Orientadores: André Deeke Sasse, Carmen Silvia Passos Lima / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-22T03:20:05Z (GMT). No. of bitstreams: 1 Scherr_AdolfoJosedeOliveira_M.pdf: 1501111 bytes, checksum: acf22564245404a459e366435fc5790b (MD5) Previous issue date: 2013 / Resumo: Pacientes com câncer renal localmente avançado são de alto risco para recidiva após ressecção cirúrgica com intuito curativo. Muitos estudos têm sido realizados na tentativa de se descobrir alguma intervenção adjuvante capaz de reduzir este risco. No entanto, até o momento não foi observado nenhum benefício clínico nas intervenções avaliadas nos estudos. O objetivo desta revisão sistemática foi avaliar o exato papel da terapia adjuvante nos pacientes com câncer renal localmente avançado após cirurgia. Foram selecionados estudos clínicos randomizados que comparavam terapia adjuvante (quimioterapia, vacinas, imunoterapia, bioquimioterapia, hormonioterapia) versus nenhum tratamento ativo após cirurgia em pacientes com câncer renal. Os desfechos clínicos avaliados foram sobrevida global (SG), sobrevida livre de doença (SLD) e toxicidades severas. A análise dos dados extraídos foi realizada no programa estatístico Review Manager 5.0 (RevMan 5; Cochrane Collaboration Software). As diferentes estratégias de tratamento adjuvante foram avaliadas em conjunto e separadamente. Dez estudos (2609 pacientes) foram incluídos. Terapia adjuvante não mostrou benefício em termos de SG (HR 1.07; IC95% 0.89 a 1.28; P = 0.48 I2= 0%) ou SLD (HR 0,96; IC95% 0.83 a 1.10; P =0.52 I2= 36%) quando comparado a nenhum tratamento adjuvante. Nenhuma análise de subgrupo (imunoterapia,vacinas, bioquimioterapia) atingiu resultado relevante. A avaliação de toxicidades mostrou uma frequencia significativamente maior de eventos adversos graves no grupo tratado (OR 73.86; IC 95% 28,32 a 192,62; P < 0,00001 I2 = 37%). O resultado final da análise não forneceu nenhum suporte para a hipótese de que os agentes estudados forneçam qualquer benefício clínico para pacientes com câncer renal no contexto adjuvante, além de aumentarem o risco de efeitos adversos graves. Estudos clínicos randomizados que avaliam o uso de terapias-alvo no cenário adjuvante estão em andamento e podem abrir uma nova fronteira terapêutica para estes pacientes. Até que os resultados destes estudos sejam conhecidos e se mostrem efetivos, nenhuma terapia adjuvante pode ser recomendada para pacientes com câncer de células renais após ressecção cirúrgica curativa / Abstract: Many adjuvant trials have been undertaken in an attempt to reduce the risk of recurrence among patients who undergo surgical resection for locally advanced renal cancer. However, no clear benefit has been identified to date. This systematic review was conducted to examine the exact role of adjuvant therapy in renal cancer setting. Randomized controlled trials were searched comparing adjuvant therapy (chemotherapy, vaccine, immunotherapy, biochemotherapy, hormone therapy) versus no active treatment after surgery among renal cell cancer patients. Clinical outcomes were overall survival (OS), disease-free survival (DFS), and severe toxicities. The extracted data was performed using the statistical software Review Manager 5.0 (RevMan 5; Cochrane Collaboration Software).Different strategies of adjuvant treatment were evaluated together and separately. Ten studies (2,609 patients) were included. Adjuvant therapy provided no benefits in terms of OS (HR 1.07; 95%CI 0.89 to 1.28; P = 0.48 I2 = 0%) or DFS (HR 0,96; CI 95% 0.83 to 1.10; P =0.52 I2 = 36%) when compared to no treatment. No subgroup analysis (immunotherapy, vaccines, biochemotherapy) had relevant results. Toxicity evaluation depicted a significantly higher frequency of serious adverse events in the adjuvant group(OR 73.86; CI 95% 28,32to 192,62; P < 0,00001 I2 = 37%).The result of the analysis provided no support for the hypothesis that the agents studied provide any clinical benefit for renal cancer patients in the adjuvant setting, in addition to increasing the risk of serious adverse events. Randomized trials are underway to test targeted therapies in adjuvant setting, which might open a new therapeutic frontier for these patients. Until these trials yield results, no adjuvant therapy can be recommended for patients who undergo surgical curative resection for renal cell cancer / Mestrado / Clinica Medica / Mestre em Clinica Medica

