NTRODUÇÃO: O carcinoma cortical da suprarrenal é uma neoplasia rara com uma incidência estimada em 0,5-2,0 por milhão por ano em adultos. No momento, poucas opções terapêuticas para os pacientes com doença metastática são disponíveis, e novas descobertas sobre a sua patogênese são necessárias. O perfil de expressão gênica dos microRNAs (miRNAs) em tumores humanos tem sido caracterizado por uma redução global da expressão dos miRNAs. A enzima DICER1 e seu cofator TRBP (codificado pelo gene TARBP2) estão envolvidos em uma etapa essencial do processamento dos miRNAs. De forma interessante, a desregulação do processamento dos miRNAs em células cancerosas devido ao silenciamento da DICER1 propiciou a emergência de células com fenótipo mais agressivo, acelerando a progressão tumoral. Recentemente, mutações somáticas missense recorrentes no domínio de clivagem RNase IIIb da enzima DICER1 foram identificadas em 29% tumores de ovários não-epiteliais esteroidogênicos (e em até 60% de tumores ovarianos de células de Leydig). Adicionalmente, mutações inativadoras no éxon 5 do gene TARBP2, com consequente prejuízo da função da DICER1, foram identificadas em linhagens celulares de tumores com instabilidade cromossômica. OBJETIVOS: Determinar a expressão gênica e proteica da DICER1 e TRBP em tumores do córtex da suprarrenal de adultos e crianças; Investigar variantes genéticas no domínio de clivagem RNAse IIIb do gene DICER1; Investigar variantes genéticas no éxon 5 do gene TARBP2; Estudar a expressão dos miR-103 e miR-107, envolvidos na regulação da DICER1, e do miR-497, envolvido na regulação da TRBP. MÉTODOS: A expressão proteica da DICER1 e da TRBP foi avaliada por imunohistoquímica em uma micromatriz tecidual contendo 198 tumores do córtex da suprarrenal [154 em adultos (75 adenomas e 79 carcinomas) e 44 em crianças (38 clinicamente benignos e 6 clinicamente malignos)]. A expressão gênica da DICER1 e TARBP2 foi avaliada em um subgrupo de 84 tumores (61 adultos e 23 pediátricos) e a expressão do miR-103, miR-107 e miR-497 em 82 tumores (59 adultos e 23 pediátricos). O sequenciamento dos genes DICER1 e TARBP2 foi realizado em um subgrupo quase idêntico de 83 tumores. RESULTADOS: Em adultos, uma expressão forte para a DICER1 foi encontrada em 24 de 75 adenomas (32%) e em 39 de 79 carcinomas (51%; X2= 4,8, p= 0,028). Similarmente, a hiperexpressão do gene DICER1 foi encontrada em 15 de 25 carcinomas (60%) e em 7 de 30 adenomas (23%; X2= 7,64, p= 0,006). Dentre os carcinomas de adultos, a imunorreatividade fraca para DICER1 foi significativamente mais frequente em carcinomas metastáticos do que em não metastáticos (66% vs. 31%; X2= 9,3, p= 0,002). Além de mais agressivos, os carcinomas com uma expressão fraca da DICER1 foram diagnosticados em pacientes com uma mediana de idade menor (35 vs. 45 anos, p= 0,02), maior tamanho (12,3 vs. 9 cm, p= 0,001), estadio mais avançado (ENSAT 3 ou 4 em 55% vs. 30%, p= 0,04) e maior escore de Weiss (6 vs. 4, p= 0,02). Adicionalmente, a expressão fraca para a DICER1 se correlacionou com uma significativa redução da sobrevida global (p= 0,004) e livre de doença (p= 0,005). Na análise multivariada, Ki67 >- 10% (p= 0,0001) e expressão proteica fraca para DICER1 (p= 0,048) permaneceram como marcadores significativos de recorrência. No grupo pediátrico, a expressão gênica e proteica da DICER1 não foi diferente entre tumores clinicamente malignos e benignos Não identificamos nenhuma variante genética nos quatro sítios de metais do domínio RNAse IIIb do gene DICER1 tanto em adultos como em crianças. Além disso, a expressão proteica e gênica da DICER1 não se correlacionou com a expressão do miR-103 e miR-107. O miR-107 foi hiperexpresso em carcinomas em relação a adenomas de adultos, mas não apresentou impacto na análise de sobrevida. Em relação ao gene TARBP2, a sua expressão gênica e proteica não teve correlação com parâmetros histopatológicos e clínicos em adultos e crianças. Variantes genéticas no sequenciamento do éxon 5 do gene TARBP2 não foram encontradas nesses tumores. Além disso, o miR-497 não foi expresso em nenhum dos tumores da nossa coorte. CONCLUSÕES: A baixa expressão proteica da DICER1 foi um marcador de prognóstico em pacientes adultos com carcinoma cortical da suprarrenal. A perda da expressão da DICER1 em carcinomas metastáticos não foi causada por mutações inativadoras no domínio RNase IIIb do gene DICER1 e nem por alteração na expressão do miR-103 e miR-107, reguladores da sua expressão em outros tecidos. Apesar do miR-107 ter sido hiperexpresso em carcinomas, a sua expressão não teve importância prognóstica. Por fim, a expressão do gene TARBP2 e da proteína TRBP não apresentou importância prognóstica nos tumores do córtex da suprarrenal / INTRODUCTION: Adrenocortical cancer is a rare neoplasia with an estimated incidence of 0.5-2.0/million/year in adults. There are currently few therapeutic options for patients with adrenocortical cancer, and new insights into the pathogenesis of this lethal disease are needed. The microRNA (miRNA) expression profile of human tumors has been characterized by an overall miRNA downregulation. DICER1 enzyme and its cofactor TRBP are a key component of the miRNA processing machinery. It was recently demonstrated that escaping miRNA control in cancer cells due to Dicer downregulation may allow the phenotypic emergence of more aggressive genetic variants, accelerating cancer progression. Recently, DICER1 mutations in the RNase IIIb domain were found in 29% of nonepithelial ovarian tumors, predominantly in Sertoli-Leydig cell tumors (60%). In addition, TARBP2 truncating mutations, causing DICER1 destabilization, were identified