• 한국독성학회:학술대회논문집
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• 한국독성학회 2003년도 추계학술대회
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• pp.188-188
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• 2003

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), a prototype of halogenated aromatic hydrocarbons, is a persistent environmental contaminant and one of the most powerful tumor promoters. The molecular mechanism underlying induction of tumor promotion by TCDD has not been elucidated.(omitted)

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권5호
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• pp.465-472
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• 2008

We experienced a rare case of oral squamous cell carcinoma arisen from gingival tissues overlying prolonged chronic osteomyelitis of the mandible. A 66 years old man complained of unhealed extraction sockets of left mandibular second premolar and first molar, and showed extensive leukoplakia in the gingival tissues of the same area. The inflammation of the socket granuloma became severe and extended into adjacent mandibular proper, resulted in diffuse suppurative chronic osteomyelitis of mandibular body, exhibiting irregular osteolytic changes of mandibular trabecular patterns in mottled radiolucent appearance. The leukoplakia was initially diagnosed under microscope, and the involved gingival tissues were radically removed. Thereafter, the gingival soft tissue inflammation involving the mandibular osteomyelitis was hardly healed for two years. During the period of repeated surgical treatments for the inflamed lesion, nine biopsies were taken sequentially. Until the eighth biopsy, there consistently showed the suppurative osteomyelitis with ingrowing gingival tissues into the bony inflammatory lesion. The gingival epithelium showed the features of leukoplakia but no evidence of malignant changes. However, the ninth biopsy, taken about 2 years after initial diagnosis, showed the early carcinomatous changes of the gingival epithelium. The neoplastic epithelial cells were relatively well differentiated with many keratin pearls, and infiltrated only into underlying connective tissues. So, we presumed that the present case of squamous cell carcinoma was caused by the persistent inflammatory condition of the mandibular osteomyelitis, and also suggest that the leukoplakia should be carefully removed in the beginning to prevent the neoplatic promotion of the chronic inflammation.

• 한국환경성돌연변이발암원학회지
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• 제25권2호
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• pp.66-70
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• 2005

Telomerase, a specialized RNA-directed DNA polymerase that extends telomeres of eukaryotic chromosomes, has activity in most malignant tumors and provides a mechanism for the unlimited potential for division of neoplastic cells. Although telomerase is known to be a regulated enzyme, the factors and mechanisms involved in telomerase regulation are not well understood. In the present study, we compared the effect of 12-O­tetradecanoyl-phorbol-13-acetate (TPA) and non-phorbol ester tumor promoters such as okadaic acid, anthralin and benzoyl peroxide on the expression of telomerase in the mouse skin carcinogenesis system, a well characterized model for studying pre-malignant and malignant progression. We found that most early papillomas harvested after 10 weeks of TPA promotion showed telomerase activity. Other papillomas harvested after 10 weeks of okadaic acid, anthralin and benzoyl peroxide promotion and after single treatment of DMBA only also showed telomerase activity, respectively. On the other hand, normal and all skins surrounded by papillomas harvested after 10 weeks of these promoters has no telomerase activity. Taken together these results, there appears to be no clear association between the level of telomerase activity and protein phosphorylation in mouse skin papillomas and telomerase may be useful as bio-markers in early detection of tumors.

• Asian Pacific Journal of Cancer Prevention
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• 제13권9호
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• pp.4815-4822
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• 2012

Invasion and metastasis are the major causes of cancer-related death. Pharmacological or therapeutic interventions such as chemoprevention of the progression stages of neoplastic development could result in substantial reduction in the incidence of cancer mortality. (-)-Epigallocatechin-3-gallate (EGCG), a promising chemopreventive agent, has attracted extensive interest for cancer therapy utilizing its antioxidant, anti-proliferative and inhibitory effects on angiogenesis and tumor cell invasion. In this study, we assessed the influence of EGCG on the proliferative potential of HeLa cells by cell viability assay and authenticated the results by nuclear morphological examination, DNA laddering assay and cell cycle analysis. Further we analyzed the anti-invasive properties of EGCG by wound migration assay and gene expression of MMP-9 and TIMP-1 in HeLa cells. Our results indicated that EGCG induced growth inhibition of HeLa cells in a dose- and time-dependent manner. It was observed that cell death mediated by EGCG was through apoptosis. Interestingly, EGCG effectively inhibited invasion and migration of HeLa cells and modulated the expression of related genes (MMP-9 and TIMP-1). These results indicate that EGCG may effectively suppress promotion and progression stages of cervical cancer development.

• Asian Pacific Journal of Cancer Prevention
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• 제16권15호
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• pp.6439-6444
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• 2015

Background: In India smokeless tobacco users account for 25.9% of total tobacco use, Gutkha being the most common form. This study evaluated the association between serum lipid profile and Gutkha use as an early diagnostic and/or prognostic indicator for oral submucous fibrosis (OSMF) and oral cancer (Oral Ca) in non-smokers and non-alcohol consumers. Materials and Methods: A total of 163 participants were recruited from two sites in India. Participants were divided into four groups: individuals without any Gutkha chewing habit and without any oral lesions (control group), individuals with Gutkha chewing habit but without any oral lesions (GWL), patients with a confirmed clinical diagnosis of OSMF, and patients with a confirmed diagnosis of Oral Ca. Mixed linear modelling (MLM) was conducted to detect the change in mean serum lipid levels among four groups. Results: The sample consisted of 69% males and 31% females. Results of MLM show an inverse relationship between serum lipid levels in OSMF, and Oral Ca groups when compared to the control group. Conclusions: The results of our study demonstrated that GWL, OSMF and Oral Ca patients had lower serum lipid levels. Low serum lipid levels could be an indicator of initial neoplastic changes in oral cancer.

