B-cell chronic lymphocytic leukemia is the most common leukemia in the adult population of Western developed countries. In 2005, an estimated 9,730 adults in the United States will be diagnosed with B-CLL and an estimated 4,600 deaths will occur. B-CLL is a common heterogeneous malignant disease with variable outcome. B-CLL is divided into two groups based on whether somatic hypermutation is observed in the variable region of the immunoglobulin heavy-chain locus (IgVH). The two distinct groups are named mutated and unmutated. The B-CLL mutated group has a more favorable prognosis than the unmutated group. Gene expression profiling has been used successfully to decipher the biological and clinical diversity of many leukemias and lymphomas. Recently, other small RNAs (microRNAs) have been shown to be important in hematopoiesis. MicroRNAs are small 20-28 nucleotide RNAs that are believed to control many important cellular and developmental processes by posttranscriptional gene silencing, translational repression, and modulating epigenetic events. We are interested in whether microRNA expression correlates with the mutational status of IgVH. This study is significant in the following ways: (1) microRNAs may become surrogate markers for the mutational status of IgVH of B-CLL, which implies a more rapid diagnostic means as compared to the current practice, and (2) microRNAs, in the particular context of B-CLL, may play some significant roles in a gene regulatory network that is further responsible for chromosomal abnormalities found in B-CLL. This thesis presents a study comparing microRNA expression in mutated and unmutated B-CLL groups. Instead of using a genome-wide expression profiling strategy, we selected a specific set of microRNAs based on their chromosome locations and mRNA targets. Specifically, we chose the following eight microRNAs (with their chromosomal abnormalities): mir16-1 (deletion 13), let-7i (trisomy 12), mir196-2 (trisomy 12), mir26a-2 (trisomy 12), mir-34b (deletion 11), mir-125b (deletion 11), mir-181C (trisomy 19), mir-125a (trisomy 19). We used solution hybridization assays to monitor the expression of microRNAs. We successfully characterized the microRNA expression in twelve B-CLL patient samples (eight mutated and four unmutated). Among the eight microRNAs examined, three (mir196-2, mir-125a, mir-125b) are not expressed in the two B-CLL groups, four (mir16-1, mir26a-2, let-7i, mir-34b) have significant differences in expressions over the two groups, and one (mir-181c) has no significant difference in expressions over the two groups.

B-cell chronic lymphocytic leukemia is the most common leukemia in the adult population of Western developed countries. In 2005, an estimated 9,730 adults in the United States will be diagnosed with B-CLL and an estimated 4,600 deaths will occur. B-CLL is a common heterogeneous malignant disease with variable outcome. B-CLL is divided into two groups based on whether somatic hypermutation is observed in the variable region of the immunoglobulin heavy-chain locus (IgVH). The two distinct groups are named mutated and unmutated. The B-CLL mutated group has a more favorable prognosis than the unmutated group. Gene expression profiling has been used successfully to decipher the biological and clinical diversity of many leukemias and lymphomas. Recently, other small RNAs (microRNAs) have been shown to be important in hematopoiesis. MicroRNAs are small 20-28 nucleotide RNAs that are believed to control many important cellular and developmental processes by posttranscriptional gene silencing, translational repression, and modulating epigenetic events. We are interested in whether microRNA expression correlates with the mutational status of IgVH. This study is significant in the following ways: (1) microRNAs may become surrogate markers for the mutational status of IgVH of B-CLL, which implies a more rapid diagnostic means as compared to the current practice, and (2) microRNAs, in the particular context of B-CLL, may play some significant roles in a gene regulatory network that is further responsible for chromosomal abnormalities found in B-CLL. This thesis presents a study comparing microRNA expression in mutated and unmutated B-CLL groups. Instead of using a genome-wide expression profiling strategy, we selected a specific set of microRNAs based on their chromosome locations and mRNA targets. Specifically, we chose the following eight microRNAs (with their chromosomal abnormalities): mir16-1 (deletion 13), let-7i (trisomy 12), mir196-2 (trisomy 12), mir26a-2 (trisomy 12), mir-34b (deletion 11), mir-125b (deletion 11), mir-181C (trisomy 19), mir-125a (trisomy 19). We used solution hybridization assays to monitor the expression of microRNAs. We successfully characterized the microRNA expression in twelve B-CLL patient samples (eight mutated and four unmutated). Among the eight microRNAs examined, three (mir196-2, mir-125a, mir-125b) are not expressed in the two B-CLL groups, four (mir16-1, mir26a-2, let-7i, mir-34b) have significant differences in expressions over the two groups, and one (mir-181c) has no significant difference in expressions over the two groups.

