RESUMO
Transforming growth factor-beta 1 (TGF-beta 1) has previously been implicated as a potential negative autocrine or paracrine growth regulator of certain cell types (Arteaga, C. L., R. J. Coffey, Jr., T. C. Dugger, C. M. McCutchen, H. L. Moses, and R. M. Lyons. 1990. Cell Growth & Differ. 1:367-374; Hafez, M. M., D. Infante, S. Winawer, and E. Friedman. 1990. Cell Growth & Differ. 1:617-626; Glick, A. B., K. C. Flanders, D. Danielpour, S. H. Yuspa, and M. B. Sporn. 1989. Cell Regulation. 1:87-97). This is based mainly on experiments assessing the effects of exogenous TGF-beta 1 or neutralizing antibodies to TGF-beta 1 on normal or tumor cell proliferation in vitro. However, direct evidence demonstrating such a negative regulation of tumor cell growth in vivo is still lacking. To overcome this problem we have constructed and used an antisense expression vector for TGF-beta 1 as a means of regulating endogenous TGF-beta 1 expression in tumor cells. Antisense-transfected FET human colon carcinoma cells showed a fivefold reduction in TGF-beta 1 mRNA and 15-fold reduction in TGF-beta 1 secretion. Antisense mRNA was detected in transfected cells by an RNase protection assay. Compared to control cells, cultured antisense-transfected cells showed a reduction in lag phase time rather than a change in doubling time. Cloning efficiencies of transfected cells were four times greater than control cells in anchorage-independent assays. Control cells did not form tumors at 5 x 10(5) in athymic nude mice. Antisense-transfected cells formed tumors in 40% of animals injected. At higher inocula (1 x 10(6) cells) antisense-transfected cells formed tumors in 100% of animals injected, but control cells still failed to form tumors. These results show that TGF-beta 1 acts as a negative growth regulator of human colon carcinoma cells in vivo as well as in vitro. Acquisition of partial or full resistance to such inhibitory effects may therefore contribute to tumor development and progression.
Assuntos
Divisão Celular , Neoplasias do Colo/patologia , RNA Antissenso/genética , RNA Mensageiro/genética , Fator de Crescimento Transformador beta/fisiologia , Animais , Anticorpos , Linhagem Celular , Clonagem Molecular , Vetores Genéticos , Humanos , Camundongos , Camundongos Nus , Transplante de Neoplasias , Plasmídeos , Transfecção , Fator de Crescimento Transformador beta/genética , Transplante HeterólogoRESUMO
Cells are complex systems that regulate a multitude of biologic pathways involving a diverse array of molecules. Cancer can develop when these pathways become deregulated as a result of mutations in the genes coding for these proteins or of epigenetic changes that affect gene expression, or both1,2. The diversity and interconnectedness of these pathways and their molecular components implies that a variety of mutations may lead to tumorigenic cellular deregulation3-6. This variety, combined with the requirement to overcome multiple anticancer defence mechanisms7, contributes to the heterogeneous nature of cancer. Consequently, tumours with similar histology may vary in their underlying molecular circuitry8-10, with resultant differences in biologic behaviour, manifested in proliferation rate, invasiveness, metastatic potential, and unfortunately, response to cytotoxic therapy. Thus, cancer can be thought of as a family of related tumour subtypes, highlighting the need for individualized prediction both of disease progression and of treatment response, based on the molecular characteristics of the tumour.
RESUMO
Although the monomeric GTPases RalA and RalB have been shown to regulate a variety of transcription factors, little is known regarding the differences or similarities in transcriptional programs regulated by RalA compared to RalB. Further, the association of these transcriptional pathways to human carcinogenesis and progression remains unclear. Here, we studied the role of RalA and/or RalB in transcriptional regulation by combining short interfering RNA depletion of Ral with gene expression profiling via microarray in the human bladder cancer cell line, UMUC-3. A large number of genes were found to be similarly modulated in cells with RalA and RalB depletion, suggesting that RalA and RalB impinge on overlapping transcriptional signaling pathways. However, smaller sets of genes were modulated by depletion of RalA or RalB, indicating that these closely related proteins also regulate nonoverlapping transcriptional pathways. Computational analysis of upstream sequences of genes modulated by Ral depletion identified Ras-responsive element-binding protein (RREB)-1, as a putative Ral transcriptional target, which we verified experimentally. Importantly, as a group, Ral-regulated probe sets identified here were disproportionally represented among those differentially expressed as a function of human bladder transformation. Taken together, these data strongly suggest that Ral family members mediate both common and specific transcriptional programs that are associated with human cancer and identify RREB-1 as a novel transcriptional effector of Ral.
