Anormalidades citogenéticas recorrentes são encontradas nas células tumorais de portadores de mieloma múltiplo. No momento do diagnóstico a t(4;14)(p16;q32) e a del(17p13) ocorrem em 10-20% e 5-10% dos casos, respectivamente, e são associadas à evolução clínica desfavorável. A del(13q14), por sua vez, ocorre em cerca de metade dos pacientes, porém não apresenta valor prognóstico importante. Entretanto, há evidências na literatura de que a del(13q14) seja um pré requisito para a expansão tumoral. O objetivo deste trabalho foi determinar a prevalência destas anormalidades cromossômicas em portadores de mieloma múltiplo recém diagnosticado e correlacioná-las com as taxas de proliferação e apoptose celular na medula óssea e a quantificação de plasmócitos em sangue. Amostras de aspirado de medula óssea provenientes de 84 portadores de mieloma múltiplo recém diagnosticado foram avaliadas quanto à presença de del(13q14), t(4;14)(p16;q32) e del(17p13) pela técnica de marcação fluorescente dos plasmócitos seguida pela hibridação in situ por fluorescência (cIg-FISH). Desta forma, foi realizada a correlação entre estas alterações e a quantificação de plasmócitos em sangue periférico, a proporção de plasmócitos positivos para o marcador de proliferação celular Ki-67 e para o marcador de apoptose anexina V, obtidos pela técnica de citometria de fluxo. Concomitantemente, foram avaliados parâmetros clínicos e laboratoriais e realizada a análise de sobrevida global (SG) e sobrevida livre de eventos (SLE). Os pacientes foram divididos em quatro grupos de acordo com a anormalidade citogenética presente: (1) grupo com t(4;14)(p16;q32), (2) grupo com del(17p13), (3) grupo com del(13q14) e sem nenhuma das outras alterações e (4) grupo sem nenhuma das anormalidades pesquisadas. Foi possível realizar a pesquisa de todas as anormalidades cromossômicas em 76 pacientes dos quais: vinte nove (38,1%) possuíam somente del(13q14), seis (7,89%) possuíam t(4;14)(p16;q32) e seis (7,89%) possuíam del(17p13). Não foi observada diferença estatisticamente significante entre os diferentes grupos de anormalidades citogenéticas quanto à mediana de expressão de Ki-67 em plasmócitos (p=0,7), a mediana de marcação dos plasmócitos com anexina V (p=0,94), a razão entre expressão de Ki-67 e marcação com anexina V (p=0,57) e a quantidade de plasmócitos em sangue periférico (p=0,07). Entretanto, observou-se tendência à correlação entre porcentagem de células acometidas pela del(13q14) e expressão de Ki-67 (p=0,06). A maior expressão de Ki-67 e a maior quantidade de plasmócitos circulantes se associaram a características clínicas e laboratoriais de mau prognóstico. Em análise multivariada somente níveis séricos elevados de desidrogenase lática (DHL) (p=0,002) se associaram à SLE e DHL elevado (p=0,013), a não realização de quimioterapia em altas doses com resgate de células tronco hematopoéticas (p=0,016), sistema de estadiamento internacional (ISS) III (p=0,001) e t(4;14)(p16;q32) (p=0,04) se associaram à pior SG / Recurrent cytogenetic abnormalities are found in multiple myeloma tumour cells. Among them, t(4;14)(p16;q32) e a del(17p13) occur respectively in 10-20% and 5-10% cases in the moment of diagnosis, and are associated with unfavorable clinical outcome. Del(13q14) occurs in half of patients, although, it has no important prognostic value. However, there are evidence in literature that del(13q14) is a pre requisite for tumour expansion. The purpose of this work was to determine the prevalence of chromosomal abnormalities in newly diagnosed multiple myeloma patients and correlate these abnormalities with the quantification of plasmocytes in blood and the rates of cellular proliferation and apoptosis. Bone marrow samples from eighty four newly diagnosed multiple myeloma patients were evaluated for the presence of del(13q14), t(4;14)(p16;q32) and del(17p13) by fluorescent in situ hybridization coupled to cytoplasmic staining of specific imunoglobulin (clg-FISH). Therefore, a correlation between these alterations and the proportion of plasmocytes positive for the proliferation antigen Ki-67 and for the apoptosis marker annexin V, measured by flow cytometry, was done. The quantification of plasmocytes in peripheral blood by flow cytometry was also made. Concurrently, clinical and laboratorial parameters, overall survival (OS) and event free survival (EFS) were also evaluated. Patients were divided in four groups accordingly to the cytogenetical abnormality