Made available in DSpace on 2016-04-04T18:28:03Z (GMT). No. of bitstreams: 1 Andreia Cristina dos Santos Kleinhans.pdf: 1304307 bytes, checksum: b48ee8803ae01d7e3e971161a1351010 (MD5) Previous issue date: 2012-02-24 / Pontif?cia Universidade Cat?lica de Campinas / A Androgenic Alopecia (AA) is characterized by progressive hair loss and thinning and it may start at any age. It is identified as a genetically determine case, in which androgenic steroid hormones play a role. The objective of this study was to verify the existence of its possible association between stress and feelings of anger, in a sample of 20 diagnosed with AA, patients at a dermatology clinic in Curitiba. The instruments utilized for data collections were: identification sheet; Visual Analogue Scale (VAS), which had the function of verifying the level of discomfort to the problem; Lipp s Stress Symptoms Inventory for Adults (LSSI); and State-Trait Anger Expression Inventory (STAXI). Data analysis was both quantitative and qualitative. For responses obtained from LSSI and STAXI, the tables and norms from their respective manuals were utilized. The analysis of the answers obtained from the question was performed according to Bardin. The results show that 85% of individuals in the sample, (n=17), presented stress. Most women with stress were in the resistance phase 55% (n=11) whereas, 15% (n= 3) were at the almost exhaustion stage, 10% (n=2) where at the exhaustion phase and only 5% (n=1) was at the alert phase, in accordance with the LSSI. In agreement with STAXI, a higher score was observed for the internal anger factor, with an average percentage of 56 (standard deviation of 18), whereas for the external anger factor, such percentage was 18 (standard deviation of 21). An important association between anger expression and the presence of stress was found (p= 0.03). There was no association between the analogue visual scale and stress. Considering the number of participants with stress and the tendency of directing anger outwardly, in addition to a high percentage for internal anger in participants of this research, there is a necessity of further studies involving psychological treatment for stress and an adequate anger management. / A Alopecia Androgen?tica (AA) ? caracterizada pela perda e afinamento progressivo dos cabelos e, pode surgir em qualquer idade. ? identificada como um quadro geneticamente determinado com a participa??o dos horm?nios ester?ides andr?genos. O objetivo desse estudo foi verificar a exist?ncia de poss?veis associa??es entre o stress e o sentimento de raiva, de uma amostra de 20 mulheres com diagn?stico m?dico para (AA), pacientes de uma cl?nica de Dermatologia em Curitiba. Os instrumentos utilizados para a coleta de dados foram: ficha de identifica??o; Escala Anal?gica Visual (EVA), cuja fun??o, foi verificar o n?vel de desconforto frente ao problema; Invent?rio de Sintomas de Stress para Adultos de Lipp (ISSL); Invent?rio de Express?o de Raiva como Estado e Tra?o (STAXI). A an?lise dos dados foi quantitativa e qualitativa. Para respostas obtidas a partir do ISSL e do STAXI utilizaram-se as tabelas e normas dos respectivos manuais. A an?lise das respostas obtidas a partir da pergunta foi realizada de acordo com Bardin. Os resultados apontaram que 85% do total da amostra, (n=17), apresentaram stress. A maioria das mulheres com stress estavam na fase de resist?ncia 55% (n=11) enquanto, 15% (n= 3) encontravam-se em quase exaust?o, 10% (n=2) na fase de exaust?o e apenas 5% (n=1) apresentou-se na fase de alerta segundo o ISSL. De acordo com o STAXI observou-se um escore superior para o fator de raiva para dentro com percentil m?dio de 56 para o fator (desvio-padr?o de 18), ao passo que para o fator raiva para fora, o percentil m?dio foi 18 (desvio-padr?o 21). Uma importante associa??o entre a express?o da raiva para fora e a presen?a de stress foi encontrada (p= 0.03). N?o houve associa??o entre a escala anal?gica visual e stress. Levando-se em considera??o o n?mero de participantes com stress e tend?ncia em direcionar a raiva para fora, al?m do alto percentil de raiva para dentro das participantes dessa pesquisa, atenta-se para a necessidade de outros estudos que envolvam o tratamento psicol?gico para o stress e o adequado manejo da raiva.

