Foram avaliados as atividades quimiopreventivas da β-ionona (BI) e do geraniol (GR) durante a etapa de promoção da hepatocarcinogênese. Ratos Wistar foram submetidos ao modelo de hepatocarcinogênese do \"Hepatócito Resistente\" e receberam durante 5 semanas consecutivas: 16 mg/100 g p.c. de BI, 25 mg/100 g p.c. de GR, 16 mg/100 g p.c. de BI + 25 mg/100 g p.c. de GR ou somente 25 ml/100 g p.c. de óleo de milho (grupo OM, controle). Em comparação ao grupo OM, o grupo BI apresentou menor multiplicidade de nódulos hepáticos e os grupos BI, GR e GR+BI apresentaram menor número de lesões pré-neoplásicas (LPN) persistentes e maior porcentagem de LPN em remodelação. Comparados ao grupo OM, o grupo BI apresentou menor área de LPN em remodelação e menor porcentagem da área do corte histológico ocupado por LPN persistentes enquanto o grupo GR apresentou menor porcentagem da área do corte histológico ocupado por LPN em remodelação. O tratamento com BI tendeu a reduzir o colesterol plasmático e inibir a proliferação celular em LPN. O grupo GR apresentou maior número de corpúsculos apoptóticos em LPN persistentes em comparação ao grupo OM. Comparados ao grupo OM, os grupos BI e GR+BI apresentaram menor porcentagem de LPN hepáticas em remodelação positivas para a proteína p53 citoplasmática. Já o grupo GR apresentou maior porcentagem de LPN hepáticas persistentes positivas para p53. Os níveis da proteína RhoA nas membranas celulares hepáticas foram menores no grupo GR quando comparados aos do grupo OM. Assim, BI e GR são quimiopreventivos supressores promissores da hepatocarcinogênese. / Chemopreventive activities of β-ionone (BI) and geraniol (GR) were evaluated during promotion phase of hepatocarcinogenesis. Wistar rats received GR (25 mg/100 g body weight), BI (16 mg/100 g body weight), GR (25 mg/100 g body weight) +BI (16 mg/100 g body weight) or corn oil (CO, control). Multiplicity of hepatic nodules were smaller in BI group, compared to CO group. BI, GR and GR+BI groups presented decreased number of persistent preneoplastic lesions (PNL) and increased % of remodeling PNL. BI group presented decreased % liver section area occupied by persistent and remodeling PNL. GR group presented decreased % liver section area occupied by remodeling PNL. BI group tended to present reduced cholesterol concentration and inhibited cell proliferation. GR group increased number of apoptotic bodies in persistent PNL. BI and GR+BI groups reduced the % of remodeling and increased the % of persistent p53 positive PNL. RhoA protein in cellular membranes was reduced in GR group. Thus, BI and GR could be considered as chemopreventive agents against hepatocarcinogenesis.

A carcinogênese é um processo longo que envolve múltiplas etapas na transformação das células normais em malignas. Duas hipóteses têm sido propostas para explicar o potencial heterogêneo de células neoplásicas e o processo de desenvolvimento de neoplasias: o modelo estocástico, em que uma população distinta de células neoplásicas adquire um conjunto de mutações somáticas e desenvolve capacidade metastática e o modelo hierárquico, no qual neoplasias primárias e suas metástases são iniciadas por um número pequeno de células, conhecidas \"cancer stem cells\" (CSC). Assim, o HCC poder ser originado de células tronco/progenitoras hepáticas ou células ovais e hepatócitos. Aventou-se a hipótese neste trabalho que a BI reduz o número de células ovais hepáticas, regulando proteínas (CK19, β-catenina e ALDH1A1) que possam estar relacionadas ao papel destas células na hepatocarcinogênese. Ratos Wistar foram submetidos ao modelo de hepatocarcinogênese do \"Hepatócito Resistente\" e receberam durante 4 semanas consecutivas: 16mg/100g p.c. de β-ionona (BI) ou somente 0,25mL/100g p.c. de óleo de milho (grupo controle - OM). Estes animais foram distribuídos em 4 pontos de eutanásia (P0, P1, P2 e P3 - 7, 14, 21 e 35 dias após a HP respectivamente), para avaliação da cinética das células ovais hepáticas. Foi observado que o tratamento com BI diminuiu a presença de células ovais GST-P positivas e reduziu o percentual de LPN positivas para ALDH1A1, β-catenina e CK19 quando comparado ao do respectivo grupo controle OM. Em conclusão, o tratamento com BI reduziu o número das células ovais, bem como os níveis de proteínas a elas relacionadas e que conferem ao HCC mau prognóstico e maior agressividade. / Carcinogenesis is a long process that involves multiple phases in the transformation of normal cells into malignant. Two hypotheses have been proposed to explain the heterogeneous potential of neoplastic cells and the process of carcinogenesis: a stochastic model in which a distinct population of neoplastic cells acquires a set of somatic mutations and develops metastatic capacity and hierarchical model in which the primary tumors and their metastases are initiated by a small number of cells, known \"cancer stem cells\" (CSC). Therefore, the HCC can be originate from stem/progenitor cells or hepatic oval cells and hepatocytes. Ventured the hypothesis in this work that β-ionone (BI) reduces the number of hepatic oval cells, regulating proteins (CK19, β-catenin and ALDH1A1) that may be related to the role of these cells in hepatocarcinogenesis. Wistar rats were submitted to hepatocarcinogenesis model of \"Resistant Hepatocyte\" and received for 4 consecutive weeks: 16mg/100g body weight of BI or 0,25 mL/100g body weight of corn oil (control group - CO). These animals were euthanized at 4 points (P0, P1, P2 and P3 - 7, 14, 21 and 35 days after PH, respectively) to evaluate the kinetics of hepatic oval cells. It was observed that the treatment of BI decreased the presence of GST-P oval cells positive and reduced the percentage of positive ALDH1A1 LPN, β-catenin and CK19 compared to the respective control group OM. In conclusion, the treatment with BI reduced the number of oval cells as well as the levels of proteins related to them and gives a poor prognosis in HCC and increased aggressiveness.