As neoplasias mieloproliferativas (NMPs) BCR-ABL1 negativas compreendem a mielofibrose primária (PMF), trombocitemia essencial (TE) e a policitemia vera (PV). A patogênese e progressão dessas NMPs não estão completamente elucidadas. As metaloproteinases de matriz (MMPs) degradam a matriz extracelular, ativando citocinas e fatores de crescimento que, por sua vez, participam da tumorigênese e angiogênese. O objetivo deste estudo foi avaliar a relação da expressão gênica das MMPs, TIMPs, HIF1-&#945; e SPARC com os marcadores angiogênicos bFGF e VEGFA em pacientes com MF e TE, considerando o status mutacional; bem como avaliar a regulação desses genes em camundongos submetidos à hipóxia, e em modelos HIF1-&#945;(-/-) e VHL(-/-). Foram incluídos 21 pacientes com MF, 21 com MF pós-TE, 6 com MF pós-PV, 23 com TE e 78 indivíduos controle. As análises realizadas foram: dosagem sérica e expressão de RNAm de MMP2, MMP9, TIMP1, TIMP2 e SPARC, hemograma, determinação da proteína C reativa ultrassensível, determinação das concentrações de VEGFA e bFGF e avaliação das mutações nos genes JAK2, cMPL e CALR. A avaliação da densidade microvascular da medula óssea foi feita em 30 dos pacientes incluídos. Os pacientes com MFP, MFPTE e TE apresentaram maior expressão de MMP2, SPARC, TIMP1, TIMP2 e bFGF quando comparados aos seus controles (P<0,05), enquanto MMP9 foi mais expressa nos pacientes com MFPTE e TE (P= 0,011 e P=0,047, respectivamente). Os pacientes com TE apresentaram maior expressão de HIF1-&#945; e VEGFA em relação ao grupo controle (P<0,05). Pacientes com MF JAK2V617F positivos apresentaram maiores concentrações de MMP9, TIMP2, bFGF e VEGFA quando comparados aos pacientes portadores de mutações na CALR (P<0,05). Os pacientes com TE JAK2V617F positivos apresentaram maiores concentrações de MMP2 e TIMP2 (P=0,049 e P=0,020, respectivamente). As concentrações das proteínas estudadas não apresentaram correlação com a carga alélica de JAK2V617F e nem com a densidade microvascular da medula óssea. Células de medula óssea de camundongos submetidos à hipóxia apresentaram maior expressão de MMP2 e TIMP1 comparados aos camundongos em normóxia. Camundongos VHL(-/-) apresentaram aumento na expressão dos genes MMP2, MMP9, TIMP1, TIMP2 e VEGFA. Diferentemente, embriões HIF1-&#945;(-/-) não foram considerados um bom modelo para este estudo devido ao envolvimento das MMPs na embriogênese/organogênese. Frente aos resultados encontrados, pode-se sugerir que a maior expressão de MMP2, SPARC e de bFGF estão associadas às NMPs. A mutação JAK2V617F foi associada a maiores concentrações de MMPs, TIMP2 VEGFA e bFGF. HIF1-&#945; foi mais expresso na PV e na TE, sugerindo uma possível regulação da expressão das MMPs e TIMPs nessas doenças. / Myeloproliferative neoplasms (MPNs) BCR-ABL1-negative include primary myelofibrosis (PMF), essential thrombocythemia (ET) and polycythemia vera (PV). The mechanisms underlying the pathology and disease progression in MPN are not completely elucidated. The matrix metalloproteinases (MMPs) cleave extracellular matrix, activating cytokines and growth factors that, in turn, regulate tumorigenesis and angiogenesis. The aim of this study was to evaluate the relationship of MMPs, TIMPs, HIF1-&#945 and SPARC gene expression with angiogenic markers bFGF and VEGFA in patients with MPN considering their mutational status; as well as to assess the regulation of these genes in animal models HIF1-&#945 and VHL knockouts. Twenty-one MF, 