• 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.

• Biomedical Science Letters
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• v.17 no.3
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• pp.177-184
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• 2011

Potassium cyanate (KOCN) is an inorganic compound and induces the carbamylation of proteins with cytotoxic effects on human cells. Although there is a potential cytotoxic molecule, the role of KOCN on the apoptosis of cancer cell is not well understood. The present study investigated the effects of KOCN on the human colorectal cancer cell line, HCT 116 cells. To understand the anti-cancer effect of KOCN on HCT 116 cells, we examined alteration of apoptosis, the intracellular $Ca^{2+}$ concentration, the intracellular signaling pathway and generation of reactive oxygen species (ROS) in these cells treated with KOCN. The apoptosis of HCT 116 cells was induced by KOCN in a dose-dependent manner at 24 hours and 48 hours, respectively. The apoptosis was processed via the cleavage of poly ADP-ribose polymerase (PARP) and activation of caspase 3 in HCT 116 cells. KOCN induced the elevation of intracellular $Ca^{2+}$ concentration and changed the expressions of Bcl-2 family proteins. The pro-apoptotic Bax was continuously up-regulated, and the anti-apoptotic Bcl-2 was down-regulated by KOCN. KOCN also induced the hyperpolarization of mitochondria and the generation of ROS in HCT 116 cells. Taken together, these results indicate that KOCN induces the apoptosis of HCT 116 cells by disruption of $Ca^{2+}$ homeostasis and via mitochondrial pathway. This study provides the compound that may be used as a potent agent for the treatment of colorectal cancer.

• Journal of Acupuncture Research
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• v.31 no.2
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• pp.87-98
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• 2014

Objectives : We investigated whether snake venom toxin(SVT) from Vipera lebetina turanica sensitizes HT29 human epithelial colorectal cancer cells to tumor necrosis factor(TNF)-related apoptosis-inducing ligand(TRAIL) induced apoptosis in cancer cells. Methods : Cell viability assay was used to assess the inhibitory effect of TRAIL on cell growth of HT29 human colorectal cancer cells. And 6-diamidino-2-phenylindole(DAPI), terminal deoxynucleotidyl transferase mediated dUTP nick end labeling assay(TUNEL) staining assay were used to evaluate cell-apoptosis. Western blot analysis were conducted to observe apoptosis related proteins and death receptor. To assess whether the synergized inhibitory effect of SVT and TRAIL on reactive oxygen species(ROS) generation was reversed by strong anti-oxidative agent. Results : SVT with TRAIL inhibited HT29 cell growth different from TRAIL alone. Consistent with cell growth inhibition, the expression of TRAIL receptors; Expression of death receptor(DR)4 and DR5 was significantly increased and intrinsic pro-apoptotic cleaved caspase-3, -9 was subsequently increased together with increase of Bax/Bcl-2 ratio and extrinsic pro-apototic caspase-8 was also activated. In addition, the expression of anti-apoptotic survival proteins, a marker of TRAIL resistance(eg, cFLIP, survivin, X-linked inhibitor of apoptosis protein(XIAP) and Bcl-2) was suppressed by the combination treatment of SVT and TRAIL. Pretreatment with the ROS scavenger N-acetylcysteine abolished the SVT and TRAIL-induced upregulation of DR4 and DR5 expression and expression of the intrinsic pro-apoptotic caspase-3 and-9. Conclusion : The collective results suggest that SVT facilitates TRAIL-induced apoptosis in $HT_{29}$ human epithelial colorectal cancer cells through up-regulation of the TRAIL receptors; DR4 and DR5 and consecutive induction of bilateral apoptosis via regulating apoptosis related proteins.

• Biomolecules & Therapeutics
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• v.30 no.6
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• pp.576-584
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• 2022

Colorectal cancer is diagnosed as the third most prevalent cancer; thus, effective therapeutic agents are urgently required. In this study, we synthesized six homoisoflavane derivatives of cremastranone and investigated their cytotoxic effects on the human colorectal cancer cell lines HCT116 and LoVo. We further examined the related mechanisms of action using two of the potent compounds, SH-19027 and SHA-035. They substantially reduced the cell viability and proliferation in a dose-dependent manner. Treatment with SH-19027 and SHA-035 induced cell cycle arrest at the G2/M phase and increased expression of p21 both of which are implicated in cell cycle control. In addition, the apoptotic cell population and apoptosis-associated marker expression were accordingly increased. These results suggest that the synthesized cremastranone derivatives have anticancer effects through the suppression of cell proliferation and induction of apoptosis. Therefore, the synthesized cremastranone derivatives could be applied as novel therapeutic agents against colorectal cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.6
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• pp.3631-3634
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• 2013

MicroRNAs (MiRNAs) play important roles in coordinating a variety of cellular processes and abnormal expression has been linked to the occurrence of several cancers. The miRNA miR-451 is downregulated in colorectal carcinoma (CRC) cells, suggested by several research groups including our own. In this study, synthetic miR-451 mimics were transfected into the SW620 human CRC cell line using Lipofectamine 2000 and expression of miR-451 was analyzed by real time PCR, while expression of CAB39, LKB1, AMPK, AKT, PI3K and Bcl2 was analyzed by Western blot, and cell growth was detected by MTT assay. In comparison to the controls, a significant increase in the expression of miR-451 was associated with significantly decreased expression of CAB39, LKB1, AMPK, AKT, PI3K and Bcl2. The capacity of cell proliferation was significantly decreased by miR-451 expression, which also inhibited cell growth. Our study confirmed that miR-451 has a repressive role in CRC cells by inhibiting cell growth through down-regulating the P13K/AKT pathway.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.21
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• pp.9185-9190
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• 2014