Terminado o sequenciamento do genoma humano, as atenções se voltaram para a determinação do conjunto completo de transcritos humanos. Diversos trabalhos sugerem que enquanto apenas uma pequena fração de mRNAs codificantes para proteína não é conhecida, existe um grande número de RNAs não-codificantes (ncRNAs) ainda não caracterizados. Nesse contexto, o presente trabalho visou explorar as informações de expressão gênica contidas em ESTs para identificar e caracterizar novos transcritos humanos. A busca genômica por membros de famílias gênicas relacionadas com câncer levou a identificação de novas pequenas GTPases, destacando uma subfamília que deve apresentar função supressora tumoral em próstata. Uma classe de ncRNAs longos, sem splicing, expressos antisenso a partir de regiões intrônicas foi descrita utilizando plataformas de microarrays, construídas pelo grupo, enriquecidas com seqüências sem anotação. O perfil de expressão de 23 ncRNAs intrônicos estava significativamente correlacionado com o grau de diferenciação de tumores de próstata (Gleason Score), e pode ser utilizado como candidato a marcador molecular de prognóstico. Um total de 39 ncRNAs intrônicos responderam à estimulação por andrógeno, apontando para um mecanismo regulatório da expressão intrônica por sinais fisiológicos hormonais. A biogênese da expressão intrônica parece ser complexa, pois uma fração não é transcrita pela RNA Polimerase II. A transcrição intrônica estava correlacionada com uso de exons em células tratadas com andrógeno. Assinaturas de expressão intrônica conservadas em tecidos humanos e de camundongos, e interações de transcritos intrônicos com proteínas regulatórias foram observadas. Este trabalho contribui com novas e originais evidências que dão apoio ao papel postulado para esses ncRNAs no controle fino do programa transcricional humano. / With the completion of the human genome sequence, attention has shifted towards determining the complete set of human transcripts. Multiple lines of evidence suggest that while only a small fraction of protein-coding mRNAs remains to be described, there is a huge amount of uncharacterized non-coding RNAs (ncRNAs). In this context, the present work sought to explore the gene expression information provided by ESTs to identify and characterize new human transcripts. A genomic-wide search for cancer related gene family members identified novel small GTPase genes, and highlighted an uncharacterized subfamily that may have a tumor suppressor role in prostate cancer. A class of long unspliced ncRNAs, expressed antisense from introns of protein-coding genes was described using custom-designed microarray platforms enriched with unannotated sequences. The expression profile of 23 intronic ncRNAs was significantly correlated to the degree of prostate tumor differentiation (Gleason Score), and could be used as a candidate prognostic molecular maker. A total of 39 intronic ncRNAs were responsive to androgen stimulation, poiting to a mechanism of intronic expression regulation by physiological hormone signals. Intronic ncRNA biogenesis seems to be complex, since a fraction of them is not transcribed by RNA Polymerase II. Intronic transcription was correlated to exon usage in androgen treated cells. Tissue expression signatures of intronic transcription were conserved in human and mouse, and intronic transcripts were found to interact with regulatory proteins. This work provides new and original contributions that support the postulated role of ncRNAs in the fine tunning of the human transcriptional program.