A &#946;-ionona (BI) é um isoprenóide que apresenta atividade quimiopreventiva durante a fase de promoção da hepatocarcinogênese. O presente trabalho teve como objetivo avaliar a expressão de genes modulados pela BI envolvidos na quimioprevenção durante a fase de promoção da hepatocarcinogênese induzida pelo modelo do \"Hepatócito Resistente\" (RH). Ratos Wistar machos foram submetidos ao modelo do RH e tratados durante 4 semanas consecutivas com BI (16 mg/100 g de p.c.) ou óleo de milho (OM) (0,25 ml/100 g de p.c.; grupo controle). O perfil da expressão de 1.176 genes foi analisado por macroarray no fígado dos grupos BI, OM e de ratos considerados normais (grupo N). A expressão gênica foi considerada aumentada, quando a razão de expressão foi &#8805; 1,5 ou diminuída, quando &#8804; 0,5. Aplicou-se análise hierárquica de clustering e classificação ontológica dos genes diferencialmente expressos. A expressão gênica foi validada por RT-PCR do tipo \"duplex\", utilizando-se tecido hepático microdissecado de: lesões pré-neoplásicas persistentes (pLPN) ou em remodelação (rLPN) e de regiões ao redor das LPN (surrounding). Um total de 133 e 32 genes foi considerado diferencialmente expresso entre os grupos OM (em relação ao N) e BI (em relação ao OM), respectivamente. Trinta e sete por cento dos genes diferencialmente expressos no grupo BI vs OM referiam-se a receptores celulares. Destes, 4 genes codificantes para receptores nucleares foram identificados como possíveis alvos da BI na quimioprevenção da hepatocarcinogênese: RXR&#945; (receptor X de retinóide &#945;), RAR&#946; (receptor de ácido retinóico &#946;), COUP-TFI (chicken ovalbumin upstream promoter-transcription factor I) e Nur77 (nuclear receptor 77). Em comparação ao grupo OM, a expressão de RXR&#945; e RAR&#946; foi maior (p<0,05) especificamente em pLPN e rLPN do grupo &#946;I, respectivamente. Em comparação ao grupo N, Nur77 apresentou maior (p<0,05) expressão no surrounding e nas rLPN do grupo OM. Por outro lado, a expressão de Nur77 em rLPN foi menor (p<0,05) no grupo BI do que no OM. Comparada ao grupo N, a expressão de COUP-TFI foi maior (p<0,05) no grupo OM, tanto no surrounding das LPN como nas pLPN e rLPN. Em comparação ao grupo OM, a expressão de COUP-TFI foi menor (p<0,05) no grupo BI, especificamente nas pLPN e nas rLPN. Os resultados sugerem que os receptores nucleares RXR&#945;, RAR&#946;, Nur77 e COUP-TFI representam alvos moleculares da BI relevantes para a quimioprevenção da hepatocarcinogênese em ratos. / &#946;-ionone (BI) is an isoprenoid which has chemopreventive activity during the promotion phase of hepatocarcinogenesis. This study aimed to evaluate the expression of genes modulated by BI involved in chemoprevention during the promotion phase of hepatocarcinogenesis induced model of \"Resistant Hepatocyte (RH). Male Wistar rats were submitted to the RH model and treated for 4 consecutive weeks with BI (16 mg/100 g bw) or corn oil (CO) (0.25 ml/100 g bw, control group). The expression profile of 1,176 genes was analyzed by macroarray in the liver of groups BI, CO and normal rats (group N). Gene expression was considered increased when the expression ratio was 1.5 or decreased when 0.5. Hierarchical clustering analysis and ontological classification of differentially expressed genes were applied. Gene expression was validated by RT-PCR \"duplex\", using microdissected hepatic tissue from: persistent pre-neoplastic lesions (pPNL) or remodeling pre-neoplastic lesions (rPNL) and regions around the PNL (surrounding). A total of 133 genes and 32 were considered differentially expressed between the two groups (CO to N) and BI (relative to CO), respectively. 37% of differentially expressed genes in group BI vs CO were related to cell receptors. Of these, four genes encoding for nuclear receptors have been identified as possible targets of BI in the chemoprevention of hepatocarcinogenesis: RXR (retinoid X receptor &#945;), RAR&#946; (retinoic acid receptor &#946;), COUP-TFI (chicken ovalbumin upstream promoter-transcription factor I) and Nur77 (nuclear receptor 77). Compared to CO group, the expression of RXR&#945; and RAR&#946; was higher (p <0.05) specifically in pPNL and rPNL of BI group, respectively. Compared to the group N, Nur77 showed higher (p <0.05) expression in the surrounding and rPNL of CO group. The expression of Nur77 in rPNL was lower (p <0.05) in BI than the CO group. Compared to N group, the expression of COUP-TFI was higher (p <0.05) in CO group (surrounding, pPNL and rPNL). Compared to CO group, the expression of COUP-TFI was lower (p <0.05) in BI group, specifically in the pPNL and rPNL. The results suggest that the nuclear receptors RXR&#945;, RAR&#946;, Nur77 and COUP-TFI represent relevant molecular targets of BI in the chemoprevention of hepatocarcinogenesis in rats.

This study investigated potential apoptotic and anti-proliferative effects of the phytochemicals, genistein and anthocyanin extract, as single and combined treatments in MCF-7 human breast cancer cells. Cells were exposed to single and combined treatments with the phytochemiclas for 48 and 72 hours. Cell viability was assessed using the MTT bioassay. Apoptosis induction was assessed using acridine orange ethidium bromide and rhodamine 123 ethidium bromide fluorescence assays. Both singe and combination treatments induced dose- and time-dependent apoptotic cell death in MCF-7 cells. The percentage of apoptosis was higher in combination treatments than single treatments with either phytochemical, although the difference was not statistically significant. The combination of genistein and anthocyanin extract peaked in efficacy at 48 hours of treatment, to exhibit significantly greater (P<. O5) dose- and time-dependent cell cytotoxicity than single treatments. This study reveals potential chemopreventive implications for the complementary effects of genistein and anthocyanin extract. / by Corine M. Stinson. / Thesis (M.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.

