• Korean Journal of Pharmacognosy
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• v.25 no.4 s.99
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• pp.382-387
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• 1994

Antineoplastic activity against human gastric and colon carcinoma cell lines was measured in 49 extracts from 46 plants using MTT (3-[4, 5-dimethyl thiazol-2-yl]-2, 5-diphenyl tetrazolium bromide) method. Six extracts from five plants have been reported to have antineoplastic effect. Extracts from remaining 41 plants failed to show significant cytotoxic effect at the concentration of less than $230\;{\mu}g/ml$.

• Molecules and Cells
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• v.38 no.11
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• pp.959-965
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• 2015

Inducible and reversible gene silencing in desired types of cells is instrumental for deciphering gene functions using cultured cells or in vivo models. However, efficient conditional gene knockdown systems remain to be established. Here, we report the generation of an inducible expression system for short hairpin RNA (shRNA) targeted to PTEN, a well-documented dual-specificity phosphatase involved in tumor suppression and ontogenesis. Upon induction by doxycycline (DOX), the reverse tetracycline transcriptional activator (rtTA) switched on the concomitant expression of GFP and a miR-30 precursor, the subsequent processing of which released the embedded PTEN-targeted shRNA. The efficacy and reversibility of PTEN knockdown by this construct was validated in normal and neoplastic cells, in which PTEN deficiency resulted in accelerated cell proliferation, suppressed apoptosis, and increased invasiveness. Transgenic mice harboring the conditional shRNA-expression cassette were obtained; GFP expression and concurrent PTEN silencing were observed upon ectopic expression of rtTA and induction with Dox. Therefore, this study provides novel tools for the precise dissection of PTEN functions and the generation of PTEN loss of function models in specific subsets of cells during carcinogenesis and ontogenesis.

• International Journal of Oral Biology
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• v.41 no.3
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• pp.105-111
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• 2016

${\beta}-carotene$ is present in carrots, pumpkins, and sweet potatoes. It suppresses many types of cancers by regulating cellular proliferation and apoptosis through a variety of mechanisms. However, the effects of ${\beta}-carotene$ on oral cancer cells have not been clearly established. The main goal of this study was to investigate the effects of ${\beta}-carotene$ on cell growth and apoptosis in oral cancer cells. Our results demonstrate that treatment with ${\beta}-carotene$ induced inhibition of cell growth, and that the effect was dependent on ${\beta}-carotene$ treatment time and concentration in KB cells. Furthermore, treatment with ${\beta}-carotene$ induced nuclear condensation and fragmentation in KB cells. ${\beta}-carotene$ promoted proteolytic cleavage of procaspase-3, -7, -8 and -9 with associated increases in the concentration of cleaved caspase-3, -7, -8 and -9. In addition, the level of cleaved PARP was increased by ${\beta}-carotene$ treatment in KB cells. These results suggest that ${\beta}-carotene$ can suppress cell growth and induce apoptosis in KB human oral cancer cells, and that it may have potential usefulness in anti-cancer drug discovery efforts.

• International Journal of Oral Biology
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• v.35 no.4
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• pp.215-220
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• 2010

Angelica decursiva has been used in Korean traditional medicine as an antitussive, an analgesic, an antipyretic and a cough remedy. However, its anti-cancer properties have not yet been well defined. In our current study, we report the cytotoxic activity and the mechanism of cell death induced by ethanol extracts of Angelica decursiva (EEAD) against the human oral cancer cell line, KB. Treatment of KB cells with EEAD induced apoptotic cell death in both a dose- and time-dependent manner as determined by MTT assay and DNA fragmentation. However, no cytotoxic effects of EEAD against human normal oral keratinocytes (HNOK) were evident. By western blot analysis, we found that apoptosis in KB cells is associated with a decrease in procaspase-7 and -9. In addition, the activation of caspase-7 was detectable in living KB cells by fluorescence microscopy. These results suggest that EEAD exhibits anti-cancer activity in KB cells via apoptosis and thus has potential as an anticancer agent in future drug development strategies.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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• pp.841-844
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• 2015