present (1) t(4;14)(p16;q32), (2) del(17p13), (3) del(13q14) and none of the other alterations and (4) group with no researched abnormality. The research of all chromosomal abnormalities was possible in 76 patients: 29 (38,1%) had only del(13q14), six (7,89%) had t(4;14)(p16;q32) and six (7,89%) had del(17p13). No significant statistical difference was observed between different groups comparing the median expression of Ki-67 in plasmocytes (p=0,7), the median plasmocytes positive for annexin V (0,94), the ratio between Ki-67 and annexin V (p=0,57), and the quantity of plasmocytes in peripheral blood (p=0,07). However, there was a tendency for a correlation between proportion of cells with del(13q14) and Ki-67 expression (p=0,06). Higher Ki-67 expression and higher number of blood plasmocytes correlated to clinical and laboratorial features associated with unfavorable outcome. In multivariate analyses, only elevated lactate dehydrogenase (p=0,002) was associated to inferior EFS, and elevated lactate dehydrogenase (p=0,013), treatment without high dose chemotherapy with stem cell support (p=0,016), International Staging System III (p=0,001) and presence of t(4;14)(p16;q32) (p=0,04) were associated to inferior OS

Introdução: Os Centros de Referência (CR) são serviços especializados, parte de um projeto inovador de parceria entre a academia e os gestores do Sistema Único de Saúde (SUS). O principal objetivo de um CR é promover a assistência através de acompanhamento multidisciplinar, facilitando o acesso ao medicamento fornecido pelas Secretarias Estaduais de Saúde (SES). Objetivos: avaliar a efetividade da assistência de pacientes com Mieloma Múltiplo (MM) em um CR no âmbito do SUS (Centro de Referência para Mieloma Múltiplo do Hospital de Clínicas de Porto Alegre [CRMM-HCPA]); comparar a qualidade de vida entre portadores de MM atendidos no CRMM-HCPA e em outros serviços de saúde que não são CR. Metodologia: Foi realizado um estudo prospectivo de 6 meses, com participantes que recebiam a Talidomida pela SES-RS, e eram tratados pelo CRMM-HCPA, em comparação com os que recebiam tratamento em outras instituições, fora de um CR. Foram incluídos 32 participantes da pesquisa, sendo 19 do CRMM-HCPA e 13 participantes de outras instituições. Para análise da efetividade do CRMM-HCPA foi considerado como desfecho principal o tempo, a partir do diagnóstico, em que os participantes da pesquisa levaram para realização do Transplante Autólogo de Células Tronco Hematopoiéticas (TACTH), por ser considerado este a terapia “padrão ouro” para o MM. Para análise deste tempo, foram aplicados questionários específicos do estudo e para análise da qualidade de vida foi aplicado o questionário SF-36. Resultados: Na análise de qualidade de vida encontramos diferença significativa em relação ao item aspecto social (do SF-36), relacionado à realização de atividades sociais (P = 0,02). O tempo (em meses) a partir do diagnóstico até o transplante de medula óssea, em cada grupo, foi medido apenas em participantes da pesquisa com idade \65 anos (n=25), dos quais, nesta análise, 15 eram do HCPA e 10 das outras instituições. Encontramos diferença significativa (P=0,036) em relação ao tempo em que os participantes da pesquisa foram encaminhados para realizarem o transplante autólogo, demonstrando que os do CRMM (HCPA) são encaminhados para o transplante em tempo significativamente inferior (mediana: 9 meses; IIQ: 8,5 a 14,5) do que são atendidos nas demais instituições (mediana: 24 meses; IIQ: 16 a 24). Conclusões: Os participantes do CRMM demonstraram mais facilidade em executar atividades sociais, com menos interferências relacionadas a problemas físicos ou emocionais. O CRMM demonstrou ser uma estratégia de tratamento mais efetiva do que outros serviços de saúde do SUS, que não são CR, uma vez que permitiu uma redução do tempo para a realização do transplante. / Introduction:Within the Brazilian Unified Health System (SUS), Referral Centers (RCs) are care facilities that provide specialized services as part of an innovative partnership project between universities and SUS managers. The main goal of RCs is to promote care through a multidisciplinary approach, facilitating access to medicines supplied by state health departments (SHDs).Objectives:To evaluate the effectiveness of care provided to patients with multiple myeloma (MM) in a RC within SUS (Hospital de Clínicas de Porto Alegre Referral Center for Multiple Myeloma, CRMM-HCPA) and to compare