• Title/Summary/Keyword: Oral carcinogenesis

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Effects of Scolopendrae corpus on turmor promotion in two-stage carcinogenesis in mice (오공(蜈蚣)이 마우스에서 2단계(段階) 발암화(發癌化) 과정(過程)에 미치는 영향(影響))

  • Kim, Kil-Sub;Hwang, Young-Guen;Yoon, Cheol-Ho;Seo, Un-Kyo;Kim, Jong-Dae;Jeong, Ji-Cheon;Nam, Kyung-Soo;Kang, Jeong-Jun
    • The Journal of Internal Korean Medicine
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    • v.20 no.1
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    • pp.133-142
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    • 1999
  • To clarifiy the effects of Scolopendrae corpus(S-C) on turmor promotion in two-stage carcinogenesis in mice was investigated. In vivo system, S-C were seen to gave an inhibitory activity on TPA-induced mouse ear edema. In addition, the S-C were proved to have antitumor-promoting activity in two-stage mouse skin carcinogenesis induced by DMBA and two-stage mouse lung carcinogenesis induced by 4-NQO as a initiator plus TPA and glycerol as a promoter. Moreover, S-C significantly exhibited an cytolytic effect in $HepG_2$ cells and showed significant antitumor activity against Sarcoma-180 bearing mice by oral administration. These results suggest that S-C could be effective in adjuvant chemotherapy for human cancer.

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American ginseng attenuates azoxymethane/dextran sodium sulfate-induced colon carcinogenesis in mice

  • Yu, Chunhao;Wen, Xiao-Dong;Zhang, Zhiyu;Zhang, Chun-Feng;Wu, Xiao-Hui;Martin, Adiba;Du, Wei;He, Tong-Chuan;Wang, Chong-Zhi;Yuan, Chun-Su
    • Journal of Ginseng Research
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    • v.39 no.1
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    • pp.14-21
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    • 2015
  • Background: Colorectal cancer is a leading cause of cancer-related death, and inflammatory bowel disease is a risk factor for this malignancy. We previously reported colon cancer chemoprevention potential using American ginseng (AG) in a xenograft mice model. However, the nude mouse model is not a gut-specific colon carcinogenesis animal model. Methods: In this study, an experimental colitis and colitis-associated colorectal carcinogenesis mouse model, chemically induced by azoxymethane/dextran sodium sulfate (DSS) was established and the effects of oral AG were evaluated. The contents of representative ginseng saponins in the extract were determined. Results: AG significantly reduced experimental colitis measured by the disease activity index scores. This suppression of the experimental colitis was not only evident during DSS treatment, but also very obvious after the cessation of DSS, suggesting that the ginseng significantly promoted recovery from the colitis. Consistent with the anti-inflammation data, we showed that ginseng very significantly attenuated azoxymethane/DSS-induced colon carcinogenesis by reducing the colon tumor number and tumor load. The ginseng also effectively suppressed DSS-induced proinflammatory cytokines activation using an enzyme-linked immunosorbent assay array, in which 12 proinflammatory cytokine levels were assessed, and this effect was supported subsequently by real-time polymerase chain reaction data. Conclusion: AG, as a candidate of botanical-based colon cancer chemoprevention, should be further investigated for its potential clinical utility.

Significance of p16 Positive Expression in Oropharyngeal Cancers

  • Bixofis, Regiane B.;Sassi, Laurindo Moacir;Patussi, Cleverson;Jung, Juliana E.;Ioshii, Sergio O.;Schussel, Juliana L.
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.23
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    • pp.10289-10292
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    • 2015
  • Background: The involvement of HPV in oral and oropharyngeal carcinogenesis was first proposed in 2004, based on epithelial HPV tropism and detection of HPV genotypes in oral squamous cell carcinoma samples. While 60-70% of oropharynx tumors may be HPV-positive, only 10 to 19% of tumors of the oral cavity, larynx and hypopharynx appear to have HPV infection. The aim of the study was to evaluate HPV infection associated with oropharyngeal cancer. Materials and Methods: Seventy-eight cases were selected for p16 immunoexpression reactions, and demographic data were collected for comparisons. Results: Most patients were over 60 years old, and 64.1% were smokers. Immunohistochemistry results showed that 86.3% of cases stained positive for p16 protein. Conclusion: The oropharyngeal cancer profile at Erasto Gaertner Hospital presented a high index of smokers over 60 years as well a high number of p16+ tumors, for what we can not determinate the main etiologic factor, but can be aware of the number of patients that presented HPV infection. Since prevention is still the best way to deal with cancer disease, it is important to analyze the interaction of these two etiologic factors and how to detect lesions at an early stage.

