -8, and -9 and degradation of caspase-3 substrate proteins, such as poly (ADP-ribose) polymerase, ${\beta}$-catenin, and phospholipase C-${\gamma}1$. However, pretreatment of a pan-caspase inhibitor, z-VAD-fmk, significantly attenuated the EESB-induced apoptosis. Taken together, these findings suggest that EESB may be a potential chemotherapeutic agent. Further studies will be needed to identify the active compounds that confer the anticancer activity of S. baicalensis.

• Journal of Life Science
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• v.31 no.5
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• pp.527-535
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• 2021

Lysosomes are organelles surrounded by membranes that contain acid hydrolases; they degrade proteins, macromolecules, and lipids. According to nutrient conditions, lysosomes act as signaling hubs that regulate intracellular signaling pathways and are involved in the homeostasis of cells. Therefore, the lysosomal dysfunction occurs in various diseases, such as lysosomal storage disease, neurodegenerative diseases, and cancers. Multiple forms of stress can increase lysosomal membrane permeabilization (LMP), resulting in the induction of lysosome-mediated cell death through the release of lysosomal enzymes, including cathepsin, into the cytosol. Here we review the molecular mechanisms of LMP-mediated cell death and the enhancement of sensitivity to anticancer drugs. Induction of partial LMP increases apoptosis by releasing some cathepsins, whereas massive LMP and rupture induce non-apoptotic cell death through release of many cathepsins and generation of ROS and iron. Cancer cells have many drug-accumulating lysosomes that are more resistant to lysosome-sequestered drugs, suggesting a model of drug-induced lysosome-mediated chemoresistance. Lysosomal sequestration of hydrophobic weak base anticancer drugs can have a significant impact on their subcellular distribution. Lysosome membrane damage by LMP can overcome resistance to anticancer drugs by freeing captured hydrophobic weak base drugs from lysosomes. Therefore, LMP inducers or lysosomotropic agents can regulate lysosomal integrity and are novel strategies for cancer therapy.