O isoprenóide geraniol (GO) apresentou atividade quimiopreventiva quando administrado continuamente durante as fases de iniciação e pós-iniciação em modelo de carcinogênese experimental de cólon por meio da redução do número de focos de criptas aberrantes (FCAs) totais FCAs &#8805; 4 criptas e aumento de apoptose no cólon distal. Dessa forma, optou-se por avaliar os eventuais efeitos de três doses de GO (GO1: 25mg/100g de peso corpóreo [p.c.], G02: 50 mg/100g de p.c. e G03: 100 mg/100g de p.c.) em categorias de lesões pré-neoplásicas (LPNs) induzidas por dimetilhidrazina (DMH) durante a fase de pós-iniciação tardia de modelo de carcinogênese experimental de cólon, caracterizada por apresentar lesões mais avançadas e com alto grau de alterações celulares morfológicas, bioquímicas e moleculares denominadas de displasia. Para isso, analisamos diferentes biomarcadores como: FCAs totais e FCAs < ou &#8805; 4 criptas em cólons corados com azul de metileno; focos depletados ou positivos de mucina (FPMs ou FDMs) em cólons corados com azul de toluidina; FCAs convencionais ou displásicos por meio de análise histopatológica em cortes corados com hematoxilina e eosina (HE) e focos positivos ou negativos para beta-catenina (FPBCs ou FNBCs) citoplasmática e/ou nuclear por meio de imunoistoquímica. Além disso, células apoptóticas foram identificadas utilizando-se critérios morfológicos clássicos em FCAs &#8805; 4 no cólon distaI e a expressão de genes envolvidos na carcinogênese de cólon foi avaliada por meio de RT-PCR: HMGCoA-redutase na mucosa colônica e K-Ras e c-myc em FCAs microdissecados. Em relação ao grupo controle, foi possível observar que o grupo tratado com a maior dose de GO (G03) reduziu a freqüência de FCAs &#8805; 4 criptas e FDMs, além de aumentar a apoptose em FCAs &#8805; 4 displásicos no cólon distaI (p &#8804; 0,05). Já, em relação aos outros biomarcadores e às expressões de HMGCoA-redutase, K-Ras e c-myc não observamos diferenças estatísticas entre os tratamentos (p > 0,05). A partir desses resultados, podemos concluir que a dose de 100 mg/100 g de p.c. de GO mostrou ser mais interessante do ponto de vista quimiopreventivo com efeitos observados principalmente no cólon distaI, onde há maiores relatos de incidência de adenocarcinomas colônicos, tanto em animais quanto em humanos. Assim, a indução da morte celular programada em FCAs &#8805; 4 preferencialmente displásicos poderia representar um mecanismo importante de atuação de G03 na redução da freqüência de FCAs &#8805; 4 criptas e de FDMs (também utilizado como marcador de displasia) durante a fase de pós-iniciação tardia de modelo de carcinogênese experimental de cólon. / The isoprenoid geraniol (GO) showed chemopreventive activity when administered continuously during the initiation and post-initiation phases in an experimental model of colon carcinogenesis by reducing the number of total aberrant crypt foci (ACF) and ACFs &#8805; 4 crypts, as well as increasing apoptosis in the distal colon. We therefore chose to evaluate the effects of three different doses of GO (GO1: 25 mg/100 g body weight [b.w.], GO2: 50 mg/100 g b.w. and GO3: 100 mg/100 g of b.w.) on preneoplastic lesions (PNLs) induced by dimethylhydrazine (DMH) during late post-initiation in an experimental model of colon carcinogenesis that is characterized by more advanced lesions and a higher degree of cellular alterations morphological, biochemical and molecular (dysplasia) than previous models. For this study, we analyzed the following biomarkers: total ACFs, ACFs < 4 crypts, and ACFs &#8805; 4 erypts in colons stained with methylene blue; mucin-depleted or mucin-positive foci (MDFs or MPFs) in colons stained with toluidine blue; ACFs, through conventional or dysplastie histopathological analysis of sections stained with hematoxylin and eosin (HE); and cytoplasmic vs. nuclear foci reactivity for beta-catenin (foci positive for beta-eatenin (FPBC) or foci negative for beta catenin (FNBC)) using immunohistochemistry. Additionally, apoptotic cells were identified using classical morphologic criteria in ACFs &#8805; 4 crypts in the distal colon, and the expression of several genes involved in colon carcinogenesis was assessed by RT-PCR, including HMG-CoA reductase in the colonic mucosa and K-Ras and c-myc in microdissected ACFs. Relative to the control group, we observed that the group receiving the highest dose of GO (GO3 group) had a reduced frequency of both ACFs &#8805; 4 crypts and MDFs and that apoptosis increased in dysplastic ACFs &#8805; 4 crypts in the distal colon (p < 0, 05). Expression of HMG-CoA reductase, K-Ras and c-myc did not differ between treatments (p > 0, 05). Based on these results, we conclude that the 100 mg/100 g b.w. dose of GO is the most promising, as it shows evidence of chemopreventive effects mainly in the distal colon, which is a region that is reported to have a higher incidence of colonic adenocarcinomas, both in animaIs and in humans. lnduction of programmed cell death by GO3 in ACFs &#8805; 4 specifically dysplastic could represent an important mechanism of action in reducing the frequency of both ACFs &#8805; 4 crypts and MDFs during late post-initiation in this experimental model of colon carcinogenesis.