Cyclo-oxygenase-2(Cox-2), a key regulator of inflammation-producing prostaglandins, promotes cell proliferation and growth. Therefore, a better understanding of the regulatory mechanisms of Cox-2 could lead to novel targeted cancer therapies. MicroRNAs are strongly implicated in colorectal cancer but their specific roles and functions have yet to be fully elucidated. MiR-1297 plays an important role in lung adenocarcinoma and laryngeal squamous cell carcinoma, but its significance in colorectal cancer (CRC) has yet to be reported. In our present study, we found miR-1297 to be down regulated in both CRC-derived cell lines and clinical CRC samples, when compared with normal tissues. Furthermore, miR-1297 could inhibit human colorectal cancer LOVO and HCT116 cell proliferation, migration, and invasion in vitro and tumorigenesis in vivo by targeting Cox-2. Moreover, miR-1297 directly binds to the 3'-UTR of Cox-2, and the expression level was drastically decreased in LOVO and HCT116 cells following overexpression of miR-1297. Additionally, Cox-2 expression levels are inversely correlated with miR-1297 expression in human colorectal cancer xenograft tissues. These results imply that miR-1297 has the potential to provide a new approach to colorectal cancer therapy by directly inhibiting Cox-2 expression.

• The Korean Journal of Food And Nutrition
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• v.35 no.6
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• pp.464-472
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• 2022

The present study was designed to investigate the antiproliferative activity and molecular mechanisms of Bibimbap in HT-29 human colorectal adenocarcinoma cells. Bibimbap extract inhibited the proliferation of HT-29 cells by 50% at a concentration of 10.1±0.17 mg/mL for 48 h. The population of live cells decreased slightly, and the morphology changed with a reduction in cell volume (pyknosis) with Bibimbap. Treatment with 5 mg/mL of Bibimbap resulted in slight cell shrinkage. Furthermore, as the Bibimbap dose increased to 10 mg/mL, these characteristics were more evident, and HT-29 cells exhibited partial detachment by staining with the DNA-binding dye Hoechst 33342. Flow cytometric analysis by Annexin V and PI double staining showed that Bibimbap increased the levels of apoptosis. Analysis of the mechanism of these events showed that Bibimbap-treated cells exhibited a mitochondria-dependent apoptotic pathway through the modulation of caspase-3, caspase-8, caspase-9, and poly-ADP ribose polymerase, as well as Bax and Bcl-2 expression in dose- and time-dependent manners. Consequently, Bibimbap exerts a significant antiproliferative effect on HT-29 human colorectal adenocarcinoma cells.

• Nutrition Research and Practice
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• v.18 no.1
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• pp.62-77
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• 2024

BACKGROUND/OBJECTIVES: Colorectal cancer (CRC) is the third most common cancer worldwide with a high recurrence rate. Oxaliplatin (OXA) resistance is one of the major reasons hindering CRC therapy. β-Carotene (BC) is a provitamin A and is known to have antioxidant and anticancer effects. However, the combined effect of OXA and BC has not been investigated. Therefore, this study investigated the anticancer effects and mechanism of the combination of OXA and BC on CRC. MATERIALS/METHODS: In the present study, the effects of the combination of OXA and BC on cell viability, cell cycle arrest, and cancer stemness were investigated using HCT116, HT29, OXA-resistant cells, and human CRC organoids. RESULTS: The combination of OXA and BC enhanced apoptosis, G₂/M phase cell cycle arrest, and inhibited cancer cell survival in human CRC resistant cells and CRC organoids without toxicity in normal organoids. Cancer stem cell marker expression and self-replicating capacity were suppressed by combined treatment with OXA and BC. Moreover, this combined treatment upregulated apoptosis and the stem cell-related JAK/STAT signaling pathway. CONCLUSIONS: Our results suggest a novel potential role of BC in reducing resistance to OXA, thereby enhances the anticancer effects of OXA. This enhancement is achieved through the regulation of cell cycle, apoptosis, and stemness in CRC.

• Korean Journal of Plant Resources
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• v.33 no.4
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• pp.263-270
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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.17 no.3
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• pp.1103-1110
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• 2016

In the present study, we investigated the effects of motesanib (AMG 706), a multikinase inhibitor alone and in combination with DuP-697, an irreversible selective inhibitor of COX-2, on cell proliferation, angiogenesis, and apoptosis induction in a human colorectal cancer cell line (HT29). Real time cell analysis (RTCA, Xcelligence system) was used to determine the effects on colorectal cancer cell proliferation. Apoptosis was assessed with annexin V staining and angiogenesis was determined with chorioallantoic membrane model. We found that motesanib alone exerted antiproliferative, antiangiogenic and apoptotic effects on HT29 colorectal cancer cells. Combination with DUP-697 increased the antiproliferative, antiangiogenic and apoptotic effects. Results of this study indicate that motesanib may be a good choice in treatment of colorectal tumors. In addition, the increased effects of combination of motesanib with DuP-697 raise the possibility of using lower doses of these drugs and therefore avoid/minimize the dose-dependent side effects generally observed.