Diversas alterações genéticas estão associadas à patogênese do carcinoma epidermoide (CE), neoplasia maligna mais comum de cabeça e pescoço. Algumas dessas alterações comprometem proteínas pertencentes à via de sinalização do Akt, envolvida em diferentes fenômenos celulares. Este trabalho teve como objetivo estudar a expressão da proteína pAkt em linhagens celulares de carcinomas epidermoides de cabeça e pescoço, de forma a verificar possíveis alterações na transcrição dessa molécula em células de CE tratadas com Curcumina. Foram utilizadas duas linhagens celulares de CE de cabeça e pescoço (FaDu e SCC9) e uma linhagem de queratinócitos normais (HaCat) divididas em dois grupos: a. Grupo controle não tratado; b. Células tratadas com Curcumina. A proliferação celular foi monitorada através do teste de viabilidade celular e a análise da expressão de proteína foi realizada através da técnica do Western Blotting que revelou supressão do pAkt na linhagem celular SCC9 nos tempos de 24 e 48 horas. Desta forma, conclui-se que a Curcumina na via do Akt em carcinomas epidermoides de cabeça e pescoço tem importante ação supressora do gene pAkt. / Several genetic alterations are associated with the pathogenesis of squamous cell carcinoma (SCC), the most common malignant neoplasm of the head and neck. Some of these changes compromise the proteins belonging to the Akt signaling pathway, involved in various cellular phenomena. The objective of this study to explores the expression of the pAkt protein in cell lines of the squamous cell carcinomas of the head and neck to verify possible changes in the transcription of this molecule in EC cells treated with curcumin. The study used two cell lines of EC head and neck (FaDu and SCC9) and a normal line of keratinocytes (HaCat), split into two groups: A. the controlled group, untreated; B. Cells treated with curcumin. The cell proliferation it was observed by cell viability test and analysis of protein expression performed through Western blotting technique revealed suppression of pAkt in SCC9 cell line at 24 and 48 hours. Thus, it is concluded that the Curcumin on the path of Akt in squamous cell carcinoma of the head and neck has a significant suppressive effect of gene Akt.

O câncer de cavidade oral é uma das neoplasias mais comuns no Brasil e no mundo, porém seu prognóstico ainda é incerto principalmente devido ao diagnóstico tardio e presença de metástases. A análise de fatores relacionados ao prognóstico dessa doença é de suma importância e, o receptor de quimiocina denominado CXCR4, está sendo relacionado a um pior prognóstico devido a maior capacidade de invasão das células que o expressam, em diversas neoplasias. Apesar dessa relação estar demonstrada em vários tipos de cânceres, com relação ao de cavidade oral pouco se sabe até o momento. Assim, objetivo desse trabalho foi analisar a expressão imuno-histoquímica do receptor de quimiocina CXCR4 em carcinomas epidermóides de cavidade oral, e relacioná-la com variáveis clínicas e histológicas. Foram obtidos 94 blocos de carcinomas epidermóides oriundos de instituições parceiras para obtenção de cortes histológicos convencionais, corados com hematoxilina e eosina (HE), e cortes de TMA (tissue microarray). Foi realizado imuno-histoquímica para anticorpo anti-CXCR4 (ab124824, ABCAM, EUA) e análise da marcação em lâminas de TMA utilizando o software Image J (versão 1.49u). A intensidade de marcação imuno-histoquímica foi correlacionada com dados clínicos (TNM, tabagismo, etilismo e sobrevida) e histopatológicos (diferenciação histológica, infiltrado inflamatório e infiltração vascular, linfática e perineural) dos pacientes. Dos casos analisados 74,4% exibiram uma marcação fortemente positiva para o CXCR4, enquanto que o epitélio não tumoral mostrou uma marcação negativa ou fracamente positiva (71,1%; p=0,011). Tumores classificados como \"bem diferenciados\" apresentaram marcação fortemente positiva para a proteína estudada (53,3%; p=0,049). Não houve associação entre a marcação imuno-histoquímica do CXCR4 com sobrevida global em 5 anos (?2= 0.3, p=0.565). Os resultados sugerem que a alta expressão dessa proteína não influencia no prognóstico e na sobrevida desses pacientes. / Oral cancer is one of the most common neoplasia in Brazil and the world. Mainly due to a late diagnosis and presence of metastases its prognosis is still uncertain. Finding biological markers related to the prognosis of this disease is of paramount importance. The chemokine