Assuntos
Proteínas de Ligação a DNA/fisiologia , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/fisiologia , Fatores de Transcrição/fisiologia , Neoplasias da Bexiga Urinária/genética , Proteínas ral de Ligação ao GTP/antagonistas & inibidores , Proteínas ral de Ligação ao GTP/deficiência , Linhagem Celular Tumoral , Humanos , Transdução de Sinais/genética , Transcrição Gênica/fisiologia , Neoplasias da Bexiga Urinária/metabolismo , Proteínas ral de Ligação ao GTP/genéticaRESUMO
Most deaths from urinary bladder cancer are owing to metastatic disease. A reduction in Rho GDP Dissociation Inhibitor 2 (RhoGDI2) protein has been associated with increased risk of metastasis in patients with locally advanced bladder cancer, whereas in animal models, RhoGDI2 reconstitution in cells without expression results in lung metastasis suppression. Recently, we noted an inverse correlation between tumor RhoGDI2 and Neuromedin U (NMU) expression, suggesting that NMU might be a target of the lung metastasis suppressor effect of RhoGDI2. Here we evaluated whether NMU is regulated by RhoGDI2 and is functionally important in tumor progression. We used small interfering RNA knockdown of endogenous RhoGDI2 in poorly tumorigenic and non-metastatic human bladder cancer T24 cells and observed increased NMU RNA expression. Although NMU overexpression did not increase the monolayer growth of T24 or related T24T poorly metastatic human bladder cancer cells, it did augment anchorage-independent growth for the latter. Overexpression of NMU in T24 and T24T cells significantly promoted tumor formation of both cell lines in nude mice, but did not alter the growth rate of established tumors. Furthermore, NMU-overexpressing xenografts were associated with lower animal body weight than control tumors, indicating a possible role of NMU in cancer cachexia. NMU overexpression in T24T cells significantly enhanced their lung metastatic ability. Bioluminescent in vivo imaging revealed that lung metastases in T24T grew faster than the same tumors in the subcutaneous microenvironment. In conclusion, NMU is a RhoGDI2-regulated gene that appears important for tumorigenicity, lung metastasis and cancer cachexia, and thus a promising therapeutic target in cancer.
Assuntos
Caquexia/etiologia , Carcinoma de Células de Transição/patologia , Inibidores de Dissociação do Nucleotídeo Guanina/metabolismo , Neoplasias Pulmonares/patologia , Neuropeptídeos/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Neoplasias da Bexiga Urinária/patologia , Animais , Biomarcadores Tumorais/metabolismo , Caquexia/metabolismo , Caquexia/patologia , Carcinoma de Células de Transição/metabolismo , Adesão Celular , Proliferação de Células , Inibidores de Dissociação do Nucleotídeo Guanina/antagonistas & inibidores , Inibidores de Dissociação do Nucleotídeo Guanina/genética , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/secundário , Camundongos , Camundongos Nus , Invasividade Neoplásica/patologia , Neuropeptídeos/genética , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Células Tumorais Cultivadas , Ensaio Tumoral de Célula-Tronco , Proteínas Supressoras de Tumor/antagonistas & inibidores , Proteínas Supressoras de Tumor/genética , Neoplasias da Bexiga Urinária/metabolismo , Inibidor beta de Dissociação do Nucleotídeo Guanina rho , Inibidores da Dissociação do Nucleotídeo Guanina rho-EspecíficoRESUMO
The utility of tumor-derived cell lines is dependent on their ability to recapitulate underlying genomic aberrations and primary tumor biology. Here, we sequenced the exomes of 25 bladder cancer (BCa) cell lines and compared mutations, copy number alterations (CNAs), gene expression and drug response to BCa patient profiles in The Cancer Genome Atlas (TCGA). We observed a mutation pattern associated with altered CpGs and APOBEC-family cytosine deaminases similar to mutation signatures derived from somatic alterations in muscle-invasive (MI) primary tumors, highlighting a major mechanism(s) contributing to cancer-associated alterations in the BCa cell line exomes. Non-silent sequence alterations were confirmed in 76 cancer-associated genes, including mutations that likely activate oncogenes TERT and PIK3CA, and alter chromatin-associated proteins (MLL3, ARID1A, CHD6 and KDM6A) and established BCa genes (TP53, RB1, CDKN2A and TSC1). We identified alterations in signaling pathways and proteins with related functions, including the PI3K/mTOR pathway, altered in 60% of lines; BRCA DNA repair, 44%; and SYNE1-SYNE2, 60%. Homozygous deletions of chromosome 9p21 are known to target the cell cycle regulators CDKN2A and CDKN2B. This loci was commonly lost in BCa cell lines and we show the deletions extended to the polyamine enzyme methylthioadenosine (MTA) phosphorylase (MTAP) in 36% of lines, transcription factor DMRTA1 (27%) and antiviral interferon epsilon (IFNE, 19%). Overall, the BCa cell line genomic aberrations were concordant with those found in BCa patient tumors. We used gene expression and copy number data to infer pathway activities for cell lines, then used the inferred pathway activities to build a predictive model of cisplatin response. When applied to platinum-treated patients gathered from TCGA, the model predicted treatment-specific response. Together, these data and analysis represent a valuable community resource to model basic tumor biology and to study the pharmacogenomics of BCa.
