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1.
Ann Oncol ; 25(4): 877-883, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24623370

RESUMO

BACKGROUND: Muscle-invasive bladder cancer (MIBC) can be cured by radical radiotherapy (RT). We previously found tumour MRE11 expression to be predictive of survival following RT in MIBC, and this was independently validated in a separate institute. Here, we investigated germline MRE11A variants as possible predictors of RT outcomes in MIBC, using next-generation sequencing (NGS). PATIENTS AND METHODS: The MRE11A gene was amplified in germline DNA from 186 prospectively recruited MIBC patients treated with RT and sequenced using bar-coded multiplexed NGS. Germline variants were analysed for associations with cancer-specific survival (CSS). For validation as a prognostic or predictive marker, rs1805363 was then genotyped in a cystectomy-treated MIBC cohort of 256 individuals. MRE11A mRNA isoform expression was measured in bladder cancer cell lines and primary tumour samples. RESULTS: Carriage of at least one of six (five novel) rare variants was associated with the worse RT outcome (hazard ratio [HR] 4.04, 95% confidence interval [95% CI] 1.42-11.51, P = 0.009). The single-nucleotide polymorphism (SNP), rs1805363 (minor allele frequency 11%), was also associated with worse CSS (per-allele HR 2.10, 95% CI 1.34-3.28, Ptrend = 0.001) following RT in MIBC, with a gene-dosage effect observed, but no effect seen on CSS in the cystectomy cohort (Ptrend = 0.89). Furthermore, rs1805363 influenced relative MRE11A isoform expression, with increased isoform 2 expression with carriage of the rs1805363 minor A allele. CONCLUSIONS: Germline MRE11A SNP rs1805363 was predictive of RT, but not of cystectomy outcome in MIBC. If successfully validated in an independent RT-treated cohort, this SNP could be a useful clinical tool for selecting patients for bladder-conserving treatment.


Assuntos
Biomarcadores Tumorais/biossíntese , Proteínas de Ligação a DNA/biossíntese , Invasividade Neoplásica/genética , Neoplasias da Bexiga Urinária/genética , Idoso , Idoso de 80 Anos ou mais , Feminino , Mutação em Linhagem Germinativa , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Proteína Homóloga a MRE11 , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica/diagnóstico , Invasividade Neoplásica/patologia , Prognóstico , Resultado do Tratamento , Neoplasias da Bexiga Urinária/diagnóstico , Neoplasias da Bexiga Urinária/patologia
2.
Urol Oncol ; 41(5): 211-218, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36266219

RESUMO

Bacillus Calmette-Guerin (BCG) remains the only FDA-approved first-line therapy in patients with high-risk non-muscle invasive bladder cancer. Recurrences, even after adequate BCG therapy, are common and the efficacy of second-line therapies remains modest. Therefore, early identification of patients likely to recur and treatment after recurrence remain critical unmet needs in the clinical care of bladder cancer patients. To address these deficits, a better understanding of the mechanisms of resistance to BCG-therapy is needed. The virtual update of the International Bladder Cancer Network (IBCN) on the biology of response to BCG focused on potential mechanisms and markers of resistance to intravesical BCG therapy. The insights from this meeting will be highlighted and put into context of previously reported mechanisms of resistance to BCG in this review.


Assuntos
Neoplasias não Músculo Invasivas da Bexiga , Neoplasias da Bexiga Urinária , Humanos , Adjuvantes Imunológicos/uso terapêutico , Vacina BCG/uso terapêutico , Imunoterapia , Administração Intravesical , Neoplasias da Bexiga Urinária/tratamento farmacológico , Biologia , Invasividade Neoplásica , Recidiva Local de Neoplasia/tratamento farmacológico
3.
Br J Cancer ; 107(1): 116-22, 2012 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-22596240