receptor CXCR4 is being related to a worse prognosis in several neoplasms because cells expressing it acquire a greater capacity of invasion. Although this relationship is demonstrated in several types of cancers, in the oral cavity it is uncertain. The aim of this study was to analyze by immunohistochemistry the CXCR4 chemokine receptor expression in oral squamous cell carcinomas, and related to clinical and histological variables. Conventional histological sections stained with hematoxylin and eosin (HE) were acquired from 94 blocks of oral squamous cell carcinoma for histological analysis. TMA (tissue microarray) was assembled from these blocks for anti-CXCR4 immunohistochemistry (ab124824, ABCAM, USA). Staining analysis was performed using Image J software (version 1.49u). The immunohistochemical signal intensity was correlated with clinical (TNM, smoking, alcoholism and survival) and histopathological parameters (histological differentiation, inflammatory infiltration, vascular, lymphatic and perineural infiltration). From the cases studied 74.4% showed a strong positivity for CXCR4, and the non-tumoral epithelium was negative or weakly positive (71.1%; p = 0.011). Tumors histologically well differentiated were strongly positive for the protein studied (53.3%; p = 0.049). There was no association between CXCR4 signal and global survival in 5 years (?2= 0.3, p=0.565). These results suggest that a high expression of CXCR4 it is not related to prognosis and survival of patients of patients with oral squamous cell carcinoma.

Submitted by Maria Aparecida (cidazen@gmail.com) on 2017-11-27T17:43:41Z No. of bitstreams: 1 Marta Belfort.pdf: 1659970 bytes, checksum: 7aca8a1f671f32a3e25959a2840b065f (MD5) / Made available in DSpace on 2017-11-27T17:43:41Z (GMT). No. of bitstreams: 1 Marta Belfort.pdf: 1659970 bytes, checksum: 7aca8a1f671f32a3e25959a2840b065f (MD5) Previous issue date: 2017-08-28 / FAPEMA,CNPQ. / Penile cancer (PeCa) is a rare neoplasm in developed countries; however, its incidence is high in underdeveloped countries. In Brazil, regions North and Northeast are those with the higher number of cases for the disease. Among the factors associated with this neoplasm we highlight: poor hygiene, phimosis, chronic inflammation and infection by human papilloma virus (HPV). Changes in the PI3K/AKT/PTEN cell signaling pathway have been reported for several malign neoplasms, but little is known about the involvement of this pathway in penile tumors. Thus, the aim of this study was to verify the role of HPV infection and the occurrence of copy number alterations (CNA) in genes from the signaling pathway mediated by receptors of growth factors and PI3K in a population characterized by advanced tumors and high frequency of high risk HPV. To achieve that, we collected tumor tissue samples (both fresh and in formalin-fixed paraffin-embedded tissue-FFPE) from 34 patients from two reference hospitals: Instituto Maranhense de Oncologia Aldenora Belo (IMOAB) and the Hospital Universitário Presidente Dutra from the Universidade Federal do Maranhão (HU-UFMA). Fresh tumors were submitted to detection and genotyping of HPV by Nested PCR (Polymerase Chain Reaction) and direct sequencing. CNA analyzes were carried out in FFPE tissue from a subgroup HPV positive (91.2%), of which 88.2% were at high oncogenic risk. TaqMan® Copy Number Assays (Life TechnologiesTM) and CopyCaller software version v2.0 were performed to determine copy number for EGFR, HER3, HER4, AKT1, AKT2, PI3KCA and PTEN. Increase of 3 and 4 copies was considered gains, while increase of 5 or more copies was considered amplifications. The presence of a single gene copy was referred to as loss, while the absence of two copies was named deletion. Clinical and histopathological parameters were analyzed as to the presence of HPV and to CNAs. Our data showed that EGFR/PI3K/AKT/PTEN signaling pathway is highly altered in PeCa. The results showed that 100% of the tumors presented an increase of the number of copies for HER3; out of those, 93.9% were amplified, with 84.4% having 10 or more copies. EGFR also showed an increase of copies in 87.8% of tumor samples, out of which 65.6% were amplifications, with 48.2% having more than 10 copies. Furthermore, HER4 and AKT1 also presented an increase in the number of copies of 20.6% and 15%, respectively. AKT1 had a higher frequency of tumors with a regular number of copies (78.8%). On the other hand, PI3KCA, HER4, PTEN and AKT2 presented a