Mutações inativadoras em homozigose no gene do transdutor de sinal e ativador de transcrição 5B (STAT5B) causam insensibilidade ao hormônio de crescimento associada a disfunção imunológica grave que se manifesta na forma de infecções exacerbadas e de repetição, pneumonia intersticial linfocítica e outros eventos autoimunes. A caracterização do fenótipo destas mutações em heterozigose não foi realizada previamente. Dois pacientes descritos com mutação em homozigose na STAT5B (c.424_427del / p.L142RfsX19) são irmãos brasileiros naturais de Criciúma - Santa Catarina, sem consanguinidade conhecida na família. Houve também o relato de dois outros casos semelhantes na cidade, já falecidos, sugerindo que mutações na STAT5B pudessem ser relativamente frequentes nesta região. Os objetivos deste estudo foram investigar a frequência da mutação c.424_427del da STAT5B na população de Criciúma, avaliar a existência de efeito fundador e caracterizar o efeito da mutação c.424_427del da STAT5B em heterozigose sobre o fenótipo antropométrico e hormonal. Para investigar a frequência desta mutação em Criciúma, 1192 indivíduos da população foram genotipados. Foram identificados sete indivíduos heterozigotos, caracterizando uma frequência alélica mínima de 0,29% (intervalo de confiança 95%: 0,08 a 0,5%), significativamente mais alta que a frequência de outras variantes patogênicas da STAT5B descritas em bases de dados públicas. Utilizando-se o equilíbrio de Hardy-Weinberg, foi possível estimar a incidência de casos de homozigotos para o alelo mutado em um a cada 40 anos. No entanto, utilizando-se a maior frequência possível de acordo com o intervalo de confiança, esta incidência poderia atingir um a cada 13 anos. Além disso, foram estudados os pais dos dois casos relatados como semelhantes aos pacientes homozigotos para mutações na STAT5B e estes pais eram portadores da mutação c.424_427del da STAT5B em heterozigose. Para avaliar o efeito fundador, foram analisados dois marcadores próximos à mutação c.424_427del da STAT5B nos pacientes homozigotos para a mesma, em 33 indivíduos heterozigotos de sete famílias independentes e em 53 indivíduos controles. O mesmo haplótipo estava presente nos pacientes homozigotos para a mutação e em todos os heterozigotos, enquanto em apenas 9,4% dos controles (p < 0,001), apontando a probabilidade de que a mutação c.424_427del nas diferentes famílias tenha sido herdada de um antepassado em comum. Para avaliar o efeito da mutação c.424_427del da STAT5B em heterozigose, foram comparados em conjunto os 33 indivíduos heterozigotos e os 38 familiares não portadores em relação à altura e a alguns exames laboratoriais (gerais e hormonais). Os indivíduos heterozigotos foram significativamente mais baixos, com uma redução na altura de 0,6 desvios-padrão (p= 0,006). Também apresentaram redução significativa dos desvios-padrão de fator de crescimento insulina-símile 1 (IGF-1) e da proteína 3 de ligação a fator de crescimento insulina-símile (IGFBP-3), sem alteração em outros exames. Esses achados mostram que as mutações na STAT5B em heterozigose causam um impacto negativo significativo na altura, mais leve que o visto em pacientes com mutações em homozigose, com altura dentro da variação normal. Esse resultado favorece a hipótese de que variantes patogênicas raras em heterozigose contribuem para a variabilidade da altura normal / Homozygous inactivating mutations in signal transducer and activator of transcription 5B gene (STAT5B) cause growth hormone insensitivity associated with signs of severe immune dysfunction, such as recurrent infections, lymphoid interstitial pneumonia and other autoimmune events. The phenotypic characterization of these mutations in heterozygous state has not been accomplished previously. Two patients with a homozygous STAT5B mutation (c.424_427del / p.L142RfsX19) are Brazilian brothers born in the city of Criciúma, Santa Catarina, and there is not known consanguinity in their family. Moreover, there was a report about two similar cases in this city, already deceased, suggesting that STAT5B mutations could be relatively frequent in this region. The objectives of this study were to evaluate the frequency of STAT5B c.424_427del mutation in Criciúma, to assess the existence of the founder effect and to characterize the effect of heterozygous STAT5B c.424_427del mutation on anthropometric and hormonal phenotypes. To evaluate the frequency of this mutation in Criciúma, 1192 individuals from the population were genotyped. Seven heterozygous individuals were identified, which characterized a minimum allele frequency of 0.29% (95% confidence interval: 0.08 to 0.5%), significantly higher than the frequency of other pathogenic variants described in public databases. By using the Hardy-Weinberg law, it was possible to estimate the incidence of cases of individuals homozygous for this mutation at one every 40 years. However, by using the highest possible frequency according to the confidence interval, this incidence could reach one every 13 years. Additionally, the parents of the two reported cases who were similar to patients with homozygous STAT5B mutations were genotyped and these parents were heterozygous for STAT5B c.424_427del mutation. To assess the founder effect, two markers near the mutation were analyzed in the two boys homozygous for STAT5B c.424_427del mutation, in 33 heterozygous individuals from seven unrelated families and in 53 control individuals. The same haplotype was present in the homozygous boys and in all heterozygous individuals, while in only 9,4% control individuals (p < 0,001), pointing to the probability that STAT5B c.424_427del mutation in different families has been inherited from a common ancestor. To study the effects of heterozygous STAT5B c.424_427del mutation, 33 heterozygous individuals were compared to 38 non-carrier relatives on height and some laboratorial tests. Heterozygous individuals were significantly shorter than their noncarrier relatives, with a height reduction of 0.6 standard deviation scores (p= 0,006). Furthermore, they had a significant reduction in insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein 3 (IGFBP-3) standard deviation scores, without differences in the other exams. These findings show that heterozygous STAT5B mutations cause a significant negative impact on height, milder than the effect seen in patients with homozygous mutations, with height within the normal range. This result favors the hypothesis that rare pathogenic variants in heterozygous state contribute to normal height variability

Poon, Fan Fong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 109-124). / Abstract also in Chinese. / Abstract --- p.i / Acknowledgements --- p.v / Table of Content --- p.vi / List of Figures --- p.xi / List of Tables --- p.xiii / List of Abbreviations --- p.xiv / List of papers published during the study --- p.xvi / Chapter Chapter 1 --- Introduction and Aim of Study --- p.1 / Chapter 1.1 --- General Introduction --- p.1 / Chapter 1.2 --- Project objective and potential significances --- p.6 / Chapter Chapter 2 --- Literature Reviews --- p.8 / Chapter 2.1 --- Cancer genetics --- p.8 / Chapter 2.1.1 --- Oncogenes and TSGs --- p.8 / Chapter 2.1.2 --- Kundsońةs two-hit event of cancer gene --- p.9 / Chapter 2.2 --- Cancer Epigenetics --- p.9 / Chapter 2.2.1 --- Types of Epigenetic regulation --- p.10 / Chapter 2.2.2 --- DNA methylation in TSGs --- p.10 / Chapter 2.2.2.1 --- Promoter CpG island in DNA methylation --- p.10 / Chapter 2.2.2.2 --- Protection system in DNA methylation --- p.11 / Chapter 2.2.2.3 --- Transcriptional