21 MF post-ET, 6 MF post-PV, 23 ET patients and 78 controls were enrolled. The analysis performed in peripheral blood were: serum and mRNA expression of MMP2, MMP9, TIMP1, TIMP2 and SPARC, blood count, high-sensitivity C-reactive protein determination and VEGFA and bFGF measurements in plasma. We also evaluate mutations in JAK2, MPL and CALR. The assessment of microvascular density (MVD) in bone marrow was performed in 30 patients. Patients with MFP, MFPET and ET presented higher expression of MMP2, SPARC, TIMP1, TIMP2 and bFGF compared to their controls (P <0.05), while MMP9 expression was higher in patients with MFPET and ET (P=0.011 and P=0.047, respectively). Higher expression of HIF1-&#945; and VEGFA was found in ET patients compared to the controls (P <0.05). PMF JAK2V617F patients had higher concentrations of MMP9, TIMP2, bFGF and VEGFA compared to CALR mutated ones (P <0.05). ET patients JAK2V617F positive had higher levels of MMP2 and TIMP2 (P=0.049 and P=0.020, respectively). The JAK2V617F allele burden was not associated with MVD in the bone marrow. Bone marrow cells from mice in hypoxia condition showed higher MMP2 and TIMP1 expression compared to the control. VHL(-/-) mice exhibited increased expression of MMP2, MMP9, TIMP1, TIMP2 and VEGFA. In contrast, the HIF1-&#945;(-/-) embryos were not considered an applicable model for this study due to MMPs role in embryogenesis/organogenesis. In view of these findings, we can conclude that increased expression of MMP2, SPARC and bFGF are associated with MPN. The JAK2V617F mutation was associated with higher concentrations of MMPs, TIMP2 VEGFA and bFGF. HIF1-&#945; is upregulated in PV and ET and perhaps regulate the MMPs and TIMPs expression in these diseases.

As neoplasias mieloproliferativas (NMPs) BCR-ABL1 negativas compreendem a mielofibrose primária (PMF), trombocitemia essencial (TE) e a policitemia vera (PV). A patogênese e progressão dessas NMPs não estão completamente elucidadas. As metaloproteinases de matriz (MMPs) degradam a matriz extracelular, ativando citocinas e fatores de crescimento que, por sua vez, participam da tumorigênese e angiogênese. O objetivo deste estudo foi avaliar a relação da expressão gênica das MMPs, TIMPs, HIF1-&#945; e SPARC com os marcadores angiogênicos bFGF e VEGFA em pacientes com MF e TE, considerando o status mutacional; bem como avaliar a regulação desses genes em camundongos submetidos à hipóxia, e em modelos HIF1-&#945;(-/-) e VHL(-/-). Foram incluídos 21 pacientes com MF, 21 com MF pós-TE, 6 com MF pós-PV, 23 com TE e 78 indivíduos controle. As análises realizadas foram: dosagem sérica e expressão de RNAm de MMP2, MMP9, TIMP1, TIMP2 e SPARC, hemograma, determinação da proteína C reativa ultrassensível, determinação das concentrações de VEGFA e bFGF e avaliação das mutações nos genes JAK2, cMPL e CALR. A avaliação da densidade microvascular da medula óssea foi feita em 30 dos pacientes incluídos. Os pacientes com MFP, MFPTE e TE apresentaram maior expressão de MMP2, SPARC, TIMP1, TIMP2 e bFGF quando comparados aos seus controles (P<0,05), enquanto MMP9 foi mais expressa nos pacientes com MFPTE e TE (P= 0,011 e P=0,047, respectivamente). Os pacientes com TE apresentaram maior expressão de HIF1-&#945; e VEGFA em relação ao grupo controle (P<0,05). Pacientes com MF JAK2V617F positivos apresentaram maiores concentrações de MMP9, TIMP2, bFGF e VEGFA quando comparados aos pacientes portadores de mutações na CALR (P<0,05). Os pacientes