Assuntos
Genômica , Modelos Biológicos , Neoplasias Urológicas/genética , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Biomarcadores , Linhagem Celular Tumoral , Deleção Cromossômica , Mapeamento Cromossômico , Cromossomos Humanos Par 9 , Análise por Conglomerados , Biologia Computacional/métodos , Variações do Número de Cópias de DNA , Metilação de DNA , Exoma , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Mutação , Fosfatidilinositol 3-Quinases/metabolismo , Polimorfismo de Nucleotídeo Único , Prognóstico , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Resultado do Tratamento , Neoplasias Urológicas/diagnóstico , Neoplasias Urológicas/tratamento farmacológico , Neoplasias Urológicas/metabolismoRESUMO
BACKGROUND: Signals from a cell's environment are sensed by receptors, which activate pathways that, in turn, transmit the signals to the nucleus, informing decisions on growth, angiogenesis, and other cell functions. Transcription of vascular endothelial growth factor (VEGF), a potent angiogenic factor, can be induced by cell-cell contact. In the current work, we sought to determine if this induction is dependent on transformation of cells to a malignant phenotype and subsequently to determine which signaling molecules mediate activation of VEGF transcription. METHODS: Normal and transformed prostate epithelial cell lines were examined at various cell densities to simulate the effect of increased cell contact on expression of VEGF messenger RNA. Transformed cells were also cotransfected with a VEGF promoter-reporter construct and with constructs that express dominant negative or activated versions of signal transduction proteins hypothesized to be involved in the cell-cell contact process, and reporter activity was assessed at various cell densities. All P values are two-sided. RESULTS: Direct cell-cell contact, but not extracellular matrix components, resulted in transcriptional activation of a VEGF promoter-reporter construct in malignant (P<.0001) but not in nonmalignant (P =.37) prostate cells. This process was mediated via a mitogen-activated protein kinase (MAPK); it required the activity of focal adhesion kinase (FAK), Rap1, and Raf and was Ras independent. In addition, transcriptional activation of a Ras-sensitive Elk-1 chimeric reporter by cell-cell contact suggests that Rap1 is a key factor in regulating the specificity of convergent MAPK-signaling pathways arising from different upstream extracellular stimuli. CONCLUSIONS: Cell contact induction of VEGF transcription via FAK and Rap1 provides a novel Ras-independent, but transformation-dependent, mechanism for stimulus-specific regulation of tumor VEGF expression via MAPK.
Assuntos
Fatores de Crescimento Endotelial/genética , Linfocinas/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Próstata/metabolismo , Neoplasias da Próstata/metabolismo , Proteínas Tirosina Quinases/metabolismo , Transcrição Gênica , Proteínas rap1 de Ligação ao GTP/metabolismo , Northern Blotting , Células Cultivadas , Epitélio/metabolismo , Quinase 1 de Adesão Focal , Proteína-Tirosina Quinases de Adesão Focal , Genes Reporter/genética , Humanos , Masculino , Proteínas Quinases Ativadas por Mitógeno/genética , Plasmídeos/genética , Regiões Promotoras Genéticas/genética , Próstata/citologia , Neoplasias da Próstata/genética , Proteínas Tirosina Quinases/genética , Proteínas Proto-Oncogênicas c-raf/metabolismo , RNA Mensageiro/genética , Transfecção , Células Tumorais Cultivadas , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular , Proteínas rap1 de Ligação ao GTP/genéticaRESUMO
Recent studies have shown that orthotopic (transurethral) transplantation of human bladder cancer cell lines into nude mice permits tumor growth that more accurately reflects their clinical malignant status in the original host. We have previously demonstrated that transfection and overexpression of normal or mutated c-Ha-ras genes into a noninvasive human papillary transitional cell carcinoma cell line confer upon these cells an invasive phenotype in vivo with behavior remarkably similar to the clinical behavior of high grade bladder carcinomas. Since elevated expression levels of the epidermal growth factor receptor (EGF-R), in addition to that of c-Ha-ras, have been correlated with transitional cell carcinoma progression, we sought to determine whether up-regulation of the EGF-R had occurred in the invasive high ras expressors and if so, what functional significance this might have. Our results show that invasive cell lines which overexpress the c-Ha-ras gene also have increased epidermal EGF-R expression. This was found to occur at both the protein and mRNA levels, and analysis of the EGF-R promoter/enhancer sequences has revealed a putative AP-1 site which may possibly enhancer sequences has revealed a putative AP-1 site which may possibly serve as a ras response element. In addition, we found that the cells overexpressing the EGF-R had acquired a positive sensitivity to the stimulatory mitogenic effects of EGF. Hence, the results obtained suggest a role for either a normal or a mutated overexpressing Ha-ras in up-regulating the surface EGF-R, possibly through an AP-1 site during human bladder carcinoma progression; they also highlight the potential that EGF may have in cooperating with this EGF-R up-regulation to help mediate enhanced tumor growth.