Hepatocellular carcmoma (HCC) is the third most common cause of cancer-related deaths worldwide, with a gender prevalence observed in men. Recent studies have suggested that elevated activity of the androgen axis is one major host factor underlying this disparity between genders. The androgen receptor (AR) mediates function of androgen in vital developmental and oncogenic pathways by binding to genomic androgen response elements, which influence the transcription of downstream target genes. AR is overexpressed in 60-80% of human HCCs. Genetic studies further established the pivotal role ofAR in hepatocarcinogenesis, where liver-specific knockout of AR significantly reduced tumorigenicity in carcinogen- and HBV-induced HCC mouse models. However, AR-inducedhepatocarcinogenesis is far from fully understood, in part because little is known about the identity and role of direct AR-dependent targeted genes in hepatocytes. / In this study, we used genome-wide location and functional analyses to identify a critical mediator of AR signaling, cell cycle-related kinase (CCRK), in driving beta-cateninl T-cell factor (TCF)-dependent hepatocarcinogenesis. Using chromatin immunoprecipitation followed by promoter array analysis of AR-overexpressing HCC cell lines, we found a number of cell cycle-related genes that are likely under the direct modulation of AR. Cell cycle-related kinase (CCRK), previously shown to promote glioblastoma tumorigenesis, was found to be the most significantly-bound AR target ( p<0.0001). CCRK was directly up-regulated by ligand-activated AR through promoter binding and required for AR-induced G1-S cell cycle progression because (1) CCRK overexpression attenuated cell cycle blockage by AR knockdown and (2) CCRK inhibition counteracted AR-mediated cell cycle progression. Ectopic CCRK expression induced immortalized liver cell proliferation, malignant transformation and tumor formation in immunodeficient mice, whereas CCRK inhibition decreased HCC cell growth in vitro and in vivo. These functional assays demonstrated that CCRK is a potential oncogene in HCC. Mechanistically, CCRK activated beta-catenin/TCF-dependent transcription through phosphorylation of glycogen synthase kinase-3beta and induced the expressions of beta-catenin target genes, cyclin D1 (CCND1) and epidermal growth factor receptor (EGFR). Inhibition of beta-catenin/TCF signaling attenuated CCRK-induced cell cycle progression, colony formation and tumorigenicity. Conversely, HCC cell growth inhibition by CCRK knockdown was rescued by constitutively active beta-catenin or TCF. In agreement with these findings, activation of the AR/CCRK/beta-catenin axis was frequently observed in primary HCCs. More importantly, CCRK over-expression was correlated with tumor staging and poor overall survival in a cohort ofhuman HCC tissues. / Together, our data reveal a new cascade for AR function in hepatocarcinogenesis via the activation of beta-catenin/TCF signaling. This study also reveals that CCRK is a novel focal link between two prominent signaling pathways vital for HCC growth and thus represents a new therapeutic target for HCC treatment. / Feng, Hai. / Adviser: Sung Jao Yiu. / Source: Dissertation Abstracts International, Volume: 73-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 161-177). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Prostate cancer (PC) is characterised by dependence upon androgen receptor (AR) as its driving oncogene. When organ-confined, radical treatment can be curative, however there is no cure for advanced, castration-resistant prostate cancer (CRPC). There is therefore a need to better understand the biology of PC, and how influencing AR can modify disease progression. Estrogen is essential for prostate carcinogenesis with evidence from epidemiological, in vitro, human tissue and animal studies. Most suggests that estrogen receptor beta (ERβ) is tumour-suppressive, but trials of ERβ-selective agents have not improved clinical outcomes. ERβ has also been implicated as an oncogene, therefore its role remains unclear. Additional evidence suggests interplay between ERβ and AR, the mechanisms of which are uncertain. The study hypothesis ‘ERβ is an important modulator of prostate carcinogenesis’ was developed to establish whether targeting ERβ could affect PC progression. Much of the confusion around ERβ stems from use of inadequately validated antibodies and cell line models. The first phase of this work was to test ERβ antibodies using an ERβ-inducible cell system. Eight ERβ antibodies were assessed by multiple techniques, showing that commonly used antibodies are either non-specific or only specific