O adenocarcinoma pancreático é a neoplasia maligna mais comum do pâncreas. A alta taxa de mortalidade deve-se ao diagnóstico tardio e a alta agressividade do tumor. Freqüentemente observam-se indivíduos com neoplasias de mesmo estadio apresentarem sobrevivência diferente. Isso demonstra a necessidade de incluir mais variáveis na caracterização da doença. O processo de angiogênese é essencial para o crescimento tanto do tumor primário, quanto para o metastático. A medida da densidade intratumoral da microvasculatura (DMV) por imunoistoquímica é o método mais confiável para medir a atividade angiogênica tumoral. A perda da função do gene p53 influencia a resposta à quimio e à radioterapia além de regular a angiogênese. A sobrevivência está inversamente relacionada à positividade do p53 e à DMV em neoplasias de mama, pulmão, ovários, estômago, cólon, laringe e bexiga. No adenocarcinoma pancreático os resultados são controversos. Idealizou-se essa pesquisa retrospectiva analisando-se dados clínicos e os resultados de estudos imunoistoquímicos obtidos de adenocarcinomas de pâncreas ressecados com intenção curativa. Analisou-se dados clínicos, patológicos, re-estadiamento e resultados da DMV e da expressão do gene p53 em 49 pacientes. A densidade média de microvasos foi de 46,2 vasos/mm2 sendo que esse valor foi utilizado para dividir os pacientes em grupos de baixa ou alta densidade de vasos. A coloração para p53 nuclear foi considerada positiva em 20 de 49 pacientes (40,8%). A DMV foi significativamente maior nos pacientes com tumores maiores que 3,0 cm e nos pacientes com ressecções incompletas. A expressão do gene p53 e a DMV, não foram fatores preditivos da sobrevivência pós-operatória. Não foi possível verificar relação entre a expressão do gene p53 e a densidade da microvasculatura tumoral / The prognostic significance of microvessel density and the p53 expression was evaluated. Between 1993 and 2006, 49 patients with pancreatic adenocarcinoma were ressected with curative intention. Specimens were stained immunohistochemically with antibodies anti- p53 anti-CD34. Microvessel density (MVD) was assessed scanning ten areas of the tumoral section and counted at a high power in an adequate area. The MVD ranged from 21,2 to 54,2 vessels/mm2 (mean 46,2 vessels/mm2). Specific nuclear staining for p53 was determined positive in 20 patients (40,8%). The overall median survival was 24,1 months after resection and there was no difference in survival rates according to the MVD and p53 positivity. There was also no relation between the MVD and p53 expression. MVD and p53 expression could not predict survival in these patients with pancreatic adenocarcinoma. There was no correlation with p53 expression and intratumoral microvessel density. High MVD was associated with tumor size grater than 3,0 cm and positive margins

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O carcinoma do córtex da supra-renal (ACC) é uma neoplasia rara e de prognóstico sombrio. Embora estudos moleculares tenham explorado diversos aspectos relacionados à tumorigênese destas neoplasias, o conhecimento das vias relacionadas à disseminação metastática é restrito. O objetivo do presente estudo é avaliar a expressão de genes relacionados a metástases em uma coorte de pacientes portadores de tumores do córtex da supra-renal metastáticos e não-metastáticos, a fim de identificar vias envolvidas na disseminação metastática destas neoplasias, novos marcadores prognósticos e eventuais alvos terapêuticos. Os perfis de expressão de 27 tumores do córtex da supra-renal de 15 pacientes adultos (8 ACC e 7 adenomas) e 12 pediátricos (5 metastáticos e 7 não-metastáticos) foram avaliados por um array de expressão contendo um painel de 113 genes que sabidamente estão envolvidos no processo de disseminação metastática de diversas neoplasias humanas. A análise de grupamentos mostrou que adenoma dos pacientes adultos forma um grupo distinto dos demais tumores (ACC de adultos e tumores pediátricos). Os genes MMP11e DENR foram identificados como diferencialmente expressos quando se compararam os adenomas e ACC de adultos. Na comparação dos tumores pediátricos nenhum gene foi diferencialmente expresso. Assim como a análise de grupamento, a PCA utilizando grupo selecionado de genes também não foi capaz partir os tumores pediátricos em subgrupos pela evolução. A expressão dos genes MMP2, TIMP3 e FN1 também foram avaliados por RT-PCR e foram concordantes com os dados gerados pelo array de expressão. O papel da LOH como causa da redução da expressão de TIMP3 foi estudado com tipagem de microssatélites. Em alguns casos, foi identificada LOH da região 22q13. Porém, em outros casos em que a expressão do TIMP3 foi bastante reduzida, não houve LOH. Em resumo, foram identificados