• Herbal Formula Science
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• v.23 no.1
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• pp.101-110
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• 2015

Objectives : The purpose of this study was to investigate the anti-cancer effects of Oldenlandia diffusa extract on WiDr human colorectal adenocarcinoma cells. Methods : We examined cell death by (3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide) MTT assay and the caspase 3 and 9 activity assay with Oldenlandia diffusa extract. To examine the inhibitory effects of Oldenlandia diffusa extract, we performed a cell cycle (sub-G1) analysis and mitochondrial membrane potential for the WiDr cells after 24 hours with Oldenlandia diffusa extract. Results : 1. Oldenlandia diffusa extract induced cell death in WiDr cells. 2. The sub-G1 peak was increased by Oldenlandia diffusa extract in WiDr cells. 3. Oldenlandia diffusa extract leads to increase the mitochondrial membrane depolarization in WiDr cells. 4. Oldenlandia diffusa extract increases caspase 3 and 9 activities in WiDr cells. 5. Oldenlandia diffusa extract combined with several anti-cancer drugs (paclitaxel, 5-fluorouracil, cisplatin, ectoposide, doxorubicin and docetaxel) markedly inhibited the growth of WiDr cells compared to Oldenlandia diffusa extract and anti-cancer drugs alone. Conclusions : Oldenlandia diffusa extract has an apoptotic role in human colorectal cancer cells and a potential role in developing therapeutic agents against colorectal cancer.

• Biomedical Science Letters
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• v.28 no.3
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• pp.200-205
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• 2022

Established cancer cell lines are widely used for developing biomarkers for the patient-specific treatment of colorectal cancer and predicting prognoses. However, cancer cell lines may exhibit different drug responses depending upon the characteristics of the cell line. Therefore, it is necessary to select a tumor cell line suitable for the purpose of the study by considering the cell characteristics. This study investigated the levels of CXCL10, which were recently been reported to play an important role in the outcome of tumor treatment, secreted by colon cancer cells. 2 × 10⁵ cells/mL of each colorectal cancer cell was seeded into a 35 mm cell culture dish. After 24 h incubation, culture supernatant was used to determine the secreted CXCL10 levels. Among six colorectal cancer cell lines (HT-29, HCT116, CaCo-2, SW620, SW480, and CT26), Caco-2 cells showed the highest level of CXCL10 secretion. HT-29 cells showed the second-highest level of CXCL10 secretion. No significantly measurable level of CXCL10 secretion was detected in HCT116 cells. These results will be helpful in investigating the molecular basis of colorectal cancer.

• Radiation Oncology Journal
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• v.28 no.3
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• pp.147-154
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• 2010

Purpose: To investigate the radiosensitizing effect of the selective epidermal growth factor receptor (EGFR) inhibitor nimotuzumab in human colorectal cancer cell lines. Materials and Methods: Four human colorectal cancer cell lines, HCT-8, LoVo, WiDr, and HCT-116 were treated with nimotuzumab and/or radiation. The effects on cell proliferation, viability, and cell cycle progression were measured by MTT, clonogenic survival assay, flow cytometry, and Western blot. Results: An immunoblot analysis revealed that EGFR phosphorylation was inhibited by nimotuzumab in colorectal cancer cell lines. Under these experimental conditions, pre-treatment with nimotuzumab increased radiosensitivity of colorectal cancer cell lines, except for cell line HCT-116. However, cell proliferation or cell cycle progression was not affected by the addition of nimotuzumab, irrespective of irradiation. Conclusion: Nimotuzumab enhanced the radiosensitivity of colorectal cancer cells in vitro by inhibiting EGFR-mediated cell survival signaling. This study provided a rationale for the clinical application of the selective EGFR inhibitor, nimotuzumab in combination with radiation in colorectal cancer cells.