higher frequency of samples with deletions, presenting 56%, 52.9%, 39% and 36%, respectively. Loss of copies was also frequent on tumors, so that genes AKT2, PTEN and PI3KCA appeared in heterozygosis in 60.6%, 54.5% and 37.5%, respectively. Our data show the occurrence of genetic alterations that may justify the differential expression of growth factor receptors and the downstream genes of the PI3K/ AKT pathway in penile carcinoma. However, in this study there was no association between CNAs and clinical and histopathological variables. On the other hand, taking into consideration the high frequency of HPV in the evaluated tumors, we suggest that CNAs are related to HPV integration into genome host. Finally, we highlight the high frequency of tumors with amplifications in HER3 and EGFR, reinforcing these markers as targets for specific therapies in CaPe. / Câncer de pênis (CaPe) é uma neoplasia rara em países desenvolvidos, entretanto, sua incidência é elevada em países subdesenvolvidos. No Brasil, as regiões Norte e Nordeste são as regiões com os maiores números de casos da doença. Dentre os fatores de risco, destaca-se a má higiene do órgão genital, fimose, inflamação crônica e infecção pelo papilomavírus-humano (HPV). Tem sido reportada alterações na via de sinalização celular PI3K/AKT/PTEN em diversas neoplasias malignas, entretanto, pouco se sabe sobre o envolvimento dessa via nos tumores de pênis. Assim, buscou-se neste trabalho verificar o papel da infecção por HPV e a ocorrência de alteração no número de cópias (CNAs) em genes da via de sinalização controlada por receptores dos fatores de crescimento e PI3K, em uma amostra caracterizada por tumor avançado e alta frequência de HPV de alto risco. Para isso, foram coletadas amostras de tecido tumoral (fresco e de tecido fixado com formalina e embebido em parafina - FFPE) de 34 pacientes provenientes de dois hospitais de referência, Instituto Maranhense de Oncologia Aldenora Belo (IMOAB) e o Hospital Universitário Presidente Dutra da Universidade Federal do Maranhão (HU-UFMA). As amostras de tumor fresco foram submetidas a detecção e genotipagem de HPV por Nested PCR (Polymerase Chain Reaction) e sequenciamento direto. As análises de CNAs foram realizadas em amostras de FFPE, HPV positivas (91,2%), das quais 88,2% eram de alto risco oncogênico. Utilizou-se o ensaio TaqMan® Copy Number Assays (Life TechnologiesTM) e o software CopyCaller versão 2.0 para determinação do número de cópias dos genes EGFR, HER3, HER4, AKT1, AKT2, PIK3CA e PTEN. Aumento de 3 e 4 cópias foi considerado ganho, enquanto aumento de 5 ou mais cópias foi considerado amplificação. A presença de uma única cópia gênica foi nomeada perda, enquanto a ausência de duas cópias foi nomeada deleção. Os parâmetros clínicos e histopatológicos foram analisados quanto a presença de HPV e também quanto a CNAs. A via de sinalização celular EGFR/PI3K/AKT/PTEN revelou-se altamente alterada nos tumores de pênis. Observou-se que 100% dos tumores apresentaram aumento de número de cópias do gene HER3. Destes, 93,9% apresentaram-se amplificados, sendo que 84,4% apresentavam 10 ou mais cópias. O gene EGFR apresentou aumento de cópias em 87,8% das amostras, das quais 65,6% eram amplificações, sendo que 48,2% apresentavam mais de 10 cópias. Além desses, os genes HER4 e AKT1 também apresentaram aumento de cópias gênicas, em 20,6% e 15%, respectivamente. AKT1 apresentou maior porcentagem de tumores com número normal de cópias (78,8%). Por outro lado, os genes PI3KCA, HER4, PTEN e AKT2 apresentaram maiores frequências de amostras com deleções, com 56%, 52,9%, 39% e 36%, respectivamente. As perdas também foram frequentes nos tumores, de modo que os genes AKT2, PTEN e PI3KCA apresentaram-se em heterozigose em 60,6%, 54,5% e 37,5%, respectivamente. Nossos dados mostram a ocorrência de alterações genéticas que podem justificar a expressão diferencial dos receptores de fatores de crescimento e de genes downstream da via PI3K/AKT em carcinoma peniano. No entanto, não foi encontrada associação entre CNAs e as variáveis clínicas e histopatológicas. Por outro lado, considerando-se a alta frequência de HPV nos tumores avaliados, levanta-se a possibilidade de haver uma relação entre a integração do HPV no genoma do hospedeiro e a ocorrência de CNAs em CaPe. Finalmente, destacamos a alta frequência de tumores com amplificações em HER3 e EGFR, abrindo a possibilidade desses marcadores serem utilizados como alvos para terapias específicas em CaPe.

