• Journal of Pharmaceutical Investigation
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• v.36 no.5
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• pp.309-314
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• 2006

The multicellular layers(MCL) of human cancer cells is a three dimensional(3D) in vitro model for human solid tumors which has been used primarily for the assessment of avascular penetration of anti-cancer drugs. For anti-cancer drugs with penetration problem, MCL represents a good experimental model that can provide clinically relevant data. Calcein-AM is a fluorescent dye that demonstrates the cellular vitality in a graded manner in cancer cell culture system. In the present study, we evaluated the use of calcein-AM for determination of anti-proliferative activity of anti-cancer agents in MCL model of DLD-1 human colorectal cancer cells. Optical sectioning of confocal imaging was compromised with photonic attenuation and penetration barrier in the deep layers of MCL. By contrast, fluorescent measurement on the cryo-sections provided a feasible alternative. Cold pre-incubation did not enhance the calcein-AM distribution to a significant degree in MCL of DLD-1 cells. However, the simultaneous determination of drug penetration and cellular vitality appeared to be possible in drug treated MCL. In conclusion, these data suggest that calcein-AM can be used for the simultaneous determination of drug-induced anti-proliferative effect and drug penetration in MCL model.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.2
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• pp.112-117
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• 2010

Aurora kinases represent a novel family of serine/threonine kinases crucial for cell cycle control. Aurora-2 kinase is mainly involved in centrosome function, mitotic entry, and spindle assembly. Aurora-2 kinase overexpression causes centrosome amplification and the formation of multipolar mitotic spindles, which leads to tumor aneuploidy and so it has been found to play an important role in tumorigenicity in many cancers such as colorectal cancer, breast cancer and cervical cancer. Hence, the goal of this study is to identify the correlation of clinicopathlogical factors and overexpression of Aurora-2 kinase in oral squamous cell carcinoma. We studied the immunohistochemical staining of Aurora-2 kinase in 20 specimens of 20 patients with oral squamous cell carcinoma and the relationships between Aurora-2 kinase over expression and each of the clinico-pathological parameters were analyzed by Pearson correlation analysis. Statistical significance was set at P < 0.05. The results were as follows. 1. In the immunohistochemical study of poorly differentiated and invasive oral squamous cell carcinoma, the high level staining of Aurora-2 kinase was observed. 2. The correlation between immunohistochemical Aurora-2 kinase expression and histopathological differentiation of specimens was significant. These findings suggest that overexpression of Aurora-2 kinase may play a important role in carcinogenesis of oral squamous cell carcinoma.

• Biomolecules & Therapeutics
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• v.30 no.2
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• pp.137-144
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• 2022

Radiation resistance represents an imperative obstacle in the treatment of patients with colorectal cancer, which remains difficult to overcome. Here, we explored the anti-proliferative and migration-inhibiting properties of the natural product shikonin on a radiation-resistant human colon carcinoma cell line (SNU-C5RR). Shikonin reduced the viability of these cells in a dose-dependent manner; 38 µM of shikonin was determined as the half-maximal inhibitory concentration. Shikonin induced apoptotic cell death, as demonstrated by increased apoptotic body formation and the number of TUNEL-positive cells. Moreover, shikonin enhanced mitochondrial membrane depolarization and Bax expression and also decreased Bcl-2 expression with translocation of cytochrome c from mitochondria into the cytosol. In addition, shikonin activated mitogen-activated protein kinases, and their specific inhibitors reduced the cytotoxic effects of shikonin. Additionally, shikonin decreased the migration of SNU-C5RR cells via the upregulation of E-cadherin and downregulation of N-cadherin. Taken together, these results suggest that shikonin induces mitochondria-mediated apoptosis and attenuates epithelial-mesenchymal transition in SNU-C5RR cells.

• Journal of Life Science
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• v.22 no.3
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• pp.360-365
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• 2012

We investigated the anti-proliferative activity of sulforaphane and expression changes of NAG-1 and p21 genes in response to sulforaphane treatment in human colorectal HCT116 cells. The results showed that sulforaphane decreased cell viabilities in a dose-dependent manner and induced expression of NAG-1 and p21 proteins in a dose-dependent and time-dependent manner. In addition, we found that NAG-1 expression by sulforaphane was not dependent on the presence of p53, whereas p21 expression was dependent on p53 presence. The results indicated that up-regulation of NAG-1 was not related with the activity of a dietary histone deacetylase inhibitor of sulforaphane. ATF3 induction was detected from 2 hr after sulforaphane treatment, indicating that ATF3 could be a transcription factor to up-regulate NAG-1 expression. The results of this study may help to increase our understanding of the molecular mechanism of anti-cancer activity mediated by sulforaphane in human colorectal cancer cells.