Introdução: o câncer de rim corresponde a aproximadamente 3% de todos os casos novos de câncer no mundo, sendo o carcinoma de células renais o tipo histológico mais frequente nos Estados Unidos da América, correspondendo a 85% das neoplasias renais malignas. A nefrectomia é o tratamento cirúrgico padrão para os pacientes diagnosticados com neoplasias renais e pode ser utilizada de forma radical ou parcial, dependendo do tamanho e localização do tumor. Alguns estudos recentes têm tentado demonstrar que diferenças no acesso ao tratamento entre pacientes com classes socioeconômicas díspares podem agravar a evolução da doença e até mesmo a sobrevida de pacientes menos favorecidos. No entanto esses dados ainda são controversos e não existem números concretos definindo qual a influência real da classe socioeconômica na evolução dos pacientes com neoplasias renais. Objetivos: 1) Verificar as chances de recorrência da neoplasia e mortalidade câncer-específica dos pacientes tratados cirurgicamente com carcinoma de células renais em instituições com perfis de pacientes socioeconômico diferentes, sendo uma pública, que atende pacientes com níveis socioeconômicos inferiores e outra privada, que atende pacientes com níveis socioeconômicos mais elevados. 2) Verificar também as características da neoplasia e as formas de tratamento de pacientes tratados em instituições públicas e privadas, supostamente influenciadas pelos diferentes níveis socioeconômicos. Métodos: foi realizado estudo retrospectivo não controlado com 398 pacientes portadores de neoplasia de rim, que foram tratados com nefrectomia radical ou parcial e acompanhados por pelo menos 5 anos. Os pacientes foram divididos em dois grupos de acordo com as instituições nas quais foram submetidos ao tratamento, sendo 300 pacientes de instituição pública (ICESP) e 98 pacientes de instituição privada (Hospital SírioLibanês). Foram realizadas comparações entre os dois grupos, incluindo as seguintes variáveis: recorrência local tumoral, mortalidade câncer-específica, dados demográficos como sexo, tipo de cirurgia realizada e aspectos anátomo-clínicos como estadiamento tumoral, tipo histológico, grau de Fuhrman e tamanho do tumor. Resultados: o tipo de cirurgia, tanto nefrectomia radical como parcial, realizada em ambas as instituições foi numericamente semelhante (p = 0,782). No que tange ao tipo histológico, houve diferença estatística significativa entre os grupos, sendo que, em ambas as instituições houve predominância do carcinoma de células claras, entretanto, com número mais elevado na instituição pública do que na instituição privada, respectivamente, 83,0% e 56,1%, observando-se, contudo, maior prevalência de tumores com componente sarcomatoide na instituição privada (6,1% versus 1%, p < 0,001). Em relação ao estágio patológico da neoplasia houve uma maior frequência de casos avançados pT3-pT4 na instituição pública, comparada à privada, respectivamente, 26,0% e 14,3% (p < 0,001). O grau de Fuhrman e o volume tumoral foram mais elevados nos pacientes submetidos ao tratamento na instituição pública, quando comparada à privada, respectivamente, 28,0% versus 24% em relação ao grau de Fuhrman (p = 0,048) e 6,7 cm versus 5,8 cm em relação ao volume tumoral (p = 0,016). Com respeito a mortalidade câncerespecífica (públicas 10,4% versus privadas 8,2%, p = 0,4250) e recorrência tumoral (públicas 15,0% versus privadas 11,2%, p = 0,304), os resultados foram semelhantes nas duas instituições estudadas. Conclusões: os