silencing by DNA methylation --- p.11 / Chapter 2.2.2.4 --- DNA methylation of TSG silencing in cancers --- p.13 / Chapter 2.2.3 --- Hypomethylation of the cancer genome --- p.14 / Chapter 2.2.4 --- Clinical relevance of cancer epigenetic --- p.14 / Chapter 2.3 --- EGFR/STAT/SOCS pathway --- p.15 / Chapter 2.3.1 --- General Introduction of the EGFR pathway --- p.15 / Chapter 2.3.2 --- EGFR survival signaling pathways --- p.16 / Chapter 2.3.3 --- EGFR/STAT/SOCS signaling --- p.17 / Chapter 2.3.4 --- EGFR/STAT/SOCS signaling and cancers --- p.18 / Chapter 2.3.4.1 --- EGF and cancers --- p.18 / Chapter 2.3.4.2 --- EGFR/STAT/SOCS pathway and cancers --- p.18 / Chapter 2.3.4.3 --- EGF survival signaling as a target for cancer therapy --- p.19 / Chapter 2.4 --- TSGs in the EGFR/STAT/SOCS pathway --- p.20 / Chapter 2.4.1 --- Suppressors of cytokine signaling (SOCS) family --- p.20 / Chapter 2.4.2 --- Signal transducers and activators of transcription (STATs) family --- p.22 / Chapter 2.4.3 --- Sprouty (SPRY) family --- p.23 / Chapter 2.4.4 --- Protein Inhibitor of Activated STAT (PIASs) family --- p.25 / Chapter 2.4.5 --- Ras and Rab Interactor (RIN) family --- p.26 / Chapter 2.4.6 --- Ras-association domain family (RASSF) --- p.26 / Chapter 2.4.7 --- Glycine N-methyltransferase (GNMT) --- p.28 / Chapter 2.5 --- Nasopharyngeal carcinoma (NPC) --- p.30 / Chapter 2.5.1 --- Epidemiology of NPC --- p.30 / Chapter 2.5.2 --- Histopathology of NPC --- p.30 / Chapter 2.5.3 --- Genetic and epigenetic alteration in NPC --- p.31 / Chapter 2.5.4 --- EGFR signaling in NPC --- p.32 / Chapter 2.6 --- Esophageal squamous cell carcinoma (ESCC) --- p.33 / Chapter 2.6.1 --- Epidemiology of ESCC --- p.34 / Chapter 2.6.2 --- Histopathology of ESCC --- p.34 / Chapter 2.6.3 --- Genetic and epigenetic alteration in ESCC --- p.35 / Chapter 2.6.4 --- EGFR signaling in ESCC --- p.36 / Chapter Chapter 3 --- Materials and Methods --- p.38 / Chapter 3.1 --- General Materials --- p.38 / Chapter 3.1.1 --- "Cell lines, tumor and normal tissue samples" --- p.38 / Chapter 3.1.2 --- Maintenance of cell lines --- p.38 / Chapter 3.1.3 --- Drugs treatment of cell lines --- p.39 / Chapter 3.1.4 --- Total RNA extraction --- p.39 / Chapter 3.1.5 --- Genomic DNA extraction --- p.40 / Chapter 3.2 --- General techniques --- p.40 / Chapter 3.2.1 --- Agarose gel electrophoresis of DNA --- p.40 / Chapter 3.2.2 --- TA cloning and blunt end cloning of PCR product --- p.40 / Chapter 3.2.3 --- Transformation of cloning products to E. coli competent cells --- p.41 / Chapter 3.2.4 --- Preparation of plasmid DNA --- p.41 / Chapter 3.2.4.1 --- Mini-prep plasmid DNA extraction --- p.41 / Chapter 3.2.4.2 --- Midi-prep of plasmid DNA --- p.42 / Chapter 3.2.5 --- Measurement of DNA or RNA concentrations --- p.42 / Chapter 3.2.6 --- DNA sequencing of plasmid DNA and PCR products --- p.42 / Chapter 3.3 --- Preparation of reagents and medium --- p.43 / Chapter 3.4 --- Semi-quatitative Reverse-Transcription (RT) PCR expression analysis --- p.44 / Chapter 3.4.1 --- Reverse transcriptin reaction --- p.44 / Chapter 3.4.2 --- Semi-quantitative RT-PCR --- p.44 / Chapter 3.4.2.1 --- Primers design --- p.44 / Chapter 3.4.2.2 --- PCR reaction --- p.46 / Chapter 3.5 --- Methylation analysis of candidate genes --- p.47 / Chapter 3.5.1 --- Bisulfite treatment of genomic DNA --- p.47 / Chapter 3.5.2 --- Methylation-specific PCR (MSP) --- p.48 / Chapter 3.5.2.1 --- Bioinformatics prediction of CpG island --- p.48 / Chapter 3.5.2.2 --- Primers design --- p.48 / Chapter 3.5.2.3 --- PCR reaction --- p.49 / Chapter 3.5.3 --- Bisulfite Genomic Sequencing (BGS) --- p.50 / Chapter 3.6 --- Construction of expression vectors of candidate genes --- p.51 / Chapter 3.6.1 --- Sub-cloning of expression vector of candidate genes --- p.51 / Chapter 3.6.1.1 --- Mouse Socsl expression vector --- p.51 / Chapter 3.6.1.2 --- SPRY1 expression vector --- p.51 / Chapter 3.6.1.3 --- GNMT expression vector --- p.52 / Chapter 3.6.2 --- Restriction digestion of cloning vectors and expression --- p.52 / Chapter 3.6.3 --- Ligation of cloning fragments --- p.53 / Chapter 3.6.4 --- Colony formation assay on monolayer culture --- p.53 / Chapter 3.6.5 --- Statistical analysis --- p.54 / Chapter Chapter 4 --- Screening of candidate TSGs in EGFR pathway --- p.55 / Chapter 5.3.3 --- Restoration of GNMT expression by pharmacological demethylation --- p.89 / Chapter 5.3.4 --- Confirmation of the methylation status of GNMT promoter by BGS --- p.90 / Chapter 5.3.5 --- Methylation status of GNMT in ESCC and NPC primary tumors --- p.90 / Chapter 5.3.6 --- GNMT inhibited the growth of tumor cells in-vitro --- p.90 / Chapter 5.3.7 --- Discussion --- p.95 / Chapter Chapter 6 --- General Discussion --- p.100 / Chapter Chapter 7 --- Summary --- p.105 / Chapter Chapter 8 --- Future Study --- p.107 / Reference --- p.109

Mutações inativadoras em homozigose no gene do transdutor de sinal e ativador de transcrição 5B (STAT5B) causam insensibilidade ao hormônio de crescimento associada a disfunção imunológica grave que se manifesta na forma de infecções exacerbadas e de repetição, pneumonia intersticial linfocítica e outros eventos autoimunes. A caracterização do fenótipo destas mutações em heterozigose não foi realizada previamente. Dois pacientes descritos com mutação em homozigose na STAT5B (c.424_427del / p.L142RfsX19) são irmãos brasileiros naturais de Criciúma - Santa Catarina, sem consanguinidade conhecida na família. Houve também o relato de dois outros casos semelhantes na cidade, já falecidos, sugerindo que mutações na STAT5B pudessem ser relativamente frequentes nesta região. Os objetivos deste estudo foram investigar a frequência da mutação c.424_427del da STAT5B na população de Criciúma, avaliar a existência de efeito fundador e caracterizar o efeito da mutação c.424_427del da STAT5B em heterozigose sobre o fenótipo antropométrico e hormonal. Para investigar a frequência desta mutação em Criciúma, 1192 indivíduos da população foram genotipados. Foram identificados sete indivíduos heterozigotos, caracterizando uma frequência alélica mínima de 0,29% (intervalo de confiança 95%: 0,08 a 0,5%), significativamente mais alta que a frequência de outras variantes patogênicas da STAT5B descritas em bases de dados públicas. Utilizando-se o equilíbrio de Hardy-Weinberg, foi possível estimar a incidência de casos de homozigotos para o alelo mutado em um a cada 40 anos. No entanto, utilizando-se a maior frequência possível de acordo com o intervalo de confiança, esta incidência poderia atingir um a cada 13 anos. Além disso, foram estudados os pais dos dois casos relatados como semelhantes aos pacientes homozigotos para mutações na STAT5B e estes pais eram portadores da mutação c.424_427del da STAT5B em heterozigose. Para avaliar o efeito fundador, foram analisados dois marcadores próximos à mutação c.424_427del da STAT5B nos pacientes homozigotos para a mesma, em 33 indivíduos heterozigotos de sete famílias independentes e em 53 indivíduos controles. O mesmo haplótipo estava presente nos pacientes homozigotos para a mutação e em todos os heterozigotos, enquanto em apenas 9,4% dos controles (p < 0,001), apontando a probabilidade de que a mutação c.424_427del nas diferentes famílias tenha sido herdada de um antepassado em comum. Para avaliar o efeito da mutação c.424_427del da STAT5B em heterozigose, foram comparados em conjunto os 33 indivíduos heterozigotos e os 38 familiares não portadores em relação à altura e a alguns exames laboratoriais (gerais e hormonais). Os indivíduos heterozigotos foram significativamente mais baixos, com uma redução