RESUMO

BACKGROUND: The potential for cancer-testis (CT) antigens as targets for immunotherapy in cancer patients has been heavily investigated, and currently cancer vaccine trials based on the CT antigens, MAGE-A3 and NY-ESO-1, are being carried out. METHODS: We used specific q-RT-PCR assays to analyse the expression of the CT genes MAGE-A3, NY-ESO-1 (CTAG1B), LAGE-1 (CTAG2) and PRAME in a panel of bladder tumours from 350 patients with long-term follow-up and detailed treatment information. RESULTS: Overall, 43% of the tumours expressed MAGE-A3, 35% expressed NY-ESO-1, 27% expressed LAGE-1 and 20% expressed PRAME. In all, 56% of the tumours expressed at least one of the CT genes analysed. Univariate Cox regression analysis of CT gene expression in non-muscle-invasive tumours showed that expression of MAGE-A3 (P=0.026), LAGE-1 (P=0.001) and NY-ESO-1 (P=0.040) was significantly associated with a shorter progression-free survival. In addition, we found that patients with tumours expressing PRAME responded poorly to chemotherapy (P=0.02, χ(2)-test). CONCLUSION: Cancer-testis genes are frequently expressed in bladder cancer and especially in tumours of high stage and grade. In addition, the CT gene expression may have both prognostic and predictive value. Development of specific immunotherapy against the CT antigens in bladder cancer may ultimately increase patient survival.


Assuntos
Antígenos de Neoplasias/genética , Proteínas de Membrana/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias da Bexiga Urinária/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos de Neoplasias/metabolismo , Antígenos de Superfície/metabolismo , Metilação de DNA , Intervalo Livre de Doença , Feminino , Expressão Gênica , Humanos , Masculino , Prognóstico
4.
Br J Cancer ; 107(8): 1392-8, 2012 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-22976798

RESUMO

BACKGROUND: Multiple clinical risk factors and genetic profiles have been demonstrated to predict progression of non-muscle invasive bladder cancer; however, no easily clinical applicable gene signature has been developed to predict disease progression independent of disease stage and grade. METHODS: We measured the intra-patient variation of an 88-gene progression signature using 39 metachronous tumours from 17 patients. For delineation of the optimal quantitative reverse transcriptase PCR panel of markers, we used 115 tumour samples from patients in Denmark, Sweden, UK and Spain. RESULTS: Analysis of intra-patient variation of the molecular markers showed 71% similar classification results. A final panel of 12 genes was selected, showing significant correlation with outcome. In multivariate Cox regression analysis, we found that the 12-gene signature was an independent prognostic factor (hazard ratio=7.4 (95% confidence interval: 3.4-15.9), P<0.001) when adjusting for stage, grade and treatment. Independent validation of the 12-gene panel and the determined cut-off values is needed and ongoing. CONCLUSION: Intra-patient marker variation in metachronous tumours is present. Therefore, to increase test sensitivity, it may be necessary to test several metachronous tumours from a patient's disease course. A PCR-based 12-gene signature significantly predicts disease progression in patients with non-muscle invasive bladder cancer.


Assuntos
Segunda Neoplasia Primária/genética , Reação em Cadeia da Polimerase , Análise Serial de Tecidos , Neoplasias da Bexiga Urinária/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Segunda Neoplasia Primária/patologia , Prognóstico , Transferência de Tecnologia , Neoplasias da Bexiga Urinária/patologia
5.
Br J Cancer ; 106(2): 366-74, 2012 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-22108519

RESUMO

BACKGROUND: Upregulation of the proto-oncogene plasminogen activator inhibitor-1 (PAI-1) is a common hallmark of various solid tumours, but the mechanisms controlling its expression are not fully understood. METHODS: We investigate microRNAs (miRNAs) regulating PAI-1 in a panel of normal bladder urothelial biopsies, superficial Ta bladder tumours and invasive T1-T4 tumours using expression microarrays and qRT-PCR. The prognostic implications of PAI-1 deregulation are established by tissue microarray staining of non-muscle-invasive bladder tumours. MicroRNA repression of PAI-1 is assayed by ectopic miRNA expression, argonaute immunoprecipitation and luciferase assays. RESULTS: We found that the miR-143/-145 cluster is downregulated in all stages of bladder cancer and inversely correlated with PAI-1 expression. Mature miR-143 and miR-145 are coordinately expressed, and both directly target the PAI-1 3'UTR, leading to reduced PAI-1 mRNA and protein levels. Furthermore, we show that PAI-1 and miR-145 levels may serve as useful prognostic markers for non-muscle-invasive bladder tumours for which accurate progressive outcome is currently difficult to predict. CONCLUSION: This report provides the first evidence for direct miRNA regulation of PAI-1 in bladder cancer. We also demonstrate mRNA co-targeting by a cluster of non-family miRNAs, and suggest miR-145 and PAI-1 as clinically relevant biomarkers in bladder cancer.