riscos de recorrência tumoral e mortalidade câncer-específica foram semelhantes em pacientes tratados em instituição pública e privada no Brasil, indicando que diferentes níveis socioeconômicos não influenciam a evolução oncológica de pacientes com câncer renal localizado tratados cirurgicamente. Os resultados do presente estudo demonstraram também que pacientes tratados em instituição pública e possivelmente de nível socioeconômico mais baixo, são diagnosticados com carcinoma de células renais mais avançado, quando comparados aos pacientes tratados em hospital privado, supostamente de nível socioeconômico mais alto / Introduction: kidney cancer corresponds to approximately 3% of all new cancer cases in the world, and kidney cell carcinoma being the most frequent histological type in the United States of America, corresponding to 85% of the malignant kidney cancer. More than 60% of kidney tumors have been incidentally diagnosed between the sixth and seventh decade of life with predominance for the male gender, and the proportion of patients under 65 had varied in the last few years. Nephrectomy has been the standard surgical treatment for patients diagnosed with kidney cancer, and it can be used in a radical or partial manner, depending on the size and the location of the tumor. Some worldwide studies have attempted to demonstrate that differences in the access to the treatment among different socioeconomic classes can contribute to the outcome of the disease, leading to a worse survival rate of the less privileged patients. However, studies are still controversial, and in fact there is no firm knowledge as to the real influence of the socioeconomic class in the evolution of patients affected by kidney cancer. Objectives: 1) to evaluate the chances of local disease local recurrence and cancer specific mortality of the patients with renal cancer treated surgically in institutions with different socioeconomic patients\' profile, one public institution attending lower socioeconomic levels, and another private taking care of higher socioeconomic level patients. 2) In addition we evaluated disease characteristics and forms of treatment of patients dealt with in both public and private institutions. Methods: a non-controlled retrospective study was carried out involving 398 patients treated with radical or partial nephrectomy for kidney cancer treatment. All patients were followed for at least 5 years and were divided in two groups in accordance with the institutions where treatment was provided, 300 of whom in a public institution and 98 in a private one. Comparisons between the two groups included the following data: tumor recurrence, cancer-specific mortality, sex, type of surgery performed, tumor staging, histologic type, Fuhrman grade and size of the tumor. Results: The type of surgery performed in both institutions was similar, showing no statistical difference (p = 0.782). Regarding the histological type, there was a statistically significant difference between the groups, and in both institutions there was a predominance of clear cell carcinoma, however, with a higher number in the public institution than in the private institution, respectively, 83.0% and 56.1%. Sarcomatoid features were prevalent in the private institution (6,1% versus 1%, p < 0,001). There was a higher frequency of pT3-pT4 advanced cases in the public institution, compared to the private one, respectively, 26.0% and 14.3% (p < 0.001). Fuhrman grade and tumor volume were higher in patients submitted to treatment at the public institution and in both variables there was a significant statistical difference (tumor grade, respectively, 28.0% and 20.4%, p = 0.048 and tumor volume, respectively, 6.7 cm and 5.8 cm, p = 0.016). In relation to cancer-specific mortality (public 10.4% and private 8.2%, p = 0.4250) and tumor recurrence (public 15.0% and private 11.2%, p = 0.304), the results were similar in the two studied institutions. Conclusions: the risks of tumor recurrence and cancer specific mortality were similar in patients treated in a public and private institution in Brazil. The results of the present study also demonstrated that patients treated at a public institution and possibly of a lower socioeconomic level are diagnosed with higher volume renal cell carcinoma and with a more advanced nuclear grade when compared to patients treated at a private hospital, supposedly of a higher socioeconomic level