in tumor cell lines with microsatellite instability. AIM: To study the mRNA and protein expression of DICER1 and TRBP in adult and pediatric adrenocortical tumors; To investigate DICER1 mutations in metal biding sites located at the RNase IIIb domain; To investigate inactivating mutations in the exon 5 of TARBP2 gene; To determine the expression of miR-103 and miR-107, DICER1 regulators, and miR-497, a TRBP regulator. METHODS: Protein expression of DICER1 and TRBP was evaluated by immunohistochemistry in a tissue microarray with 198 adrenocortical tumors [154 in adults (75 adenomas and 79 carcinomas) and 44 in children (38 clinically benign and 6 malignant)]. Expression of DICER1 and TARBP2 genes was assessed in a subgroup of 84 tumors (61 adults and 23 children) and miRNA expression in 82 tumors (59 adults and 23 children). The DICER1 and TARBP2 gene sequencing was performed in a subgroup of 83 tumors. RESULTS: In adults, a strong DICER1 expression was demonstrated in 39 out of 79 carcinomas (51%) and in 24 out of 75 adenomas (32% X2= 4.8, p= 0.028). Similarly, DICER1 gene overexpression was demonstrated in 15 out of 25 carcinomas (60%) and in 7 out of 30 adenomas (23%; X2= 7.64, p= 0.006). Among adult adrenocortical carcinomas, a weak DICER1 expression was significantly more frequent in metastatic than in non-metastatic adrenocortical carcinomas (66% vs. 31%; X2= 9.3, p= 0.002). Besides being more aggressive, adult adrenocortical carcinomas with a weak DICER expression were diagnosed in younger patients (median 35 vs. 45 yrs, p= 0.02) and had larger size (12.3 vs. 9 cm, p= 0.001), more advanced staging (ENSAT 3 or 4 in 55% vs. 30%, p= 0.04) and higher Weiss score (6 vs. 4, p= 0.02). Additionally, a weak DICER1 expression was significantly correlated with a reduced overall (p= 0.004) and disease-free (p= 0.005) survival. In the multivariate analysis, Ki67 >- 10% (p= 0.0001) and a weak DICER1 expression (p= 0.048) remained as independent predictors of recurrence. In the pediatric group, DICER protein and gene expression was not different between clinically benign and malignant tumors. No variant was identified in the metal binding sites of the RNase IIIb domain of DICER1 gene in both adult and pediatric tumors. Furthermore, DICER1 protein and gene expression did not correlate with miR-103 e miR-107 expression. miR-107 was overexpressed in adult carcinomas compared to adenomas, but it was not a predictor of poor outcome. Regarding TARBP2 gene, its gene and protein expression did not correlate with histopathological and clinical parameters in both children and adults. No variant was identified in exon 5 TARBP2 gene. Additionally, miR-497 was not expressed neither in the normal adrenal cortex and in adrenocortical tumors. CONCLUSION: A weak DICER1 protein expression was significantly associated with poor outcome in adult adrenocortical carcinomas. However, DICER1 deregulation in adult ACCs was not caused by mutations within the RNase IIIb domain and not associated with expression of its regulatory miRNAs. Although miR-107 was overexpressed in adult adrenocortical carcinomas, its expression was not correlated with a reduced survival. Finally, TARBP2 gene and protein expression was not associated with poor outcome in adrenocortical tumors

Introdução: O câncer gástrico (CG) foi recentemente categorizado em subtipos moleculares, os quais incluem os tumores Epstein-Barr (EBV)-positivo e com instabilidade de microssatélites (MSI). Esta distinção pode nos fornecer informações prognósticas e identificar alvos terapêuticos, tais como o PD-L1. Objetivo: O objetivo desse estudo foi avaliar a presença de EBV, MSI e expressão de PD-L1 no CG e suas associações com características clinicopatológicas e prognósticas. Métodos: Foram avaliados retrospectivamente 287 pacientes com CG submetidos à gastrectomia D2 com intenção curativa entre 2009 e 2016, através da técnica de tissue microarray. As proteínas de reparo do DNA (MLH1, MSH2, MSH6, PMS2) e o PD-L1 foram avaliados por imuno-histoquímica. O EBV foi avaliado por hibridação in situ. Resultados: Identificou-se a presença de EBV e MSI em 10,5% e 27% dos CGs, respectivamente. A maioria dos CGs com MSI apresentou perda simultânea da expressão de MLH1 e PMS2 (60%). O CG EBV-positivo associou-se ao sexo masculino (p=0,032), localização proximal (p < 0,001), tipo indeterminado de Lauren (p < 0,001), histologia pouco diferenciada (p=0,043) e infiltrado inflamatório acentuado (p < 0,001). Os tumores com MSI foram associados à idade mais avançada (p=0,002), gastrectomia subtotal (p=0,004), pN0 (p=0,024) e ao estágio pTNM menos avançado (p=0,020). Observou-se a imunoexpressão de PD-L1 em 8,8% dos casos, com expressão predominante no CG EBV-positivo (p < 0,001). O CG com MSI apresentou melhor sobrevida livre de doença (p=0,006) e sobrevida global (p=0,049) comparado ao EBV-negativo/microssatélite estável (MSS). Na análise multivariada, o status MSI/MSS permaneceu como fator de risco independente associado à recidiva da doença. Conclusão: O CG EBV-positivo apresentou aumento da expressão de PD-L1, enquanto o CG com MSI relacionou-se à melhor sobrevida. Ambos os subgrupos representam entidades distintas de CG e sua identificação é viável por técnicas diagnósticas convencionais. A caracterização destes subtipos de CG possibilita a aplicação de terapias direcionadas e permite ampliar o poder prognóstico dos atuais sistemas de classificação e estadiamento / Introduction: Gastric cancer (GC) has recently been categorized in molecular subtypes, which include Epstein-Barr (EBV)-positive and microsatellite instable (MSI) tumors. This distinction provides prognostic information