Assuntos
Fator de Crescimento Epidérmico/farmacologia , Receptores ErbB/metabolismo , Genes ras , Northern Blotting , Carcinoma de Células de Transição/genética , Carcinoma de Células de Transição/patologia , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Receptores ErbB/genética , Humanos , Invasividade Neoplásica , Fenótipo , RNA Neoplásico/genética , RNA Neoplásico/isolamento & purificação , Regulação para Cima , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologiaRESUMO
Environmental signals in the cellular milieu such as hypoxia, growth factors, extracellular matrix (ECM), or cell-surface molecules on adjacent cells can activate signaling pathways that communicate the state of the environment to the nucleus. Several groups have evaluated gene expression or signaling pathways in response to increasing cell density as an in vitro surrogate for in vivo cell-cell interactions. These studies have also perhaps assumed that cells grown at various densities in standard in vitro incubator conditions do not have different pericellular oxygen levels. However, pericellular hypoxia can be induced by increasing cell density, which can exert profound influences on the target cell lines and may explain a number of findings previously attributed to normoxic cell-cell interactions. Thus, we first sought to test the hypothesis that cell-cell interactions as evaluated by the surrogate approach of increasing in vitro cell density in routine normoxic culture conditions results in pericellular hypoxia in prostate cancer cells. Second, we sought to evaluate whether such interactions affect transcription mediated by the hypoxia response element (HRE). Thirdly, we sought to elucidate the signal transduction pathways mediating the induction of HRE in response to cell density induced pericellular hypoxia in routine normoxic culture conditions. Our results indicate that paracrine cell interactions can induce nuclear localization of HIF-1a protein and this translocation is associated with strong stimulation of the HRE-reporter activity. We also make the novel observation that cell density-induced activity of the HRE is dependent on nitric oxide production, which acts as a diffusible paracrine factor secreted by densely cultured cells. These results suggest that paracrine cell interactions associated with pericellular hypoxia lead to the physiological induction of HRE activity via the cooperative action of Ras, MEK1, HIF-1a via pericellular diffusion of nitric oxide. In addition, these results highlight the importance of examining pericellular hypoxia as a possible stimulus in experiments involving in vitro cell density manipulation even in routine normoxic culture conditions.
Assuntos
Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Óxido Nítrico/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Fatores de Transcrição/metabolismo , Proteínas ras/metabolismo , 2,2'-Dipiridil/farmacologia , Contagem de Células , Hipóxia Celular , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia , Quelantes de Ferro/farmacologia , MAP Quinase Quinase 1 , Masculino , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II , Neoplasias da Próstata , Elementos de Resposta , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genética , Células Tumorais Cultivadas , Proteínas Quinases p38 Ativadas por MitógenoRESUMO
PURPOSE: Current methods used to determine the pathological stage of the primary tumor and associated lymphatics after radical cystectomy are tedious, costly, and may lack the sensitivity afforded by molecular approaches such as reverse transcription-PCR (RT-PCR) for markers specific for urothelial tissue such as the uroplakin II (UPII) gene. Thus, we sought to evaluate an objective and sensitive molecular approach for the assessment of perivesical extension and lymph node status after radical cystectomy, based on the detection of UPII expression using RT-PCR and compare this assay to standard clinical and pathological examination. EXPERIMENTAL DESIGN: From November 1999 to September 2000, 27 patients with clinical T(a)-T(3)N(0)M(0) urothelial bladder cancer underwent radical cystectomy, 19 (70%) of which also had pelvic lymphadenectomy. At the completion of cystectomy, systematic biopsies of the external surface of the bladder specimen as well as from the largest palpable lymph node found at lymphadenectomy were obtained for molecular analysis. RT-PCR analysis for UPII mRNA was carried out on these biopsy specimens, and results were compared with data obtained from conventional pathological examination. RESULTS: Pathologically organ-confined tumors had a 42% (5 of 12) incidence of positive signals in the perivesical tissues and 17% (1 of 7) in the lymph nodes. Corresponding percentages for pT(3a)N(0) and pT(3b)-T(4)N(0) lesions were 67% (4 of 6)/25% (1 of 4) and 67% (4 of 6)/33% (2 of 6), respectively. Overall, pathologically node-negative cancers had a perivesical positivity rate of 54% (13 of 24) and a lymph node positivity rate of 25% (4 of 16). All patients with pathologically positive nodes had positive UPII signals in the lymph node sample. CONCLUSIONS: This molecular assay aimed at assessing perivesical extension and lymph node status after radical cystectomy appears to identify patients that may harbor residual disease not appreciated by conventional histology. Larger studies with 5-7-year follow-up will be required to determine the prognostic significance of such molecular information.
Assuntos
Metástase Linfática , Neoplasias da Bexiga Urinária/diagnóstico , Neoplasias da Bexiga Urinária/cirurgia , Urotélio/patologia , Idoso , Feminino , Humanos , Masculino , Proteínas de Membrana/biossíntese , Pessoa de Meia-Idade , Metástase Neoplásica , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Resultado do Tratamento , Células Tumorais Cultivadas , Neoplasias da Bexiga Urinária/metabolismo , Uroplaquina IIRESUMO
p27 restrains normal cell growth, but PI3K-dependent C-terminal phosphorylation of p27 at threonine 157 (T157) and T198 promotes cancer cell invasion. Here, we describe an oncogenic feedforward loop in which p27pT157pT198 binds Janus kinase 2 (JAK2) promoting STAT3 (signal transducer and activator of transcription 3) recruitment and activation. STAT3 induces TWIST1 to drive a p27-dependent epithelial-mesenchymal transition (EMT) and further activates AKT contributing to acquisition and maintenance of metastatic potential. p27 knockdown in highly metastatic PI3K-activated cells reduces STAT3 binding to the TWIST1 promoter, TWIST1 promoter activity and TWIST1 expression, reverts EMT and impairs metastasis, whereas activated STAT3 rescues p27 knockdown. Cell cycle-defective phosphomimetic p27T157DT198D (p27CK-DD) activates STAT3 to induce a TWIST1-dependent EMT in human mammary epithelial cells and increases breast and bladder cancer invasion and metastasis. Data support a mechanism in which PI3K-deregulated p27 binds JAK2, to drive STAT3 activation and EMT through STAT3-mediated TWIST1 induction. Furthermore, STAT3, once activated, feeds forward to further activate AKT.