in one modality. Two reliable antibodies were identified. Next, cell lines previously used to study ERβ were assessed using validated antibodies and independent approaches. No ERβ expression was detected; an important finding that casts doubt on previously published ERβ biology. Subsequently, a PC cell line with inducible ERβ expression (LNCaP-ERβ) was developed and validated to enable controlled experiments on the effects of ERβ on proliferation, gene expression and ERβ/AR genomic cross-talk. Phase three of this work focused on ERβ biology in PC and its relationship to AR. Interrogation of clinical datasets showed that greater ERβ expression associated with favourable prognosis. Gene expression data from men treated with androgen deprivation therapy revealed that AR represses ERβ. This was confirmed in vitro. The LNCaP-ERβ cell line was treated with androgen and/or ERβ-selective estrogen. Activated ERβ in the presence of androgen-stimulated AR inhibited cell proliferation and down-regulated androgen-dependent genes. Genome-wide mapping of ERβ binding sites reveals that ERβ antagonises AR through competition for shared DNA binding sites. In conclusion, ERβ expression is down-regulated by AR during malignant transformation of prostate epithelium. We reveal an antagonistic relationship between ERβ and AR whereby sustaining or replacing ERβ may inhibit tumour growth through down-regulation of AR-target genes. In future, an ERβ-selective compound may be used to slow or abrogate PC progression.

Afin de mettre en évidence les principaux éléments de la voie androgénique et œstrogénique dans l’épididyme du rat des sables adulte, capturé dans la région de Beni Abbès, en Algérie, l’aromatase, l’œstradiol, les récepteurs des androgènes (RA) et des œstrogènes (REα, REβ, GPR30) ont été recherchés chez des animaux en saison d’activité, en saison de repos sexuel, chez des animaux castrés, castrés puis traités par la testostérone et chez des animaux ayant subi la ligature des canaux efférents. En saison d’activité, les RA sont ubiquitaires, l’aromatase est cytoplasmique par contre l’œstradiol est nucléaire et cytoplasmique. Les REα et le GPR30 sont principalement dans le cytoplasme apical par contre les REβ sont nucléaires. En saison de repos sexuel, les RA, l’aromatase, l’œstradiol, les REα et le GPR30 persistent, cependant, les REβ subissent une translocation cytoplasmique. Chez les animaux castrés, les RA, l’aromatase et l’œstradiol sont réduits par contre les REα persistent avec une faible intensité. Le GPR30 est cytoplasmique et nucléaire. Chez les animaux castrés puis traités, les RA, l’aromatase, l’œstradiol, les REα, les REβ et le GPR30 sont restaurés. Chez les animaux ligaturés, le RA est faiblement conservé uniquement dans l’épididyme proximal. L’aromatase et l’œstradiol sont conservés. Le signal des REα, des REβ et du GPR30 est fortement exprimé dans le noyau et le cytoplasme dans l’épididyme proximal par contre il est fortement exprimé uniquement pour les REα dans l’épididyme distal. Par western blot, les RA, REα, REβ et GPR30 sont de 122, 64, 55 et 55 kDa respectivement. / In order to highlight the main elements of androgen and estrogen pathway in the epididymis of sand rat, captured in Beni Abbès area, in Algeria, androgen receptor (AR), aromatase, estradiol, estrogen receptors (ERα, ERβ and GPR30) were explored in breeding season, in resting season and in animals underwent castration, castration then testosterone treatment and ligation of efferent ducts. In breeding season, AR has a ubiquitous distribution, aromatase is exclusively cytoplasmic and estradiol is nuclear and cytoplasmic. The ERα and GPR30 were distributed with a high intensity in the apical cytoplasm contrarily to ERβ which were nuclear. In resting season, AR, aromatase, estradiol, ERα persist with lower staining. However, ERβ undergo cytoplasmic translocation and GPR30 persist in cytoplasm. In castrated animals, AR, aromatase and estradiol are reduced. ERα persist with low intensity in the apical cytoplasm. GPR30 is distributed in the cytoplasm and the nucleus. In castrated then treated animals, AR is restored; aromatase and estradiol reappear with a cytoplasmic localization for aromatase, nuclear and apical for ERα. ERβ and GPR30 are restored and have a cytoplasmic localization. In ligatured, RA is preserved in the caput, aromatase and estradiol persist caput and cauda. The signal of ERα, ERβ and GPR30 is highly expressed in the nucleus and cytoplasm of caput epididymis and highly expressed of ERα exclusively in cauda. By Western blot, RA, ERα, ERβ and GPR30 are found with molecular weights of 122, 64, 55 and 55 kDa respectively.