Renal cell carcinoma (RCC) is the most deadly of urological malignancies. While metastatic disease affects one third of patients at diagnosis, a further third of patients who undergo extirpative surgery with curative intent subsequently develop metastatic disease. Inconsistency in the clinical course ensures predicting subsequent metastasis is notoriously difficult, despite the routine use of prognostic clinico-pathological parameters in risk stratification. With greater understanding of pathways involved in disease pathogenesis, a number of biomarkers have been proposed to be of prognostic significance; however there are currently no molecular prognostic markers in clinical use. Genetic intra-tumoural heterogeneity (genetic ITH) has been described in clear cell RCC (ccRCC) and may limit the clinical translation of biomarkers. There has been no assessment of ITH at other molecular levels. The aim of this work was to define and compare proteomic, transcriptomic and DNA methylation ITH in ccRCC, and identify potential prognostic biomarkers. Using reverse phase protein arrays to study protein expression in multiple spatially separate regions of primary and metastatic ccRCC, proteomic ITH was demonstrated for the first time. Interestingly there was no significant difference in proteomic ITH in metastatic ccRCC tumour deposits compared to primary tumours. However, on analysis of differential protein expression between primary and metastatic ccRCC tissue using a tissue microarray and automated analysis of immunofluorescence, there was significantly greater expression of Ki67, p53, VEGFR1, SLUG and SNAIL in the metastases compared to the primary tumours. Subsequent profiling of gene expression and DNA methylation in multiple areas of the same primary tumours confirmed transcriptomic and methylomic ITH. On comparison of this multimolecular ITH, significantly greater proteomic ITH was seen compared to gene expression and DNA promoter methylation heterogeneity. Recent evidence suggests DNA methylation may be prognostically important in RCC and given the lower methylomic ITH in ccRCC, the identification of prognostic DNA methylation changes in ccRCC were pursued using the Infinium HumanMethylation450K Beadchip. Following development of an analysis pipeline, identification and validation of prognostic differentially methylated regions (DMR) was performed on an experimental cohort and published dataset respectively. Five DMRs, which were associated with disease recurrence in ccRCC, were identified. NEFM gene promoter methylation was the only DMR associated with cancer specific survival, independent of TNM stage and nuclear grade on multivariate analysis, which was confirmed on a third independent published dataset. This thesis therefore demonstrates multi-molecular ITH in ccRCC for the first time. Despite this, NEFM promoter methylation may be a useful independent prognostic marker of cancer specific survival.

There is some evidence to suggest that human papilloma virus (HPV) may play a causal role in head and neck carcinoma (HNSCC). The aim of this study was to investigate the prevalence of HPV DNA in HNSCC and to determine whether any correlation exists with p16 or survival. An initial pilot study of sixty formalin-fixed HNSCC was carried out in order to optimise the methodology for the PCR and immunohistochemistry. A further 84 benign lesions, 12 dysplasias and additional 80 HNSCC were also included. In the pilot study the prevalence of all HPV types was 67% of which 18% were high risk-HPV (HR-HPV) and for the combined carcinoma sample it was 59% of which 25% were HR-HPV. The overall HPV prevalence was 51% and 42% for benign lesions and dysplasias with HR-HPV accounting for 14% and 8% respectively. A total of four alpha HPV types were identified and eleven beta HPV types. Multiple HPV types co-existed in the same tissue and in some cases both alpha and beta HPV. The results may suggest that HR-HPV may play a role in a small subset of HNSCC. An association was found between HPV status and gender, age group, survival, nodal metastasis and T3 tumour size and smoking. HPV16 was predominantly present in female patients and was associated with an improved overall survival and recurrence free survival. p16 positivity varied from 76-78% in carcinomas, 51% in benign lesions and 66% in dysplasias. p16 status was not associated with disease recurrence or nodal metastasis. Positive p16 staining and high staining intensity was associated with a poorer overall survival and the male gender, an older age group, anatomic site, and T2 tumour size. Overall HPV status was not correlated with p16 expression but a correlation found between p16 and HPV16 may suggest that p16 could potentially act as a surrogate marker of HPV16. However, the lack of concordance would suggest that in isolation p16 may not be a reliable marker for HR-HPV and should not be relied upon in isolation. Our findings could suggest that HPV16 and p16 status may be independent predictors for prognosis and disease recurrence.