A ingestão de folato é inversamente associada com o risco de diversos cânceres. Apesar da deficiência dessa vitamina ser classicamente considerada fator de risco para câncer de fígado, não existem estudos avaliando o efeito da suplementação com ácido fólico (AF) durante as etapas iniciais da hepatocarcinogênese. Assim, o objetivo do presente estudo foi avaliar o efeito da suplementação com AF continuamente durante as etapas de iniciação e seleção/promoção da hepatocarcinogênese em ratos. Os animais receberam diariamente 0,08 mg (grupo AF8) ou 0,16 mg (grupo AF16) de AF/100 g de peso corpóreo ou água (grupo controle [GC]). Após duas semanas de tratamento, todos os animais foram submetidos ao modelo de hepatocarcinogênese do &#8220;Hepatócito Resistente&#8221; (iniciação com dietilnitrosamina, seleção/promoção com 2-acetilaminofluoreno e hepatectomia parcial a 70%). A eutanásia dos animais ocorreu após 8 semanas de tratamento. Quando comparado ao GC, o grupo AF16, mas não o AF8, apresentou menores nódulos macroscópicos (p<0,05), menor (p<0,05) número de lesões pré-neoplásicas (LPN) persistentes, maior (p<0,05) número de LPN em remodelação, menor (p<0,05) proliferação celular nas LPN persistentes, menos (p<0,05) danos no DNA hepático e tendência (p<0,10) a apresentar menor expressão de c-myc em LPN microdissecadas. Não foram observadas diferenças significativas (p>0,05) entre os grupos experimentais com relação à indução de apoptose nas LPN persistentes e em remodelação bem como no padrão de metilação global do DNA em LPN microdissecadas. Em resumo, a suplementação com AF durante as etapas iniciais da hepatocarcinogênese resultou em atividade quimiopreventiva de forma dose-efeito. Alteração no fenótipo das LPN, inibição de danos no DNA hepático e da expressão de c-myc representam relevantes efeitos celulares e moleculares dessa vitamina. / Dietary intake of folate is inversely associated with the risk of several malignancies. Although folate deficiency is associated with liver cancer, there is no data on folic acid (FA) supplementation during hepatocarcinogenesis. The aim of the present study was to evaluate the effect of FA supplementation during early hepatocarcinogenesis. Rats receiving daily 0.08 mg (FA8 group) or 0.16 mg (FA16 group) of FA/100 g body weight or water (CO group, controls) were used. After a 2 week-treatment, all animals were submitted to the resistant hepatocyte model of hepatocarcinogenesis (initiation with diethylnitrosamine, selection/promotion with 2-acetylaminofluorene and partial hepatectomy). All animals were euthanized after 8 weeks of treatment. When compared to CO group, FA16 group, but not FA8 group, presented: smaller (p < 0.05) macroscopic nodules; reduced (p < 0.05) number of persistent and increased (p < 0.05) number of remodeling preneoplastic lesions (PNL); reduced (p < 0.05) cell proliferation in persistent PNL; decreased (p < 0.05) hepatic DNA damage; and a tendency (p < 0.10) of decreased c-myc expression in microdissected PNL. No differences (p > 0.05) were observed between CO, FA8 and FA16 groups regarding apoptosis in both persistent and remodeling PNL, and global DNA methylation pattern in microdissected PNL. In conclusion, FA supplementation during early hepatocarcinogenesis resulted in a dose-response chemopreventive activity. Reversion of PNL phenotype and inhibition of DNA damage and of c-myc expression represent relevant FA cellular and molecular effects.

A utilização da radioterapia e da quimioterapia em maior escala no tratamento do câncer de cabeça e pescoço tem elevado a incidência de efeitos colaterais, em especial da mucosite bucal. O presente estudo estabeleceu como objetivo a avaliação do efeito da suplementação da vitamina E e do selênio na prevenção da mucosite causada pela radioterapia e/ou quimioterapia em pacientes com neoplasias malignas das vias aerodigestivas superiores. Como metodologia, decidiu-se por um ensaio clínico III, randomizado, duplo cego, realizado no Serviço de Oncologia da Faculdade de Odontologia da Universidade Federal de Minas Gerais. A amostra foi constituída por 95 pacientes portadores de câncer nas vias aerodigestivas superiores, com indicação de radioterapia, sendo 78 (82,1%) do gênero masculino e 17 (17,9%) do gênero feminino, com média de idade de 54 ± 13,4 anos, variando entre 20 e 85 anos. O mineral selênio e a vitamina E foram classificados como grupo A e grupo B, respectivamente. Do primeiro dia da sessão de radioterapia até uma semana após o término da radioterapia, os pacientes tomaram uma cápsula por dia do suplemento. A mucosite foi avaliada semanalmente pelos cirurgiões dentistas do próprio serviço. Foram coletados dados de 115 pacientes. Como 20 deles foram excluídos, analisaram-se os resultados de apenas 95 indivíduos. Durante as dez semanas de acompanhamento desses pacientes, a avaliação da presença de mucosite foi realizada semanalmente. Do total de pacientes analisados, 88,2% desenvolveram mucosite (41 pacientes do grupo selênio e 41 pacientes do grupo vitamina E) decorrente do tratamento radioterápico realizado concomitantemente ou não com a quimioterapia. Na avaliação dos efeitos da suplementação nos diferentes graus de mucosite, observou-se que a maioria dos indivíduos se enquadrava na classificação grau II (alimentando-se normalmente, mas com dor). Independentemente do grau de mucosite, não foram encontradas diferenças entre os grupos suplementados (p=0,559). Em um período prévio a este trabalho, observou- se em pacientes avaliados semanalmente no mesmo ambulatório frequência de mucosite de 93% (noventa e três), dos quais 10,3% (dez) classificaram- se entre grau 0 e grau 1; 72,5% (setenta e dois) grau 2 e 17,2%.(dezessete) entre grau 3 e grau 4.Esses resultados sugerem que a suplementação com 100 µg de selênio ou de 400 mg de vitamina E não foi eficiente na prevenção da mucosite. Como conclusão, este estudo demonstra que a frequência de mucosite decorrente de tratamento radioterápico, com ou sem quimioterapia, é alta (88,2%) e que a suplementação do mineral selênio não é diferente da vitamina E na prevenção, intensidade ou retardo do aparecimento dessa enfermidade. / The increase of radiotherapy and chemotherapy intensity in the treatment of head and neck cancer has raised the incidence of side effects, specially of mouth mucositis. To evaluate the effect of the vitamin E and selenium supplementation in the prevention of the mucositis caused by the radiotherapy and/or chemotherapy in patients with upper aerodigestive ducts malign tumors. This study referred to at the Oncology Service of the UFMGs Oncology College. The sample has been constituted by patients with head and neck cancer and radiotherapy. 95 individuals were included, 78 (82,1%) male and 17 (17,9%) female, with a mean of age of 54+- 13,4, varying between 18 and 82 years old. The Selenium mineral and the Vitamin E were classified as Group A and B, respectively. The patients took one supplement capsule a day. The treatment started in the day of the radiotherapy session and ended one week after the radiotherapy . The mucositis was evaluated weekly by the services dentist surgeries. Data from 115 patients were collected. However, 20 patients were excluded from the study, therefore, 95 patients were analyzed. During the 10 weeks of patient follow-up, the mucositis presence evaluation was made weekly. We observed that 41 patients developed mucusitis during the radiotherapy treatment with or without chemotherapy, in both selenium and vitamin E groups. By evaluating the supplementation effects in the different levels of mucositis, it was observed that the great majority of individuals can be put in the level II classification (feed themselves normally, but with pain). Regardless the mucositis level, we have not found differences between the supplemented groups (p=0,559).In a period prior to this work, we observed in patients evaluated in the same clinic on a weekly frequency of mucositis 93% (ninety- three), of which 10.3% (ten) rated between grade 0 and grade 1, 72 , 5% (seventy two) grade 2 and 17.2%. (seventeen) of grade 3 and grade 4.We can suggest, therefore, that the supplementation with 10µg of selenium or 400mg of vitamin E have not been efficient in the mucositis prevention.In conclusion, this study has shown that the Selenium mineral and the Vitamin E supplementation did not prevent or retard the mucositis appearance.