• Journal of Microbiology and Biotechnology
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• v.22 no.1
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• pp.50-57
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• 2012

Phospholipase C-${\gamma}l$ (PLC-${\gamma}l$) expression is associated with cellular transformation. Notably, PLC-${\gamma}$ is up-regulated in colorectal cancer tissue and breast carcinoma. Because exotoxins released by Clostridium botulinum have been shown to induce apoptosis and promote growth arrest in various cancer cell lines, we examined here the potential of Clostridium difficile toxin A to selectively induce apoptosis in cells transformed by PLC-${\gamma}l$ overexpression. We found that PLC-${\gamma}l$-transformed cells, but not vector-transformed (control) cells, were highly sensitive to C. difficile toxin A-induced apoptosis and mitotic inhibition. Moreover, expression of the proapoptotic Bcl2 family member, Bim, and activation of caspase-3 were significantly up-regulated by toxin A in PLC-${\gamma}l$-transformed cells. Toxin A-induced cell rounding and paxillin dephosphorylation were also significantly higher in PLC-${\gamma}l$-transformed cells than in control cells. These findings suggest that C. difficile toxin A may have potential as an anticancer agent against colorectal cancers and breast carcinomas in which PLC-${\gamma}l$ is highly up-regulated.

• Animal cells and systems
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• v.15 no.1
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• pp.9-17
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• 2011

Colorectal cancer is the third leading cause of cancer-related death in Western countries. Chemotherapeutic agents with different mechanisms of action have shown an increase in cure rates. In the present study, we investigated the effect of a combination of low concentration of paclitaxel (taxol, 5 nM) and topoisomerase 1 inhibitor camptothecin (CPT) on HCT116 colon cancer cells. Although the viability of cells treated with taxol alone was similar to that of control cells, sequential treatment with taxol and CPT exhibited high cytotoxicity. However, the opposite sequence of treatment did not exert cytotoxic effects on HCT116 cells. This enhanced cytotoxicity of the sequential combination therapy was the result of mitotic arrest, which increased the level of $p21^{Cip1/WAF1}$ through the p38 mitogen-activated protein kinase (MAPK) pathway. Knockdown by $p21^{Cip1/WAF1}$ siRNA or treatment with a p38 inhibitor reduced the viability of cells sequentially exposed to taxol and CPT. Taken together, a low taxol concentration in combination with CPT induced mitotic arrest in HCT116 cells, leading to synergistic cell death through enhanced expression of $p21^{Cip1/WAF1}$ and p38 MAPK pathway. Therefore, taxol could playa role as a sensitizer of CPT in colon cancer cells.

• YAKHAK HOEJI
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• v.53 no.4
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• pp.184-188
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• 2009

Fluorouracil (5-FU) is one of the most widely used chemotherapeutic drugs in the treatment of advanced colorectal cancer patients. Capsaicin (N-vanillyl-8-methyl-alpha-nonenamide), a spicy component of hot pepper, is a homovanillic acid derivative that preferentially induces cancer cells to undergo apoptosis. The purpose of the present study is to examine whether capsaicin enhances the anticancer effect of 5-fluorouracil in HT-29 human colon cancer cells by inducing apoptosis, and whether PPARgamma is involved in the capsaicin action in combination treatment with 5-FU. Treatment of the cells with either 5-FU or capsaicin alone for 48 h had little effect on the cell viability up to $50{\mu}M$ concentration, whereas co-treatment of the cells with capsaicin in the presence of 5-FU for 48 h significantly decreased the cell viability in a concentration-dependent manner. In addition, caspase-3 activity, a marker enzyme for apoptosis, was significantly increased by the combined treatment with 5-FU and capsaicin compared to the 5-FU or capsaicin alone treatment. Also, treatment with troglitazone, a peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$) agonist, further enhanced the effect of the combination treatment on the cell viability and caspase-3 activity, and bisphenol A diglycidyl ether (BADGE), a $PPAR{\gamma}$ antagonist, blocked the effect of the combination treatment. These results suggest that the combination treatment of HT-29 cells with 5-FU and capsaicin induces apoptotic cell death at relatively low concentration than each drug alone, and the combination treatment may be associated with the $PPAR{\gamma}$ pathway activation.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.4999-5005
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• 2013