and identifies therapeutic targets, such as PD-L1. Objective: The aim of this study was to evaluate the presence of EBV, MSI and PD-L1 expression in GC and their associations with clinicopathological characteristics and prognosis. Methods: We retrospectively evaluated 287 patients with GC who underwent D2-gastrectomy with curative intent from 2009 to 2016 through tissue microarray technique. DNA mismatch repair proteins (MLH1, MSH2, MSH6, PMS2) and PD-L1 were assessed by immunohistochemistry. EBV was detected by in situ hybridization. Results: The presence of EBV and MSI was identified in 10.5% and 27% of GCs, respectively. Most MSI GCs showed simultaneous loss of MLH1 and PMS2 expression (60%). EBV positivity was related to male (p=0.032), proximal location (p < 0.001), undetermined Lauren type (p < 0.001), poorly differentiated histology (p=0.043) and intense inflammatory infiltrate (p < 0.001). MSI-tumors were associated with older age (p=0.002), subtotal gastrectomy (p=0.004), pN0 (p=0.024) and more initial pTNM stage (p=0.020). PD-L1 immunoexpression was observed in 8.8% of cases, with predominant expression in EBV-positive GC (p < 0.001). MSI correlated with better disease-free survival (p=0.006) and overall survival (p=0.049) compared to the EBV-negative/microsatellite stable (MSS). In the multivariate analysis, the MSI/MSS status remained as independent risk factor associated with disease recurrence. Conclusion: EBV-positive GCs had increased PD-L1 expression, while MSI GC had better survival outcome. Both subgroups are distinct GC entities and their recognition is feasible by conventional diagnostic techniques. The characterization of these GC subtypes enables the application of targeted therapies and allows to extend the prognostic power of current classification and staging systems

Como neoplasia maligna que mais acomete a cavidade oral, o carcinoma epidermóide gera infinidade de estudos acerca de sua gênese e progressão. O variado perfil genético e protéico observado leva a freqüente insucesso nas terapias adotadas, contribuindo para pobres prognósticos. Este estudo visa compreender melhor o papel da proteína Akt, tida como chave para a proliferação de diversas neoplasias, frente ao estímulo das células derivadas de carcinoma epidermóide humano em cultura (HaCat, HN6, HN19, HN30, HN31) com EGF 10ng/ml e TGF &#946; 5ng/ml. Para tanto, analisou-se a expressão de pAkt, ciclina D1, Bad, caspase-3 e PTEN, através de imunofluorescência, western-blot e imunoprecipitação. Os resultados mostraram aumento da expressão de pAkt e ciclina D1 frente ao tratamento com EGF, bem como diminuição de Bad e PTEN, com exceção de HN31. A imunoprecipitação revelou neste caso que pAkt previne a apoptose através de inativação direta de Bad. Já nas células tratadas com TGF &#946; , obtivemos resultados diferentes do esperado para este supressor de tumor. A expressão de pAkt mostrou-se aumentada nas linhagens celulares, mas estável em HN19 e HN31. Ciclina D1 mostrou aumento em HN6 e HN30, manutenção em HaCat e HN19 e diminuição em HN31. HaCat mostrou queda dos níveis de caspase-3 e Bad, manutenção em HN6, aumento em HN30, aumento somente de Bad em HN31 e HN19 com níveis inalterados após o tratamento para ambas as proteínas. Estes achados sugerem o importante papel desempenhado pelo EGF nas linhagens de carcinoma epidermóide estudadas, e como esta via é importante candidata a ser visada em tratamentos quimioterápicos. A ação do TGF &#946; mostrou discrepâncias, revelando seu comportamento dúbio frente os diversos tipos celulares, e sugerindo possível relação entre este receptor e a via do pAkt, o que requer estudos mais apropriados. A baixa ocorrência de apoptose também reforça esta possibilidade, mostrando como a via do Akt é essencial para a progressão neoplásica e pode estar relacionada a mais eventos celulares do que já sabido. / Squamous cell carcinoma raises a great interest regarding carcinogenesis and its proliferative pathways, due to the high incidence and poor prognosis. The broad genetic and proteic profiles contribute to this poor prognosis. The present study aims to better comprehend the role played by pAkt, key protein for the development of many neoplasms. Cell lines derived from oral squamous cell carcinoma (HaCat, HN6, HN19, HN30 and HN31) were induced with 10ng/ml EGF and 5ng/ml TGF &#946; . The expressions of pAkt, cyclin D1, Bad, caspase-3 and PTEN were analyzed through immunofluorescence, western-blot and immunoprecipitation. Results showed higher pAkt and cyclin D1 expression after EGF treatment, as well as a decrease in Bad and PTEN levels, except for HN31. Immunoprecipitation revealed that pAkt prevents apoptosis through Bad direct inactivation. However, TGF &#946; treatment revealed different results, from what expected for this tumor supressor. pAkt expression revealed to be increased in all cells lines, but stable for HN19 and HN31. HaCat exhibited decreased levels of caspase-3 and Bad, which were unaltered in HN6, augmented in HN30. HN31 revealed only Bad increased levels, and no alterations in HN19. These findings suggest the crucial role played by EGF stimulation in the studied cell lines, and a good candidate to be targeted by chemotherapeutical approaches. TGF &#946; treatment showed discrepancies, revealing diverse behaviors in the different cell lines. An exhisting relation between TGF &#946; receptors and pAkt pathway may not be discharged, requiring further studies. The low occurrence of apoptosis reinforces this possibility, showing how important is Akt and related pathways for neoplastic progression, and its possible relation to cellular events not described to date.