The von Hippel-Lindau (VHL) disease is a hereditary cancer syndrome that is transmitted in an autosomal dominant manner. The disease is characterized by the formation of highly angiogenic tumors in many organs but the main causes of mortality are renal cell carcinomas and hemangioblastomas. Mutations in the VHL protein are responsible for the pathogenesis of the disease. VHL associates with elongin Band C to form the VBC complex. The cullin 2 protein (CUL2) and ring box protein 1 (RBX1) also associate with the VBC complex to form an E3 ubiquitin ligase involved in the ubiquitination and subsequent degradation of the hypoxia inducible transcription factor (HIF2alpha). Mutations in VHL that abrogate its E3 ligase activity lead to increased levels ofHIF2alpha and the subsequent accumulation of pro-proliferative and pro-angiogenic HIF2alpha target genes. VHL also has an important function in the regulation of extracellular matrix (ECM) assembly which is independent of its HIF2alpha regulation pathway. VHL's regulation of ECM assembly was shown to have important consequences for tumor angiogenesis and cell invasion. It was shown to be necessary for the proper assembly of a fibronectin matrix and was most recently found to interact with collagen IV alpha 2 (COL4A2). The aim of this thesis is to further characterize the VHL-COL4A2 interaction. VHL was shown to interact directly and specifically to COL4A2 and is necessary for proper COL4A2 matrix assembly. The association of VHL with COL4A2 appears to be independent of its functions as an E3 ubiquitn ligase and CUL2 was identified as part of the VBC complex that associates with collagen IV (COL4). Furthermore, a strategy to identify the binding site of VHL on COL4A2 has been employed and is in progress. These experiments represent the beginning of investigations into the novel interaction between VHL and COL4A2.

Diss. (sammanfattning) Umeå : Univ., 2006. / Härtill 5 uppsatser.

Thesis (Ph.D. in Human Medical Genetics) -- University of Colorado Denver, 2007. / Typescript. Includes bibliographical references (leaves 117-126). Free to UCD affiliates. Online version available via ProQuest Digital Dissertations;

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Objetivou-se descrever os padrões de sinal nos exames de ressonância magnética (RM) dos carcinomas de células renais (CCR) de células claras e papilares tipos 1 e 2, correlacionando-os com os achados histopatológicos, bem como avaliar o realce dos tumores após a administração intravenosa do meio de contraste paramagnético. Pesquisa no banco de dados da patologia nos últimos 5 anos identificou 49 CCR avaliados com imagens por ressonância magnética (RM), dos quais 37 (17 CCR papilares tipo 1, 4 CCR papilares tipo 2 e 16 CCR de células claras) tinham espécimes patológica disponíveis para avaliação. A intensidade do sinal (IS) dos CCR comparados ao córtex renal, qualitativamente e quantitativamente (IS do tumor/IS do córtex renal x 100), nas imagens por RM ponderadas em T1 e T2, assim como o realce do tumor (qualitativamente e quantitativamente) foram avaliados por 2 radiologistas independentes. Um patologista avaliou as características das células tumorais e achados associados como a presença de hemosiderina, ferritina, sangue fresco, necrose, fibrose e calcificação. Os três subtipos de CCR avaliados tinham padrão diverso nas imagens ponderadas em T1 (p>0.05). Na análise qualitativa das imagens ponderadas em T2, o hiposinal foi observado predominantemente