quality of life between patients with MM treated at CRMM-HCPA and other non-RC health care facilities. Methods: A 6-month prospective cohort study was conducted in patients receiving thalidomide from the Rio Grande do Sul SHD (SHD-RS) and treated at CRMM-HCPA, as compared to patients receiving treatment at other non-RC health care facilities. Thirty-two patients were included in the study, 19 from CRMM-HCPA and 13 from other institutions. To analyze the effectiveness of CRMM-HCPA, the main outcome measure was the time from diagnosis to referral for autologous hematopoietic stem cell transplantation (HSCT), as this is considered the gold-standard treatment for MM. Time from diagnosis to referral for autologous HSCT was assessed using questionnaires specifically designed for this study, and quality of life was assessed using the SF-36 questionnaire. Results: On quality of life analysis, there was a significant difference in the “social functioning” domain of the SF-36 questionnaire, which relates to performance of social activities (P=0.02). The time (in months) from diagnosis to referral for autologous HSCT, in each group, was measured only in patients aged \65 years (n=25); of these, 15 were from CRMM-HCPA and 10 from other institutions. In this analysis, there was a significant difference (P=0.036) in time between diagnosis and referral for autologous HSCT, which was significantly shorter for patients treated at CRMM-HCPA (median, 9 months; IQR, 8.5–14.5) than for those treated elsewhere (median, 24 months; IQR, 16–24).Conclusions:Patients treated at CRMM-HCPA demonstrated greater ease in performing social activities, with less interference from physical or emotional problems. CRMM-HCPA offers a more effective treatment strategy as compared with other non-RC health care facilities, as it enabled a reduction in time to transplantation.

Multiple myeloma (MM) is a prevalent B-cell neoplasm that remains incurable with currently available chemotherapeutic drugs. Existing drug regimens result in initial disease remission but MM often relapses with an aggressive, drug resistant phenotype with uniform mortality. Bortezomib (BTZ, proteasome inhibitor) is a frontline anti-MM drug that is used for treatment of newly diagnosed and relapsed MM. However both intrinsic and acquired BTZ resistance is observed. Hence, gaining a mechanistic understanding of BTZ-resistance can provide novel targets to increase and restore BTZ cytotoxicity in MM. Studies show that BTZ-mediated proteasome inhibition generates oxidative stress therefore, BTZ resistance can be caused by an increase in cellular antioxidant capacity of MM cells. Antioxidants like superoxide dismutases (SODs), glutathione (GSH), and glutathione peroxidases (GPxs) can maintain cellular redox homeostasis and confer resistance to oxidative stress. Additionally, an increased glucose metabolism can assist in maintaining low reactive oxygen species (ROS) levels formed as by-products of endogenous or therapy induced oxidative stress. This led us to test the hypothesis that BTZ resistance in MM is linked to redox regulation via the antioxidant network and generation of reducing equivalents. Retrospective analysis of clinically annotated MM dataset shows a correlation between SOD1 gene expression, MM progression, and poor overall and event free survival. In a MM cell line model with intrinsic or acquired BTZ resistance, our results show a correlation between half maximal inhibitory concentration (IC50) of BTZ and CuZnSOD activity. Upon inhibition of CuZnSOD activity with a clinically approved drug, disulfiram (DSF, Antabuse), BTZ cytotoxicity was increased. Furthermore, enforced overexpression of CuZnSOD conferred BTZ resistance in an otherwise BTZ sensitive MM cell line. MM cell lines with differential intrinsic BTZ cytotoxicity displayed a correlation between BTZ IC50 and GSH levels as well as GPx-1 activity. Gene expression profiling data from patients showed that poor prognosis associates with increased glycolytic gene expression in MM. Also, MM cell lines with intrinsic resistance toward BTZ exhibited increased glucose uptake, increased mRNA expression and activity of glucose-6-phosphate dehydrogenase (G6PD) with increased cytotoxicity with glucose deprivation or 2-deoxyglucose (2-DG) treatment. In conclusion, our results provide a rationale for utilizing redox-based combination protocols of clinically approved drugs (i.e. DSF and 2-DG) with BTZ to improve MM therapy responses.