Assuntos
Citoplasma/genética , Transição Epitelial-Mesenquimal/genética , Metástase Neoplásica/genética , Proteínas Nucleares/genética , Antígeno Nuclear de Célula em Proliferação/genética , Fator de Transcrição STAT3/genética , Proteína 1 Relacionada a Twist/genética , Regulação para Cima/genética , Animais , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Células Epiteliais/metabolismo , Feminino , Células HEK293 , Humanos , Janus Quinase 2/genética , Células MCF-7 , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Fosfatidilinositol 3-Quinases/genética , Regiões Promotoras Genéticas/genética , Transdução de Sinais/genética , Neoplasias da Bexiga Urinária/genéticaRESUMO
We have recently characterized a human bladder cancer cell line T24 and a more aggressive lineage related variant of it, T24T. To gain further insights, we have studied their metastatic ability in an in vivo model system. Results show that T24 forms significantly fewer [4/12 (1/11) mice had metastases with 1-2 lesions/mouse] metastasis in SCID/bg mice than T24T [14/14 (6/6) mice had metastases with a mean of 24-28 lesions/mouse]. To begin exploring the mechanisms underlying this difference, we evaluated the mRNA and protein expression levels of metastasis-suppressor genes, known to be important in the progression of other cancers, in our model of bladder cancer progression. A higher mRNA expression of BRMS1, a metastasis suppressor in breast cancer, was observed in T24 cells. In addition, RhoGDI2 mRNA expression was only observed in T24 when compared to T24T, suggesting that Rho activation might play a significant role in the metastatic cascade. However, a basal level mRNA expression of KISS1, described as metastasis suppressor in melanoma and breast, was observed in both the lines and had slightly higher expression in T24T. No difference of Nm23-H1, KAI1, MKK4/SEK1 and E-Cadherin protein levels were noted between these two lines. In summary, it appears that the T24/T24T paired cell lines constitute a useful model for the study of human bladder cancer metastasis that will allow both the discovery and mechanistic evaluation of genes potentially involved in this process.
Assuntos
Carcinoma de Células de Transição/patologia , Expressão Gênica , Inibidores de Dissociação do Nucleotídeo Guanina/genética , Metástase Neoplásica , Proteínas de Neoplasias , Proteínas/genética , Neoplasias da Bexiga Urinária/patologia , Proteínas rho de Ligação ao GTP/genética , Animais , Western Blotting , Carcinoma de Células de Transição/genética , Humanos , Camundongos , Camundongos SCID , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Repressoras , Células Tumorais Cultivadas , Neoplasias da Bexiga Urinária/genética , Inibidor beta de Dissociação do Nucleotídeo Guanina rho , Inibidores da Dissociação do Nucleotídeo Guanina rho-EspecíficoRESUMO
BACKGROUND: Rapid, robust and reversible induction of transgene expression would significantly facilitate cancer gene therapy as well as allow the in vivo functional study of newly discovered genes in tumor formation and progression. The popularity of the ecdysone inducible gene switch system has led us to investigate whether such a system can successfully regulate gene expression in a syngeneic tumor system in vivo. RESULTS: MBT-2 and Panc02 carcinoma cells were transfected with components of a modification of the ecdysone switch system driving firefly luciferase (F-Luc). In vitro luciferase expression +/- ecdysone analog GS-E indicated a robust induction with minimal baseline activity and complete decay after 24 hours without drug. In vitro selection of MBT-2 transfected cell clones which had complete absence of F-Luc expression in the absence of stimulation but which expressed this gene at high levels in response to GS-E were chosen for in vivo evaluation. Tumors from engineered MBT-2 cells were grown to 5 mm in diameter prior to GS-E administration, animals euthanized and tumors removed at 6, 12 and 24 hours after GS-E administration and assayed for F-Luc activity. GS-E resulted in a maximal induction of F-Luc activity at 6 hours in tumor tissue with almost complete reversion to control levels by 12 hours. CONCLUSIONS: This study is the first demonstration that robust and reversible transgene expression in tumors is feasible using the ecdysone system, allowing future rapid in vivo functional characterization of gene function or gene therapy applications.