Wang Huan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 148-158). / Abstracts in English and Chinese. / TABLE OF CONTENTS --- p.I / LIST OF FIGURES AND TABLES --- p.VIII / ABSTRACT --- p.1 / 摘要 --- p.3 / Chapter CHAPTER 1 --- GENERAL INTRODUCTION / Chapter I. --- The essential factors related to cancer --- p.5 / Chapter a. --- Carcinogens --- p.5 / Chapter b. --- Carcinogenesis pathways --- p.7 / Chapter c. --- DNA adducts formation and breast cancer --- p.7 / Chapter II. --- Cytochrome P450 I enzyme family --- p.8 / Chapter a. --- CYP450 superfamily --- p.8 / Chapter b. --- CYP1A1 --- p.10 / Chapter c. --- CYP1B1 --- p.11 / Chapter III. --- Transactivation of CYP1 enzymes by aryl hydrocarbon receptor (AhR) --- p.12 / Chapter IV. --- Phase II enzyme UGT and cancer prevention --- p.13 / Chapter V. --- Estrogen metabolism and the hormone-dependent breast cancer --- p.15 / Chapter a. --- Estrogen and breast cancer initiation --- p.15 / Chapter b. --- Estrogen Receptor (ER) --- p.15 / Chapter c. --- Estradiol hydroxylation pathways --- p.15 / Chapter VI. --- Phytochemicals and cancer prevention --- p.18 / Chapter VII. --- Outline of this study --- p.20 / Chapter CHAPTER 2 --- MATERIALS AND METHODS / Chapter I. --- Chemicals --- p.21 / Chapter II. --- Cell culture and treatments --- p.21 / Chapter 1. --- Maintenance of cells --- p.21 / Chapter 2. --- Preparation of cell stock --- p.22 / Chapter 3. --- Cell recovery from liquid nitrogen stock --- p.22 / Chapter 4. --- Measurement of cell viability --- p.22 / Chapter 5. --- Preparation of cell lysates --- p.23 / Chapter 6. --- XRE-luciferase gene reporter assay --- p.23 / Chapter a. --- Transient transfection of cell using lipofectamine PLUS reagent --- p.23 / Chapter b. --- Dual Luciferase Assay --- p.24 / Chapter III. --- Enzyme Activities --- p.24 / Chapter 1. --- Isolation of microsomes --- p.24 / Chapter 2. --- EROD activities in intact cells --- p.24 / Chapter 3. --- EROD inhibition assay --- p.25 / Chapter IV. --- Manipulation of Nuclear Acid --- p.26 / Chapter 1. --- Preparation of transfected DNA --- p.26 / Chapter a. --- Separation and purification of DNA from agarose gel --- p.26 / Chapter b. --- Restriction digestion --- p.26 / Chapter c. --- Ligation of DNA fragments --- p.27 / Chapter d. --- Transformation of DH5a --- p.27 / Chapter e. --- Small scale plasmid purification from DH5a (mini prep) --- p.28 / Chapter f. --- Large scale plasmid isolation from DH5a (maxi-prep) --- p.28 / Chapter g. --- Construction of XRE activated luciferase reporter gene --- p.29 / Chapter 2. --- Measurement of DMBA-DNA adduct formation --- p.29 / Chapter 3. --- Semi-quantitative RT-PCR Assay --- p.30 / Chapter a. --- Isolation of RNA using TRIzol® Reagent --- p.30 / Chapter b. --- RT-PCR --- p.31 / Chapter V. --- Phase II enzyme-UGT activity assay --- p.32 / Chapter VI. --- HPLC for estradiol-hydroxylation analysis --- p.33 / Chapter 1. --- HPLC condition for hydroxyestradiol separation and measurement --- p.33 / Chapter 2. --- Determination of microsomal estradiol hydroxylase activity --- p.34 / Chapter 3. --- Assay of estradiol metabolism in MCF-7 cells --- p.34 / Chapter VII. --- Statistical Analysis --- p.35 / Chapter CHAPTER 3 --- CHALCONES ANTAGONIZE DMBA-INDUCED CARCINOGENESIS BY MODULATION OF CYP1A1/1B1 AND UGT ACTIVITIES / Chapter Part One --- Introduction --- p.36 / Chapter Part Two --- Results --- p.40 / Chapter Section One --- Chalcones antagonize DMBA carcinogenesis by inhibiting CYP1A1 and CYP1B1 activities --- p.40 / Chapter I. --- Chalcones inhibited DMBA-induced EROD activities in MCF-7 cells --- p.40 / Chapter II. --- Inhibition of chalcones on microsomal CYP1A1 & 1B1 enzyme activities --- p.43 / Chapter III. --- Reduction of DMBA-induced DNA adduct by chalcones --- p.52 / Chapter IV. --- Chalcones antagonized CYP1A1 XRE transactivation --- p.54 / Chapter V. --- Chalcones suppressed DMBA-induced CYP1 gene expression --- p.56 / Chapter Section Two --- Chalcones modulate DMBA carcinogenesis by regulating UGT activities --- p.63 / Chapter I . --- Chalcones regulated UGT1A1 gene expression in MCF-7 cells --- p.63 / Chapter II. --- Chalcones affected UGT enzyme activity in HepG2 cells --- p.70 / Chapter III. --- Chalcones regulated UGT1A1 gene expression in HepG2 cells --- p.73 / Chapter Part Three --- Discussion --- p.80 / Chapter I . --- Chalcones are potential chemopreventive agents --- p.80 / Chapter II. --- Chalcones modulated Phase I enzyme activities --- p.80 / Chapter III. --- Chalcones regulated Phase II enzyme activities --- p.82 / Chapter IV. --- Chalcones suppressed DMBA-induced DNA-adduct formation in MCF-7 cells --- p.82 / Chapter V. --- The anti-carcinogenic properties of chalcones and their structures --- p.83 / Chapter CHAPTER 4 --- EFFECTS OF PERILLYL ALCOHOL AND LIMONENE ON CYP1 AND UGT ENZYMES / Chapter Part One --- Introduction --- p.85 / Chapter Part Two --- Results --- p.87 / Chapter I. --- Perillyl alcohol and limonene modulated