A neoplasia escamosa da superfície ocular constitui é uma das lesões mais frequentes que envolve a conjuntiva ou a córnea e tem como principais fatores de risco a exposição solar (radiação ultravioleta), a infecção pelo vírus do papiloma humano (HPV) e os estados de imunodeficiência, especialmente a infecção pelo vírus da imunodeficiência humana (HIV). Em suas formas mais avançadas, a neoplasia pode cursar com infiltração do globo ocular, da órbita e, mais raramente, com ocorrência de metástases para linfonodos ou a distância. O presente estudo teve como objetivo investigar os dados clínicos, histopatológicos, a presença de HPV e a expressão das proteínas p16 e p53 em 45 casos de neoplasia escamosa da superfície ocular diagnosticados no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, no período de 2005-2015. Avaliação histopatológica das lesões, estudo imuno-histoquímico para a detecção das proteínas e hibridização in situ cromogênica (CISH) para a detecção do DNA de HPV de alto e baixo grau foram realizados em todas as amostras. As lesões foram mais frequentes em homens de cor branca, com idade superior a 40 anos. A avaliação histopatológica revelou 31 casos (69%) de carcinoma invasivo e 14 casos (31%) de carcinoma in situ. Em 6 casos (13%) foi detectado DNA de HPV de alto grau por CISH. A frequência de expressão de proteínas p53 e p16 foi alta nas lesões, 89% e 53%, respectivamente. Em nosso estudo, a neoplasia escamosa da superfície ocular predomina em homens de cor branca, com idade acima dos 40 anos, com presença de HPV de alto grau em 13% dos casos. A expressão de p16 não apresentou um valor preditivo positivo alto quanto a possibilidade de associação com o vírus. / Ocular surface squamous neoplasia (OSSN) is one the most frequent lesions involving the conjunctiva or cornea and its main risk factors are solar exposure (ultraviolet radiation), human papilloma virus (HPV) infection and immunodeficiency states, especially human immunodeficiency virus (HIV) infection. In advanced cases one can observe eyeball or orbital infiltration and, rarely, lymph node or distant metastases. The present study aimed to investigate the clinical and histopathological data, as well as the presence of HPV and the expression of proteins p16 e p53 in 45 cases of OSSN diagnosed at the Clinics Hospital of Ribeirão Preto Medical School, University of São Paulo, from 2005 through 2015. Histopathological examination, immunohistochemical study for proteins p16 and p53, and chromogenic in situ hybridization (CISH) for low and high grade HPV were performed in all samples. Lesions were more frequent in white males, above 40 years old. Histopathological examination revealed 31 cases (69%) of invasive carcinoma and 14 cases (31%) of carcinoma in situ. In 6 cases (13%) high grade HPV was detected by CISH. The expressions of p53 and p16 were high, 89% and 53%, respectively. In our study, increased incidence of OSSN was observed in white males, above 40 years old, with high grade HPV in 13% of the cases. The expression of p16 did not show a high positive predictive value for HPV positivity in OSSN.