Das diversas neoplasias denominadas câncer de boca, mais de 95% tem o diagnóstico de carcinoma epidermóide (CE). O carcinoma epidermóide apresenta etiologia e patogênese complexas e não totalmente compreendidas determinando altos índices de morbidade e mortalidade. Por isso crescentes esforços têm sido empregados para a melhor compreensão dos eventos celulares, da susceptibilidade genética e dos fatores de risco que atuando em conjunto dão origem e atuam na progressão do carcinoma epidermóide de boca. Buscando novas facetas da carcinogênese oral e baseando-se no papel pró-carcinogênico que os hormônios esteróides desempenham nas neoplasias dos órgãos reprodutivos, alguns estudos passaram a avaliar o papel desses hormônios na patogênese e progressão do CE. O propósito deste trabalho foi avaliar a presença dos receptores de androgênio, estrogênio (alfa e beta) e da enzima aromatase em carcinomas epidermóides de boca (CE), através das técnicas de imuno-histoquímica, western-blotting e imunofluorescência, e comparar, com base no gênero (masculino e feminino), os resultados encontrados. Da amostra de CE utilizada, 30 eram pertencentes a pacientes do gênero feminino e 30 do masculino. Para as reações de Western blotting e imunofluorescência foram utilizadas duas linhagens celulares: OSCC9 e OSCC25, derivadas de CE de língua. Nas reações imunohistoquímicas, apesar de um número maior de casos negativos do que positivos, observou-se que o receptor de estrogênio beta foi o mais expresso, seguido pelo receptor de androgênio e aromatase. O receptor de estrogênio alfa apresentou menor imunoexpressão. Houve diferença estatisticamente significante entre os gêneros apenas na expressão dos receptores de androgênio. Os resultados obtidos pelo western blotting e imunofluorescência evidenciaram que as duas linhagens celulares utilizadas apresentaram receptores de estrogênio beta no núcleo, bem como, a presença da enzima aromatase com localização citoplasmática. Os receptores de androgênio foram observados no núcleo somente na linhagem OSCC9 enquanto que os receptores de estrogênio alfa não foram evidenciados em nenhuma das linhagens. Esses resultados sugerem que em alguns casos de CE possa existir contribuição hormonal na progressão da doença, evidenciando a necessidade da utilização desses marcadores nesse tipo de neoplasia. / Oral squamous cell carcinoma (OSCC) is the main type of oral cancer presenting complex and not completely understood pathogenesis. OSCC implies quite significant mortality and morbidity rates and in spite of the vast amount of research and the advances in the field of oncology and surgery, the overall survival remains largely unchanged. Therefore, the identification of new pathways involved in the mechanisms of carcinogenesis can bring knowledge to the control and advent of new treatments. The role of androgens and estrogens in several endocrine-related malignancies is well known. The successful use of these hormones antagonists in the treatment of these neoplasms has prompted researches to investigate the presence of hormones receptors in other tissues and tumor types. The aim of this study was to asses through immunohistochemistry, western blot and immunoflorescence assays the expression, genderrelated, of androgen, estrogen alpha and beta receptors and aromatase enzyme in cases of OSSC. A total of 60 cases of OSCC (30 from males and 30 from females) were retrieved and submitted to immunohistochemical assay. Two OSCC cell lines were used for western blot and immunoflurescence techniques: OSCC-9 and OSCC-25, originated from the tongue. Immunohistochemical staining demonstrated that estrogen beta and androgen receptors and aromatase enzyme, respectively, were more frequently expressed in OSCC. Estrogen alpha receptor had the lower immuno expression. Only androgen receptors presented differences statistically significant between genders. Western blotting and immunofluorescence analysis demonstrated that estrogen beta receptor was abundantly present in nuclear region of SCC9 and SCC25 cell lines, as well as aromatase protein, although its localization was cytoplasmatic. Androgen receptor was observed in the nucleus of SCC9 cell line and absent in the SCC25 cell line. On the other hand, estrogen alpha receptor was not detected either in western blot assay or in immunofluorescence. Even though these proteins presented a variable expression in OSCC, it is interesting to conduct more studies about them, since we could have more possibilities to predict and control oral squamous cell carcinoma.