nos CCR papilares tipos 1 e 2, e hipersinal apenas identificado entre os CCR de células claras (p<0.05); dado confirmado na avaliação quantitativa da IS dos tumores (CCR papilares tipo 1: 71% ±16%, CCR papilares tipo 2: 54% ±23% e CCR de células claras: 141% ±44%) (p<0.01). Nas imagens ponderadas em T2, uma IS do tumor de 96% ou menos teve uma sensibilidade de 96% e especificidade de 89% para CCR papilar quando comparado com CCR de células claras e uma IS de 66% ou menos teve uma sensibilidade de 54% e especificidade de 100%. A arquitetura tumoral predominante (papilar para os tumores com hiposinal e em ninho para os tumores com hipersinal) foi o único achado histopatológico que se correlacionou com a IS nas imagens por RM ponderadas em T2 (p<0.05). A maioria dos CCR de células claras apresentou um realce heterogêneo enquanto os CCR papilares tipos 1 e 2 apresentaram um realce variado. Os CCR papilares tipos 1 e 2 realçaram menos do que os CCR de células claras em todas as fases após administração do meio de contraste, sendo essa diferença estatisticamente significativa nas fases córtico-medular e nefrográficas precoce e tardia. Em conclusão, nas imagens ponderadas em T2, o hiposinal foi observado predominantemente nos CCR papilares tipos 1 e 2, e hipersinal apenas identificado entre os CCR de células claras. Houve correlação entre a IS dos tumores e a arquitetura tumoral predominante, papilar para os tumores com hiposinal em T2 e em ninho para os tumores com hipersinal em T2. Os CCR de células claras tiveram um realce mensurado maior que os CCR papilares. / The purpose of this study is to describe magnetic resonance imaging (MRI) tumor signal intensity (SI) of clear cell, and types 1 and 2 papillary renal cell carcinomas (RCC), correlating with histopathologic findings, as well as to evaluate tumor enhancement after intravenous administration of paramagnetic contrast. A query on our pathology database for the past 5 years identified 49 RCC, which were evaluated with MRI. Of these, 37 (17 papillary type 1, 4 papillary type 2, and 16 clear cell) pathology specimens were available for review. Two independent radiologists assessed tumor SI compared to renal cortex, both qualitatively and quantitatively (tumor SI/renal cortex SI x 100), on T1 and T2 weighted MRI, as well as tumor enhancement. A pathologist evaluated tumor cell characteristics and associated findings, such as the presence of hemosiderin, ferritin, fresh blood, necrosis, fibrosis, and calcification. T1 tumor SI varied among RCC subtypes. On T2-weighted images, most types 1 and 2 papillary RCC had hypo signal, whereas hyper signal was only seen among clear cell RCC (p<0.05); which was confirmed with a quantitative assessment (type 1 papillary RCC= 71% ±16%, type 2 papillary RCC= 54% ±23%, and clear cell RCC= 141% ±44%, p<0.01). Tumor T2 SI of 96% or less had a sensitivity of 96% and specificity of 89% for papillary RCC, when compared to clear cell RCC; and tumor SI of 66.2% or less had a sensitivity of 54% and specificity of 100%. Tumor predominant architecture, papillary for tumors with hypo signal and nested for tumors with hyper signal, was the only histopathologic finding to correlate with tumor SI on T2 weighted MRI (p<0.05). Most clear cell RCC had a heterogeneous enhancement, and there was no typical enhancement pattern for both type 1 and type 2 papillary RCC. Types 1 and 2 papillary RCC enhanced less than clear cell RCC on all phases and this difference was statistically significant in the cortico-medullary, as well as early and late nephrographic phases. In summary, on T2-weighted images, most types 1 and 2 papillary RCC had hypo signal, whereas hyper signal was only seen among clear cell RCC. On T1 tumor SI varied among RCC subtypes. There was correlation between tumor predominant architecture and SI on T2 weighted images, papillary for hypo signal and nested for high signal tumors. Clear cell RCC enhanced more than papillary RCC.