• Biomolecules & Therapeutics
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• v.30 no.3
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• pp.265-273
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• 2022

Resistance to chemotherapeutic drugs is a significant problem in the treatment of colorectal cancer, resulting in low response rates and decreased survival. Recent studies have shown that shikonin, a naphthoquinone derivative, promotes apoptosis in colon cancer cells and cisplatin-resistant ovarian cells, raising the possibility that this compound may be effective in drug-resistant colorectal cancer. The aim of this study was to characterize the molecular mechanisms underpinning shikonin-induced apoptosis, with a focus on endoplasmic reticulum (ER) stress, in a 5-fluorouracil-resistant colorectal cancer cell line, SNU-C5/5-FUR. Our results showed that shikonin significantly increased the proportion of sub-G₁ cells and DNA fragmentation and that shikonin-induced apoptosis is mediated by mitochondrial Ca²⁺ accumulation. Shikonin treatment also increased the expression of ER-related proteins, such as glucose regulatory protein 78 (GRP78), phospho-protein kinase RNA-like ER kinase (PERK), phospho-eukaryotic initiation factor 2 (eIF2α), phospho-phosphoinositol-requiring protein-1 (IRE1), spliced X-box-binding protein-1 (XBP-1), cleaved caspase-12, and C/EBP-homologous protein (CHOP). In addition, siRNA-mediated knockdown of CHOP attenuated shikonin-induced apoptosis, as did the ER stress inhibitor TUDCA. These data suggest that ER stress is a key factor mediating the cytotoxic effect of shikonin in SNU-C5/5-FUR cells. Our findings provide an evidence for a mechanism in which ER stress leads to apoptosis in shikonin-treated SNU-C5/5-FUR cells. Our study provides evidence to support further investigations on shikonin as a therapeutic option for 5-fluorouracil-resistant colorectal cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.15
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• pp.6321-6326
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• 2014

${\alpha}$-Methyl-n-butylshikonin (MBS), one of the active components in the root extracts of Lithospermum erythrorhizon, posses antitumor activity. In this study, we assess the molecular mechanisms of MBS in causing apoptosis of SW620 cells. MBS reduced the cell viability of SW620 cells in a dose-and time-dependent manner and induced cell apoptosis. Treatment of SW620 cells with MBS down-regulated the expression of Bcl-2 and up-regulated the expression of Bak and caused the loss of mitochondrial membrane potential. Additionally, MBS treatment led to activation of caspase-9, caspase-8 and caspase-3, and cleavage of PARP, which was abolished by pretreatment with the pan-caspase inhibitor Z-VAD-FMK. MBS also induced significant elevation in the phosphorylation of JNK and p38. Pretreatment of SW620 cells with specific inhibitors of JNK (SP600125) and p38 (SB203580) abrogated MBS-induced apoptosis. Our results demonstrated that MBS inhibited growth of colorectal cancer SW620 cells by inducing JNK and p38 signaling pathway, and provided a clue for preclinical and clinical evaluation of MBS for colorectal cancer therapy.

• BMB Reports
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• v.56 no.10
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• pp.557-562
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• 2023

Dysregulation of the E3 ubiquitin ligase Parkin has been linked to various human cancers, indicating that Parkin is a tumor suppressor protein. However, the mechanisms of action of Parkin remain unclear to date. Thus, we aimed to elucidate the mechanisms of action of Parkin as a tumor suppressor in human lung and colorectal cancer cells. Results showed that Parkin overexpression reduced the viability of A549 human lung cancer cells by inducing G2/M cell cycle arrest. In addition, Parkin caused DNA damage and ATM (Ataxia telangiectasia mutated) activation, which subsequently led to p53 activation. It also induced the p53-mediated upregulation of p21 and downregulation of cyclin B1. Moreover, Parkin suppressed the proliferation of HCT-15 human colorectal cancer cells by a mechanism similar to that in A549 lung cancer cells. Taken together, our results suggest that the tumor-suppressive effects of Parkin on lung and colorectal cancer cells are mediated by DNA damage/p53 activation/cyclin B1 reduction/cell cycle arrest.

• 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.