Assuntos
Biomarcadores Tumorais/fisiologia , MicroRNAs/fisiologia , Família Multigênica , Inibidor 1 de Ativador de Plasminogênio/fisiologia , Neoplasias da Bexiga Urinária/metabolismo , Regiões 3' não Traduzidas , Sequência de Bases , Biomarcadores Tumorais/genética , Linhagem Celular Tumoral , Primers do DNA , Humanos , Imuno-Histoquímica , Imunoprecipitação , Hibridização In Situ , MicroRNAs/genética , Análise de Sequência com Séries de Oligonucleotídeos , Inibidor 1 de Ativador de Plasminogênio/genética , Prognóstico , Proto-Oncogene Mas , RNA Mensageiro/genética , Neoplasias da Bexiga Urinária/patologia
6.
Br J Cancer ; 105(9): 1379-87, 2011 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-21979422

RESUMO

BACKGROUND: Markers for outcome prediction in bladder cancer are urgently needed. We have previously identified a molecular signature for predicting progression in non-muscle-invasive bladder cancer. ANXA10 was one of the markers included in the signature and we now validated the prognostic relevance of ANXA10 at the protein level. METHODS: We investigated ANXA10 expression by immunohistochemistry using a tissue microarray with 249 Ta and T1 urothelial carcinomas. The expression of ANXA10 was also investigated in an additional set of 97 more advanced tumours. The functional role of ANXA10 in cell lines was investigated by siRNA-mediated ANXA10 knockdown using wound-healing assays, proliferation assays, and ingenuity pathway analysis. RESULTS: Low expression of ANXA10 correlated with shorter progression-free survival in patients with stage Ta and T1 tumours (P<0.00001). Furthermore, patients with more advanced tumours and low ANXA10 expression had an unfavourable prognosis (P<0.00001). We found that ANXA10 siRNA transfected cells grew significantly faster compared with control siRNA transfected cells. Furthermore, a wound-healing assay showed that ANXA10 siRNA transfected cells spread along wound edges faster than control transfected cells. CONCLUSION: We conclude that ANXA10 may be a clinical relevant marker for predicting outcome in both early and advanced stages of bladder cancer.


Assuntos
Anexinas/metabolismo , Neoplasias da Bexiga Urinária/metabolismo , Biomarcadores Tumorais/análise , Progressão da Doença , Intervalo Livre de Doença , Regulação para Baixo , Feminino , Técnicas de Silenciamento de Genes , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Células Neoplásicas Circulantes , Prognóstico
7.
Oncogene ; 32(31): 3577-86, 2013 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-22926521