Objective: This study aimed to investigate expression of the proto-oncogene POK erythroid myeloid ontogenic factor (Pokemon) in colorectal cancer (CRC), and assess inhibitory effects of a small interference RNA (siRNA) expression vector in SW480 and SW620 cells. Methods: Semi-quantitative reverse transcription-polymerase chain reaction (PCR) and immunohistochemistry were performed to determine mRNA and protein expression levels of Pokemon in CRC tissues. Indirect immunofluorescence staining was applied to investigate the location of Pokemon in SW480 and SW620 cells. The siRNA expression vectors that were constructed to express a short hairpin RNA against Pokemon were transfected to the SW480 and SW620 cells with a liposome. Expression levels of Pokemon mRNA and protein were examined by real-time quantitative-fluorescent PCR and western blot analysis. The effects of Pokemon silencing on proliferation of SW480 and SW620 cells were evaluated with reference to growth curves with MTT assays. Results: The mRNA expression level of Pokemon in tumor tissues ($0.845{\pm}0.344$) was significantly higher than that in adjacent tumor specimens ($0.321{\pm}0.197$). The positive expression ratio of Pokemon protein in CRC (87.0%) was significantly higher than that in the adjacent tissues (19.6%). Strong fluorescence staining of Pokemon protein was observed in the cytoplasm of the SW480 and SW620 cells. The inhibition ratios of Pokemon mRNA and protein in the SW480 cells were 83.1% and 73.5% at 48 and 72 h, respectively, compared with those of the negative control cells with the siRNA. In the SW620 cells, the inhibition ratios of Pokemon mRNA and protein were 76.3% and 68.7% at 48 and 72 h, respectively. MTT showed that Pokemon gene silencing inhibited the proliferation of SW480 and SW620 cells. Conclusion: Overexpression of Pokemon in CRC may have a function in carcinogenesis and progression. siRNA expression vectors could effectively inhibit mRNA and protein expression of Pokemon in SW480 and SW620 cells, thereby reducing malignant cell proliferation.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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• pp.683-687
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• 2015

Aloe vera gel exhibits protective effects against insulin resistance as well as lipid-lowering and anti-diabetic effects. The anti-diabetic compounds in this gel were identified as Aloe-sterols. Aloe vera gel extract (AVGE) containing Aloe-sterols has recently been produced using a new procedure. We previously reported that AVGE reduced large-sized intestinal polyps in Apc-deficient Min mice fed a high fat diet (HFD), suggesting that Aloe vera gel may protect against colorectal cancer. In the present study, we examined the effects of Aloe vera gel powder (AVGP) and AVGE on azoxymethane-induced colorectal preneoplastic aberrant crypt foci (ACF) in mice fed a HFD. Male C57BL/6J mice were given a normal diet (ND), HFD, HFD containing 0.5% carboxymethyl cellulose solution, which was used as a solvent for AVGE (HFDC), HFD containing 3% or 1% AVGP, and HFDC containing 0.0125% (H-) or 0.00375% (L-) AVGE. The number of ACF was significantly lower in mice given 3% AVGP and H-AVGE than in those given HFD or HFDC alone. Moreover, 3% AVGP, H-AVGE and L-AVGE significantly decreased the mean Ki-67 labeling index, assessed as a measure of cell proliferation in the colonic mucosa. In addition, hepatic phase II enzyme glutathione S-transferase mRNA levels were higher in the H-AVGE group than in the HFDC group. These results suggest that both AVGP and AVGE may have chemopreventive effects on colorectal carcinogenesis under the HFD condition. Furthermore, the concentration of Aloe-sterols was similar between 3% AVGP and H-AVGE, suggesting that Aloe-sterols were the main active ingredients in this experiment.

• Journal of Digestive Cancer Research
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• v.8 no.1
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• pp.1-50
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• 2020

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.