O carcinoma espinocelular (CEC) é a segunda forma de neoplasia cutânea mais prevalente. Os mecanismos exatos envolvidos na progressão desse tipo de tumor ainda não estão elucidados. Estudos recentes têm mostrado que a citocina IL33 é uma citocina reguladora da resposta imune adaptativa, principalmente como potente indutor do perfil Th2. Juntamente com seu receptor ST2, apresenta-se com os níveis elevados em alguns tipos de câncer, corroborando para a evidência de que essa citocina contribui para a carcinogênese. Baseado nessas informações, testamos a hipótese de que a presença de IL33 em carcinoma espinocelular, poderia estar relacionada a um melhor prognóstico. Neste estudo foram utilizadas amostras de carcinoma espinocelular, em diferentes gradações de malignidade tumoral (Grau I, Grau II e Grau III). Os resultados mostraram um infiltrado inflamatório mais intenso em tumores com Grau I e II. Imunorreatividade para IL33 foi observada em tumores de Grau I e II tanto por células epiteliais como por células do infiltrado inflamatório. A análise por microscopia confocal evidenciou que um grande número de células TCD4+ e TCD8+ que expressavam IL33 foi observado em tumores de Grau II. Esses resultados indicam a presença de um intenso infiltrado inflamatório e expressão de IL33 em amostras de carcinoma espinocelular com níveis menores de malignidade tumoral. / Squamous cell carcinoma (SCC) is the second most common form of cutaneous neoplasm. The exact mechanisms involved in the progression of this type of tumor have not yet been elucidated. Recent studies have shown that the cytokine IL33 is a cytokine regulating the adaptive immune response, mainly as a potent inducer of Th2 profile. Together with its ST2 receptor, its presents with elevated levels in some types of cancer, corroborating to evidence that this cytokine contributes to carcinogenesis. Based on this information, we tested the hypothesis that the presence of IL33 in squamous cell carcinoma could be related to a better prognosis. In this study, squamous cell carcinoma samples were used in three different gradations of tumor malignancy (Grade I, Grade II and Grade III). The results showed that a more intense inflammatory infiltrate in Grade I and II tumors. Immunoreactivity for IL33 was observed in Grade I and Grade II tumor, by epithelial cells and by inflammatory infiltrate cells. The analysis by confocal microscopy evidenced that a great number of TCD8+ and TCD4+ cells expressing IL33 was observed in grade II tumors. These results indicate the presence of an intense inflammatory infiltrate and expression of IL33 in samples of squamous cell carcinoma with lower levels of tumor malignancy.

Title: Inhibition of interleukin-6 trans-signaling by sgp130Fc is anti-tumorigenic in head and neck squamous cell carcinoma. Background: Head and neck squamous cell carcinoma (HNSCC) is a highly inflammatory cancer type, and interleukin-6 (IL-6) is associated with this phenotype. Elevated expression of IL-6 is linked to tumor progression, recurrence, metastasis, and resistance to therapy in HNSCC. However, targeting IL-6 or IL-6 receptor (IL-6R) has demonstrated little to no clinical efficacy. IL-6 signals through a classical signaling pathway via membrane IL-6R or a trans-signaling pathway via soluble IL-6R (sIL-6R). Recent evidence suggests that classical signaling induces acute, transient inflammation, eventually resulting in homeostasis; whereas trans-signaling may induce chronic, pro-tumorigenic inflammation. Therefore we propose that IL-6 trans-signaling is associated with the pro-inflammatory phenotype observed in HNSCC. We wanted to determine whether inhibition of IL-6 trans-signaling by sgp130Fc would better demonstrate anti-tumor efficacy and increase HNSCC tumor response to radiation, chemotherapy, and targeted therapy (cetuximab) compared to global IL-6 pathway inhibition. Method/Results: Baseline levels of IL-6, IL-6R, sIL-6R, and sgp130 proteins in HNSCC cells were determined using ELISA and flow cytometry. Cisplatin, radiation, and cetuximab treatments each induced HNSCC cell secretion of IL-6 and sIL-6R in vitro, yet adding sgp130Fc to those treatments did not further reduce clonogenic survival. Sgp130Fc treatment significantly suppressed SQ20B tumor growth in nude mice, whereas global IL-6 pathway inhibition by IL-6R antagonist tocilizumab did not; however, cetuximab reduced the efficacy of sgp130Fc in this animal model. Sgp130Fc also sensitized SQ20B xenograft tumors to radiation and chemotherapy in nude mice and suppressed SCCVII tumor growth in male but not female C3H/HeJ mice. Conclusion: Inhibition of IL-6 trans-signaling by sgp130Fc displayed significant anti-tumor effects as a single therapy and sensitized resistant HNSCC tumors to radiation and chemotherapy in vivo; however, sgp130Fc did not reduce survival of HNSCC cells in vitro. These results suggest that the efficacy of sgp130Fc relies on targeting another part of the microenvironment instead of tumor cells directly. Sgp130Fc has promise both as a single therapy and potentially as combined therapy with radiation and chemotherapy in HNSCC.