INTRODUÇÃO: A nefrectomia radical está associada com algum grau de comprometimento da função do rim remanescente em pacientes com câncer renal. A etiologia da insuficiência renal crônica (IRC) nesses casos é complexa, tem prevalência relativamente alta e existem poucas alternativas terapêuticas quando ela se estabelece. Métodos que permitem prever o aparecimento desse quadro e possibilitem condutas terapêuticas que minimizem e retardem a perda de função renal são altamente desejáveis. OBJETIVOS: Em pacientes submetidos à nefrectomia radical: 1. Objetivo primário: Avaliar o impacto de alterações do parênquima renal não neoplásico, dados demográficos, clínicos e laboratoriais sobre o desenvolvimento de insuficiência renal crônica. 2. Objetivo secundário: Correlacionar alterações do parênquima renal não neoplásico, dados demográficos, clínicos e laboratoriais com a variação da taxa de filtração glomerular estimada pré e pós-operatória. MÉTODOS: Foram selecionados 65 pacientes submetidos à nefrectomia radical por quadros de carcinoma de células renais. Nesses casos, procedeu-se a análise histológica do parênquima renal não neoplásico e as alterações encontradas foram correlacionadas com o aparecimento subsequente de IRC. Para avaliação da função renal, foi utilizada a taxa de filtração glomerular estimada (TFGe) por meio da fórmula MDRD (Modification of Diet in Renal Disease) pré-operatória e última consulta. O estado do parênquima renal não neoplásico foi avaliado por meio de parâmetros histológicos: 1. Presença de glomerulosclerose, calculada pelo número total de glomérulos escleróticos dividido pelo número total de glomérulos avaliados, e expressa em porcentagem e presença de glomérulos hialinizados; 2. Alterações vasculares com a presença de arteriolosclerose. A extensão da oclusão arterial foi quantificada em três grupos: menos de 25%, 26% a 50% e acima de 50%. 3. Presença de fibrose intersticial e atrofia tubular. O impacto destas alterações no comportamento da função renal foi avaliado por meio do desenvolvimento IRC, definida com uma TFGe menor que 60ml/minuto/1,73m2 na avaliação mais recente e de acordo com os protocolos do Kidney Disease Outcomes Quality Initiative. RESULTADOS: Após um seguimento médio de 49,06 meses, foi observado uma queda média de 26,52% na função renal nos pacientes submetidos à nefrectomia radical. Trinta e cinco dos 65 pacientes evoluíram para IRC. Em uma análise univariada, presença de glomerulosclerose (OR=3,8), arteriosclerose (OR=3.3), fibrose intersticial (OR=3.8), hipertensão arterial (OR=3.7), Diabetes Mellitus (OR=11.6) e idade maior que 60 anos (OR=3.4) associaram-se à evolução para IRC (p < 0.05). Em uma regressão logística multivariada, índice de comorbidade de Charlson (OR= 2,3), GS (OR= 1,2) e TFGe pré-operatória (OR= 0,96) foram estatisticamente significantes. Para cada 2,5% de aumento de alterações glomérulos, houve uma diminuição percentual de 28% da TFGe. CONCLUSÕES: Alterações histológicas do parênquima renal não neoplásico e parâmetros clínicos podem ser utilizados para predizer pacientes que evoluirão para IRC após uma nefrectomia radical / INTRODUCTION: Radical nephrectomy is inevitably associated with a variable renal function decrease. Chronic Kidney disease (CKD) is highly prevalent and there are few options for treatment in end stage CKD. The goal, as urologist, should be on optimizing renal function after surgery and not just avoiding dialysis. OBJECTIVES: In patients submitted to radical nephrectomy: 1. Primary objective: Assess the association of histopathological parameters in non-neoplastic renal parenchyma with new onset chronic kidney disease after surgery. 2. Secondary objective: Assess the association of demographic and clinical parameters with new onset chronic kidney disease after surgery. METHODS: Data were extracted from 65 patients who underwent radical nephrectomy. Using The MDRD (Modification of Diet in Renal Disease) formula, we calculated the estimated glomerular filtration rate preoperatively and at last follow-up. The study end point was development of CKD, defined as an estimated glomerular filtration rate (eGFR) of less than 60ml/minute/1,73m2. A renal pathologist assessed three histological features in the nonneoplastic parenchyma, including global glomerulosclerosis, arteriosclerosis, interstitial fibrosis and tubular atrophy. For glomerulosclerosis assessment, the percent of affected glomeruli was determined. Arteriosclerosis or the extent of arterial luminal occlusion was graded into three groups, including 1-0% to 25%, 2-26% to 50% and 