Le myélome multiple (MM) est un cancer hématologique qui se caractérise par une prolifération et une accumulation de cellules plasmocytaires malignes au niveau de la moelle osseuse (MO). Il représente 10% des hémopathies malignes et 2% de la mortalité par cancer dans le monde occidental. La principale conséquence de l’expansion plasmocytaire clonale médullaire est la sécrétion excessive d’une immunoglobuline (Ig) unique qui va être à l’origine du caractère multi-symptomatique de cette pathologie. Ainsi, les manifestations du MM se caractérisent par des lésions osseuses, une atteinte rénale, une anémie, une hypercalcémie et une immunodéficience humorale conduisant à des infections récidivantes. Son pronostic est mauvais avec une médiane de survie qui se situe entre cinq et sept ans sous chimiothérapie qui vise à éliminer les cellules plasmocytaires malignes.A partir de la lignée U266 de myélome, nous avons dérivé des clones résistants au bortézomib (R6). Grâce à une analyse par biopuces à ADN, nous avons identifié 160 gènes significativement régulés dans les cellules R6 par rapport à la lignée parentale U266. Nous avons établi, par une approche fonctionnelle, que la surexpression de la protéine HspB8 conduit, via l’activation de la dégradation autophagique, à l’élimination des agrégats protéiques et à compenser l’effet de l’inhibition du protéasome conférant ainsi la résistance des cellules de myélome aux inhibiteurs du protéasome.Dans un second temps, nous nous sommes intéressés à l’implication de la protéine Bcl-B (BCL2L10) dans la pathogenèse du MM. Nous avons confirmé que Bcl-B est impliqué dans la pathogénèse du MM (patients et modèle murin). / Velcade is one of the inescapable drug to treat patient suffering from multiple myeloma (MM) and resistance to this drug represents a major drawback for patients. However, the mechanisms underlying velcade resistance remain incompletely understood. We derived several U266 MM cell clones that resist to velcade. We derived several U266 MM cell clones that resist to velcade. U266- resistant cells were resistant to velcade-induced cell death but exhibited a similar sensitivity to various proapoptotic stimuli. Careful analysis of proteosomal subunits and proteasome enzymatic activities showed that neither the composition nor the activity of the proteasome was affected in velcade-resistant cells.In addition, pangenomic profiling of velcade-sensitive and resistant cells showed that the small heat shock protein HSPB8 was overexpressed in resistant cells. Finally, gain and loss of function experiment demonstrated that HSPB8 is a key factor for velcade resistance. In conclusion, HSPB8 plays an important role for the elimination of aggregates in velcade-resistant cells that contributes to their enhanced survival. Multiple myeloma (MM) evolves from a premalignant condition known as monoclonal gammopathy of undetermined significance (MGUS). However, the factors underlying the malignant transformation of plasmocytes in MM are not fully characterized. We report an MM phenotype in transgenic mice with Eμ-directed expression of the Bcl-B protein. With age, Eμ-bcl-b transgenic mice develop the characteristic features of human MM. In addition, this MM-like disease is serially transplantable, underlying the tumoral origin of plasmocytes.

Bibliography: leaves 86-103. Investigates the effect of zoledronic acid on myeloma cells and osteoblast-like cells to establish the molecular and cellular mechanisms responsible for the clinical effectiveness of bisphosphonates in the treatment of patients with myelomatosis. Concludes that zoledronic acid inhibits myelomatosis-induced osteolysis thorugh the mechanisms of myeloma cell death and proliferation and maturation of osteoblasts.

<p>Multiple myeloma (MM) is a hematological tumor of plasma blast/plasma cell origin heterogeneous with respect to the morphological differentiation stage of the tumor cells, genetic alterations and course of disease. A challenge in MM research is to overcome resistance to therapy, which inevitably arises. In this thesis, we have used different strategies to sensitize MM cells to apoptosis and explored possible mechanisms of apoptotic control by the insulin-like growth factor-1 receptor (IGF-1R) survival pathway.</p><p>mTOR is a key molecule in the regulation of translation activated by survival signaling pathways in MM. We demonstrate that the mTOR-inhibitor rapamycin alone induced apoptosis in primary MM cells. In addition, rapamycin sensitized MM cells to apoptosis induced by dexamethasone, a glucocorticoid frequently used in MM therapy. MM survival factors IGF-1 and IL-6 could neither restore phosphorylation of the mTOR target p70S6K, nor cell growth inhibited by rapamycin and dexamethasone.</p><p>To study the regulation of inhibitors of apoptosis (IAP), we induced apoptosis and cell cycle arrest with dexamethasone and simultaneously abrogated IGF-1R signaling using the antagonistic antibody αIR3 or the selective IGF-1R inhibitor picropodophyllin (PPP). Dexamethasone transiently up-regulated c-IAP2. The subsequent down-regulation of c-IAP2 and XIAP was associated with the onset of apoptosis. c-IAP2 and XIAP levels further decreased when enhancing dexamethasone-induced apoptosis using αIR3 or PPP indicating a role for IAPs in regulating resistance to apoptosis in MM.