Inhibitory effect of dietary turmeric (Curcuma longa L.) ethanol extract on DMBA-induced mammary carcinogenesis in rats (울금 투여에 의한 DMBA 유발 랫드 유선암화과정 억제효과)

  • Kim, Min Sook;Jeong, Kyu Shik;You, Mi-Kyoung;Kim, Hyeon-A
    • Food Science and Preservation
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    • v.21 no.3
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    • pp.301-307
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    • 2014
  • The purpose of this study was to examine the potential of turmeric (Curcuma longa L.) to inhibit 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary carcinogenesis in rats. Female Sprague Dawley rats were fed a control diet (NC and DC) or an ethanol extract of turmeric (DT) diet until the end of the experiment. The rats in the DC and DT groups were administered a single dose of DMBA (50 mg/Kg) by oral gavages at 50 days of age. The turmeric ethanol extracts decreased the incidence and multiplicity of DMBA-induced mammary tumor. The turmeric ethanol extract significantly decreased the tumor cell proliferation. The turmeric also significantly decreased the tumor grade based on the degree of the tubule formation. The results suggest that the ethanol extract of turmeric has an inhibitory effect against mammary carcinogenesis, and that such chemopreventive effect may be related to the inhibition of the initiation and the proliferation of tumor cells.

Oral Concentrated Grape Juice Suppresses Expression of NF-kappa B, TNF-α and iNOS in Experimentally Induced Colorectal Carcinogenesis in Wistar Rats

  • de Lima Pazine Campanholo, Vanessa Maria;Silva, Roseane Mendes;Silva, Tiago Donizetti;Neto, Ricardo Artigiani;Paiotti, Ana Paula Ribeiro;Ribeiro, Daniel Araki;Forones, Nora Manoukian
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.3
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    • pp.947-952
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    • 2015
  • The aim of this study was to evaluate the effects of grape juice on colon carcinogenesis induced by azoxymethane (AOM) and expression of NF-kB, iNOS and TNF-${\alpha}$. Methods: Forty male Wistar rats were divided into 7 groups: G1, control; G2, 15 mg/kg AOM; G3, 1% grape juice 2 weeks before AOM; G4, 2% grape juice 2 weeks before AOM; G5, 1% grape juice 4 weeks after AOM; G6, 2% grape juice 4 weeks after AOM; G7, 2% grape juice without AOM. Histological changes and aberrant crypt foci (ACF) were studied, while RNA expression of NF-kB, TNF- and iNOS was evaluated by qPCR. Results: The number of ACF was higher in G2, and G4 presented a smaller number of crypts per focus than G5 (p=0.009) and G6. Small ACF (1-3) were more frequent in G4 compared to G2, G5 and G6 (p=0.009, p=0.009 and p=0.041, respectively). RNA expression of NF-kB was lower in G3 and G4 compared to G2 (p=0.004 and p=0.002, respectively). A positive correlation was observed between TNF-${\alpha}$ and NF-kB gene expression (p=0.002). In conclusion, the administration of 2% grape juice before AOM reduced the crypt multiplicity, attenuating carcinogenesis. Lower expression of NF-kB was observed in animals exposed to grape juice for a longer period of time, regardless of concentration.

The Molecular Mechanism of Safrole-induced DNA Adducts and its Role to Oral Carcinogenesis