O carcinoma epidermóide (CE) representa mais de 90% das neoplasias malignas encontradas na boca. Em casos avançados, quando o controle locoregional já não é possível somente com o tratamento cirúrgico mais a radioterapia, a quimioterapia adjuvante e neoadjuvate torna-se uma importante modalidade de tratamento para aumentar a qualidade de vida e sobrevida desses pacientes. Eventos moleculares que ocorrem durante a carcinogênese assemelham-se àqueles observados no processo da inflamação. Dessa forma, o estudo de substâncias anti-inflamatórias pode ser um importante caminho para o desenvolvimento e aperfeiçoamento de novos agentes quimioterápicos para o câncer. O objetivo deste estudo foi verificar uma possível ação antineoplásica de 2 anti-inflamatórios naturais (óleos de Copaiba e Andiroba) e um sintético (Dexametasona) numa linhagem de carcinoma epidermóide de orofaringe (FaDu), além de verificar se há uma correlação da expressão da proteína NFkB (fator de transcrição de genes envolvidos nos processos de carcinogênese e inflamação) com a inibição da proliferação celular. Para tanto, foram feitas análises quantitativas (curvas de crescimento, curva de viabilidade celular e Western Blot) e qualitativas (imunofluorescência) antes e depois do tratamento celular com os fármacos. O grupo controle foi representado pelas mesmas células (FaDu) cultivadas na ausência dos fármacos pesquisados. Após tratamento foi observado diminuição do crescimento e da viabilidade celular promovida por todos os fármacos, porém com potenciais de ação diferentes. O óleo de Copaíba apresentou uma potente ação inibição da proliferação e indução de apoptose, este último verificado pela positividade do teste Tunel para células apoptóticas. O óleo de Andiroba e Dexametasona promoveram inibição da proliferação dessas células, mas não indução de apoptose, sendo que para o último fármaco a ação foi dependente da concentração e tempo. Também pôde-se observar uma diminuição da expressão e marcação nuclear do NFkB por western Blot e imunofluorescência, respectivamente, após tratamento com os três antiinflamatórios. Os óleos de Copaíba e Andiroba e a Dexametasona, anti-inflamatórios naturais e sintético, respectivamente, promoveram ação de inibição da proliferação celular da linhagem FaDu, tendo uma relação com os níveis diminuídos da proteína NFkB que é responsável pela regulação de genes envolvidos nos processos de proliferação e sobrevivência celular. / Squamous cell carcinoma represents more than 90% of oral cavity malignancies. In advanced cases, when locoregional control is not possible using only surgery and radiotherapy adjuvant chemotherapy may play an important role to improve the quality of life and survival of these patients. Molecular events that occur during carcinogenesis are similar to those observed in the inflammatory process. So, the study of anti-inflammatory substances may be an important way for the development of new chemotherapeutic drugs for cancer. The aim of this study was to analyze a possible antitumoral effect of 2 natural anti-inflammatory oils (Copaiba and Andiroba) and a synthetic drug (dexamethasone) in a cell lineage of oropharynx squamous cell carcinoma (FaDu). Moreover, we tried to correlate NFkB protein expression with the inhibition of cell proliferation. Drugs effects were evaluated through quantitative methods (Western Blot method, growth and cell viability curves) and qualitative analyses (Immunofluorescence methods) before and after cell treatment. The control group was represented by the same cells (FaDu) grown in the absence of the drugs studied. After treatment all drugs promoted reduced growth and cell viability but with different potential actions. Copaiba oil showed a potent anti-proliferation action and to be inductor of apoptosis; the latter checked by testing positive for Tunel apoptotic cells. Andiroba oil and Dexamethasone promoted inhibition of cell proliferation, but not induction of apoptosis. The Dexamethasone action was time and dose dependent. There was a decrease expression and nuclear staining of NFkB by Western Blot and Immunofluorescence methods, respectively, after treatment with three anti-inflammatory substances. Oils of Copaiba and Andiroba and the dexamethasone promoted inhibition of cell proliferation FaDu lineage, showing an association with the level of expression of NFkB, which regulate genes that are involved in proliferation and cell survival.

O processo da carcinogênese é provocado por múltiplos estágios, envolvendo desordens potencialmente malignas, iniciação, invasão, progressão e metástase. O prognóstico do carcinoma epidermoide de boca (CEB) ainda permanece desfavorável devido ao diagnóstico tardio. Para mitigar esta complicação, biomarcadores tem sido utilizados para ajudar no diagnóstico precoce e entender melhor a influência sobre a carcinogênese oral, onde vias de sinalização são ativadas, principalmente a PI3K/AKT. MIF foi relacionada a progressão de diversos tipos cânceres, porém pouco se sabe seu papel na evolução do CEB. Por isso, o objetivo deste estudo foi identificar e caracterizar através do padrão de expressão imuno-histoquímico proteínas participantes da via de sinalização de PI3K/AKT: AKT1 e PAKT e sua associação com a expressão de MIF em fragmento de mucosa, hiperqueratose sem e com displasia e CEB correlacionando com a progressão da doença e características clinico-demográficos. Foram utilizados 73 blocos de parafina, avaliados quanto à porcentagem da expressão de cada marcador e coletados os dados clínicos epidemiológicos referentes para correlaciona-los à imunomarcação. A imunonopositividade ocorreu nos casos de mucosa normal, sem e com displasia e CEB. Nos casos de mucosa normal foram positivos para PAKT (50%), AKT (60%), MIF (80%). Em sem displasia, foi observado imunomarcação para PAKT (50%) e MIF (50%). Com displasia houve marcação PAKT (81,81%) e MIF (81%). Nos espécimes de CEB ocorreu em PAKT(100%), AKT (95,23%) e MIF (90,5%). Todos os anticorpos tiveram alta expressão no CEB em comparação com a mucosa normal (p<0,0001), sem displasia (p<0,0001) e com displasia (p<0,0001). Observou-se também influência sobre o fator de risco como tabagismo, etilismo e etnia, respectivamente para os grupos sem displasia, CEB e com displasia. Assim, estas proteínas podem ser consideradas potenciais marcadores preditores do CEB. / The carcinogenesis process is caused by multiple stages, involving potentially malignant disorders, initiation, invasion, progression and metastasis. The prognosis of squamous cell carcinoma (CEB) remains unfavorable due to late diagnosis. To mitigate this complication, biomarkers have been used to aid in early diagnosis and better understand the influence on oral carcinogenesis, which are activated signaling pathways, particularly PI3K / AKT. MIF was related to progression of many types cancers, but its role in the evolution of CEB is little known. Therefore, the aim of this study was to identify and characterize by the expression pattern of immunohistochemical participants proteins signaling pathway PI3K / AKT: AKT1 and PAKT and its association with MIF expression in normal mucosa, hyperkeratosis with and without dysplasia and CEB correlating with the progression of the disease and clinical and demographic characteristics. 73 paraffin blocks were used, in which evaluated the percentage of expression of each marker and collected epidemiological clinical data to correlate them to immunostaining. The imunonopositividade occurred in cases of normal mucosa, hyperkeratosis with and without dysplasia. In cases of normal mucosa were positive for PAKT (50%), AKT (60%), MIF (80%). In no dysplasia, immunostaining was observed PAKT (50%) and MIF (50%). With dysplasia was marking PAKT (81.81%) and MIF (81%). In CEB specimens occurred in PAKT (100%), AKT (95.23%) and MIF (90.5%). All antibodies had high expression in the CEB compared to normal mucosa (p <0.0001) without dysplasia (p <0.0001), and dysplasia (p <0.0001). It was also observed influence on the risk factors such as smoking, alcohol consumption and the ethnicity, respectively, for with dysplasia groups, CEB and without dysplasia. Thus, these proteins can be considered potential early diagnostic markers of CEB.