Doctor of Philosophy(PhD) / BCC is the commonest cancer in European-derived populations and Australia has the highest recorded incidence in the world, creating enormous individual and societal cost in management of this disease. The incidence of this cancer has been increasing internationally, with evidence of a 1 to 2% rise in incidence in Australia per year over the last two decades. The main four epidemiological risk factors for the development of BCC are ultraviolet radiation (UVR) exposure, increasing age, male sex, and inability to tan. The pattern and timing of UVR exposure is important to BCC risk, with childhood and intermittent UVR exposure both associated with an increased risk. The complex of inherited characteristics making up an individual’s ‘sun sensitivity’ is also important in determining BCC risk. Very little is known about population genetic susceptibility to BCC outside of the rare genodermatosis Gorlin syndrome. Mutations in the tumour suppressor gene patched (PTCH) are responsible for this BCC predisposition syndrome and the molecular pathway and target genes of this highly conserved pathway are well described. Derangments in this pathway occur in sporadic BCC development, and the PTCH gene is an obvious candidate to contribute to non-syndromic susceptibility to BCC. The melanocortin 1 receptor (MC1R) locus is known to be involved in pigmentary traits and the cutaneous response to UVR, and variants have been associated with skin cancer risk. Many other genes have been considered with respect to population BCC risk and include p53, HPV, GSTs, and HLAs. There is preliminary evidence for specific familial aggregation of BCC, but very little known about the causes. 56 individuals who developed BCC under the age of 40 in the year 2000 were recruited from the Skin and Cancer Foundation of Australia’s database. This represents the youngest 7 – 8% of Australians with BCC from a database that captures approximately 10% of Sydney’s BCCs. 212 of their first degree relatives were also recruited, including 89 parents and 123 siblings of these 56 probands. All subjects were interviewed with respect to their cancer history and all reports of cancer verified with histopathological reports where possible. The oldest unaffected sibling for each proband (where available) was designated as an intra-family control. All cases and control siblings filled out a questionnaire regarding their pigmentary and sun sensitivity factors and underwent a skin examination by a trained examiner. Peripheral blood was collected from these cases and controls for genotyping of PTCH. All the exons of PTCH for which mutations have been documented in Gorlin patients were amplified using PCR. PCR products were screened for mutations using dHPLC, and all detectable variants sequenced. Prevalence of BCC and SCC for the Australian population was estimated from incidence data using a novel statistical approach. Familial aggregation of BCC, SCC and MM occurred within the 56 families studied here. The majority of families with aggregation of skin cancer had a combination of SCC and BCC, however nearly one fifth of families in this study had aggregation of BCC to the exclusion of SCC or MM, suggesting that BCCspecific risk factors are also likely to be at work. Skin cancer risks for first-degree relatives of people with early onset BCC were calculated: sisters and mothers of people with early-onset BCC had a 2-fold increased risk of BCC; brothers had a 5-fold increased risk of BCC; and sisters and fathers of people with early-onset BCC had over four times the prevalence of SCC than that expected. For melanoma, the increased risk was significant for male relatives only, with a 10-fold increased risk for brothers of people with early-onset BCC and 3-fold for fathers. On skin examination of cases and controls, several phenotypic factors were significantly associated with BCC risk. These included increasing risk of BCC with having fair, easyburning skin (ie decreasing skin phototype), and with having signs of cumulative sun damage to the skin in the form of actinic keratoses. Signs reflecting the combination of pigmentary characteristics and sun exposure - in the form of arm freckling and solar lentigines - also gave subjects a significantly increased risk BCC. Constitutive red-green reflectance of the skin was associated with decreased risk of BCC, as measured by spectrophotometery. Other non-significant trends were seen that may become significant in larger studies including associations of BCC with propensity to burn, moderate tanning ability and an inability to tan. No convincing trend for risk of BCC was seen with the pigmentary variables of hair or eye colour, and a non-significant reduced risk of BCC was associated with increasing numbers of seborrhoeic keratoses. Twenty PTCH exons (exons 2, 3, 5 to 18, and 20 to 23) were screened, accounting for 97% of the coding regions with published mutations in PTCH. Nine of these 20 exons were found to harbour single nucleotide polymorphisms (SNPs), seen on dHPLC as variant melting curves and confirmed on direct sequencing. SNPs frequencies were not significantly different to published population frequencies, or to Australian general population frequencies where SNP database population data was unavailable. Assuming a Poisson distribution, and having observed no mutations in a sample of 56, we can be 97.5% confident that if there are any PTCH mutations contributing to early-onset BCC in the Australian population, then their prevalence is less than 5.1%. Overall, this study provides evidence that familial aggregation of BCC is occurring, that first-degree relatives are at increased risk of all three types of skin cancer, and that a combination of environmental and genetic risk factors are likely to be responsible. The PTCH gene is excluded as a major cause of this increased susceptibility to BCC in particular and skin cancer in general. The weaknesses of the study design are explored, the possible clinical relevance of the data is examined, and future directions for research into the genetics of basal cell carcinoma are discussed.