DMBA-induced CYP1A1/1B1 activities in MCF-7 cells --- p.87 / Chapter II. --- Perillyl alcohol and limonene regulated microsomal CYP1A1/1B1 activities --- p.89 / Chapter III. --- Perillyl alcohol and limonene regulated DMBA-induced DNA adduct formation in MCF-7 cells --- p.93 / Chapter IV. --- Perillyl alcohol and limonene regulated CYP1A1 & CYP1B1 gene expressions in MCF-7 cells --- p.95 / Chapter V. --- Effect of perillyl alcohol on CYP1A1 XRE transactivation --- p.97 / Chapter VI. --- Cytotoxic effect of perillyl alcohol and limonene on MCF-7 cells --- p.98 / Chapter VII. --- Perillyl alcohol and limonene modulated UGT1A1 gene expression in MCF-7 cells --- p.99 / Chapter VIII. --- Perillyl alcohol and limonene modulated UGT enzyme in HepG2 cells --- p.101 / Chapter Part Three --- Discussion --- p.106 / Chapter CHAPTER 5 --- LYCOPENE MEDIATED DMBA-INDUCED PHASE I & PHASE II ENZYME ACTIVITIES AND GENE EXPRESSIONS / Chapter Part Three --- Introduction --- p.109 / Chapter I. --- Biochemical properties of lycopene --- p.109 / Chapter II. --- Bioavailability of lycopene --- p.110 / Chapter III. --- Lycopene and cancers in hormonal sensitive tissues --- p.110 / Chapter Part Two --- Results --- p.111 / Chapter I . --- Lycopene modulated DMBA-induced CYP1A1/1B1 activities in MCF-7 cells --- p.111 / Chapter II. --- Lycopene competitively inhibited microsomal CYP1A1 & CYP1B1 activities --- p.113 / Chapter III. --- Lycopene suppressed DMBA-induced DNA adduct formation in MCF-7 cells --- p.115 / Chapter IV. --- Lycopene regulated CYP1A1 & CYP1B1 gene expression in MCF-7 cells --- p.116 / Chapter V. --- Effect of lycopene on CYP1A1 XRE trasactivation --- p.117 / Chapter VI. --- Cytotoxic effect of lycopene on MCF-7 cells --- p.118 / Chapter VII. --- Lycopene modulated UGT enzyme in MCF-7 cells --- p.119 / Chapter VIII. --- Lycopene modulated UGT enzyme in HepG2 cells --- p.121 / Chapter Part Three --- Discussion --- p.123 / Chapter CHAPTER 6 --- CHALCONES AND PERILLYL ALCOHOL REGULATEDCYP1A1 & CYP1B1 MEDIATED ESTRADIOL METABOLIZING PATHWAYS / Chapter Part One --- Introduction --- p.125 / Chapter I . --- Estrogen hydroxylation and human breast cancer risk --- p.125 / Chapter II. --- CYP1 enzymes catalyze estradiol-hydroxylation in human breast cancer cells --- p.126 / Chapter III. --- Phytochemicals mediate estrogen-hydroxylation pathways --- p.126 / Chapter Part Two --- Estrogen metabolite detection and separation by HPLC --- p.127 / Chapter Part Three --- Results --- p.129 / Chapter I . --- Perillyl alcohol modulated CYP1A1 & CYP1B1-mediated Estradiol hydroxylation --- p.129 / Chapter II. --- Kinetics assays of chalcones on CYP1A1 & CYP1B1 microsomes induced estradiol hydroxylation --- p.131 / Chapter III. --- Chalcones suppressed Estradiol-hydroxylase activities in MCF-7 cells --- p.137 / Chapter Part Four --- Discussion --- p.140 / Chapter CHAPTER 7 --- SUMMARY / Chapter I . --- Chalcones displayed inhibitory effects on DMBA-induced carcinogenesis --- p.142 / Chapter II. --- Perillyl alcohol and limonene modulated DMBA-induced carcinogenesis --- p.143 / Chapter III. --- Lycopene also possessed chemoproventive properties --- p.143 / APPENDIX 1 ABBREVIATIONS --- p.144 / APPENDIX 2 REAGENTS --- p.145 / APPENDIX 3 PRIMER LISTS --- p.147 / REFERENCE --- p.148

Introdução: O carcinoma de células escamosas da via aerodigestiva superior (VADS) geralmente é unifocal e advém da progressão das lesões pré-neoplásicas. O risco de segundos tumores primários é de 3 a 7% ao ano para pacientes tratados previamente de câncer da VADS, sendo importante avançar em estratégias de quimioprevenção. Nos estudos clínicos realizados, as drogas promissoras mostraramse ineficazes quando aplicadas em doses baixas para minimizar a toxicidade. Neste trabalho, ácidos graxos poliinsaturados ômega-3 (óleo de peixe) e pioglitazone, um agonista PPAR-?, foram utilizados com intenção quimiopreventiva, em modelo animal de carcinogênese da VADS, induzida com o uso de 4- nitroquinolina-1-óxido (4-NQO). Métodos: Camundongos Swiss foram submetidos à indução tumoral com 4-NQO nas doses: 25, 50 ou 100 g/ml diluído em água por 8 semanas. Quimioprevenção foi testada com óleo de peixe nas concentrações de 10% ou 5%. Também foi realizada, em outros grupos, quimioprevenção com pioglitazone nas concentrações de 300 ppm ou 100 ppm. A quimioprevenção foi realizada na iniciação e pós-iniciação tumorais (por 32 semanas) ou apenas na pós- iniciação (por 24 semanas). Resultados: As incidências de neoplasias oral e esofágica foram, respectivamente, similares entre os grupos 4-NQO 100 77,7% e 55,5% e 4-NQO 50 72,9% e 37,8%. O grupo 4-NQO 25, ao ser observado 24 semanas a mais, obteve 78,2% de neoplasia oral e 34,7% de esofágica. A mortalidade por câncer nas 24 semanas após o término do 4-NQO foi de 55,6% no grupo 4-NQO 100, de 11,6% no 4-NQO 50 e de 13,6% no 4-NQO 25; sendo significante na comparação entre os grupos 100 com 50 (p<0,01) e 100 com 25 (p<0,01). Assim, foi