3-greater than 50%. Interstitial fibrosis and tubular atrophy were evaluated as absent/present. RESULTS: After a mean follow-up of 49,06 months, the eGFR rate decreased 26,52% after radical nephrectomy. Thirty five patients developed CKD. In a univariate analysis, the incidence of CKD was associated with glomerulosclerosis (OR=3,8), interstitial fibrosis (OR=3,8), arteriosclerosis (OR=3,3), hypertension (OR=3,7), Diabetes Mellitus (OR=11,6) and age (OR=3,4) after surgery. In a multivariate analysis, Charlson comorbidity index (OR= 2,3), glomerulosclerosis (OR= 1,2) and baseline eGFR(OR= 0,96) were associated with new onset CKD after radical nephrectomy. For each 2,5% increase in glomerular abnormality the eGFR rate decreased 28% from baseline. CONCLUSIONS: Histologic findings in the nonneoplasic tissue, in addition to clinical parameters, can be used to predict which patients are more likely to develop CKD after radical nephrectomy

The PAX gene family of transcription factors plays a prominent role during embryogenesis however can be aberrantly re-activated during tumorigenesis and contributes to the malignant phenotype. / During embryonic kidney development, PAX2 exerts an anti-apoptotic function however its expression typically attenuates during the post-natal period. On the other hand, PAX2 aberrant expression is observed in the majority of Renal Cell Carcinomas (RCC). RCC is resistant to chemotherapy; up-regulation of anti-apoptotic genes is recognized to contribute to tumor resistance to chemotherapy. We hypothesized that the anti-apoptotic effect of the PAX2 gene that is expressed in RCC cells contributes to RCC and their resistance to chemotherapy-induced cell death. / Human embryonic kidney (HEK293) cells transfected with a PAX2 expression vector and exposed to cisplatin, were protected from apoptosis compared to control cells. Conversely, murine collecting duct cells stably transfected with PAX2 antisense cDNA had twofold increases in cisplatin-induced apoptosis. Similarly, PAX2 knockdown using PAX2 siRNA in RCC cells CAKI-1 and ACHN enhances cisplatin-induced apoptosis in vitro. / To test the combination of PAX2 expression silencing and cisplatin treatment in vivo we developed a model of renal tumors by injecting ACHN cells as a xenograft under the skin of nude mice. I showed that a PAX2 shRNA successfully knocks down PAX2 mRNA and protein levels in a RCC cell line (ACHN). ACHN cells stably transfected with shRNAs targeted against the PAX2 homeodomain, are more susceptible to cisplatin-induced caspase-3 activation than the control ACHN cell line. Furthermore, growth of subcutaneous ACHN/shPAX2 xenografts in nude mice is significantly more responsive to cisplatin therapy than control of ACHN cell tumors. This work proposes PAX2 as a potential therapeutic gene target in metastatic renal cell carcinoma and suggests that adjunctive PAX2 knockdown may enhance the efficacy of chemotherapeutic agents such as cisplatin. / Wilms tumor, the most common pediatric renal cancer, is thought to arise from a progenitor cell of the metanephric mesenchyme that fails to complete nephrogenesis. In addition to its characteristic triphasic histology, WT can exhibit myogenic differentiation. Myogenic programming during muscle development is controlled by a PAX3 transcription factor determinant for muscle development; unexpectedly PAX3 transcriptional activity has been recently identified in the embryonic mouse kidney. These observations led us to hypothesize that PAX3 plays a role during kidney development. Furthermore, we predict that if PAX3 expression is verified during renal development, PAX3 may also be expressed in Wilms tumor with a myogenic component. / I showed that PAX3 is expressed in the metanephric mesenchyme and stromal compartment of the developing mouse kidney. In a panel of 20 Wilms tumors, PAX3 was identified in tumor samples with myogenic histopathology. Furthermore, mutations of WT1 were consistently associated with PAX3 expression in Wilms tumors and modulation of WT1 expression in HEK293 cells was inversely correlated with the level of endogenous PAX3 protein. / This work supports a novel model of normal renal development in which progenitor cells of the metanephric blastema express PAX3 when targeted toward the stromal cell fate. Suppression of PAX3 is integral to the mesenchyme-to-epithelium transition, which defines the nephrogenic cell fate and may be accomplished, in part, by WT1. Conversely, failure to suppress PAX3 may account for the myogenic phenotype in a subset of WT1-negative Wilms tumors.