Assuntos
Ecdisona/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Transplante de Neoplasias , Neoplasias da Bexiga Urinária/genética , Animais , Linhagem Celular Tumoral , Genes Reporter/genética , Engenharia Genética , Terapia Genética/métodos , Proteínas de Fluorescência Verde , Luciferases/genética , Luciferases/metabolismo , Proteínas Luminescentes/análise , Proteínas Luminescentes/genética , Camundongos , Neoplasias Pancreáticas/genética , Transgenes/genéticaRESUMO
PURPOSE: To prospectively evaluate the effect of ionizing radiation on the results of the bladder tumor-associated antigen (BTA) test. By examining this question, we sought to determine its potential use as a monitoring test for the detection of recurrent transitional carcinoma of the bladder in patients who have received prior radiotherapy for bladder preservation. MATERIALS AND METHODS: Between February 1996 and April 1997, 18 patients with nonbladder pelvic malignancies and no history of bladder cancer, received irradiation to the bladder. These patients were prospectively evaluated using the BTA test at the end of the external-beam radiation (EBRT) and at 3-month follow-up intervals. Urine cytology was analyzed in 16 of the 18 patients at the end of EBRT. A median of 3 separate measurements were made (range 1-6) on each patient. The median dose of EBRT was 50.4 Gy (range 30-68 Gy). Seven patients underwent brachytherapy as part of their treatment course. BTA results and time intervals were recorded and analyzed using univariate and Kaplan-Meyer methodologies. RESULTS: A total of 10 (56%) of the 18 patients had a positive BTA test at some time following completion of EBRT. Of the 10 positive tests, 9 returned to negative in a median of 42 weeks from completion of EBRT. Treatment with chemotherapy, brachytherapy, calculated bladder dose, and total external beam dose did not significantly influence either the number of positive tests or the time to resolution of the positive test in this small group of patients. All screened urine samples were negative for malignant cells and 11 (69%) of 16 showed changes consistent with ionizing radiation. CONCLUSION: Our findings support the hypothesis that ionizing radiation can cause transient positive results in the BTA test, but that these normalize with time. Although it requires further testing, it seems that the BTA test may be useful in the detection of recurrence in patients with bladder cancer who have been treated with definitive irradiation for bladder preservation.
Assuntos
Biomarcadores Tumorais/análise , Carcinoma de Células de Transição/diagnóstico , Recidiva Local de Neoplasia/diagnóstico , Neoplasias da Bexiga Urinária/diagnóstico , Bexiga Urinária/efeitos da radiação , Antígenos de Neoplasias/análise , Carcinoma de Células de Transição/urina , Feminino , Humanos , Masculino , Recidiva Local de Neoplasia/urina , Neoplasias Pélvicas/radioterapia , Valor Preditivo dos Testes , Estudos Prospectivos , Neoplasias da Bexiga Urinária/urinaRESUMO
Current in vitro assays used in assessing tumor motility could be improved by the development of a simple technique that would facilitate studies of the impact of specific genes on pharmacologically altered chemotaxis. We developed a technique that improves on the classic transwell assay by using fluorescence and luminescence to assess chemotaxis. In this transient transfection system, co-transfection of a reporter construct and a gene with an unknown impact on motility are coupled with biochemical assays to quantitate the number of cells that have received a transferred gene, which subsequently crosses the membrane. This assay was found to be less variable than the conventional transwell chamber and is easily adaptable to studies of cell motility or cell invasion. We also demonstrate that this assay can detect the effect of both genetic and pharmacological inhibition of motility alone and in combination. It therefore has the potential to reveal additive or synergistic effects.
Assuntos
Contagem de Células , Membrana Celular/metabolismo , Movimento Celular , Fluorescência , Luciferases/análise , Neoplasias da Bexiga Urinária/patologia , Quimiotaxia/genética , Corantes Fluorescentes , Expressão Gênica , Humanos , Invasividade Neoplásica , Espectrometria de Fluorescência , Transfecção , Células Tumorais CultivadasRESUMO
Carcinoma of the urinary bladder is the second most common urologic malignancy. In addition, these tumors are one of the best understood genitourinary neoplasms with a well defined etiology, natural history, tumor biology, treatment options and outcome. This level of understanding arises as a consequence of multiple factors and represents a convergence of knowledge from diverse scientific disciplines. Insight provided by these disciplines, coupled with unique features of this neoplasm which make it assessable for detection, monitoring and treatment, combine to make this disease a model system for modern oncology. The intent of this review is to provide the reader an overview of our current understanding of this tumor from the standpoint of its molecular biology as related to tumor development and progression.
Assuntos
Neoplasias da Bexiga Urinária/etiologia , Neoplasias da Bexiga Urinária/genética , Urotélio/fisiopatologia , Caderinas/genética , Caderinas/metabolismo , Receptores ErbB/genética , Receptores ErbB/metabolismo , Humanos , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/fisiopatologia , Proteína do Retinoblastoma/genética , Proteína do Retinoblastoma/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Neoplasias da Bexiga Urinária/fisiopatologiaRESUMO
The purpose of this review is to provide information on the molecular basis of prostate cancer biology and to identify some of the targets for therapy, and highlight some potential strategies for molecular treatment. Here we give a synopsis of what we have learned regarding molecular biology of cancer in general and the directions research might take in the future in order to impact prostate cancer specifically. This work is certainly not encyclopedic in nature and we apologize in advance to colleagues whose work we were no able to include. Hope lies in learning to utilize some of these molecular workings for better prevention, diagnosis, and treatment of the most common solid organ cancer in men. Prostate cancer is a formidable disease and at current rates of diagnosis will affect one-in-six men living in the United States (Greenlee et al., 2000) Many of these men are diagnosed at an early stage of the disease and can be effectively treated by surgery or radiation. However, a significant fraction of men are diagnosed with later stage disease or progress despite early curative therapeutic attempts. Unfortunately, many of these men succumb to prostate cancer, as management options are limited and not always successful. Through an understanding of the molecular processes that occur in the development and progression of prostate cancer, novel therapies will arise that will provide longer survival, better quality of life, and a chance for cure in men afflicted with this disease.