na altura de 0,6 desvios-padrão (p= 0,006). Também apresentaram redução significativa dos desvios-padrão de fator de crescimento insulina-símile 1 (IGF-1) e da proteína 3 de ligação a fator de crescimento insulina-símile (IGFBP-3), sem alteração em outros exames. Esses achados mostram que as mutações na STAT5B em heterozigose causam um impacto negativo significativo na altura, mais leve que o visto em pacientes com mutações em homozigose, com altura dentro da variação normal. Esse resultado favorece a hipótese de que variantes patogênicas raras em heterozigose contribuem para a variabilidade da altura normal / Homozygous inactivating mutations in signal transducer and activator of transcription 5B gene (STAT5B) cause growth hormone insensitivity associated with signs of severe immune dysfunction, such as recurrent infections, lymphoid interstitial pneumonia and other autoimmune events. The phenotypic characterization of these mutations in heterozygous state has not been accomplished previously. Two patients with a homozygous STAT5B mutation (c.424_427del / p.L142RfsX19) are Brazilian brothers born in the city of Criciúma, Santa Catarina, and there is not known consanguinity in their family. Moreover, there was a report about two similar cases in this city, already deceased, suggesting that STAT5B mutations could be relatively frequent in this region. The objectives of this study were to evaluate the frequency of STAT5B c.424_427del mutation in Criciúma, to assess the existence of the founder effect and to characterize the effect of heterozygous STAT5B c.424_427del mutation on anthropometric and hormonal phenotypes. To evaluate the frequency of this mutation in Criciúma, 1192 individuals from the population were genotyped. Seven heterozygous individuals were identified, which characterized a minimum allele frequency of 0.29% (95% confidence interval: 0.08 to 0.5%), significantly higher than the frequency of other pathogenic variants described in public databases. By using the Hardy-Weinberg law, it was possible to estimate the incidence of cases of individuals homozygous for this mutation at one every 40 years. However, by using the highest possible frequency according to the confidence interval, this incidence could reach one every 13 years. Additionally, the parents of the two reported cases who were similar to patients with homozygous STAT5B mutations were genotyped and these parents were heterozygous for STAT5B c.424_427del mutation. To assess the founder effect, two markers near the mutation were analyzed in the two boys homozygous for STAT5B c.424_427del mutation, in 33 heterozygous individuals from seven unrelated families and in 53 control individuals. The same haplotype was present in the homozygous boys and in all heterozygous individuals, while in only 9,4% control individuals (p < 0,001), pointing to the probability that STAT5B c.424_427del mutation in different families has been inherited from a common ancestor. To study the effects of heterozygous STAT5B c.424_427del mutation, 33 heterozygous individuals were compared to 38 non-carrier relatives on height and some laboratorial tests. Heterozygous individuals were significantly shorter than their noncarrier relatives, with a height reduction of 0.6 standard deviation scores (p= 0,006). Furthermore, they had a significant reduction in insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein 3 (IGFBP-3) standard deviation scores, without differences in the other exams. These findings show that heterozygous STAT5B mutations cause a significant negative impact on height, milder than the effect seen in patients with homozygous mutations, with height within the normal range. This result favors the hypothesis that rare pathogenic variants in heterozygous state contribute to normal height variability