The dissertation consists of three major projects with the focus on the immunotoxicity of chromium and the behavior disorders caused by early ETOH exposure respectively. Hexavalent chromium [Cr(VI)] is widely used in various industrial processes and has been recognized as a carcinogen. As the first line of host defense system, the immune system can be a primary target of Cr(VI). T cell population represents a major arm of the immune system that plays a critical role in host anti-tumor immunity. Dysfunction of T cells compromises host anti-tumor immunity resulting in oncogenesis. Using mouse splenic T cells as an in vitro model system, the present study assessed the effects of Cr(VI) on T cell functions, as the first step of our investigation of the mechanism underlying Cr(VI)-inhibited immunosurveillance and carcinogenesis. Our results showed that Cr(VI) decreased the viability of CD4+ and CD8+ T cells, inhibited T cell activation, functions, including cytokine release, and degranulation. Fetal ethanol (ETOH) exposure can damage the developing central nervous system and lead to cognitive and behavioral deficits, known as fetal alcohol spectrum disorders (FASD). The use of animal models, especially mouse models is essential for investigating the neurogenetic mechanism of fetal ETOH effects and screening pharmacotherapies against it, due to the extensive knowledge of mouse genetics. However, the availability of mouse model is limited. Via adopting various dosage, timing and administration routes of ETOH exposure, we developed two mouse models to assess behavioral or cognitive changes caused by fetal ETOH exposure in pre-weaning and adolescent period. Our results show that high dosage of ETOH exposure (4 g/kg) during PD 4-10 resulted in hyperactivity, disinhibition, and deficits in learning and memory in mouse offspring, which lays the groundwork for the future FASD research.

This thesis explores the experience of living with cancer-related cachexia (CRC) from the patient perspective. Critique of the literature indicates few examples where patients have had the opportunity to speak. Following a challenging recruitment process, six people living with the syndrome were interviewed to elicit their narrative. Their stories were examined and themes identified relating to their personal feelings and how these affected social interactions. Thematic analysis was applied to produce what is a rich qualitative description of the experience from this small sample. Living with CRC requires development of strategies to survive. Emergent themes included the loss of sense of self and a changing relationship to the social world, social isolation and dissatisfaction with truth-telling by health professionals. Recommendations are made to mitigate the suffering of patients by empowering them through better information and acknowledgement of their condition. The balance between nutrition and wellbeing is re-examined, calling for a reorientation of perspective from a focus on intake towards a focus on quality of life. This clearly falls within the nurse-as patient-advocate paradigm and the relevance and meaning of this research to the nursing profession is explored. Potential areas for further research in regards to both patient experience and nursing practice are extrapolated.

This thesis examines cancer and mortality rates among people diagnosed with hepatitis B (HBV) and C (HCV) infection in New South Wales (NSW) from 1990 through 2002, by linking hepatitis notifications with the NSW Central Cancer Registry (CCR) and National Death Index. Of the 39101 HBV, 75834 HCV and 2604 HBV/HCV co-infection notifications included 1052, 1761 and 85 were linked to cancer notifications and 1233, 4008 and 186 were linked to death notifications respectively. Of 2072 hepatocellular carcinoma (HCC) notifications to the CCR 323, 267 and 85 were linked to HBV, HCV and HBV/HCV co-infection notifications. Incidence of HCC was 6.5, 4.0 and 5.9 per 1000 person years for HBV, HCV and HBV/HCV co-infected groups. Risk of HCC in those diagnosed with hepatitis was 20 to 30 times greater than the standard population. There was a marginally statistically significant increased risk of immunoproliferative malignancies associated with HCV infection (SIR=5.6 95% CI 1.8 ???17.5). Risk of death for those with hepatitis was significantly greater, 1.5 to 5 fold, than the general population with the greatest risk among those with HBV/HCV co-infection. The primary cause of HBV deaths was liver related, particularly HCC, whereas in the HCV groups drug related deaths were most frequent. Among people with HCV, risk of dying from drug related causes was significantly greater than from liver related causes (p=0.012), with the greatest increased risk in females age 15- 24 years (SMR 56.9, 95%CI 39.2???79.9). Median age at diagnosis of HCC varied markedly by country of birth and hepatitis group: HBV 66, 63 and 57years ; HCV 51, 68 and 71 years; unlinked 69, 70 and 64 years for Australian, European, and Asian-born groups, respectively (P<0.0001 for all groups). While the risk of cancer, particularly HCC, is elevated among people with HBV and HCV infection, the absolute risk remains low. Young people with HCV face a higher mortality risk from continued drug use than from liver damage related to their HCV infection. The influence of IDU in the epidemiology of HCC in New South Wales was possibly reflected in the varying distributions of age and country of birth.

Ph.D. / Molecular and Medical Genetics / The objective of this study is to examine, in light of the expression of multiple p53 family member isoforms, the specific role of p73 in malignant conversion, cellular response to DNA damage, and direct or indirect cooperation with other p53 family members in a clonal model of epidermal carcinogenesis. We first focused on the role of p73 in malignant conversion. Whether sporadic or siRNA induced, loss of p73 in initiated p53+/+ keratinocytes lead to conversion to squamous cell carcinoma (SCC) in vivo which was reversible upon reconstitution of TAp73α but not ΔNp73α. Second, we investigated the cellular response to ionizing radiation (IR) in the presence and absence of p73, showing that loss of p73 at malignant conversion was associated with resistance to IR in vitro. The loss of radiation sensitivity and malignant conversion was characterized by reduced steady state DNA binding levels of transcriptionally active p63 isoforms to the p21 promoter, failure to induce specific p53 family transcriptional targets, and failure to arrest in G1. Reconstitution of TAp73α, but not ΔNp73α, increased steady state DNA binding capabilities of TAp63β, TAp63γ, and ΔNp63γ, and steady state levels of p53 family target mRNA, but did not restore cellular sensitivity to IR. We thus uncovered a functional cooperation between TA isoforms of p73 and p63 and showed that p73-mediated DNA damage response was uncoupled from its tumor suppressive role. We observed preferential DNA binding of the inhibitory ΔNp63α isoform both in vitro and invivo in SCC suggesting that in the absence of TAp73α a balance is tipped toward DNA binding of the inhibitory isoforms. Third, we studied the role of the p53 family inkeratinocyte response to UVB. Tumorigenic cells lacking p73 that were resistant to IR remained sensitive to UVB, accompanied by DNA binding of the TAp63γ isoform, suggesting that keratinocyte response to UVB is not dependent upon p73 and suggesting a hierarchy of p53 family member responses to DNA damage. Finally, we examined TAp73α interaction with the p53 family inhibitor Mdm2. Mdm2 was in complex with DNA-bound p53 family members in malignant cells, but reconstitution of cells withTAp73α correlated with removal of Mdm2 from the complex, making them more like primary keratinocytes or initiated cells. Like the initiated cells, cells expressing TAp73α were refractory to treatment with the Mdm2-p53 inhibitor Nutlin-3 while cells lacking p73 expression or expressing ΔNp73α were sensitive. Thus, we suggest that p73 may be acting as a molecular shield to keep p53 family member inhibitors, such as ΔNp63α andMdm2, at bay. Further understanding of p53 family interplay in tumor development and DNA damage response could lead to new therapies or optimization of current therapeutic strategies in solid tumors of epithelium, particularly where deregulation or loss of p63 and p73 expression is associated with increased tumor invasiveness, treatment resistance, and poor patient prognosis.