RESUMO

One major challenge in cancer research is to understand the complex interplay between the DNA damage response (DDR), genomic integrity, and tumor development. To address these issues, we analyzed 43 bladder tumor genomes from 22 patients using single nucleotide polymorphism (SNP) arrays, and tissue expression of multiple DDR proteins, including Timeless and its interaction partner Tipin. The SNP profiles confirmed and extended known copy number alterations (CNAs) at high resolution, showed clustering of CNAs at nine common fragile sites, and revealed that most metachronous tumors were clonally related. The occurrence of many novel uniparental disomy regions (UPDs) was of potential functional importance in some tumors because UPDs spanned mutated FGFR3 and PIK3CA alleles, and also homozygous deletion of the CDKN2A tumor suppressor locus. The DDR signaling as evaluated by phospho-epitope-specific antibodies against Ser139-phosphorylated H2A histone family member X (γH2AX), ataxia telangiectasia mutated (ATM), and ATM- and Rad3-related (ATR) was commonly activated in tumors with both moderate and high extent of accumulated genomic aberrations, the latter tumors showing a more frequent loss of ATM expression. Strikingly, the tumor genomes exhibiting the most complex alterations were associated with a high Ki67-proliferation index, abundant Timeless but not Tipin expression, aberrant p53 expression, and homozygous CDKN2A deletions. Of clinical relevance, evaluation of a tissue microarray (TMA; n=319) showed that abundant Timeless expression was associated with risk of progression to muscle-invasive disease (P<0.0005; hazard ratio, 2.4; 95% confidence interval, 1.6-3.8) and higher T stage (P<0.05). Univariate analysis confirmed this association (P=0.006) in an independent cohort (n=241) but statistical significance was not reached in a multivariate model. Overall, our results are consistent with DDR activation preceding the accumulation of genomic aberrations. Tumors with extensive genomic rearrangements were associated with inactivation of CDKN2A, excessive proliferation, and robust Timeless expression, the latter also correlating with the risk of disease progression. Moreover, we provide evidence to suggest that UPDs likely contribute to bladder tumorigenesis.


Assuntos
Dano ao DNA/genética , Genômica/métodos , Neoplasias da Bexiga Urinária/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Proteínas de Transporte/genética , Proteínas de Ciclo Celular/genética , Proliferação de Células , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Proteínas de Ligação a DNA , Progressão da Doença , Feminino , Predisposição Genética para Doença/genética , Homozigoto , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Masculino , Pessoa de Meia-Idade , Proteínas Nucleares/genética , Análise de Sequência com Séries de Oligonucleotídeos , Polimorfismo de Nucleotídeo Único , Deleção de Sequência , Transdução de Sinais/genética , Transcriptoma , Proteína Supressora de Tumor p53/metabolismo , Dissomia Uniparental , Neoplasias da Bexiga Urinária/patologia
8.
Cell Death Differ ; 20(11): 1485-97, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23852374

RESUMO

Oncogenic stimuli trigger the DNA damage response (DDR) and induction of the alternative reading frame (ARF) tumor suppressor, both of which can activate the p53 pathway and provide intrinsic barriers to tumor progression. However, the respective timeframes and signal thresholds for ARF induction and DDR activation during tumorigenesis remain elusive. Here, these issues were addressed by analyses of mouse models of urinary bladder, colon, pancreatic and skin premalignant and malignant lesions. Consistently, ARF expression occurred at a later stage of tumor progression than activation of the DDR or p16(INK4A), a tumor-suppressor gene overlapping with ARF. Analogous results were obtained in several human clinical settings, including early and progressive lesions of the urinary bladder, head and neck, skin and pancreas. Mechanistic analyses of epithelial and fibroblast cell models exposed to various oncogenes showed that the delayed upregulation of ARF reflected a requirement for a higher, transcriptionally based threshold of oncogenic stress, elicited by at least two oncogenic 'hits', compared with lower activation threshold for DDR. We propose that relative to DDR activation, ARF provides a complementary and delayed barrier to tumor development, responding to more robust stimuli of escalating oncogenic overload.


Assuntos
Carcinogênese/genética , Dano ao DNA , Neoplasias/genética , Proteína Supressora de Tumor p14ARF/genética , Sequência de Aminoácidos , Animais , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Modelos Animais de Doenças , Expressão Gênica , Xenoenxertos , Humanos , Imuno-Histoquímica , Camundongos , Dados de Sequência Molecular , Neoplasias/metabolismo , Neoplasias/patologia , Oncogenes , Transfecção , Proteína Supressora de Tumor p14ARF/metabolismo
9.
Oncogene ; 29(7): 1073-84, 2010 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-19915607