aspectos moleculares importantes envolvidos na disseminação e metástases de neoplasias do córtex da supra-renal de adultos e crianças, bem como características biológicas deste processo. Diferentes padrões de expressão identificados em tumores metastáticos e não-metastáticos podem ajudar na predição do prognóstico / Adrenocortical carcinoma (ACC) is a rare neoplasm with a poor prognosis. Although molecular studies have uncovered many aspects of ACC tumorigenesis, little is known about molecular pathways involved in metastatic spread. The objective of our study is to analyze the expression profile of metastasis-related genes in a cohort of metastatic and nonmetastatic adrenocortical tumors in order to identify genes involved in the metastatic spread, as well as to find new prognostic markers. The expression profiles of 27 adrenocortical tumors from 15 adults (8 ACC and 7 adenomas) and 12 children (5 metastatic and 7 non-metastatic) were evaluated by an array of 113 known to be involved in human metastasis. Cluster analysis showed adult adrenocortical adenomas form a group distinct from other adrenocortical tumors (adult carcinomas and pediatric tumors). The comparison of adult adenoma and ACC revealed that MMP11 and DENR were differentially expressed between these two groups while no gene was differentially expressed among pediatric adrenocortical tumors. Similarly to cluster analysis, Principal component analysis failed to identify partition amongst pediatric tumors categorized by their evolution. The expression data of MMP2, TIMP3 and FN1 genes by RT-PCR agreed with those generated by the arrays. LOH of 22q12.3 region was detected in some cases in which TIMP3 down regulation was verified (but not in all cases). In conclusion, we have identified important aspects of molecular pathways and biological characteristics involved in metastatic spread of adrenocortical tumors. Distinctive patterns of gene expression between metastatic and nonmetastatic tumors may help in prognosis prediction

Estudos sugerem que a presença de células metastáticas ocultas em medula óssea pode ser fator prognóstico em câncer de mama. Além disso, é possível que um perfil gênico tumoral específico, caracterizado por repressão da expressão gênica, esteja associado à detecção de células tumorais na medula óssea. O silenciamento de genes é controlado pela desacetilação de histonas e metilação de DNA, esta última catalisada por enzimas DNA metil transferases. Outro alvo de metil-transferases são as histonas, e histona H3 quando sofre metilação em lisina 9, gera sítio de ligação a proteínas HP1 (Heterocromatin protein-1 ou cromobox). Membros da família HP1 (HP1Hsalfa, HP1Hsbeta e HP1HsY) participam da formação da heterocromatina e da regulação da expressão de genes. Logo, nosso objetivo foi determinar no tumor primário de mama, a expressão de HP1Hsalfa, HP1Hsbeta e HP1Hsy , que participam da repressão gênica, em relação à presença ou ausência de células metastáticas ocultas na medula óssea. Neste estudo foram incluídas 37 pacientes de forma prospectiva, atendidas no Instituto Brasileiro de Controle do Câncer (IBCC) no período de junho de 2004 a julho de 2005, com diagnóstico histopatológico de carcinoma invasivo de mama, estádio clínico (EC) I (16,2%), II (51,4%) ou III (32,4%), segundo a classificação patológica. A idade mediana das pacientes foi 63 anos (41 a 90) e 62.2% delas encontravam-se na pós-menopausa, sendo que 24.3% relatava história familiar para câncer de mama. O tipo histológico predominante foi carcinoma ductal invasivo (89.2% dos casos), sendo, o restante, representado por carcinoma lobular invasivo (10.8%). Foram coletadas amostras de tumor primário de mama e de aspirado de medula óssea de cada paciente. A presença de células metastáticas ocultas (CMO) na medula óssea (MO) foi detectada através da expressão de citoqueratina 19 (CK19) pelo método de nested RT-PCR. A expressão relativa dos genes HP1Hsalfa, HP1Hsbeta e HP1Hsy foi determinada no tumor primário, usando-se a técnica de RT-PCR em tempo real. Presença de CMO foi detectada na MO de 20 pacientes (54.1%). Não observamos diferença na expressão de HP1Hs? (1,93 ± 2,25 MO- vs 3,84 ± 5,53 MO+), HP1Hs? (6,74 ± 6,31 MO- vs 6,49 ± 5,86 MO+) e HP1Hs? (24,58 ± 11,14 MO- vs 24,91 ± 15,88 MO+) entre as amostras tumorais de pacientes com presença (MO+) ou ausência (MO-) de micrometástase medular. Também não observamos variação da expressão de genes HP1 em relação ao comprometimento linfonodal, dimensão e grau histológico do tumor, expressão tumoral de receptores de estrógeno e estado menopausal da paciente. A expressão de HP1Hsalfa em tumores de pacientes com câncer de mama ERBB2 negativos, entretanto, foi maior do que em tumores ERBB2 positivos. Nossos dados indicam que em