  • Liu, Tsung-Yun
    • Environmental Mutagens and Carcinogens
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    • v.23 no.3
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    • pp.99-102
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    • 2003
  • IARC classified areca quid as a human carcinogen. Areca quid chewed in Taiwan includes Piper betle inflorescence, which contains high concentrations of safrole (15 mg/fresh weight). Safrole is a documented rodent hepatocarcinogen, and chewing areca quid may contribute to human exposure (420 $\mu$m in saliva). The carcinogenicity of safrole is mediated through 1'-hydroxysafrole formation, followed by sulfonation to an unstable sulfate that reacts to form DNA adducts. Using human liver microsomes and Escherichia coli membranes expressing bicistronic human P450s, CYP2E1 and CYP2C9 were identified as the main P450s involved in the activation of safrole. We have demonstrated the presence of stable safrole-dGMP adducts in human oral tissues following areca quid chewing using $^{32}$ P-postlabeling and HPLC mass spectrometry methods. By studying 88 subjects with a known AQ chewing history and 161 matched controls, we have demonstrated that the presence of safrole-DNA adducts in peripheral blood cells was correlated to AQ chewing, and CYP2E1 seemed to play an important role in the modulation of safrole-DNA adduct formation. We have also shown that safrole can form stable safrole-DNA adducts as well as oxidative damages in rodent liver. However, the stable safrole-DNA adducts may represent a more significant initial lesion as compared to the rapidly repaired safrole-induced 8-hydroxy-2'-deoxyguanosine. This oxidative DNA damage is mediated through the formation of hydoryxchavicol, the major safrole metabolite in human urine. Hydroxychavicol may have gone through two-electron oxidation to the o-quinone; then via one-electron reduction to semiquinone radicals to generate oxidative DNA damage. However, these reactive metabolites can be efficiently conjugated by GSH. These data suggest that safrole may contribute to the initiation of oral carcinogenesis through safrole-DNA adduct and not oxidative DNA damage. In addition, CYP2E1 may modulate this adduct formation.

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Benzo[a]pyrene Alters the Expression of Genes in A549 Lung Cancer Cells and Cancer Stem Cells

  • Bak, Yesol;Jang, Hui-Joo;Seo, Ji-Hye;No, Su-Hyun;Chae, Jung-il;Hong, Jintae;Yoon, Do-Young
    • Journal of Microbiology and Biotechnology
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    • v.28 no.3
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    • pp.425-431
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    • 2018
  • Benzo[a]pyrene (B[a]P), a polycyclic aromatic hydrocarbon, is a principal component of cigarette smoke. B[a]P can cause lung carcinogenesis and plays a key role in lung cancer progression. The role of B[a]P has been reported in lung cancer, but its effects on lung cancer stem cells (CSCs) have not been investigated. Emerging evidence indicates that CSCs are associated with carcinogenesis, tumor initiation, relapse, and metastasis. Therefore, targeting CSCs to defeat cancer is a challenging issue in the clinic. This study explored whether B[a]P alters gene expression in lung cancer cells and CSCs. The lung adenocarcinoma A549 cell line was used to investigate the role of B[a]P on lung cancer cells and lung CSCs using microarray and quantitative PCR. B[a]P ($1{\mu}M$) provoked gene expression changes in A549 cancer cells and CSCs by deregulating numerous genes. Gene pathway analysis was performed using GeneMANIA and GIANT. We identified genes that were coexpressed and showed physical interactions. These findings improve our understanding of the mechanism of B[a]P in lung cancer and cancer stem cells and can be an attractive therapeutic target.

AN EXPERIMENTAL STUDY ON THE CHEMOPREVENTIVE EFFECT OF CHLOROPHYLLIN IN HAMSTER CHEEK POUCH TUMOR INDUCED BY 7, 12-DIMETHYLBENZ[A]ANTHRACENE (7, 12-dimethylbenz[a]anthracene(DMBA)로 유발된 햄스터 협낭암에서 chlorophylln의 암예방효과에 관한 실험적 연구)

  • Yoon, Kyu-Ho
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.26 no.2
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    • pp.137-145
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    • 2000
  • Carcinogenesis is a multi-stage process that generally consists of at least three steps; initiation, promotion, and progression. If one of these carcinogenic steps were suppressed or delayed, the cancer could be prevented. Cancer chemoprevention is defined to be inhibition or reversal of the carcinogenic process by the specific chemical agents and is a novel approach to cancer management alternative to conventional chemotherapy. Chlorophylln(CHL), a water-soluble derivative of chlorophyll, containing sodium and copper, has been known to be strong antimutagen in several test systems, but its mechanism of antimutagenic action is unknown. In the present experiment, the possibility of CHL as chemopreventive drugs on 7,12-dimethylbenz[a]anthracene(DMBA)-induced hamster buccal pouch carcinogenesis was investigated by mutagenicity test, carcinogenicity test, and frequency or spectrum of H-ras mutations in the both of DMBA-induced and chlorophylln-pretreated-DMBA induced tumor by polymerase chain reaction and non-isotopic restriction fragment length polymorphism. The treatment of CHL reduced the yields and multiplicity of the 0.5% DMBA-induced tumor, 86% to 62.5% and $3.7{\pm}0.6$ to $1.4{\pm}0.3$, respectively. The occurrence of histidine revertant by $20{\mu}mole$ DMBA was inhibited 25.6 to 81.7% by 1 to $5{\mu}M$ CHL in a dose-dependent manner. The mutation rates of H-ras gene in DMBA-induced and CHL-pretreated-DMBA induced tumor were 96%, 94% of which the most mutations were in codon 12/13. These results suggest that CHL inhibits the carcinogenic action of DMBA by the formation of complex between CHL and DMBA or the inhibition of the activation of DMBA in vivo. But CHL did not affect the mutation rates or its spectrum in already formed tumor.