Ο καρκίνος του παχέος εντέρου αποτελεί ένα από τα συχνότερα κακοήθη νεοπλάσματα παγκοσμίως, προκαλώντας σημαντική νοσηρότητα και θνητότητα. Η συστηματική διερεύνηση της παθογένειας συντελεί σημαντικά στην πρόληψη, έγκαιρη διάγνωση, θεραπεία και πρόγνωση της νόσου. Στην εποχή της μοριακής ιατρικής, η κατανόηση των μοριακών μηχανισμών καρκινογένεσης έχει αναδείξει το ρόλο ενδοκυττάριων σηματοδοτικών μονοπατιών, τα οποία ρυθμίζουν κυτταρικές διαδικασίες, όπως πολλαπλασιασμός, διαφοροποίηση, απόπτωση, αγγειογένεση, διήθηση. Κομβικά συστατικά τέτοιων μοριακών δικτύων αποτελούν οι υποδοχείς αυξητικών παραγόντων, όπως ο Human Εpidermal Receptor-1 (ΗΕR-1/EGFR), ο ρόλος του οποίου έχει τεκμηριωθεί στο αδενοκαρκίνωμα παχέος εντέρου, επιτείνοντας το ενδιαφέρον στη διευκρίνηση του ρόλου γειτονικών υποδοχέων, όπως του Human Εpidermal Receptor-3 (HER-3). O HER-3 συνιστά μεμβρανικό υποδοχέα που συμμετέχει σε μοριακά μονοπάτια ενδοκυτταρικής σηματοδότησης. Επομένως, ποσοτικές μεταβολές στην έκφρασή του αλλά και ποιοτικές αλλαγές στη δομή του, συντελούν δυνητικά στην κυτταρική εξαλλαγή. Τα δεδομένα από τη μελέτη του HER-3 στο αδενοκαρκίνωμα παχέος εντέρου είναι περιορισμένα και ο ρόλος του στην παθογένεια, πρόγνωση και θεραπεία της νόσου παραμένει ασαφής. Αντίστοιχα με τους μεμβρανικούς υποδοχείς, πυρηνικοί υποδοχείς ενέχονται σε διαδικασίες ρύθμισης γονιδιακής έκφρασης. Οι οιστρογονικοί υποδοχείς (ER) α και β διαμεσολαβούν την επίδραση των οιστρογόνων σε κυτταρικό επίπεδο, μεταποιώντας τα επίπεδα των ορμονών σε μεταβολές γονιδιακής έκφρασης. Οι διαφορές στην επίπτωση του καρκίνου του παχέος εντέρου ανάμεσα στα δύο φύλα καθώς και πρόσφατα βιβλιογραφικά δεδομένα έχουν αναδείξει τη σημασία της έκφρασης αυτών των υποδοχέων στην καρκινογένεση του παχέος έντερου. Παράλληλα, η εξειδίκευση της οιστρογονικής δράσης σε επίπεδο ιστού και κυττάρου εξασφαλίζεται μέσω της δράσης συγκεκριμένων συμπαραγόντων (ενεργοποιητών/καταστολέων). Αυτές οι πρωτεΐνες είναι ειδικοί μεταγραφικοί παράγοντες, οι οποίοι συνδεόμενοι με τους οιστρογονικούς αλλά και άλλους υποδοχείς «εξατομικεύουν» την ορμονική επίδραση στο γονιδίωμα. Ο proline-, glutamic acid-, and leucine-rich protein 1 (PELP1), γνωστός και ως modulator of non-genomic activity of ER (MNAR), ο amplified in breast cancer-1 (AIB1) και ο transcriptional intermediary factor-2 (TIF2) είναι σημαντικοί συμπαράγοντες οιστρογονικών υποδοχέων, με συνέπεια η μελέτη τους να αποτελεί αναπόσπαστο μέρος της διερεύνησης οιστρογονο-εξαρτώμενων μηχανισμών. Η συνεχής αλληλεπίδραση HER- και ER-εξαρτώμενων μονοπατιών έχει περιγραφεί σε ποικίλλους ιστούς. Σκοπός της παρούσας μελέτης είναι η διερεύνηση του ρόλου της (υπερ)έκφρασης του μεμβρανικού υποδοχέα HER-3, των οιστρογονικών υποδοχέων (ER) και των συμπαραγόντων PELP1/MNAR, AIB-1 και TIF-2 στον καρκίνο του παχέος εντέρου. Υλικά και μέθοδοι Στην παρούσα μελέτη χρησιμοποιήθηκαν ιστικά δείγματα, μονιμοποιημένα σε φορμόλη και εκλεισμένα σε παραφίνη από 140 ασθενείς με αδενοκαρκίνωμα παχέος εντέρου. Η έκφραση των επιπέδων HER-3 mRNA εκτιμήθηκε με τη μέθοδο της ποσοτικής αλυσιδωτής αντίδρασης πολυμεράσης (RT-PCR) σε 54 αδενοκαρκινώματα και 29 δείγματα φυσιολογικού βλεννογόνου. Η έκφραση των επιπέδων της φωσφορυλιωμένης (pHER-3) και μη φωσφορυλιωμένης HER-3 πρωτείνης εκτιμήθηκε με τη μέθοδο της ανοσοιστοχημείας σε 110 δείγματα φυσιολογικού βλεννογόνου, 24 αδενώματα και 140 αδενοκαρκινώματα. Η έκφραση των επιπέδων του οιστρογονικού υποδοχέα α και β και του PELP1/ΜΝΑR εκτιμήθηκε με τη μέθοδο της ανοσοιστοχημείας σε 113 αδενοκαρκινώματα, 30 αδενώματα και 88 δείγματα φυσιολογικού βλεννογόνου. Αντίστοιχα η έκφραση των επιπέδων του ΑΙΒ1 και TIF-2 εκτιμήθηκε με τη μέθοδο της ανοσοιστοχημείας σε 110 αδενοκαρκινώματα, 30 αδενώματα και 83 δείγματα φυσιολογικού βλεννογόνου. Αποτελέσματα Η πρωτεΐνη HER-3 εκφράζεται στο κυτταρόπλασμα και στον πυρήνα επιθηλιακών κυττάρων παχέος εντέρου σε φυσιολογικό βλεννογόνο, αδενώματα και αδενοκαρκινώματα και φαίνεται να μεταβάλλεται τοπογραφικά (από τον πυρήνα στο κυτταρόπλασμα) κατά τη διαδικασία της καρκινογένεσης. Ωστόσο, η έκφραση της πρωτεΐνης HER-3 σε αδενοκαρκινώματα δε φαίνεται να συσχετίζεται σημαντικά με τις κλινικοπαθολογικές παραμέτρους της νόσου. Η φωσφορυλιωμένη μορφή της πρωτεΐνης HER-3 (pHER-3) εκφράζεται στον πυρήνα και τη μεμβράνη επιθηλιακών και λείων μυικών κυττάρων παχέος εντέρου σε φυσιολογικό βλεννογόνο, αδενώματα και αδενοκαρκινώματα. Η πυρηνική έκφραση pHER-3 δε διαφέρει σημαντικά ανάμεσα σε φυσιολογικό βλεννογόνο, αδενώματα και αδενοκαρκινώματα. Ωστόσο, αυξημένα επίπεδα πυρηνικής έκφρασης pHER-3 συσχετίζονται σημαντικά με μεγαλύτερο στάδιο της νόσου, χωρίς να συσχετίζονται με τα επίπεδα έκφρασης της μη φωσφορυλιωμένης μορφής. Τα επίπεδα έκφρασης του γονιδίου ΗER-3 δε φαίνεται να αυξάνουν σημαντικά κατά την καρκινογένεση. Ωστόσο, αυξημένα επίπεδα HER-3 mRNA στα αδενοκαρκινώματα σχετίζονται με μεγαλύτερη ηλικία των ασθενών, εντόπιση του όγκου στο αριστερό κόλον και το ορθό και με λεμφαδενική διήθηση. Επίσης, συχετίστηκαν με αυξημένη πιθανότητα υποτροπής