tumores de mama, a expressão de HP1Hsalfa, HP1Hsbeta e HP1Hsy não parece se associar à presença de células ocultas em medula óssea / Studies suggest that the presence of occult metastatic cells (OMC) in the bone marrow (BM) may be a prognostic factor in breast cancer. Besides, it is possible that a specific tumor gene profile, characterized by repression of gene expression, may be associated to the presence of tumoral cells in the bone marrow. Gene silencing is controlled by histone deacetylation and DNA methylation, the last one catalized by enzymes DNA methyltransferases (DNMTs). Histones are another target of methyltransferases, and methylation of histone H3 on lysine-9 generate a binding site for HP1 proteins (Heterocromatin protein-1 or chromobox). Members of the HP1 family (HP1Hsalfa, HP1Hsbeta e HP1Hsy) take part in heterochromatin formation and gene expression regulation. Hence, our aim was to determine in the primary tumor of the breast, the expression of HP1Hsalfa, HP1Hsbeta e HP1Hsy, which participate in gene repression, in the presence or absence of occult metastatic cells in the bone marrow. In this study, 37 patients treated at Instituto Brasileiro de Controle do Câncer, from June 2004 to July 2005, with invasive breast cancer histopathologically confirmed, pathological clinical stages I (16,2%), II (51,4%) or III (32,4), were included. The median age of the patients was 63 years (41 to 90), 62.2% were post-menopausal and 24.3% reported family history of breast cancer. Invasive ductal carcinoma was diagnosed in most patients (89.2%), and invasive lobular carcinoma was detected in the other patients (10.8%). Tumor samples and bone marrow aspirates were obtained from each patient. The presence of CMO in BM was detected by keratin-19 (CK19) expression by nested RT-PCR. The relative expression of the genes HP1Hsalfa, HP1Hsbeta e HP1Hsy was determined by real-time RT-PCR. Occult metastatic cells (OMC) in BM were detected in 20 patients (54.1%). No differences were observed in the expression of HP1Hs? (1,93 ± 2,25 BM- vs 3,84 ± 5,53 BM+), HP1Hsalfa (6,74 ± 6,31 BM- vs 6,49 ± 5,86 BM+) and HP1Hsbeta (24,58 ± 11,14 BM- vs 24,91 ± 15,88 BM+) between tumor samples of BM+ patients and BM- patients. Variations of HP1 gene expression were neither observed according to lymph node involvement, tumor size, histological grade, estrogen receptor status and menopausal status. However, HP1Hsbeta expression in ERBB2-negative tumors was higher than in ERBB2-positive tumors. Our data indicate that in breast cancer tumors, expression of HP1Hsalfa, HP1Hsbeta e HP1Hsy does not seem to be associated with the presence of occult metastatic cells in the bone marrow

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

Chan, Ho Yin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 263-283). / Abstracts in English and Chinese. / Examination Committee List --- p.i / Acknowledgements --- p.ii / Abstract --- p.iv / 摘要 --- p.vi / Table of Contents --- p.viii / List of Abbreviations --- p.xvii / List of Figures --- p.xx / List of Tables --- p.xxv / Chapter Chapter I --- Introduction --- p.1 / Chapter 1.1 --- SUMO (Small Ubiquitin-like Modifier) and SUMOylation --- p.1 / Chapter 1.1.1 --- "Ubiquitin, Ubiquitin-like proteins and SUMO isoforms" --- p.2 / Chapter 1.1.2 --- SUMO cycle --- p.5 / Chapter 1.1.2.1 --- SUMO conjugation consensus sequence --- p.5 / Chapter 1.1.2.2 --- SUMO maturation --- p.6 / Chapter 1.1.2.3 --- SUMO conjugation cascade --- p.7 / Chapter 1.1.2.4 --- SUMO deconjugation --- p.9 / Chapter 1.1.3 --- Mode of SUMO action --- p.12 / Chapter 1.1.4 --- Biological functions of SUMO --- p.13 / Chapter 1.1.4.1 --- SUMO in cancer --- p.14 / Chapter 1.2 --- Human cervical cancer and human papillomavirus (HPV) --- p.17 / Chapter 1.2.1 --- Infectious cycle of HPV-16 --- p.18 / Chapter 1.2.1.1 --- Viral entry --- p.18 / Chapter 1.2.1.2 --- Maintenance --- p.18 / Chapter 1.2.1.3 --- Deregulation of cell cycle --- p.19 / Chapter 1.2.1.4 --- Amplification and virion release --- p.20 / Chapter 1.2.2 --- Viral cancer induction --- p.22 / Chapter 1.2.2.1 --- Integration into the host genome --- p.22 / Chapter 1.2.2.2 --- Viral oncoproteins E6 and E7 --- p.23 / Chapter 1.2.3 --- SUMOylation and HPV --- p.24 / Chapter 1.2.3.1 --- Known examples of virus-host SUMOylation system interaction --- p.24 / Chapter 1.2.3.2 --- Other possible mode of virus-SUMO interaction --- p.26 / Chapter 1.3 --- A novel labeling method: biarsenical-tetracysteine labeling in SUMO study --- p.28 / Chapter 1.3.1 --- Potential use of 2As-4Cys system in SUMO studies --- p.31 / Chapter 1.3.2 --- Potential use of 2As-4Cys system in SUMO proteomics --- p.31 / Chapter 1.4 --- Objectives of the present study --- p.34 / Chapter Chapter II --- Proteomics