com TE JAK2V617F positivos apresentaram maiores concentrações de MMP2 e TIMP2 (P=0,049 e P=0,020, respectivamente). As concentrações das proteínas estudadas não apresentaram correlação com a carga alélica de JAK2V617F e nem com a densidade microvascular da medula óssea. Células de medula óssea de camundongos submetidos à hipóxia apresentaram maior expressão de MMP2 e TIMP1 comparados aos camundongos em normóxia. Camundongos VHL(-/-) apresentaram aumento na expressão dos genes MMP2, MMP9, TIMP1, TIMP2 e VEGFA. Diferentemente, embriões HIF1-&#945;(-/-) não foram considerados um bom modelo para este estudo devido ao envolvimento das MMPs na embriogênese/organogênese. Frente aos resultados encontrados, pode-se sugerir que a maior expressão de MMP2, SPARC e de bFGF estão associadas às NMPs. A mutação JAK2V617F foi associada a maiores concentrações de MMPs, TIMP2 VEGFA e bFGF. HIF1-&#945; foi mais expresso na PV e na TE, sugerindo uma possível regulação da expressão das MMPs e TIMPs nessas doenças. / Myeloproliferative neoplasms (MPNs) BCR-ABL1-negative include primary myelofibrosis (PMF), essential thrombocythemia (ET) and polycythemia vera (PV). The mechanisms underlying the pathology and disease progression in MPN are not completely elucidated. The matrix metalloproteinases (MMPs) cleave extracellular matrix, activating cytokines and growth factors that, in turn, regulate tumorigenesis and angiogenesis. The aim of this study was to evaluate the relationship of MMPs, TIMPs, HIF1-&#945 and SPARC gene expression with angiogenic markers bFGF and VEGFA in patients with MPN considering their mutational status; as well as to assess the regulation of these genes in animal models HIF1-&#945 and VHL knockouts. Twenty-one MF, 21 MF post-ET, 6 MF post-PV, 23 ET patients and 78 controls were enrolled. The analysis performed in peripheral blood were: serum and mRNA expression of MMP2, MMP9, TIMP1, TIMP2 and SPARC, blood count, high-sensitivity C-reactive protein determination and VEGFA and bFGF measurements in plasma. We also evaluate mutations in JAK2, MPL and CALR. The assessment of microvascular density (MVD) in bone marrow was performed in 30 patients. Patients with MFP, MFPET and ET presented higher expression of MMP2, SPARC, TIMP1, TIMP2 and bFGF compared to their controls (P <0.05), while MMP9 expression was higher in patients with MFPET and ET (P=0.011 and P=0.047, respectively). Higher expression of HIF1-&#945; and VEGFA was found in ET patients compared to the controls (P <0.05). PMF JAK2V617F patients had higher concentrations of MMP9, TIMP2, bFGF and VEGFA compared to CALR mutated ones (P <0.05). ET patients JAK2V617F positive had higher levels of MMP2 and TIMP2 (P=0.049 and P=0.020, respectively). The JAK2V617F allele burden was not associated with MVD in the bone marrow. Bone marrow cells from mice in hypoxia condition showed higher MMP2 and TIMP1 expression compared to the control. VHL(-/-) mice exhibited increased expression of MMP2, MMP9, TIMP1, TIMP2 and VEGFA. In contrast, the HIF1-&#945;(-/-) embryos were not considered an applicable model for this study due to MMPs role in embryogenesis/organogenesis. In view of these findings, we can conclude that increased expression of MMP2, SPARC and bFGF are associated with MPN. The JAK2V617F mutation was associated with higher concentrations of MMPs, TIMP2 VEGFA and bFGF. HIF1-&#945; is upregulated in PV and ET and perhaps regulate the MMPs and TIMPs expression in these diseases.