της νόσου και μειωμένο χρονικό διάστημα ως την υποτροπή. Ο ERα εκφράζεται σπάνια στο παχύ έντερο σε αντίθεση με τον ERβ, ο οποίος εκφράζεται συχνά στον πυρήνα επιθηλιακών αλλά και στρωματικών κυττάρων. Η έκφραση της πρωτεΐνης ERβ καθίσταται πιο έντονη κατά τη διάρκεια της καρκινογένεσης σε άνδρες, και στα αδενοκαρκινώματα συσχετίζεται με την πιθανότητα υποτροπής της νόσου. Ο συμπαράγοντας PELP1/MNAR ανιχνεύεται στον πυρήνα επιθηλιακών αλλά και στρωματικών κυττάρων του παχέος εντέρου και η έκφρασή του αυξάνει κατά την καρκινογένεση και στα αδενοκαρκινώματα συσχετίζεται με την έκφραση του ERβ. Ωστόσο, η υπερέκφραση του PELP1/MNAR στα ERβ θετικά αδενοκαρκινώματα συσχετίζεται με μεγαλύτερη συνολική επιβίωση των ασθενών. Ο AIB1 και ο TIF2 ανιχνεύονται στον πυρήνα επιθηλιακών αλλά και στρωματικών κυττάρων του παχέος εντέρου. Η έκφραση του ΑΙΒ1 αυξάνει κατά την καρκινογένεση και συσχετίζεται με τοπική ανάπτυξη του όγκου. Ωστόσο, στην πολυπαραγοντική ανάλυση ο ΑΙΒ1 αναδεικνύεται ως ανεξάρτητος ευνοϊκός προγνωστικός παράγοντας ως προς τη συνολική επιβίωση. Η έκφραση του ΤΙF2 αυξάνει κατά την καρκινογένεση και στα αδενοκαρκινώματα συσχετίζεται με την έκφραση του AIB1. Ωστόσο, η έκφρασή του στα αδενοκαρκινώματα δε σχετίζεται με κλινικοπαθολογικές παραμέτρους της νόσου. Το πρότυπο έκφρασης των συμπαραγόντων AIB1 και TIF2 δε σχετίζεται σημαντικά με εκείνο του ERβ. Συζήτηση-συμπεράσματα-προοπτικές Η παρούσα μελέτη αναδεικνύει τη σημασία της έκφρασης και φωσφορυλίωσης του ΗΕR3 στην καρκινογένεση του παχέος εντέρου, υποστηρίζοντας τον πιθανό ρόλο τους στην πρόγνωση της νόσου. Τα ευρήματα της μελέτης συμφωνούν με συγκεκριμένα βιβλιογραφικά δεδομένα ως προς τη συχνότητα ανίχνευσης του υποδοχέα στον παχύ έντερο, ενώ είναι η πρώτη η οποία αναδεικνύει τα επίπεδα HER-3 mRNA ως πιθανό προγνωστικό βιοδείκτη. Η διερεύνηση της έκφρασης του οιστρογονικού υποδοχέα β (ERβ1) ανέδειξε αύξηση των επιπέδων του κατά την καρκινογένεση, εύρημα που βρίσκεται σε συμφωνία με μερικά και σε αντιδιαστολή με άλλα βιβλιογραφικά δεδομένα. Η προγνωστική σημασία της έκφρασης των πυρηνικών υποδοχέων εξαρτάται από ποικίλους παράγοντες, όπως τα επίπεδα ειδικών συμπαραγόντων, ομοιοπολικές τροποποιήσεις, την τοπογραφία τους μέσα στο κύτταρο και τα επίπεδα συγκεκριμένων συγκεντρώσεων προσδέτη/ορμόνης. Η αύξηση των επιπέδων των συμπαραγόντων του οιστρογονικού υποδοχέα PELP1/MNAR, ΑΙΒ1 και ΤΙF2 κατά την καρκινογένεση υποδηλώνει πιθανή συμμετοχή τους σε οιστρογονοεξαρτώμενη ογκογόνο σηματοδότηση. Ωστόσο, η απουσία ισχυρής συσχέτισης ανάμεσα στα επίπεδα έκφρασής τους και στα επίπεδα έκφρασης του οιστρογονικού υποδοχέα (ERβ1) υπογραμμίζει την πλειοτροπική τους δράση και τον επιπρόσθετο ρόλο τους σε οιστρογονο-ανεξάρτητη ενδοκυττάρια σηματοδότηση. Περισσότερες μελέτες σε μεγάλο αριθμό ασθενών, κατάλληλα σχεδιασμένες και εκτελεσμένες, με τη χρήση ευαίσθητων και ειδικών πειραματικών τεχνικών καθώς και μεθόδων στατιστικής ανάλυσης απαιτούνται για την επιβεβαίωση των ευρημάτων της παρούσας μελέτης. Στην εποχή της μεταγονιδιωματικής ιατρικής, η αναζήτηση χρήσιμων μοριακών βιοδεικτών δύναται να συντελέσει στη βελτίωση της πρόγνωσης και της ποιότητας ζωής των ασθενών με καρκίνο του παχέος εντέρου. / Colorectal cancer is a major cause of cancer-related morbidity and mortality in the western world and has a significant impact on the health care systems. The deep understanding of molecular mechanisms that underline cellular transformation and tumor progression leads to the identification of key-molecules that are appropriate targets for sophisticated therapy in cancer. One such targeted approach exploits the presence of specific biomarkers that could be considered essential for tumor development. The role of such a biomarker, Human Εpidermal Receptor-1 (ΗΕR-1/EGFR), has been established in the development of colorectal cancer, suggesting the potential involvement of neighboring receptors, such as Human Εpidermal Receptor-3 (HER-3). HER-3 is a membranic receptor implicated in intracellular cell proliferation signaling. Thus, quantitative modifications in its expression and/or qualitative changes in its structure may contribute to cellular malignant transformation. The significance of HER3 expression, localization and phosphorylation remains elusive and data regarding its role in the pathogenesis, diagnosis, prognosis and management of colorectal cancer is limited. Apart from their mebranic counterparts, nuclear receptors are implicated in the regulation of gene transcription. Estrogen receptors (ER) α and β mediate the estrogen actions in the subcellular microenvironment. Differences in the incidence of colorectal cancer in the two genders have underlined the significance of ER expression in colorectal carcinogenesis. The specificity of estrogen activities in various cell types is mediated by the presence of tissue-specific coregulators (coactivators/corepressors). These proteins are specific transcription factors that bind to nuclear receptors, orchestrating their actions on the genome. Frequently, such