investigation of SUMOylation in human cervical carcinoma cell line HeLa --- p.35 / INTRODUCTION --- p.35 / Chapter 2.1 --- MATERIALS --- p.37 / Chapter 2.1.1 --- Vectors for expression of SUMO and SUMOylation enzymes in E. coli --- p.37 / Chapter 2.1.2 --- E.coli cell strains --- p.38 / Chapter 2.1.3 --- Mammalian cell lines --- p.39 / Chapter 2.1.4 --- E.coli growth mediums --- p.40 / Chapter 2.1.5 --- Mammalian cell growth medium --- p.41 / Chapter 2.1.6 --- Reagents and buffers --- p.41 / Chapter 2.1.6.1 --- Reagents and buffers for molecular cloning --- p.41 / Chapter 2.1.6.2 --- Reagents and buffers for E.coli protein expression --- p.43 / Chapter 2.1.6.3 --- Reagents and buffers for mammalian cell culture --- p.44 / Chapter 2.1.6.4 --- Reagents and buffers for Western blot study --- p.45 / Chapter 2.1.7 --- Reagents and solutions for two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS) sample preparation --- p.46 / Chapter 2.1.7.1 --- Reagents and solutions for 2-DE --- p.46 / Chapter i. --- 2-DE sample preparation --- p.46 / Chapter ii. --- First dimensional gel electrophoresis -isoelectric focusing (IEF) --- p.46 / Chapter iii. --- Second dimensional gel electrophoresis -SDS-PAGE --- p.47 / Chapter iv. --- Silver staining --- p.47 / Chapter 2.1.7.2 --- Reagents and solutions for mass spectrometry sample preparation --- p.48 / Chapter i. --- Destaining of silver stained gel spots --- p.48 / Chapter ii. --- Trypsin digestion --- p.48 / Chapter iii. --- Peptide extraction --- p.48 / Chapter iv. --- Desalting and concentration of peptide mixture --- p.49 / Chapter 2.2 --- METHODS --- p.50 / Chapter 2.2.1 --- Molecular cloning of SUMO-1 into pET-28m and pHM6 vectors --- p.50 / Chapter 2.2.1.1 --- Design of primers for the cloning of SUMO-1 --- p.50 / Chapter 2.2.1.2 --- DNA amplification by polymerase chain reaction (PCR) --- p.51 / Chapter 2.2.1.3 --- DNA extraction from agarose gels --- p.52 / Chapter 2.2.1.4 --- Restriction digestion of vectors and purified PCR products --- p.54 / Chapter 2.2.1.5 --- Ligation of SUMO cDNA into expression vector pET-28m and pHM6 --- p.55 / Chapter 2.2.1.6 --- Preparation of competent cells --- p.56 / Chapter 2.2.1.7 --- Transformation of ligated mixture into competent DH5a --- p.56 / Chapter 2.2.1.8 --- Preparation of plasmid DNA --- p.57 / Chapter 2.2.1.8.1 --- Mini-preparation of plasmid DNA --- p.57 / Chapter 2.2.1.8.2 --- Midi-preparation of plasmid DNA --- p.58 / Chapter 2.2.1.8.3 --- DNA quantification and quality measurement --- p.60 / Chapter 2.2.2 --- "Expression of His6-tagged SUMO, ubc9, TDG, GST-tagged El and MBP-tagged Prdx 1 with E.coli" --- p.60 / Chapter 2.2.3 --- "Purification of His6-tagged SUMO, ubc9, TDG, GST-tagged El and MBP-tagged Prdx 1" --- p.62 / Chapter 2.2.3.1 --- Affinity chromatography --- p.65 / Chapter 2.2.3.1.1 --- Ni-NTA affinity chromatography --- p.65 / Chapter 2.2.3.1.2 --- Heparin affinity chromatography --- p.66 / Chapter 2.2.3.1.3 --- Glutathione affinity chromatography --- p.66 / Chapter 2.2.3.1.4 --- Amylose affinity chromatography --- p.67 / Chapter 2.2.3.2 --- Ion exchange chromatography --- p.68 / Chapter 2.2.3.2.1 --- Anion exchange chromatography --- p.68 / Chapter 2.2.3.2.2 --- Cation exchange chromatography --- p.68 / Chapter 2.2.3.3 --- Size exclusion chromatography --- p.69 / Chapter 2.2.3.4 --- Purification strategies --- p.70 / Chapter 2.2.3.4.1 --- Purification of His6-tagged SUMO --- p.70 / Chapter 2.2.3.4.2 --- Purification of His6-tagged TDG --- p.71 / Chapter 2.2.3.4.3 --- Purification of His6-tagged ubc9 --- p.72 / Chapter 2.2.3.4.4 --- Purification of GST-tagged El --- p.73 / Chapter 2.2.3.4.5 --- Purification of MBP-tagged Prdx 1 --- p.74 / Chapter 2.2.4 --- HeLa and C-33A cell culturing and protein extraction --- p.75 / Chapter 2.2.4.1 --- HeLa and C-33A cell culturing --- p.75 / Chapter 2.2.4.2 --- Protein extraction for in vitro SUMOylation assay --- p.76 / Chapter 2.2.5 --- Protein quantification with Bradford assay --- p.76 / Chapter 2.2.6 --- In vitro SUMO conjugation assay --- p.77 / Chapter 2.2.6.1 --- In vitro SUMO conjugation system optimization --- p.77 / Chapter 2.2.6.2 --- In vitro SUMO conjugation of HeLa cell extract --- p.78 / Chapter 2.2.7 --- Transient transfection of pHM6-SUMO-l into HeLa cells and protein extraction from HeLa cells --- p.79 / Chapter 2.2.7.1 --- Transfection with lipofection method --- p.79 / Chapter 2.2.7.2 --- Determination of transfection efficiency --- p.80 / Chapter 2.2.7.3 --- Whole cell protein extraction of transfected cells --- p.81 / Chapter 2.2.8 --- Protein quantification with BCA assay --- p.81 / Chapter 2.2.9 --- SDS-polyacrylamide gel electrophoresis (SDS-PAGE) --- p.83 / Chapter 2.2.10 --- Western blot analysis --- p.84 / Chapter 2.2.10.1 --- Electro-transfer