observado que 4- NQO 100 g/ml gerou uma mortalidade mais acelerada neste grupo. A maioria dos animais desenvolvia lesões invasoras em mais de um órgão ou a associação destas com pré-neoplásicas. A incidência de neoplasia oral foi similar na comparação entre o grupo 4-NQO 100 (77,7%) com óleo de peixe 10% (80%) p=1,00 e com o grupo pioglitazone 300 ppm (61,1%) p=0,27. Entre os grupos 4-NQO 50 com óleo de peixe 5% (controle - 72,9%, com óleo de peixe na pós- iniciação - 84,2% e com óleo de peixe na iniciação e pós- iniciação - 64,7%) p=0,34 e entre os grupos 4-NQO 50 com pioglitazone 100 ppm (controle - 72,9%, com pioglitazone na pós-iniciação - 76,1% e com pioglitazone na iniciação e pós-iniciação - 62,5%) p=0,63, a incidência de neoplasia oral foi semelhante na comparação entre os grupos. A presença de neoplasia esofágica não diferiu entre o grupo 4-NQO 100 (55,5%) com óleo de peixe 10% (50%) p=0,73 e com o grupo pioglitazone 300 ppm (50%) p=0,73; e foi também similar entre os grupos 4-NQO 50 com pioglitazone 100 ppm (controle - 37,8%, com pioglitazone na pós- iniciação - 57,1% e com pioglitazone na iniciação e pós- iniciação - 31,2%) - p=0,22; porém diferiu nos grupos 4-NQO 50 com óleo de peixe 5% (controle37,8%, com óleo de peixe na pós-iniciação68,4% e com óleo de peixe na iniciação e pós- iniciação29,4%), sendo estatisticamente significante - p=0,02. Interessante foi a observação de que o grupo que realizou quimioprevenção com pioglitazone desenvolveu câncer gástrico na mesma proporção dos demais grupos, porém apresentou uma doença mais agressiva, com disseminação metastática, fato não observado nos outros grupos. Considerando-se a sobrevida, não foi observada diferença estatística significante nas 24 semanas comparando-se os grupos 4-NQO 100 e entre os grupos 4-NQO 50 com ou sem quimioprevenção com óleo de peixe ou com pioglitazone. Conclusão: A indução tumoral com 4-NQO, independente da dose, foi obtida com sucesso em camundongos Swiss. Neste estudo, não foram observados efeitos de quimioprevenção do óleo de peixe e do pioglitazone nas diferentes fases da carcinogênese estudadas. O óleo de peixe na pós-iniciação pode ter potencializado a ação carcinogênica do 4-NQO no esôfago, assim como a associação do 4-NQO com o pioglitazone possa ter criado um novo modelo de carcinogênese gástrica, não vista nos grupos que não receberam esta associação. / Introduction: The squamous cell carcinoma of the upper aerodigestive tract (UADT) is generally unifocal and arises from the progression of premalignant lesions. Between 3% to 7% of patients with head and neck carcinoma will develop subsequent primary tumors of the UADT annually; therefore, the importance of advancing in new chemopreventive strategies is unquestionable. In clinical studies, promising drugs were ineffective when used at low doses to minimize toxicity. In the present study, the potential chemopreventive effects of polyunsaturated fatty acids omega-3 (fish oil) and of a PPAR-? ligand (pioglitazone) were tested in an animal model of UADT carcinogenesis induced by 4-nitroquinoline-1-oxide (4-NQO) in Swiss mice. Methods : The animals underwent tumor induction with 25, 50 or 100 g/ml of 4-NQO diluted in water for eight weeks. Chemoprevention was tested with 10% or 5% fish oil and with 300 ppm or 100 ppm pioglitazone in other groups. Chemoprevention was conducted on tumor initiation and postinitiation for 32 weeks or only on postinitiation for 24 weeks. Results : The incidence rates of oral and esophageal neoplasms were similar between groups 4-NQO 100 (77,7% and 55,5%, respectively) and 4-NQO 50 (72,9% and 37,8%, respectively). Group 4-NQO 25 was followed for 24 weeks longer than the others and showed incidence rates of 78,2% for oral neoplasia and 34,7% for esophageal neoplasia. Cancer-related mortality rates in the 24 weeks following the conclusion of the tumor induction phase were 55,6%, 11,6% and 13,6% in groups 4-NQO 100, 4-NQO 50 and 4-NQO 25, respectively. The differences were statistically significant when comparing groups 100 with 50 (p<0,01) and 100 with 25 (p<0,01). The dose of 100 g/ml 4-NQO led to faster mortality compared with 50 g/ml or 25 g/ml 4-NQO. Most animals developed invasive lesions in more than one site of the UADT or, more frequently, an association of premalignant and malignant lesions. The incidence of oral neoplasia was similar in the comparison of the control group 4-NQO 100 with 10% fish oil (77,7% vs 80%, p=1,00) or with 300 ppm pioglitazone (77,7% vs 61,1%, p=0,27). Results were also similar when comparing 4-NQO 50 groups with 5% fish oil (control72,9%, fish oil on postinitiation84,2%, and fish oil on initiation and postinitiation64,7%, p=0,34), and between 4-NQO 50 groups with 100 ppm pioglitazone (control72,9%, pioglitazone on postinitiation76,1%, and pioglitazone on initiation and postinitiation62,5%, p=0,63). The incidence of esophageal neoplasia reached no statistical difference either when 4-NQO 100 control group