coregulators are located in the cytoplasm, regulating the non genomic activity of the estrogens. Proline-, glutamic acid-, and leucine-rich protein 1 (PELP1), also known as modulator of non-genomic activity of ER (MNAR), amplified in breast cancer-1 (AIB1) and transcriptional intermediary factor-2 (TIF2) are considered major ER-coregulators. Thus, the investigation of their expression is inherent to the evaluation of estrogen-mediated mechanisms. The dynamic cross-talk between HER- and ER-driven signaling pathways has been described. The aim of this study is the investigation of the role of HER3, ER and coregulators PELP1/MNAR, AIB-1, TIF-2 (over)expression in the pathogenesis and prognosis of colorectal cancer. Material and Methods Sections from formalin-fixed, paraffin-embedded colorectal tissue blocks, derived from 140 patients with colorectal cancer, were used. HER-3 mRNA levels of expression were assessed by quantitative RT-PCR in 54 colorectal adenocarcinomas and 29 normal mucosa specimens. The expression levels of both phosphorylated and unphosphorylated HER-3 protein were assessed by immunohistochemistry in 110 normal mucosa specimens, 24 adenomas and 140 adenocarcinomas. The expression levels of ER α and β, PELP1/ΜΝΑR were assessed by immunohistochemistry in 88 normal mucosa specimens, 30 adenomas and 113 adenocarcinomas. Additionally, the expression levels of ΑΙΒ1 and TIF-2 protein were assessed by immunohistochemistry in 83 normal mucosa specimens, 30 adenomas and 110 adenocarcinomas. Results HER-3 was detected both in the cytoplasm and nucleus, whereas pHER-3 was observed in the nucleus and membrane of cells. A possible switch in HER-3 topography from the nucleus to the cytoplasm during colorectal tumorigenesis is suggested. The expression of pHER-3 did not differ significantly in normal tissue, adenomas and carcinomas, but was related to disease stage. HER-3 mRNA overexpression was significantly associated with decreased time to disease progression. It was also correlated with higher median age, left colon and rectal tumour sites and lymph node involvement. ERα expression was extremely rare in colorectal tissue of our cohort and its expression did not appear to be associated with colorectal carcinogenesis. ERβ and PELP1/MNAR were detected in the nucleus of epithelial, endothelial, inflammatory, smooth muscle cells and myofibroblasts. When intensity of staining was taken into account, the expression of both proteins was significantly increased in epithelial cells of carcinomas compared to normal mucosa. ERβ expression in epithelial cells was correlated with decreased disease progression-free survival. PELP1/MNAR overexpression in epithelial cells was found to be an independent favorable prognostic factor. AIB1 and TIF2 were detected in the nucleus of epithelial, endothelial, inflammatory, smooth muscle cells and myofibroblasts. The expression of both proteins was significantly increased in epithelial cells of carcinomas compared to normal mucosa. In carcinomas, a significant correlation between the levels of expression of AIB1 and TIF2 was noted, but there was no correlation between the expression patterns of these two proteins and ERβ. Although AIB1 overexpression was associated with local tumor invasion, it was also found to correlate independently with prolonged overall survival. TIF2 overxpression did not appear to correlate with clinicopathological parameters. Conclusion/Discussion This study highlights the significance of ΗΕR3 expression and phosphorylation in colorectal carcinogenesis, supporting also its potential prognostic significance. This study supports literature data regarding HER3 expression in colorectal tissue, while is the first to imply a possible prognostic significance of HER-3 mRNA expression levels and to suggest a topographic switch of HER3 protein during colorectal carcinogenesis. ERβ1 protein levels were found to increase during colorectal carcinogenesis, a finding which corresponds only to a small portion of literature data. The prognostic role of nuclear receptors depends on a number of factors, such as coregulator expression levels, chemical modifications, subcellular localization and ligand/hormone levels. The concomitant increase in the expression levels of coregulators PELP1/MNAR, ΑΙΒ1 and ΤΙF2 during colorectal carcinogenesis might imply their potential participation in estrogen-mediated signaling. However, the characteristic absence of strong correlation between their expression pattern and ERβ1 expression pattern underlines their pluripotent role and their possible contribution to estrogen-independent signaling. Further studies with a large number of patients, appropriately designed and conducted using sensitive experimental and statistical methods, are required for the confirmation of our hypothesis generation results. In the post-genomic era, identification of useful molecular biomarkers might contribute to the improvement of the management and prognosis of patients with colorectal cancer.