Das diversas neoplasias denominadas câncer de boca, mais de 95% tem o diagnóstico de carcinoma epidermóide (CE). O carcinoma epidermóide apresenta etiologia e patogênese complexas e não totalmente compreendidas determinando altos índices de morbidade e mortalidade. Por isso crescentes esforços têm sido empregados para a melhor compreensão dos eventos celulares, da susceptibilidade genética e dos fatores de risco que atuando em conjunto dão origem e atuam na progressão do carcinoma epidermóide de boca. Buscando novas facetas da carcinogênese oral e baseando-se no papel pró-carcinogênico que os hormônios esteróides desempenham nas neoplasias dos órgãos reprodutivos, alguns estudos passaram a avaliar o papel desses hormônios na patogênese e progressão do CE. O propósito deste trabalho foi avaliar a presença dos receptores de androgênio, estrogênio (alfa e beta) e da enzima aromatase em carcinomas epidermóides de boca (CE), através das técnicas de imuno-histoquímica, western-blotting e imunofluorescência, e comparar, com base no gênero (masculino e feminino), os resultados encontrados. Da amostra de CE utilizada, 30 eram pertencentes a pacientes do gênero feminino e 30 do masculino. Para as reações de Western blotting e imunofluorescência foram utilizadas duas linhagens celulares: OSCC9 e OSCC25, derivadas de CE de língua. Nas reações imunohistoquímicas, apesar de um número maior de casos negativos do que positivos, observou-se que o receptor de estrogênio beta foi o mais expresso, seguido pelo receptor de androgênio e aromatase. O receptor de estrogênio alfa apresentou menor imunoexpressão. Houve diferença estatisticamente significante entre os gêneros apenas na expressão dos receptores de androgênio. Os resultados obtidos pelo western blotting e imunofluorescência evidenciaram que as duas linhagens celulares utilizadas apresentaram receptores de estrogênio beta no núcleo, bem como, a presença da enzima aromatase com localização citoplasmática. Os receptores de androgênio foram observados no núcleo somente na linhagem OSCC9 enquanto que os receptores de estrogênio alfa não foram evidenciados em nenhuma das linhagens. Esses resultados sugerem que em alguns casos de CE possa existir contribuição hormonal na progressão da doença, evidenciando a necessidade da utilização desses marcadores nesse tipo de neoplasia. / Oral squamous cell carcinoma (OSCC) is the main type of oral cancer presenting complex and not completely understood pathogenesis. OSCC implies quite significant mortality and morbidity rates and in spite of the vast amount of research and the advances in the field of oncology and surgery, the overall survival remains largely unchanged. Therefore, the identification of new pathways involved in the mechanisms of carcinogenesis can bring knowledge to the control and advent of new treatments. The role of androgens and estrogens in several endocrine-related malignancies is well known. The successful use of these hormones antagonists in the treatment of these neoplasms has prompted researches to investigate the presence of hormones receptors in other tissues and tumor types. The aim of this study was to asses through immunohistochemistry, western blot and immunoflorescence assays the expression, genderrelated, of androgen, estrogen alpha and beta receptors and aromatase enzyme in cases of OSSC. A total of 60 cases of OSCC (30 from males and 30 from females) were retrieved and submitted to immunohistochemical assay. Two OSCC cell lines were used for western blot and immunoflurescence techniques: OSCC-9 and OSCC-25, originated from the tongue. Immunohistochemical staining demonstrated that estrogen beta and androgen receptors and aromatase enzyme, respectively, were more frequently expressed in OSCC. Estrogen alpha receptor had the lower immuno expression. Only androgen receptors presented differences statistically significant between