RESUMO

Downregulation of miR-145 in a variety of cancers suggests a possible tumor suppressor function for this microRNA. Here, we show that miR-145 expression is reduced in bladder cancer and urothelial carcinoma in situ, compared with normal urothelium, using transcription profiling and in situ hybridization. Ectopic expression of miR-145 induced extensive apoptosis in urothelial carcinoma cell lines (T24 and SW780) as characterized by caspase activation, nuclear condensation and fragmentation, cellular shrinkage, and detachment. However, cell death also proceeded upon caspase inhibition by the pharmacological inhibitor zVAD-fmk and ectopic expression of anti-apoptotic Bcl-2, indicating the activation of an alternative caspase-independent death pathway. Microarray analysis of transcript levels in T24 cells, before the onset of cell death, showed destabilization of mRNAs enriched for miR-145 7mer target sites. Among these, direct targeting of CBFB, PPP3CA, and CLINT1 was confirmed by a luciferase reporter assay. Notably, a 22-gene signature targeted on enforced miR-145 expression in T24 cells was significantly (P<0.00003) upregulated in 55 Ta bladder tumors with concomitant reduction of miR-145. Our data indicate that reduction in miR-145 expression may provide bladder cancer cells with a selective advantage by inhibition of cell death otherwise triggered in malignant cells.


Assuntos
Caspases/metabolismo , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Neoplasias da Bexiga Urinária/enzimologia , Neoplasias da Bexiga Urinária/patologia , Sequência de Bases , Inibidores de Caspase , Morte Celular/genética , Linhagem Celular Tumoral , Biologia Computacional , Regulação para Baixo , Perfilação da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Hibridização In Situ , Dados de Sequência Molecular , Fenótipo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais , Fatores de Tempo , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/metabolismo
10.
Histol Histopathol ; 23(9): 1069-76, 2008 09.
Artigo em Inglês | MEDLINE | ID: mdl-18581278

RESUMO

BACKGROUND: The identification of new prognostic markers in prostate cancer (PC) is essential to improve patient treatment and management. Data suggest that SMARCC1 protein, a part of the intranuclear SWI/SNF complex which enhances the transactivation of the androgen receptor, is upregulated in PC and therefore a possible candidate marker for PC progression. MATERIALS: Expression of SMARCC1 immunostaining was analysed on a tissue microarray containing specimens from 327 patients with prostate cancer and clinical follow-up information. Furthermore, 30 specimens from patients with benign prostate hyperplasia were included as controls as well as 30 specimens of benign prostate tissue from PC patients. Also, 18 specimens from lymph node metastases were analysed. RESULTS: All benign specimens showed no or minimal staining for SMARCC1. In contrast, 20% of the specimens from patients with non-metastatic and non-recurrent disease showed moderate to marked staining. In 31% of the patients with recurrent disease and in 31% of the patients with metastatic disease we found moderate to strong SMARCC1 immunostaining. In total, 23% of lymph node metastases expressed SMARCC1. SMARCC1 expression was also positively correlated to Gleason score (p<0.05), clinical T stage (p<0.01) and time to recurrence (p<0.001). In a logistic regression analysis, patients with a marked SMARCC1 immunostaining had a significantly elevated odds ratio (OR) of 16 for recurrent cancer and an OR of 4.5 for metastatic disease. Conclusions. Our present results demonstrate an increased expression of SMARCC1 protein in prostate cancer and reveal a positive correlation with tumour dedifferentiation, progression, metastasis and time to recurrence.


Assuntos
Adenocarcinoma/metabolismo , Neoplasias da Próstata/metabolismo , Fatores de Transcrição/metabolismo , Adenocarcinoma/secundário , Adenocarcinoma/cirurgia , Animais , Biomarcadores Tumorais/metabolismo , Células COS , Desdiferenciação Celular , Núcleo Celular/metabolismo , Núcleo Celular/patologia , Chlorocebus aethiops , Técnica Direta de Fluorescência para Anticorpo , Humanos , Técnicas Imunoenzimáticas , Linfonodos/metabolismo , Linfonodos/patologia , Metástase Linfática , Masculino , Recidiva Local de Neoplasia , Razão de Chances , Próstata/metabolismo , Próstata/patologia , Hiperplasia Prostática/metabolismo , Hiperplasia Prostática/patologia , Neoplasias da Próstata/patologia , Neoplasias da Próstata/cirurgia , Análise Serial de Tecidos , Regulação para Cima
11.
Br J Cancer ; 95(10): 1415-8, 2006 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-17003783

RESUMO

We report on the location of 283 miRNAs in the human genome in relation to copy number changes in three distinct types of tumours: prostate, bladder and colon. In prostate and colon tumours, we find miRNAs over-represented in regions with copy number gain and under-represented in regions with copy number loss. Surprisingly this pattern appears to be reversed in bladder cancer. We compared our miRNA copy number data to published miRNA expression data; unexpectedly, we did not find a statistically significant relationship between miRNA copy number and expression level. This suggests that miRNA expression is regulated through different mechanisms than mRNA expression.