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Expression of Cyclooxygenase-2 (COX-2) in Colorectal Adenocarcinoma: an Immunohistochemical and Histopathological Study

  • Mahmoud, Abla Sayed;Umair, Ayesha;Azzeghaiby, Saleh Nasser;Alqahtani, Fahad Hussain;Hanouneh, Salah;Tarakji, Bassel
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.16
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    • pp.6787-6790
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    • 2014
  • Background: The aim of this study was to evaluate cyclooxygenase-2 (COX-2) immunoreactivity in colorectal adenocarcinomas and to find correlations with different pathological features. Materials and Methods: This study included 35 cases of colorectal carcinoma foir which surgical colectomy specimens were collected. Immunohistochemical staining of COX-2 (cyclooxygenase-2) is done by using the Streptavidin-biotin technique. Results: This work reveals that COX-2 is positive in most cases of colorectal carcinoma and negative in normal colon tissue with statistically non significant relations between COX-2 immunostaining and different pathological features. Conclusions: Our data suggest over expression of COX-2 protein in colorectal carcinoma in contrast to normal mucosa, with a possible role in cell proliferation in carcinogenesis.

EXPRESSION OF PROTEIN KINASE C ISOFORMS IN CHEMICAL CARCINOGEN-INDUCED NEOPLASTIC TRANSFORMATION OF HUMAN EPITHELIAL CELLS (화학적 발암화에 따른 Protein Kinase C의 발현 변화)

  • Byeon, Ki-Jeong;Hong, Lak-Won;Kim, Chin-Soo
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.23 no.4
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    • pp.295-305
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    • 2001
  • Protein kinase C (PKC) is known to play a pivotal role in neoplastic transformation cells and its high expression is often found in a variety of types of tumors including oral cancer. While PKC is associated with the altered signal transduction pathway of the tumor cells, it is still unclear which isoform is involved in the carcinogenesis process. Since the cellular distributions and the roles of PKC are isoform-specific, it is very important to identify the specific target molecules to improve our understanding of the carcinogenesis processes. Thus, the present study attempted to perform chemical carcinogen-induced neoplastic transformation of human epithelial cells and analyze the specific isoform of PKCs involved in the cellular transformation. The study analyzed overall PKC responses upon MNNG(N-Methyl-N'-nitro-N-nitroso guanidine) exposure with [$^3H$] PDBu binding assay. PKC translocation was observed at high doses of MNNG treatment in the presence of extracellular calcium. Such effects were not observed in the absence of extracellular calcium. Translocational effects with exposure of MNNG was further enhanced in the presence of hydrocortisone. The result suggests that the type of PKC involved may be $Ca^{2+}$-dependent classical isoform and steroid hormone enhances PKC activation. Among cPKC isoforms examined, only $PKC-{\alpha}$ and r showed significant translocation of protein levels from cytosolic fraction to membrane fraction, as analyzed by immunoblot. $PKC-{\varepsilon}$ in nPKC class showed an inch·eased translocation, but other forms in this class did not show the effect. None of isoforms in aPKC class was affected by MNNG treatment. The study demonstrated that there was a certain specificity in the patterns of isoform induction follwong chemical carcinogen exposure and helped identify all the types of PKC isoforms expressed in human epithelial cells. It was revealed that PKC isoforms were activated in an early resonse to chemical carcinogen, suggesting that PKC be associated with carcinogenesis process from an early stage in this particular cell system. The study will contribute to improving our understanding of chemical-induced carcinogenesis in human cells and may provide a scientific basis to introduce the specific PKC inhibitors as an anticancer drug of epithelial cell-origin cancers including oral cancer.

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