was compared with 10% fish oil (55,5% vs 50%, p=0,73) or with 300 ppm pioglitazone (55,5% vs 50%, p=0,73). The same was true between 4-NQO 50 groups with 100 ppm pioglitazone (control37,8%, pioglitazone on postinitiation57,1%, and pioglitazone on initiation and postinitiation31,2%, p=0,22). Statistically significant differences were found between 4-NQO 50 groups with 5% fish oil (control37,8%, fish oil on postinitiation68,4%, and fish oil on initiation and postinitiation29,4%, p=0,02). Interestingly, the group receiving chemoprevention with 300 ppm pioglitazone had a gastric cancer incidence rate comparable to that of other groups, but with more aggressive disease and metastatic dissemination, unlike the others. No statistically significant differences were found in the survival rates for the 24-week period after induction when comparing the control groups 4-NQO 100 and 4-NQO 50 with their respective experimental groups, which received chemoprevention with fish oil or pioglitazone. Conclusions : Tumor induction with 4-NQO was successfully achieved in Swiss mice, regardless of the dose. In this study, no chemopreventive effects of fish oil or pioglitazone were observed either on postinitiation or on initiation and postinitiation. The introduction of fish oil on the postinitiation phase may have potentialized the carcinogenic action of 4-NQO on the esophageal epithelium; the same can be said about the association of 4-NQO and pioglitazone, which may have created a new model of gastric carcinogenesis not seen in the groups that did not receive that combination of drugs.

O carcinoma hepatocelular (HCC) apresenta mau prognóstico o que torna importante sua quimioprevenção. Nesse sentido, a tributirina (TB), um inibidor de desacetilases de histonas (HDACi), mostrou-se um quimiopreventivo promissor da hepatocarcinogênese. Avaliaram-se aqui efeitos quimiopreventivos de lipídios estruturados (EST) obtidos por interesterificação enzimática a partir da TB com o óleo de linhaça (LIN). Ratos foram tratados com EST (grupo EST; 165 mg/100g peso corpóreo [p.c]), TB (grupo TB; 200 mg/100g p.c), LIN (grupo LIN; 133 mg/100g p.c), mistura de TB com LIN (grupo LIN; 165 mg/100g p.c) ou maltodextrina (MD) (grupo MD; controle isocalórico; 300 mg/100g p.c) diariamente durante 8 semanas consecutivas por gavagem. Duas semanas após início dos tratamentos, os animais foram submetidos ao modelo de hepatocarcinogênese do \"hepatócito resistente\" (RH). Os grupos EST e TB apresentaram atividade quimiopreventiva bloqueadora e supressora, respectivamente, da hepatocarcinogênese. TB induziu a apoptose, ao contrário dos EST. O tratamento com TB resultou na acetilação e trimetilação da H3K9 e H3K27, enquanto EST atuaram somente na trimetilação das mesmas. Quando analisada a expressão de genes envolvidos com modificações em histonas, EST e TB reduziram a expressão de Ezh2 e de Hdac4. Por outro lado, somente os EST aumentaram a expressão de Hdac6. Tal efeito por parte dos EST merece ser mais investigado, uma vez que esta desacetilase vem sendo sugerida como alvo potencial para o desenvolvimento de fármacos. Em conclusão, a atividade quimiopreventiva de EST e da TB envolve na hepatocarcinogênese experimental mecanismos epigenéticos que podem ou não ser distintos. / Hepatocellular carcinoma (HCC) has a poor prognosis, which makes its chemoprevention important. Tributyrin (TB), which is a histone deacetylase inhibitor (HDACi), is a promising chemopreventive agent of hepatocarcinogenesis. The chemopreventive effects of structured lipids (STLs) that were obtained by the enzymatic interesterification of TB with flaxseed oil (FSO) were evaluated in the present study. Rats were treated with STLs (STL group, 165 mg/100 g body weight (bw)), TB (TB group, 200 mg/100 g bw), FSO (FSO group, 133 mg/100 g bw), TB mixed with FSO (BLD group, 165 mg/100g bw) or maltodextrin (MD) (MD group; isocaloric control; 300 mg/100 g bw) daily for eight consecutive weeks by gavage. Two weeks after the initiation of treatment, the animals were subjected to the resistant hepatocyte hepatocarcinogenesis model (RH). The STL and TB groups developed blocker and suppressive chemopreventive activity against hepatocarcinogenesis, respectively. TB treatment induced apoptosis, unlike the STL treatment. Additionally, TB treatment resulted in the acetylation and trimethylation of H3K9 and H3K27, whereas the STLs acted only in the trimethylation of these histones. When analyzing the expression of genes involved in histone modifications, the STLs and TB reduced enhancer of zeste homolog 2 (Ezh2) and histone deacetylase 4 (Hdac4) gene expression. Conversely, only the STLs increased Hdac6 gene expression. This effect of the STLs warrants further investigation because this deacetylase has been suggested as a potential drug development target. In conclusion, the chemopreventive activities of the STLs and TB in experimental hepatocarcinogenesis involve epigenetic mechanisms that may be distinct.