blotting --- p.84 / Chapter 2.2.10.2 --- Immunoblotting with antibodies --- p.84 / Chapter 2.2.10.3 --- ECL detection --- p.85 / Chapter 2.2.10.4 --- Mild stripping for re-probing --- p.86 / Chapter 2.2.11 --- Two-dimensional gel electrophoresis (2-DE) --- p.86 / Chapter 2.2.11.1 --- Sample preparation --- p.86 / Chapter 2.2.11.2 --- First dimension gel electrophoresis -isoelectric focusing (IEF) --- p.87 / Chapter 2.2.11.3 --- Second dimension gel electrophoresis -SDS-PAGE --- p.88 / Chapter 2.2.11.3.1 --- Strip equilibration --- p.88 / Chapter 2.2.11.3.2 --- 16 x 18cm SDS-PAGE --- p.88 / Chapter 2.2.11.4 --- Visualization of proteins on SDS-polyacrylamide gel --- p.90 / Chapter 2.2.11.4.1 --- Silver staining --- p.90 / Chapter 2.2.11.4.2 --- Coomassie Blue® R250 staining --- p.91 / Chapter 2.2.12 --- Sample preparation for mass spectrometry analysis --- p.92 / Chapter 2.2.12.1 --- Destaining and trypsin digestion --- p.92 / Chapter 2.2.12.2 --- Extraction of peptide mixture --- p.93 / Chapter 2.2.12.3 --- Desalting and concentration of peptide mixture --- p.93 / Chapter 2.3 --- RESULTS --- p.95 / Chapter 2.3.1 --- Construction of recombinant pET-28m-SUMO-l and pHM6-SUMO-l --- p.95 / Chapter 2.3.2 --- "Purification of His6-tagged SUMO, ubc9, TDG and GST-tagged El" --- p.98 / Chapter 2.3.2.1 --- Purification of His6-SUMO --- p.98 / Chapter 2.3.2.2 --- Purification of His6-TDG --- p.101 / Chapter 2.3.2.3 --- Purification of His6-ubc9 --- p.104 / Chapter 2.3.2.4 --- Purification of GST-El --- p.106 / Chapter 2.3.3 --- In vitro SUMO conjugation assay --- p.108 / Chapter 2.3.3.1 --- Optimization of in vitro SUMO conjugation system --- p.108 / Chapter 2.3.3.2 --- In vitro SUMO conjugation of HeLa cell protein extract --- p.111 / Chapter 2.3.3.2.1 --- Protein extraction for in vitro sumoylation assay --- p.111 / Chapter 2.3.3.2.2 --- In vitro SUMOylation of HeLa cell lysate --- p.114 / Chapter 2.3.4 --- Differential proteomes of control and in vitro SUMOylated HeLa total cellular extract --- p.116 / Chapter 2.3.4.1 --- Mass spectrometric identification of differential protein candidates --- p.123 / Chapter 2.3.5 --- Overexpression of SUMO-1 in HeLa cells by transient transfection --- p.127 / Chapter 2.3.6 --- Differential proteomes of total cellular protein extract from control and SUMO-1 transfected HeLa cells --- p.128 / Chapter 2.3.6.1 --- Mass spectrometric identification of differential protein candidates --- p.132 / Chapter 2.4 --- Proteins identified in proteomic study with in vitro SUMOylation -Analysis of protein candidate --- p.133 / Chapter 2.4.1 --- Proteins identified from the in vitro investigation --- p.133 / Chapter 2.4.2 --- Verification of putative SUMO substrate Prdx 1 --- p.139 / Chapter 2.4.2.1 --- Purification of Prdx 1 --- p.139 / Chapter 2.4.2.2 --- In vitro SUMOylation of Prdx 1 --- p.142 / Chapter 2.4.3 --- Highlights of the proteins identified --- p.145 / Chapter 2.4.3.1 --- DJ-1 protein --- p.145 / Chapter 2.4.3.2 --- nm23A --- p.145 / Chapter 2.4.3.3 --- v-crk protein of CT10 --- p.146 / Chapter 2.4.3.4 --- Annexin I --- p.146 / Chapter 2.4.3.5 --- "Enolase 1, aldolase A, triosephosphate isomerase (TIM) and phosphoglycerate mutase 1" --- p.147 / Chapter 2.4.3.6 --- CyclophilinA(CypA) --- p.148 / Chapter 2.4.3.7 --- Stress induced phosphoprotein 1 (Stip 1) --- p.148 / Chapter 2.4.3.8 --- TSA and peroxiredoxin 1 (Prdx 1) --- p.149 / Chapter 2.5 --- Proteins identified in proteomic study with overexpression of SUMO-1 in HeLa cells -Analysis of protein candidate --- p.150 / Chapter 2.5.1 --- Proteins identified from the in vivo investigation --- p.150 / Chapter 2.5.2 --- Verification of upregulation of keratin 17 --- p.157 / Chapter 2.5.2.1 --- Immunoblotting against keratin 17 --- p.157 / Chapter 2.5.3 --- Highlights of the proteins identified --- p.159 / Chapter 2.5.3.1 --- "Heat shock proteins (Hsp 60, 70 and 27)" --- p.159 / Chapter 2.5.3.2 --- 14-3-3σ protein (SFN protein) --- p.161 / Chapter 2.5.3.3 --- PDZ-RGS3 --- p.162 / Chapter 2.5.3.4 --- "Keratins 8, 17" --- p.163 / Chapter 2.5.3.5 --- XIAP-1 --- p.164 / Chapter 2.5.3.6 --- ISG15 --- p.164 / Chapter 2.6 --- DISCUSSION --- p.166 / Chapter Chapter III --- Characterization of a novel fluorescent labeling method: Biarsencial-tetracysteine labeling in SUMO study --- p.182 / INTRODUCTION --- p.182 / Chapter 3.1 --- MATERIALS --- p.184 / Chapter 3.1.1 --- "Molecular cloning, protein expression and purification of pET-28m-4Cys 1 -SUMO-1 and pET-28m-4Cys2-SUMO-1" --- p.184 / Chapter 3.1.2 --- Mammalian cell culture and transient transfection of pHM6-4Cysl-SUMO-1 and pHM6-4Cys2-SUMO-l into HeLa cells --- p.184 / Chapter 3.1.3 --- Reagents and buffers --- p.184 / Chapter 3.1.3.1 --- Reagents and buffers for Lumio´ёØ in-gel labeling --- p.184 / Chapter 3.1.3.2 --- Reagents and buffers for Lumio´ёØ in cell labeling --- p.185 / Chapter 3.1.3.3 --- Reagents and buffers for immunostaining --- p.186 / Chapter 3.2 --- METHODS --- p.187 / Chapter 3.2.1 --- Molecular cloning of tetracysteine-tagged SUMO (4Cys-SUMO) into pET-28m and pHM6 vectors --- p.187 / Chapter 3.2.1.1 --- Design of primers and oligonucleotides encoding tetracysteine tag --- p.187 / Chapter 3.2.1.1.1 --- For 4Cysl-SUMO-1 --- p.187 / Chapter 3.2.1.1.2 --- For 4Cys2-SUMO-l --- p.188 / Chapter 3.2.1.2 --- DNA amplification of 4Cysl-SUMO-1 by Polymerase chain reaction (PCR) --- p.189 / Chapter 3.2.1.3 --- Restriction digestion of vectors and purified PCR products of 4Cysl-SUMO-1 --- p.191 / Chapter 3.2.1.4 --- Ligation of 4Cysl-SUMO into expression vector pET-28m and pHM6 --- p.191 / Chapter 3.2.1.5 --- Restriction digestion of pET-28m-SUMO and pHM6-SUMO for ligation with 4Cys2 oligos --- p.192 / Chapter 3.2.1.6 --- Ligation of 4Cys2 oligos to the digested pET-28m-SUMO and pHM6-SUMO plasmids --- p.193 / Chapter 3.2.1.6.1 --- Self-annealing of the 4Cys oligonucleotides --- p.193 / Chapter 3.2.1.6.2 --- Phosphorylation of ds 4Cys2 oligos and ligation to the plasmids --- p.193 / Chapter 3.2.2 --- Expression and purification of pET-28m-4Cys 1 -SUMO-1 and pET-28m-4Cys2-SUMO-1 in E.coli expression system --- p.195 / Chapter 3.2.3 --- Immunohistochemistry (IHC) staining of endogenous SUMO in HeLa cells --- p.196 / Chapter 3.2.4 --- In-cell labeling of 4Cysl/2-SUMO with Lumio´ёØ Reagent --- p.197 / Chapter 3.2.4.1 --- Preparation --- p.197 / Chapter 3.2.4.2 --- In-cell Lumio´ёØ labeling --- p.198 / Chapter 3.2.4.3 --- Detection and imaging of the labeled cells --- p.199 / Chapter 3.2.5 --- In-gel labeling of 4Cysl/2-SUMO with Lumio´ёØ Reagent --- p.199 / Chapter 3.2.5.1 --- Lumio´ёØ in-gel labeling --- p.199 / Chapter 3.2.5.2 --- Visualization and imaging of the labeled gel --- p.200 / Chapter a. --- UV illumination at 302 nm --- p.200 / Chapter b. --- Typhoon Trio TMLaser-scanning at 532 nm --- p.201 / Chapter 3.2.5.3 --- Detection limit of fluorescent 4Cys2-SUMO-l in SDS-PAGE --- p.201 / Chapter 3.2.5.4 --- In-gel labelling in two-dimensional electrophoresis (2-DE) --- p.202 / Chapter 3.2.5.4.1 --- Modification of equilibration buffer before SDS-PAGE --- p.202 / Chapter 3.3 --- RESULTS --- p.203 / Chapter 3.3.1 --- Adoption of old version of 4Cys-tag (4Cys 1) in SUMO study --- p.203 / Chapter 3.3.1.1 --- Construction of recombinant pET-28m-4Cys 1 -SUMO-1 and pHM6-4Cysl-SUMO-1 --- p.203 / Chapter 3.3.1.2 --- In vivo HA-4Cysl-SUMO-1 Lumio´ёØ labelling --- p.205 / Chapter 3.3.1.3 --- Immunohistochemistry (IHC) staining of endogenous SUMO in HeLa cells --- p.207 / Chapter 3.3.1.4 --- Expression and purification of His6-4Cysl-SUMO-1 --- p.208 / Chapter 3.3.1.5 --- Validation of 4Cys1-SUMO-1 conjugate by Lumio´ёØ in-gel labeling --- p.211 / Chapter 3.3.2 --- Adoption of a modified version of 4Cys-tag (4Cys2) in SUMO study --- p.213 / Chapter 3.3.2.1 --- Construction of recombinant pET-28m-4Cys2-SUMO-l and pHM6-4Cys2-SUMO-l --- p.213 / Chapter 3.3.2.2 --- In vivo HA-4Cys2-SUMO-l Lumio´ёØ labelling --- p.216 / Chapter 3.3.2.3 --- Expression and purification of His6-4Cys2-SUMO-1 --- p.219 / Chapter 3.3.2.4 --- Validation of 4Cys2-SUMO-l conjugate Lumio´ёØ in-gel labeling --- p.221 / Chapter 3.3.3 --- 2As-4Cys labeling in two-dimensional electrophoresis (2-DE) --- p.223 / Chapter 3.3.3.1 --- Detection limit of 4Cys2-SUMO-l in SDS-PAGE --- p.224 / Chapter 3.3.3.2 --- Lumio´ёØ labeling in 2-DE --- p.226 / Chapter 3.4 --- DISCUSSION --- p.232 / Chapter Chapter IV --- Conclusion and Future Perspectives --- p.242 / Chapter 4.1 --- Conclusion on proteomic study of SUMOylation --- p.242 / Chapter 4.2 --- Future perspectives of proteomic study of SUMOylation --- p.245 / Chapter 4.2.1 --- In vitro study --- p.245 / Chapter 4.2.2 --- In vivo study --- p.246 / Chapter 4.3 --- Conclusion of the investigation of biarsencial-tetracysteine (2As-4Cys) system application on SUMO study --- p.247 / Chapter 4.4 --- Future perspectives of the application of 2As-4Cys system application on SUMO study --- p.249 / Chapter 4.4.1 --- In cell study --- p.249 / Chapter 4.4.2 --- In gel study --- p.250 / Appendices --- p.251 / Chapter 1. --- Genotype of E.coli strains --- p.251 / Chapter 2. --- Vector maps --- p.252 / Chapter a. --- Vector map and MCS of pET-28a --- p.252 / Chapter b. --- Vector map and MCS of pHM6 --- p.253 / Chapter c. --- Vector information of pTwo-E --- p.254 / Chapter 3. --- Primers used in this study --- p.255 / Chapter 4. --- Nikon TE2000 filter sets spectrums --- p.257 / Chapter a. --- FITC/GFP filter set --- p.257 / Chapter b. --- RFP filter set --- p.257 / Chapter c. --- UV/DAPI/Hoechst filter set --- p.258 / Chapter 5. --- Akt signalling pathway diagram --- p.259 / Chapter 6. --- DNA sequence of SUMOs and 4Cys2 oligonucleotide --- p.260 / Chapter 7. --- Electrophoresis markers --- p.261 / References --- p.263