Assuntos
Genoma Humano , MicroRNAs/genética , Neoplasias/genética , Neoplasias do Colo/patologia , Dosagem de Genes , Perfilação da Expressão Gênica , Humanos , Masculino , Neoplasias/patologia , Hibridização de Ácido Nucleico/métodos , Análise de Sequência com Séries de Oligonucleotídeos , Neoplasias da Próstata/patologia , Neoplasias da Bexiga Urinária/genética
12.
Br J Cancer ; 93(10): 1182-90, 2005 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-16265353

RESUMO

At present, the mechanism leading to bladder cancer is still poorly understood, and our knowledge about early events in tumorigenesis is limited. This study describes the changes in gene expression occurring during the neoplastic transition from normal bladder urothelium to primary Ta tumours. Using DNA microarrays, we identified novel differentially expressed genes in Ta tumours compared to normal bladder, and genes that were altered in high-grade tumours. Among the mostly changed genes between normal bladder and Ta tumours, we found genes related to the cytoskeleton (keratin 7 and syndecan 1), and transcription (high mobility group AT-hook 1). Altered genes in high-grade tumours were related to cell cycle (cyclin-dependent kinase 4) and transcription (jun d proto-oncogene). Furthermore, we showed the presence of high keratin 7 transcript expression in bladder cancer, and Western blotting analysis revealed three major molecular isoforms of keratin 7 in the tissues. These could be detected in urine sediments from bladder tumour patients.


Assuntos
Perfilação da Expressão Gênica , Análise de Sequência com Séries de Oligonucleotídeos , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologia , Análise por Conglomerados , Humanos , Invasividade Neoplásica , Estadiamento de Neoplasias , Proto-Oncogene Mas , Taxa de Sobrevida , Neoplasias da Bexiga Urinária/metabolismo
13.
Br J Cancer ; 92(12): 2240-8, 2005 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-15956967

RESUMO

The majority of microsatellite instable (MSI) colorectal cancers are sporadic, but a subset belongs to the syndrome hereditary non-polyposis colorectal cancer (HNPCC). Microsatellite instability is caused by dysfunction of the mismatch repair (MMR) system that leads to a mutator phenotype, and MSI is correlated to prognosis and response to chemotherapy. Gene expression signatures as predictive markers are being developed for many cancers, and the identification of a signature for MMR deficiency would be of interest both clinically and biologically. To address this issue, we profiled the gene expression of 101 stage II and III colorectal cancers (34 MSI, 67 microsatellite stable (MSS)) using high-density oligonucleotide microarrays. From these data, we constructed a nine-gene signature capable of separating the mismatch repair proficient and deficient tumours. Subsequently, we demonstrated the robustness of the signature by transferring it to a real-time RT-PCR platform. Using this platform, the signature was validated on an independent test set consisting of 47 tumours (10 MSI, 37 MSS), of which 45 were correctly classified. In a second step, we constructed a signature capable of separating MMR-deficient tumours into sporadic MSI and HNPCC cases, and validated this by a mathematical cross-validation approach. The demonstration that this two-step classification approach can identify MSI as well as HNPCC cases merits further gene expression studies to identify prognostic signatures.


Assuntos
Adenocarcinoma/genética , Neoplasias do Colo/genética , Neoplasias Colorretais Hereditárias sem Polipose/genética , Expressão Gênica/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Pareamento Incorreto de Bases/genética , Instabilidade Cromossômica/genética , Reparo do DNA/genética , Perfilação da Expressão Gênica , Humanos , Repetições de Microssatélites/genética , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Valor Preditivo dos Testes
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