• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.127-131
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• 2013

Trastuzumab is the first molecular targeting drug to increase the overall survival rate in advanced gastric cancer. However, it has also been found that a high intrinsic or primary trastuzumab resistance exists in some proportion of gastric cancer patients. In order to explore the mechanism of resistance to trastuzumab, firstly we investigated the expression of MUC1 (membrane-type mucin 1) in gastric cancer cells and its relationship with drug-resistance. Then using gene-silencing, we transfected a siRNA of MUC1 into drug-resistant cells. The results showed the MKN45 gastric cell line to be resistant to trastuzumab, mRNA and protein expression of MUC1 being significantly upregulated. After transfection of MUC1 siRNA, protein expression of MUC1 in MKN45cells was significantly reduced. Compared with the junk transfection and blank control groups, the sensitivity to trastuzumab under MUC1 siRNA conditions was significantly increased. These results imply that HER2-positive gastric cancer cell MKN45 is resistant to trastuzumab and this resistance can be cancelled by silencing expression of the MUC1 gene.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.12
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• pp.5185-5188
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• 2016

Objective: Targeted-drug-delivery based lipid nanoparticles has emerged as a new and effective approach in cancer chemotherapy. Here, we investigated the ability of folate-modified nanostructured lipid carriers (NLCs) to enhance letrozol (LTZ) efficacy in MCF-7 breast cancer cells. Methods: New formulations were evaluated regarding to particle size and scanning electron microscope (SEM) features. Anti-proliferative effects of LTZ loaded nanoparticles were examined by MTT assay. To understand molecular mechanisms of apoptosis and cell cycle progression, flow cytometric assays were applied. Results: Optimum size of nanoparticles was obtained in mean average of $98{\pm}7nm$ with a poly dispersity index (PDI) of 0.165. The IC50 value was achieved for LTZ was $2.2{\pm}0.2{\mu}M$. Folate-NLC-LTZ increased the percentage of apoptotic cells from 24.6% to 42.2% compared LTZ alone (p<0.05). Furthermore, LTZ loaded folate targeted NLCs caused marked accumulation of cells in the subG1 phase. Conclusion: Taken together, our results concluded that folate targeted LTZ can be considered as potential delivery system which may overcome limitations of clinical application of LTZ and improve drug efficacy in tumor tissue.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2425-2430
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• 2015

Clinical resistance to chemotherapeutic agents is one of the major hindrances in the treatment of human cancers. EHZ2 is involved in drug resistance and is overexpressed in drug-resistant cancer cell lines. In this study, we investigated the effects of EHZ2 on cisplatin -resistance in A549/DDP and AGS/DDP cells. EHZ2 mRNA and protein were found to be significantly overexpressed in A549/DDP and AGS/DDP cells, compared to parental cells. EHZ2 siRNA successfully silenced EHZ2 mRNA and protein expression. Proliferation was inhibited and drug resistance to cisplatin was improved. Flow cytometry showed that silencing of EHZ2 arrested A549/DDP and AGS/DDP cells in the G0/G1 phase, increasing apoptosis, rh-123 fluorescence intensity and caspase-3/8 activities. Silencing of EHZ2 also significantly reduced the mRNA and protein expression levels of cyclin D1 and MDR1,while up-regulating p15, p21, p27 and miR-218 in A549/DPP cells. Furthermore, silencing of EHZ2 also significantly increased the expression level of tumor suppressor factor miR-218. We also found down-regulating EHZ2 expression increased methylation in A549/DDP and AGS/DDP cells. This study demonstrates that drug resistance can be effectively reversed in human cisplatin-resistant lung and gastric cancer cells through delivery of siRNAs targeting EHZ2.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3631-3636
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• 2012

Objective: To determine whether silence of $PKC-{\alpha}$ expression by small interference RNA (siRNA) might regulate MDR1 expression and reverse chemoresistance of ovarian cancer. Methods: We measured gene and protein expression of MDR1 and $PKC-{\alpha}$ in ovarian cancer cells and assessed their correlation with cell drug resistance. We also examined whether blocking $PKC-{\alpha}$ by RNA interference (RNAi) affected MDR1 expression and reversed drug resistance in drug sensitivity tests. Results: The drug resistance cell lines, OV1228/DDP and OV1228/Taxol, had higher gene and protein expression of MDR1 and $PKC-{\alpha}$ than their counterpart sensitive cell line, OV1228. SiRNA depressed $PKC-{\alpha}$ gene protein expression, as well as MDR1 and protein expression and improved the drug sensitivity in OV1228/DDP and OV1228/Taxol cells. Conclusion: These results indicated that decreasing $PKC-{\alpha}$ expression with siRNA might be an effective method to improve drug sensitivity in drug resistant cells with elevated levels of $PKC-{\alpha}$ and MDR1. A new siRNA-based therapeutic strategy targeting $PKC-{\alpha}$ gene could be designed to overcome the chemoresistance of ovarian cancer.