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Neoplasias da Próstata , Androgênios/fisiologia , Apoptose/fisiologia , Metilação de DNA , Di-Hidrotestosterona/metabolismo , Terapia Genética , Substâncias de Crescimento/genética , Humanos , Masculino , Mutação , Invasividade Neoplásica/fisiopatologia , Metástase Neoplásica/fisiopatologia , Neovascularização Patológica/fisiopatologia , Neoplasias da Próstata/genética , Neoplasias da Próstata/fisiopatologia , Neoplasias da Próstata/terapia , Transdução de Sinais/fisiologia , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
OBJECTIVES: Urinary continence is one of the most significant outcomes after radical surgery for prostate cancer. Although both retropubic and perineal approaches to radical prostatectomy are commonly used, they have not yet been compared with respect to urinary continence and voiding function in a single-institution study using a validated patient-administered instrument. This study had two primary objectives: first, to assess whether differences exist between these two procedures with respect to the overall prevalence and resolution of postoperative urinary incontinence, and second, to determine the impact of the urinary incontinence on patient lifestyle in this patient population. METHODS: A written instrument composed of the Urinary Function Questionnaire for Men after Radical Prostatectomy, the American Urological Association (AUA) Symptom Score, and seven items querying urinary retention and urinary function bother were mailed in February 1996 to 209 men who underwent radical prostatectomy by either the perineal (43%) or retropubic (57%) approach between January 1990 and December 1995. Descriptive statistics were used to summarize the prevalence of urinary incontinence and urinary function bother as reported from this cross-sectional questionnaire. Logistic regression models were used to assess the association between reported urinary incontinence and surgical approach, AUA symptom scores, and treatment of incontinence after adjusting for possible confounders (eg, the time between surgery and questionnaire, and patient age). RESULTS: One hundred sixty-seven men (80%) responded to the questionnaire. The median age of the participants at questionnaire administration was 68 years (range 43 to 80). Overall, 57% (95% confidence interval [CI] 50% to 63%) of the responders reported complete urinary continence at the time of the questionnaire, with a median time between surgery and the questionnaire of 2.7 years (range 0.3 to 5.4). When continence was defined as either complete dryness or minimal urinary leakage, 75% (95% CI 69% to 81%) of the responders reported being continent. In men who responded to the questionnaire within 2 years of surgery, the probability of experiencing complete urinary continence was similar between the two surgical approaches. In men who responded to the questionnaire more than 2 years after surgery, patients who had undergone perineal prostatectomy were more likely to report complete continence than those who underwent retropubic surgery. However, this observed difference disappears when continence was defined as either complete dryness or minimal urinary leakage. The major impact of urinary incontinence on patient lifestyle was observed in patients with more than just minimal leakage. CONCLUSIONS: Radical perineal and radical retropubic prostatectomy have similar outcomes when patients with minor degrees of incontinence are grouped together with continent patients. Since the impact of a minimal degree of urinary incontinence on the patient's lifestyle after radical prostatectomy seems to be minor, currently we do not believe that postoperative continence status is a major factor in choosing one procedure over the other.
Assuntos
Prostatectomia/métodos , Incontinência Urinária/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Pessoa de Meia-Idade , Prostatectomia/efeitos adversos , Inquéritos e Questionários , Incontinência Urinária/etiologia , Incontinência Urinária/terapia , Doenças Urológicas/epidemiologia , Doenças Urológicas/etiologiaRESUMO
OBJECTIVES: Because of renewed interest in the radical perineal prostatectomy, we chose to evaluate factors influencing differences in biochemical failure as measured by prostate-specific antigen (PSA) between radical perineal and the radical retropubic prostatectomies. METHODS: We undertook a retrospective review of 87 men with clinically localized prostate cancer who underwent radical retropubic (64%) or radical perineal (36%) prostatectomy, noting age, race, preoperative PSA, Gleason score, clinical stage, capsular penetration, surgical approach, and completeness of seminal vesicle (SV) excision. The two groups were comparable with respect to tumor factors such as preoperative PSA, Gleason score, clinical stage, and capsular penetration. Time to postoperative PSA failure (0.2 ng/mL or greater) was evaluated with univariate and multivariate analysis of multiple contributing factors. RESULTS: Twenty-eight percent of patients had a PSA level rising to 0.2 ng/mL or greater in the follow-up period. Patients who underwent perineal prostatectomy had a higher PSA failure rate (45%) than those treated by the retropubic approach (18%) and patients with incomplete SV excision had a higher failure rate (69%) than patients with bilateral SV excision (20%). When time to PSA failure was examined by multivariate analysis, completeness of SV excision, clinical stage, and Gleason score had a statistically significant impact on this outcome. In perineal prostatectomy patients, bilateral SV excision had a significantly longer time to PSA failure than in patients with incomplete excision. There was no significant difference in time to PSA failure between patients who underwent radical retropubic prostatectomy and the patients who underwent perineal prostatectomy with bilateral SV excision. CONCLUSIONS: Incomplete excision of SVs during a radical perineal prostatectomy contributes to an earlier postoperative biochemical recurrence as measured by a rising PSA, and may explain the higher disease recurrence rate for radical perineal prostatectomies as opposed to radical retropubic prostatectomies in this study.