• Toxicological Research
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• 제14권4호
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• pp.475-481
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• 1998

This study was performed to investigate the modifying effect of the general (GPA) and the fermented pilose antler (FPA) on experimental hepatocarcinogenesis and Natural Killer cell activity in rats. Specific pathogen free, 5-week male Sprague-Dawley rats were divided into four groups. To induce hepatocarcinogenesis, diethylnitrosamine (DEN, 200 mg/kg, i.p.) was used as a tumor initiator and was given in a single dose at experimental onset. All rats were given a partial hepatectomy (PH) at 3 weeks after experimental onset. Sodium phenobarbital (PB, 0.05% in diet), GPA (0.075% in diet) and FPA (0. 075% in diet) were given from 2 to 8 weeks. Group I of the initiation control group was only given DEN. As initiation-promotion group, Group II was given DEN and then PB. Group III and IV were given DEN-PB-GPA and DEN-PB-FPA, respectively. In hematological analysis, as compared with Group I. the number of white blood cells were significantly increased in the GPA (p<0.01) and the FPA treated group (p<0.05), respectively. Natural killer (NK) cell activity by flow cytometer (FCM) analysis was higher in group of treated with the GPA (35%) than that of the FPA (27.5%), but not significant. Result of the immunohistochemical staining of the glutathione S-transferase placental form (GST-p) indicated that the number of and area of the pre-neoplastic lesions was not significantly changed in Group III and IV compared Group II, respectively. In conclusion, the GPA and the FPA treatment significantly increased the number od WBC in peripheral blood, but the enhancing NK activity and the modifying effect on the experimental hepatocarcinogenesis were not observed.

• Clinical and Experimental Pediatrics
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• 제52권2호
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• pp.213-219
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• 2009

목 적:철은 세포 성장과 분화, 전자 전달 반응, 산소 전달, 해독작용 등 여러 가지 중요한 생체 반응에 반드시 필요한 요소로서 종양세포의 성장과 증식에도 절대적으로 필요하다. 최근에 철킬레이트제인 deferoxamine이 악성 구강 각질세포의 성장을 억제하고 세포자멸사를 유도하며, 난소암세포의 증식을 억제하고 세포자멸사를 유도하여 난소암의 성장을 억제하였다고 보고되었다. 그러므로 반복적인 수혈에 의하여 헤모시데린침착증이 발생한 소아 종양 환아에서 deferoxamine이 철을 제거 할 뿐만 아니라 암세포의 세포자멸사를 유도하는지에 대하여 알아보고 세포자멸사를 유도한다면 그 경로에 대하여 알아보고자 하였다. 방 법:골육종세포인 Saos-2에서 deferoxamine에 대한 효과를 알아보기 위하여 크리스탈 바이올렛과 트리판 블루 염색으로 세포의 성장 및 증식을 측정하였고, DNA 분획, 핵 응축, 세포주기분석으로 세포자멸사를 분석하였고, 세포자멸사와 관련된 분자들의 발현을 Western hybridization으로 분석하였다. 결 과:Deferoxamine은 Saos-2 세포에 대하여 시간과 농도에 의존적으로 세포 증식 억제 효과를 나타내었다. 이러한 세포 증식 억제 효과는 DNA 단편화, 핵 응축, 세포주기 분석에서의 $A_{0}$ 기의 증가, PARP의 활성도의 증가 등 세포자멸사가 유도되었음을 알 수 있었다. 또한 Saos-2 세포에서 deferoxamine 처리 후 Akt/PKB의 활성화가 억제되어 caspase 9의 활성화, 그 하류의 caspase 3의 활성화로 이어지는 미토콘드리아 매개되는 경로로 세포자멸사가 유도되었다. 결 론:결론적으로 철킬레이트제인 deferoxamine이 세포증식을 억제시키고 세포자멸사를 유도시킴으로써 골육종 세포의 증식을 억제하는 것을 보여주었다. 따라서 반복적 대량 수혈에 의한 철 과부하에 따른 장기손상이 우려되는 각종 소아 종양환자들에서 deferoxamine은 체내 축적된 철을 제거할 뿐만 아니라 종양 환자의 치료에 있어서 항암제 치료의 효과를 증가시킬 수 있는 새로운 치료법으로 개발될 수 있을 것이다.

• 문화기술의 융합
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• 제5권4호
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• pp.431-438
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• 2019

본 연구는 로페라마이드로 처리된 흰쥐의 결장점막에 1,2-dimethylhydrazine (DMH)로 유도시 aberrant crypt foci(ACF)에 대한 길항 작용 효과를 갖는 초임계 열처리된 무 복합추출물의 화학적 암 예방 효과를 알아보고자 하였다. 초임계 열처리된 무 복합물추출물을 DMH유발 발암의 개시(12주 동안) 또는 개시 후 단계(9주 동안)에 식수(3.2 mg/ml)에 투여 하였다. 12주 동안 DMH와 함께 초임계 열처리된 무 복합추출물 투여군은 비정상적인 선와(전신경병변)의 총 수와 ACF의 수를 각각 35 %와 30 %로 크게 줄였다. 12주 동안 초임계 열처리된 무 복합추출물을 투여한 흰쥐의 결장에서 4가지 이상의 이상선와소(ACF)가 있는 ACF의 수가 현저히 감소하였다. 9주 동안 개시후 초임계 열처리된 무 복합추출물을 투여한 그룹에서, 4 이상의 이상선와소(ACF)의 수만이 현저히 감소하였다. 12주 동안 단독으로 투여한 초임계 열처리된 무 복합추출물은 ACF의 발생을 유발하지 않았다. 이러한 결과는 초임계 열처리된 무 복합추출물이 화학적으로 유도된 흰쥐의 결장 발암에 화학적 암예방 효과를 가지고 있음을 시사한다.