• Biomolecules & Therapeutics
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• v.26 no.3
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• pp.313-321
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• 2018

Anti-cancer drug resistance is a major problem in colorectal cancer (CRC) research. Although several studies have revealed the mechanism of cancer drug resistance, molecular targets for chemotherapeutic combinations remain elusive. To address this issue, we focused on the expression of cellular prion protein ($PrP^C$) in 5-FU-resistant CRC cells. In 5-FU-resistant CRC cells, $PrP^C$ expression is significantly increased, compared with that in normal CRC cells. In the presence of 5-FU, $PrP^C$ increased CRC cell survival and proliferation by maintaining the activation of the PI3K-Akt signaling pathway and the expression of cell cycle-associated proteins, including cyclin E, CDK2, cyclin D1, and CDK4. In addition, $PrP^C$ inhibited the activation of the stress-associated proteins p38, JNK, and p53. Moreover, after treatment of 5-FU-resistant CRC cells with 5-FU, silencing of $PrP^C$ triggered apoptosis via the activation of caspase-3. These results indicate that $PrP^C$ plays a key role in CRC drug resistance. The novel strategy of combining chemotherapy with $PrP^C$ targeting may yield efficacious treatments of colorectal cancer.

• The Korean Journal of Physiology and Pharmacology
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• v.28 no.3
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• pp.183-196
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• 2024

Ferroptosis is a novel mechanism of programmed cell death, characterized by intracellular iron overload, intensified lipid peroxidation, and abnormal accumulation of reactive oxygen species, which ultimately resulting in cell membrane impairment and demise. Research has revealed that cancer cells exhibit a greater demand for iron compared to normal cells, indicating a potential susceptibility of cancer cells to ferroptosis. Stomach and colorectal cancers are common gastrointestinal malignancies, and their elevated occurrence and mortality rates render them a global health concern. Despite significant advancements in medical treatments, certain unfavorable consequences and drug resistance persist. Consequently, directing attention towards the phenomenon of ferroptosis in gastric and colorectal cancers holds promise for enhancing therapeutic efficacy. This review aims to elucidate the intricate cellular metabolism associated with ferroptosis, encompassing lipid and amino acid metabolism, as well as iron metabolic processes. Furthermore, the significance of ferroptosis in the context of gastric and colorectal cancer is thoroughly examined and discussed.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.2
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• pp.1003-1007
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• 2013

Objective: This work aimed to investigate the correlations of tumor-associated macrophages (TAMs) and their subtypes M1 and M2 with liver metastasis of colorectal cancer, and provide useful references for seeking predictors of liver metastasis and studying mechanisms. Methods: 120 patients with colorectal cancer from 2000 to 2009 were divided into low, middle and high liver metastasis groups (group A, B and C, respectively). S-P immunohistochemical staining and microscopic observation were conducted to compare expression in CD68-positive cells (TAMs), CD80-positive cells (M1) and CD163-positive cells (M2) in three groups. Correlations of TAMs, M1, M2, and M2/M1 ratio with clinical and pathological parameters were analyzed. Results: With increase of liver metastatic ability, the number of TAMs decreased gradually, with no significant difference between any two of the three groups (P > 0.05), while the numbers of M1 and M2 were significantly decreased and increased, respectively, with significant difference between any two of three groups (P < 0.05 or P < 0.01). In addition, the M2/M1 ratio increased with increase of liver metastatic ability (P < 0.01). There was no statistical significance of correlation of TAMs with each clinical and pathological parameter. M1 was negatively related with lymphatic metastasis and liver metastatic ability. M2 was positively correlated with preoperative CEA level, lymphatic metastasis, tumor differentiation degree and liver metastatic ability. The same was the case for the M2/M1 ratio. Conclusions: Effects of TAMs on liver metastasis of colorectal cancer do not depend on the total number of TAMs, but on the number and proportion of functional subtypes M1 and M2. M2 number and M2/M1 ratio are more accurate predictors for liver metastasis of colorectal cancer.