O carcinoma do córtex da supra-renal (ACC) é uma neoplasia rara e de prognóstico sombrio. Embora estudos moleculares tenham explorado diversos aspectos relacionados à tumorigênese destas neoplasias, o conhecimento das vias relacionadas à disseminação metastática é restrito. O objetivo do presente estudo é avaliar a expressão de genes relacionados a metástases em uma coorte de pacientes portadores de tumores do córtex da supra-renal metastáticos e não-metastáticos, a fim de identificar vias envolvidas na disseminação metastática destas neoplasias, novos marcadores prognósticos e eventuais alvos terapêuticos. Os perfis de expressão de 27 tumores do córtex da supra-renal de 15 pacientes adultos (8 ACC e 7 adenomas) e 12 pediátricos (5 metastáticos e 7 não-metastáticos) foram avaliados por um array de expressão contendo um painel de 113 genes que sabidamente estão envolvidos no processo de disseminação metastática de diversas neoplasias humanas. A análise de grupamentos mostrou que adenoma dos pacientes adultos forma um grupo distinto dos demais tumores (ACC de adultos e tumores pediátricos). Os genes MMP11e DENR foram identificados como diferencialmente expressos quando se compararam os adenomas e ACC de adultos. Na comparação dos tumores pediátricos nenhum gene foi diferencialmente expresso. Assim como a análise de grupamento, a PCA utilizando grupo selecionado de genes também não foi capaz partir os tumores pediátricos em subgrupos pela evolução. A expressão dos genes MMP2, TIMP3 e FN1 também foram avaliados por RT-PCR e foram concordantes com os dados gerados pelo array de expressão. O papel da LOH como causa da redução da expressão de TIMP3 foi estudado com tipagem de microssatélites. Em alguns casos, foi identificada LOH da região 22q13. Porém, em outros casos em que a expressão do TIMP3 foi bastante reduzida, não houve LOH. Em resumo, foram identificados aspectos moleculares importantes envolvidos na disseminação e metástases de neoplasias do córtex da supra-renal de adultos e crianças, bem como características biológicas deste processo. Diferentes padrões de expressão identificados em tumores metastáticos e não-metastáticos podem ajudar na predição do prognóstico / Adrenocortical carcinoma (ACC) is a rare neoplasm with a poor prognosis. Although molecular studies have uncovered many aspects of ACC tumorigenesis, little is known about molecular pathways involved in metastatic spread. The objective of our study is to analyze the expression profile of metastasis-related genes in a cohort of metastatic and nonmetastatic adrenocortical tumors in order to identify genes involved in the metastatic spread, as well as to find new prognostic markers. The expression profiles of 27 adrenocortical tumors from 15 adults (8 ACC and 7 adenomas) and 12 children (5 metastatic and 7 non-metastatic) were evaluated by an array of 113 known to be involved in human metastasis. Cluster analysis showed adult adrenocortical adenomas form a group distinct from other adrenocortical tumors (adult carcinomas and pediatric tumors). The comparison of adult adenoma and ACC revealed that MMP11 and DENR were differentially expressed between these two groups while no gene was differentially expressed among pediatric adrenocortical tumors. Similarly to cluster analysis, Principal component analysis failed to identify partition amongst pediatric tumors categorized by their evolution. The expression data of MMP2, TIMP3 and FN1 genes by RT-PCR agreed with those generated by the arrays. LOH of 22q12.3 region was detected in some cases in which TIMP3 down regulation was verified (but not in all cases). In conclusion, we have identified important aspects of molecular pathways and biological characteristics involved in metastatic spread of adrenocortical tumors. Distinctive patterns of gene expression between metastatic and nonmetastatic tumors may help in prognosis prediction