Sonic hedgehog (Shh) is a secreted morphogen involved in patterning a wide range of structures in the developing embryo. When cells receive the Shh signal a cascade of effects begin which in turn regulate downstream target genes. The genes controlled by Sonic hedgehog provide messages instructing cells how to differentiate or when to divide. Disruption of the hedgehog signalling cascade leads to a number of developmental disorders and plays a key role in the formation of a range of human cancers. Patched, the receptor for Shh, acts as a tumour suppressor and is mutated in naevoid basal cell carcinoma syndrome (NBCCS). NBCCS patients display a susceptibility to tumour formation, particularly for basal cell carcinoma (BCC). The discovery of Patched mutations in sporadic BCCs and other tumour types further highlights the importance of this pathway to human cancer. The identification of genes regulated by hedgehog is crucial for understanding how disruption of this pathway leads to neoplastic transformation. It is assumed that the abnormal expression of such genes plays a large role in directing cells to divide at inappropriate times. Only a small number of genes controlled by Shh have been described in vertebrate tissues. In the work presented in this thesis a Sonic hedgehog responsive embryonic mouse cell line, C3H/10T1/2, was used as a model system for hedgehog target gene discovery. Known downstream target genes were profiled to determine their induction kinetics, building up a body of knowledge on the response to Shh for this cell type. During this work, it was discovered that C3H/10T1/2 cells do not become fully competent to respond to Shh stimulation until the cells reach a critical density, a factor that had to be taken into account when determining timepoints of interest for further investigation. Several techniques were employed to identify genes that show expression changes between Shh stimulated and control cells. In one of these techniques, RNA from cell cultures activated with Shh was used to interrogate cDNA microarrays, and this provided many insights into the downstream transcriptional consequences of hedgehog stimulation. Microarrays consist of thousands of spots of DNA of known sequence gridded onto glass slides. Experiments using this technology allow the expression level of thousands of genes to be measured simultaneously. Independent stimulation methods combined with northern blotting were used to investigate individual genes of interest, allowing genuine targets to be confirmed and false positives eliminated. This resulted in the identification of eleven target genes. Seven of these are induced by Sonic hedgehog (Thrombomodulin (Thbd), Glucocorticoid induced leucine zipper (Gilz), Brain factor 2 (Bf2), Nuclear receptor subfamily 4, group A, member 1 (Nr4a1), Insulin-like growth factor 2 (Igf2), Peripheral myelin protein 22 (Pmp22), Lim and SH3 Protein 1 (Lasp1)), and four are repressed (Secreted frizzled related proteins 1 and 2 (Sfrp1 and Sfrp2), Macrophage inflammatory protein-1 gamma (Mip-1?), and Anti-mullerian hormone (Amh)). The majority of these represent novel downstream genes not previously reported as targets of Shh. The new target genes have a diverse range of functions, and include transcriptional regulators and molecules known to be involved in regulating cell growth or apoptosis. The corroboration of genes previously implicated in hedgehog signalling, along with the finding of novel targets, demonstrates both the validity and power of the C3H/10T1/2 system for Shh target gene discovery. The identification of novel Sonic hedgehog responsive genes provides candidates whose abnormal expression may be decisive in initiating tumour formation and future studies will investigate their role in development and disease. It is expected that such findings will provide vital clues to the aetiology of various human cancers, and that an understanding of their roles may ultimately provide greater opportunities in the future design of anti-tumour therapies.