genders. Western blotting and immunofluorescence analysis demonstrated that estrogen beta receptor was abundantly present in nuclear region of SCC9 and SCC25 cell lines, as well as aromatase protein, although its localization was cytoplasmatic. Androgen receptor was observed in the nucleus of SCC9 cell line and absent in the SCC25 cell line. On the other hand, estrogen alpha receptor was not detected either in western blot assay or in immunofluorescence. Even though these proteins presented a variable expression in OSCC, it is interesting to conduct more studies about them, since we could have more possibilities to predict and control oral squamous cell carcinoma.

Thousands of animal experiments have demonstrated that androgenic hormones, such as testosterone, during the prenatal and early postnatal periods, masculinise and defeminise various neural and behavioural characteristics that differ by sex. Can these findings from animal experiments be generalised to human behaviour? Can early androgen exposure shape subsequent gender-related disorders in humans? Chapter 1 (Introduction) provides an overview of the literature. Chapter 2 (Kung et al., 2016a) is the first study to demonstrate that testosterone concentrations in saliva samples collected during the early postnatal testosterone surge at 1 to 3 months of age can negatively predict subsequent expressive vocabulary size (how many words a child can say) during toddlerhood. Notably, males typically have a smaller expressive vocabulary than do females during toddlerhood and a small expressive vocabulary is predictive of subsequent language difficulties, such as dyslexia and stuttering, which are more common in boys. Chapters 3 (Kung et al., 2016b) and 4 (Kung et al., 2016c) evaluate a popular theory of autism, the extreme male brain theory, which argues that heighted androgen exposure during early development causes the male preponderance in autism. To test the hypothesised relationship, Chapters 3 and 4 use different measures and study populations, including testosterone concentrations in amniotic fluid samples obtained prenatally and saliva samples obtained during the early postnatal testosterone surge in typically developing children, as well as examining the adjustment in children exposed to unusually high levels of androgens prenatally due to congenital adrenal hyperplasia (CAH), a rare clinical condition occurring in approximately 1 in 18,000 births. Findings from these two chapters converge to show that any relationship between early androgen exposure and subsequent development of autistic traits is small, non-existent, or unreliable, providing a much-needed clarification of the role of early androgen exposure in the aetiology of autism. Using data from a general population study, Chapter 5 (Kung et al., 2018a) is the first study to show that male-typical play behaviour in early childhood, a trait that has been linked to increased early androgen exposure in previous research, can positively predict adolescent physical aggression, which is typically higher in males than in females. This positive association between play and aggression supports potential influences of early androgen exposure, as well as socio-cognitive influences involved in gender development. Chapter 6 (Kung et al., 2018b) is the first study to compare emotional and behavioural adjustment in children with CAH, their unaffected siblings, and children in the general population. Findings from this chapter suggest that although within the families with a child with CAH there are generally no differences in emotional or behavioural problems between boys or girls with CAH and their unaffected same-sex siblings, both girls with CAH and their unaffected sisters are at risk of developing behavioural problems when compared with girls in the general population. Familial influences and social stigma may contribute to