Estudos sugerem que a presença de células metastáticas ocultas em medula óssea pode ser fator prognóstico em câncer de mama. Além disso, é possível que um perfil gênico tumoral específico, caracterizado por repressão da expressão gênica, esteja associado à detecção de células tumorais na medula óssea. O silenciamento de genes é controlado pela desacetilação de histonas e metilação de DNA, esta última catalisada por enzimas DNA metil transferases. Outro alvo de metil-transferases são as histonas, e histona H3 quando sofre metilação em lisina 9, gera sítio de ligação a proteínas HP1 (Heterocromatin protein-1 ou cromobox). Membros da família HP1 (HP1Hsalfa, HP1Hsbeta e HP1HsY) participam da formação da heterocromatina e da regulação da expressão de genes. Logo, nosso objetivo foi determinar no tumor primário de mama, a expressão de HP1Hsalfa, HP1Hsbeta e HP1Hsy , que participam da repressão gênica, em relação à presença ou ausência de células metastáticas ocultas na medula óssea. Neste estudo foram incluídas 37 pacientes de forma prospectiva, atendidas no Instituto Brasileiro de Controle do Câncer (IBCC) no período de junho de 2004 a julho de 2005, com diagnóstico histopatológico de carcinoma invasivo de mama, estádio clínico (EC) I (16,2%), II (51,4%) ou III (32,4%), segundo a classificação patológica. A idade mediana das pacientes foi 63 anos (41 a 90) e 62.2% delas encontravam-se na pós-menopausa, sendo que 24.3% relatava história familiar para câncer de mama. O tipo histológico predominante foi carcinoma ductal invasivo (89.2% dos casos), sendo, o restante, representado por carcinoma lobular invasivo (10.8%). Foram coletadas amostras de tumor primário de mama e de aspirado de medula óssea de cada paciente. A presença de células metastáticas ocultas (CMO) na medula óssea (MO) foi detectada através da expressão de citoqueratina 19 (CK19) pelo método de nested RT-PCR. A expressão relativa dos genes HP1Hsalfa, HP1Hsbeta e HP1Hsy foi determinada no tumor primário, usando-se a técnica de RT-PCR em tempo real. Presença de CMO foi detectada na MO de 20 pacientes (54.1%). Não observamos diferença na expressão de HP1Hs? (1,93 ± 2,25 MO- vs 3,84 ± 5,53 MO+), HP1Hs? (6,74 ± 6,31 MO- vs 6,49 ± 5,86 MO+) e HP1Hs? (24,58 ± 11,14 MO- vs 24,91 ± 15,88 MO+) entre as amostras tumorais de pacientes com presença (MO+) ou ausência (MO-) de micrometástase medular. Também não observamos variação da expressão de genes HP1 em relação ao comprometimento linfonodal, dimensão e grau histológico do tumor, expressão tumoral de receptores de estrógeno e estado menopausal da paciente. A expressão de HP1Hsalfa em tumores de pacientes com câncer de mama ERBB2 negativos, entretanto, foi maior do que em tumores ERBB2 positivos. Nossos dados indicam que em tumores de mama, a expressão de HP1Hsalfa, HP1Hsbeta e HP1Hsy não parece se associar à presença de células ocultas em medula óssea / Studies suggest that the presence of occult metastatic cells (OMC) in the bone marrow (BM) may be a prognostic factor in breast cancer. Besides, it is possible that a specific tumor gene profile, characterized by repression of gene expression, may be associated to the presence of tumoral cells in the bone marrow. Gene silencing is controlled by histone deacetylation and DNA methylation, the last one catalized by enzymes DNA methyltransferases (DNMTs). Histones are another target of methyltransferases, and methylation of histone H3 on lysine-9 generate a binding site for HP1 proteins (Heterocromatin protein-1 or chromobox). Members of the HP1 family (HP1Hsalfa, HP1Hsbeta e HP1Hsy) take part in heterochromatin formation and gene expression regulation. Hence, our aim was to determine in the primary tumor of the breast, the expression of HP1Hsalfa, HP1Hsbeta e HP1Hsy, which participate in gene repression, in the presence or absence of occult metastatic cells in the bone marrow. In this study, 37 patients treated at Instituto Brasileiro de Controle do Câncer, from June 2004 to July 2005, with invasive breast cancer histopathologically confirmed, pathological clinical stages I (16,2%), II (51,4%) or III (32,4), were included. The median age of the patients was 63 years (41 to 90), 62.2% were post-menopausal and 24.3% reported family history of breast cancer. Invasive ductal carcinoma was diagnosed in most patients (89.2%), and invasive lobular carcinoma was detected in the other patients (10.8%). Tumor samples and bone marrow aspirates were obtained from each patient. The presence of CMO in BM was detected by keratin-19 (CK19) expression by nested RT-PCR. The relative expression of the genes HP1Hsalfa, HP1Hsbeta e HP1Hsy was determined by real-time RT-PCR. Occult metastatic cells (OMC) in BM were detected in 20 patients (54.1%). No differences were observed in the expression of HP1Hs? (1,93 ± 2,25 BM- vs 3,84 ± 5,53 BM+), HP1Hsalfa (6,74 ± 6,31 BM- vs 6,49 ± 5,86 BM+) and HP1Hsbeta (24,58 ± 11,14 BM- vs 24,91 ± 15,88 BM+) between tumor samples of BM+ patients and BM- patients. Variations of HP1 gene expression were neither observed according to lymph node involvement, tumor size, histological grade, estrogen receptor status and menopausal status. However, HP1Hsbeta expression in ERBB2-negative tumors was higher than in ERBB2-positive tumors. Our data indicate that in breast cancer tumors, expression of HP1Hsalfa, HP1Hsbeta e HP1Hsy does not seem to be associated with the presence of occult metastatic cells in the bone marrow