</p><p>Finally, we explored glycogen synthase kinase (GSK)3 as a possible pro-apoptotic molecule and its role in regulating sensitization to apoptosis. We show that inhibition of GSK3 counteracts growth inhibition induced by dexamethasone alone and in combinatorial treatments with inhibitors against PI 3-kinase, mitogen-activated protein kinase (MEK), mTOR and IGF-1R. CT99021 also reversed cell cycle arrest induced by LY294002 or rapamycin. Importantly, the GSK3 inhibitor CT99021 sustained viability in untreated and dexamethasone-treated primary MM cells.</p>

Multiple myeloma (MM) is a hematological tumor of plasma blast/plasma cell origin heterogeneous with respect to the morphological differentiation stage of the tumor cells, genetic alterations and course of disease. A challenge in MM research is to overcome resistance to therapy, which inevitably arises. In this thesis, we have used different strategies to sensitize MM cells to apoptosis and explored possible mechanisms of apoptotic control by the insulin-like growth factor-1 receptor (IGF-1R) survival pathway. mTOR is a key molecule in the regulation of translation activated by survival signaling pathways in MM. We demonstrate that the mTOR-inhibitor rapamycin alone induced apoptosis in primary MM cells. In addition, rapamycin sensitized MM cells to apoptosis induced by dexamethasone, a glucocorticoid frequently used in MM therapy. MM survival factors IGF-1 and IL-6 could neither restore phosphorylation of the mTOR target p70S6K, nor cell growth inhibited by rapamycin and dexamethasone. To study the regulation of inhibitors of apoptosis (IAP), we induced apoptosis and cell cycle arrest with dexamethasone and simultaneously abrogated IGF-1R signaling using the antagonistic antibody αIR3 or the selective IGF-1R inhibitor picropodophyllin (PPP). Dexamethasone transiently up-regulated c-IAP2. The subsequent down-regulation of c-IAP2 and XIAP was associated with the onset of apoptosis. c-IAP2 and XIAP levels further decreased when enhancing dexamethasone-induced apoptosis using αIR3 or PPP indicating a role for IAPs in regulating resistance to apoptosis in MM. Finally, we explored glycogen synthase kinase (GSK)3 as a possible pro-apoptotic molecule and its role in regulating sensitization to apoptosis. We show that inhibition of GSK3 counteracts growth inhibition induced by dexamethasone alone and in combinatorial treatments with inhibitors against PI 3-kinase, mitogen-activated protein kinase (MEK), mTOR and IGF-1R. CT99021 also reversed cell cycle arrest induced by LY294002 or rapamycin. Importantly, the GSK3 inhibitor CT99021 sustained viability in untreated and dexamethasone-treated primary MM cells.

Multiple myeloma (MM) is an incurable plasma cell malignancy. NK cells have demonstrated anti-MM activity in allogeneic transplants and donor lymphocyte infusions, and may provide a more effective therapy for MM. This work demonstrates cytotoxicity of NK-92 and KHYG-1 against MM cells in chromium release and flow cytometry cytotoxicity assays. At a 10:1 effector to target ratio, the cytotoxicity of NK cell lines against MM cells is 50-90%. Blocking NKp30 significantly reduces the cytotoxicity of NK-92 and KHYG-1, while blocking NKG2D and DNAM-1 only reduces the cytotoxicity of NK-92. Notably, NK-92 and KHYG-1 have shown preferential cytotoxicity against the clonogenic population, killing 89-99% in a methylcellulose cytotoxicity assay. Preliminary results in a xenograft bioluminescent mouse model show that NK-92, but not KHYG-1, reduces the tumor burden detected by bioluminescence imaging and bone marrow engraftment by flow cytometry. Therefore, NK cell lines may offer a more effective therapy for MM.

Multiple myeloma (MM) is an incurable plasma cell malignancy. NK cells have demonstrated anti-MM activity in allogeneic transplants and donor lymphocyte infusions, and may provide a more effective therapy for MM. This work demonstrates cytotoxicity of NK-92 and KHYG-1 against MM cells in chromium release and flow cytometry cytotoxicity assays. At a 10:1 effector to target ratio, the cytotoxicity of NK cell lines against MM cells is 50-90%. Blocking NKp30 significantly reduces the cytotoxicity of NK-92 and KHYG-1, while blocking NKG2D and DNAM-1 only reduces the cytotoxicity of NK-92. Notably, NK-92 and KHYG-1 have shown preferential cytotoxicity against the clonogenic population, killing 89-99% in a methylcellulose cytotoxicity assay. Preliminary results in a xenograft bioluminescent mouse model show that NK-92, but not KHYG-1, reduces the tumor burden detected by bioluminescence imaging and bone marrow engraftment by flow cytometry. Therefore, NK cell lines may offer a more effective therapy for MM.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2010. / Härtill 5 uppsatser.