Background: Gastric cancer as one of the most important diseases affecting health in all worldwide. Current studies have confirmed associations of cytokine gene polymorphisms with the risk of gastric cancer development. The current research aimed to assess the association of IL-1B+3954 genotypes with the risk of gastric cancer in the Iranian population. Materials and Methods: This case-control study covered 49 gastric cancer patients compared to 53 cancer free individuals as a control group. Genomic-DNA extraction was carried out from bioptic samples of patients and peripheral blood of healthy volunteers. Polymorphism of IL-1B +3954 genotypes were analysed with a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Results: The frequencies of IL-1B +3954 A1A1, A1A2 and A2A2 genotypes in healthy individuals were 26.4, 66 and 7.6 %, respectively. However, in gastric cancer patients, A1A1, A1A2 and A2A2 with 4.1, 51 and 44.9% were observed (p<0.05). Conclusions: The findings of our results show a positive association between the IL-1B+3954 genotype distribution and the risk of gastric cancer disease in the Iranian population.

• Korean Journal of Pharmacognosy
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• v.27 no.2
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• pp.105-110
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• 1996

Antineoplastic activity against human gastric and colon carcinoma cell lines was tested in eighty-three species of Korean plants including Korean medicinal plants which have been frequently used in oriental herb prescriptions. The plant materials were extracted with methanol and the cytotoxic activity was tested using a calorimetric tetrazolium assay (MTT assay). Twenty-six plant extracts against gastric carcinoma cell line, eighteen extracts against colon carcinoma cell line and fourteen plant extracts against both carcinoma cell lines showed antineoplastic activity at the concentration of less than $100{\mu}g/ml$. The effective components from four species have been isolated and reported.

• Korean Journal of Pharmacognosy
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• v.25 no.2
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• pp.171-177
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• 1994

Antineoplastic activity against human gastric and colon carcinoma cell lines was measured in 100 extracts from 90 plants using MTT (3-[4,5-dimethyl thiazo-2-yl]-2, 5-diphenyl tetrazolium bromide) method. Four extracts from four plants have been reported to have antineoplastic effect. Extracts from remaining 86 plants failed to show significant cytotoxic effect at the concentration of less than $230\;{\mu}/ml$.

• Molecules and Cells
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• v.42 no.3
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• pp.237-244
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• 2019

Understanding the mechanisms of cancer drug resistance is a critical challenge in cancer therapy. For many cancer drugs, various resistance mechanisms have been identified such as target alteration, alternative signaling pathways, epithelial-mesenchymal transition, and epigenetic modulation. Resistance may arise via multiple mechanisms even for a single drug, making it necessary to investigate multiple independent models for comprehensive understanding and therapeutic application. In particular, we hypothesize that different resistance processes result in distinct gene expression changes. Here, we present a web-based database, CDRgator (Cancer Drug Resistance navigator) for comparative analysis of gene expression signatures of cancer drug resistance. Resistance signatures were extracted from two different types of datasets. First, resistance signatures were extracted from transcriptomic profiles of cancer cells or patient samples and their resistance-induced counterparts for >30 cancer drugs. Second, drug resistance group signatures were also extracted from two large-scale drug sensitivity datasets representing ~1,000 cancer cell lines. All the datasets are available for download, and are conveniently accessible based on drug class and cancer type, along with analytic features such as clustering analysis, multidimensional scaling, and pathway analysis. CDRgator allows meta-analysis of independent resistance models for more comprehensive understanding of drug-resistance mechanisms that is difficult to accomplish with individual datasets alone (database URL: http://cdrgator.ewha.ac.kr).

• BMB Reports
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• v.43 no.10
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• pp.698-703
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• 2010

In this study, we characterized two blocks of minisatellites in the 5' upstream region of the BORIS gene (BORIS-MS1, -MS2). BORIS-MS2 was found to be polymorphic; therefore, this locus could be useful as a marker for DNA fingerprinting. We assessed the association between BORIS-MS2 and breast cancer by a case-control study with 428 controls and 793 breast cancers cases. Rare alleles in the younger group (age, <40) were associated with a statistically significant increased risk of breast cancer (odds ratio, 4.84; 95% confidence interval, 1.06-22.22; and P = 0.026). A statistically significant association between the short rare alleles and cancer was identified in the younger group (8.02; 1.01-63.83; P = 0.021). Kaplan-Meier estimates showed that poor prognosis was associated with patients who contained the rare alleles. Our data suggest that the short rare alleles of BORIS-MS2 could be used to identify the risk for breast cancer in young patients.

• 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.