this gender-specific pattern of behavioural adjustment. Finally, Chapter 7 (Discussion) integrates the findings and previous research and provides directions for further research. Chapter References Chapter 2 Kung, K. T. F., Browne, W. V., Constantinescu, M., Noorderhaven, R. M., and Hines, M. (2016). Early Postnatal Testosterone Predicts Sex-Related Differences in Early Expressive Vocabulary. Psychoneuroendocrinology, 68, 111-116. Chapter 3 Kung, K. T. F., Constantinescu, M., Browne W. V., Noorderhaven, R. M., and Hines, M. (2016). No Relationship Between Early Postnatal Testosterone and Autistic Traits in 18 to 30-Month-Old Children. Molecular Autism, 7:15. Chapter 4 Kung, K. T. F., Spencer, D., Pasterski, V., Neufeld, S., Glover, V., O'Connor, T. G., Hindmarsh, P. C., Hughes, I. A., Acerini, C. L., and Hines, M. (2016). No Relationship Between Prenatal Androgen Exposure and Autistic Traits: Convergent Evidence from Studies of Children with Congenital Adrenal Hyperplasia and of Amniotic Testosterone Concentrations in Typically-Developing Children. Journal of Child Psychology and Psychiatry, 57, 1455-1462. Chapter 5 Kung, K. T. F., Li, G., Golding, J., and Hines, M. (2018). Preschool Gender-Typed Play Behavior at Age 3.5 Years Predicts Physical Aggression at Age 13 Years. Archives of Sexual Behavior, 47, 905-914. Chapter 6 Kung, K. T. F., Spencer, D., Pasterski, V., Hindmarsh, P. C., Neufeld, S. A. S., Hughes, I. A., Acerini, C. L., and Hines, M. (2018). Emotional and Behavioral Adjustment in 4- to 11-Year-Old Boys and Girls with Classic Congenital Adrenal Hyperplasia and Unaffected Siblings. Psychoneuroendocrinology. 97, 104-110.

FoxO proteins are transcriptional factors acting downstream of the tumor suppressor PTEN. Their activity is negatively regulated by AKT-mediated phosphorylation. Our previous studies showed a mutual suppression between PTEN and the androgen receptor (AR) in regulating growth and apoptosis in prostate cancer (PCa) cells. We hypothesize that nuclear FoxO proteins are involved in mediating this mutual antagonism. In this dissertation, we report that PTEN inhibits AR activity through FoxO1 and provide evidence for the involvement of FoxO factors in the androgen-mediated suppression of PTEN-induced apoptosis. Our studies identify a novel mechanism for AR inhibition by FoxO1 and demonstrated the participation of FoxO1 in AR inhibition by PTEN. Ectopic expression of active FoxO1 decrease the transcriptional activity of the AR as well as androgen-induced cell proliferation and production of prostate-specific antigen in PCa cells. FoxO1 knock down by RNA interference increased the transcriptional activity of the AR in PTEN intact cells and relieved its inhibition by ectopic PTEN in PTEN null cells. Mutational analysis revealed that FoxO1 region 150-655, which contains the fork head box and C-terminal activation domain, was required for AR inhibition. Mammalian two-hybrid assays demonstrated that the inhibition of AR activity by PTEN through FoxO1 involved the interference of androgen-induce interaction of the N- and C- termini of the AR and the recruitment of the p160 coactivators to the AR N-terminus. In addition to the inhibition of AR by FoxO1, we also demonstrated that PTEN-induced apoptosis is mediated through FoxO factors and that AR inhibited FoxO1 activity by yet-to-be identified downstream target gene. Mutation of AR DNA binding domain partially relieved the inhibition of FoxO1 trasnscriptional activity by androgens. Inhibiton of new protein synthesis abolished the AR-mediated decrease in the mRNA level of FoxO1 target gene. Overall, these studies reveal novel mechanisms for the mutual inhibition of AR and FoxO1 activity and establish FoxO proteins as important nuclear factors that mediate the mutual antagonism between AR and PTEN tumor suppressor in PCa cells.

Résumé indisponible / Résumé indisponible