Assuntos
Antígeno Prostático Específico/sangue , Prostatectomia/métodos , Neoplasias da Próstata/sangue , Neoplasias da Próstata/cirurgia , Glândulas Seminais/cirurgia , Adulto , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Períneo , Neoplasias da Próstata/etnologia , Neoplasias da Próstata/patologia , Estudos RetrospectivosRESUMO
OBJECTIVES: Interstitial brachytherapy (BT) is increasingly utilized as a curative treatment for localized prostate cancer because it is perceived as less morbid than surgical alternatives. However, to date no studies have directly compared the quality of life and symptoms of patients with localized prostate cancer treated with curative intent by radical prostatectomy with those treated by either BT alone or BT combined with external beam radiation. METHODS: On June 1, 1998, 242 men with clinically localized Stage T1c to T3 adenocarcinoma of the prostate, treated at our institution with curative intent from January 1, 1997 to June 1, 1998, were mailed a questionnaire. Cross-sectional analysis of returned questionnaires was carried out. Patients were treated with either radical prostatectomy (RP), palladium-103 (Pd(103)) brachytherapy (115 Gy) monotherapy (BTM), or Pd(103) combined brachytherapy (90 Gy) and external beam radiation (40 to 45 Gy) (BTC). The primary outcome measures were the Functional Assessment of Cancer Therapy scale (FACT-G), American Urological Association (AUA)/international prostate symptom score (IPSS), "Urinary Function Questionnaire for Men after Radical Prostatectomy," and Brief Sexual Function Inventory. RESULTS: Data from 138 patients were included in the analysis; 27 had RP, 70 had BTM, and 41 had BTC. Total FACT-G and personal well-being scores were significantly lower in the BTC group. Brachytherapy monotherapy and RP had similar scores on the FACT-G, with surgical patients having the lowest IPSS scores. Correlations were noted between total FACT-G and urinary symptom score, degree of sexual function, frequency of diarrhea, and frequency of hot flashes. Bothersomeness of urinary function correlated with the degree of urinary control. The radical prostatectomy and BTM groups had improvement in quality of life, voiding, diarrhea, and sexual function with time, whereas the BTC group experienced a decline. CONCLUSIONS: Patients treated with BTC had an overall lower quality of life compared with those treated by RP and BTM, and RP patients reported fewer irritative or obstructive voiding complaints. Although the consistency and magnitude of these trends require further study, our data suggest that RP remains a well-tolerated and accepted option.
Assuntos
Adenocarcinoma/radioterapia , Adenocarcinoma/cirurgia , Braquiterapia , Prostatectomia , Neoplasias da Próstata/radioterapia , Neoplasias da Próstata/cirurgia , Qualidade de Vida , Adulto , Idoso , Idoso de 80 Anos ou mais , Braquiterapia/efeitos adversos , Estudos Transversais , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Prostatectomia/efeitos adversos , Inquéritos e QuestionáriosRESUMO
In patients presenting with clinically localized prostate cancer, the risk of biochemical failure increases significantly with higher Gleason scores, prostate specific antigen (PSA) levels, and clinical stages. Current surgical and radiotherapeutic approaches appear to offer limited success in patients with highly adverse prognostic factors. In an attempt to improve on these outcomes, we have combined external beam radiotherapy (EBRT) with a brachytherapy (BT) boost and neo adjuvant and adjuvant androgen ablation in a population at significant risk of biochemical failure. Here we present early biochemical progression data for this approach. From October 1997 to July 1999, 72 men with a serum PSA >or=10 ng/ml or Gleason score >or=7 or clinical stage >or=T2c (AJC/UICC 1992) underwent EBRT followed by palladium-103 BT. All patients underwent 8 months of combined androgen ablation with leuprolide and an oral antiandrogen beginning 3 months prior to initiation of EBRT. Patients were followed by PSA and digital rectal examination (DRE) at 3-month intervals and a chart review on all patients was carried out during July 2001. To allow comparisons to contemporary literature, Kaplan-Meier survival curves were generated utilizing three alternate definitions of biochemical recurrence: PSA >0.2 ng/ml, PSA >1.0 ng/ml, and the American Society for Therapeutic Radiology and Oncology (ASTRO) consensus definition of three consecutive rising PSAs. Our results indicate that when PSA >0.2 ng/ml was used to define biochemical progression, 88% (95% CI 80-97) of patients remained free of disease at 24 months. When PSA >1.0 ng/ml was used, 97% (CI 92-100) of patients remained disease free at 24 months. ASTRO criteria yielded 90% (CI 82-98) recurrence-free survival at 24 months. In conclusion, this very early report indicates that in patients who are at increased risk of biochemical failure, EBRT with a BT boost in conjunction with short-term androgen ablation offers potentially superior biochemical disease-free survival to contemporary alternative approaches in the literature. Clearly, longer follow-up is required to confirm the durability of this approach.