• The Journal of Korean Medicine
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• v.31 no.3
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• pp.128-132
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• 2010

Objectives: This study aimed to review the general features of drug induced liver injury (DILI) and the important factors in consideration of herbal drugs and DILI. Methods: We reviewed general aspects of DILI such as classification, inducible factors, diagnosis methods, prevention, and the status of herbal drug-associated DILI via literature. Results: Besides the drug itself, genetic and environmental factors affect hepatic toxicity. There is a lack of definitive diagnoses of DILI by drugs, including herbal remedies. The possibility of herbal drug-associated DILI is exaggerated, and majority of herbal drug-derived hepatic injury could be easily prevented if Oriental doctors pay attention to this issue. Conclusion: This study can provide Oriental doctors an overview and be helpful in minimizing the episodes of hepatotoxicity in use of herbal drugs.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2001.10b
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• pp.85-86
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• 2001

• Journal of the Korean Society of School Health
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• v.9 no.2
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• pp.249-266
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• 1996

AIDS and the spectrum of Human Immunodeficiency Virus(HIV) infections present a monumental challenge to the health of the Korean public. In response to this special challenge, I think public education and voluntary behavior changes are the most effective measures to fight the spread of the disease. Adolescents represent a critical risk group for prevention and intervention programming. Research indicates sexually active adolescents, homosexual contact, illicit drug use are an gradually increasing. These characteristically adolescent risk-taking behaviors suggest the need for schools and communities to mobilize intervention strategies. Schools are highly efficient ways to reach a majority of young people in Korea with HIV prevention programs. These programs include substantial attention to sexual and drug use behaviors with the long term objective of a multidimensional school health program. Information resulting from risk behavior surveillance activities and guidance on school health curricula is particularly useful. What is needed for adolescents is a revamping of education to give students the critical thinking and analytic skills that allow them to apply knowledge, make decisions, and think independently. The best HIV preventive education provides young people with opportunities to learn and practice just those skills. In the early stages of HIV education were focused solely on information. Providing information is easy but unfortunately, behavior change is not that simple to activate. Information must be combined with values exploration and skilly building, including responsible decision making, negotiation, refusal, and critical thinking skills. The same knowledge, attitudes and skills needed for effective HIV prevention also prevent or reduce other risks, including other sexually transmitted diseases, unwanted pregnancies, and alcohol or other drug use. The role of other youth serving organizations in HIV prevention is also important: parental and youth involvement is needed; it's important to presidential and governament leadership is essential to prevention education; promote integrated adolescent programs, to enhance health and education sector collaboration; and of course, we need to expand research on adolescent health and engage the media in health promotion. Among these changes, a school-based systematic health education of AIDS is certainly one of the essentials.

• Journal of the FoodService Safety
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• v.1 no.1
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• pp.37-44
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• 2020

The virus isolated from patients with severe pneumonia of unknown etiology in Wuhan City, Hubei province in China was termed SARS-CoV-2 and the World Health Organization (WHO) named the disease caused by this virus as coronavirus disease 2019 (COVID-19). The COVID-19 infection has spread rapidly and become a pandemic. In July 2020, there were 13.25 million infected patients and over 570,000 deaths worldwide, and 13,711 infected patients and 294 deaths were reported in South Korea. Since the primary mode of transmission of COVID-19 is through respiratory droplets, the importance of preventive measures, including social distancing, has become important in daily life. In response to the continuous spread of COVID-19, this study developed three guidelines for preventing COVID-19 for the food service industry including childcare centers, institutional foodservices and restaurants by the integration of the manual of controlling foodborne illness. These are included the COVID-19 prevention action methods for food deliverers, for food service administrator, for foodservice works and for customers. All guidelines were designed for easy understanding using illustrations and have been systematically explained subject wise. Thus, these COVID-19 prevention guidelines can be appropriately applied depending on the specific situation and workplace. In addition, they are worthy as educational materials that contribute to the food safety.

• Journal of Korean Academy of Nursing
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• v.29 no.1
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• pp.127-138
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• 1999

This study was done to examine consciousness and preventive strategies of adolescent drug abuse. This study design was descriptive survey. The data were collected from 1,830 students from 32 middle and high schools from November 11 to December 20, 1997, using qestionnaires. The data were analyzed using SAS computer programs. The study results are as follows ; Most of adolescent get the information on narcotics and drug abuse from TV, newspaper, magazine and advertisement. Some of them(48.8%) have received education on drug prevention. However, respondants (49.3%) answered unsatisfactory on preventive education. 69.2% of respondants do not know the legal regulation on alcohol and cigarette. The survey on the degree of cognition on drug abuse shows the serious results : cigarette(79.1%), alcohol(74.1%), bonds(55.1%), gas(49.8%), excitants(48.5%), narcotics(29%), marihwana(27.8%) and, diuretics (21.9%). The situation of adolescent drug abuse is also serious in the order of alcohol 38. 2%, cigarette 14.3%, marihwana 9.4%.

• Osong Public Health and Research Perspectives
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• v.9 no.6
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• pp.363-363
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• 2018