Gene expression and SNP profiling discriminates chromophobe renal cell carcinoma and oncocytoma
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ABSTRACT: Gene expression profiles, high-throughput SNP genotyping, and pathway analysis effectively distinguish chRCC from oncocytoma. We have generated a novel transcript predictor that is able to discriminate between the two entities accurately, and which has been validated both in an internal and an independent data-set, implying generalizability. A cytogenetic alteration, loss of chromosome 1p, common to renal oncocytoma and chRCC has been identified, providing the opportunities for identifying novel tumor suppressor genes and we have identified a series of immunohistochemical markers that are clinically useful in discriminating chRCC and oncocytoma. Oncocytoma and Chromophobe RCC samples - SNP chip analysis
Project description:[original title] Genomic expression and single-nucleotide polymorphism profiling discriminates chromophobe renal cell carcinoma and oncocytoma. Background : Chromophobe renal cell carcinoma (chRCC) and renal oncocytoma are two distinct but closely related entities with strong morphologic and genetic similarities. While chRCC is a malignant tumor, oncocytoma is usually regarded as a benign entity. The overlapping characteristics are best explained by a common cellular origin, and the biologic differences between chRCC and oncocytoma are therefore of considerable interest in terms of carcinogenesis, diagnosis and clinical management. Previous studies have been relatively limited in terms of examining the differences between oncocytoma and chromophobe RCC. Methods : Gene expression profiling using the Affymetrix HGU133Plus2 platform was applied on chRCC (n=15) and oncocytoma specimens (n=15). Supervised analysis was applied to identify a discriminatory gene signature, as well as differentially expressed genes. Immunohistochemical validation was performed in an independent set of tumors. Results : A novel 14 probe-set signature was developed to classify the tumors internally with 93% accuracy, and this was successfully validated on an external data-set with 94% accuracy. Parafibromin, aquaporin 6, and synaptogyrin 3 were novel immunohistochemical markers effectively discriminating the two pathologic entities. Conclusion : Gene expression profiles and pathway analysis effectively distinguish chRCC from oncocytoma. We have generated a novel transcript predictor that is able to discriminate between the two entities accurately, and which has been validated both in an internal and an independent data-set, implying generalizability. We have identified a series of immunohistochemical markers that are clinically useful in discriminating chRCC and oncocytoma.
Project description:Gene expression profiles, high-throughput SNP genotyping, and pathway analysis effectively distinguish chRCC from oncocytoma. We have generated a novel transcript predictor that is able to discriminate between the two entities accurately, and which has been validated both in an internal and an independent data-set, implying generalizability. A cytogenetic alteration, loss of chromosome 1p, common to renal oncocytoma and chRCC has been identified, providing the opportunities for identifying novel tumor suppressor genes and we have identified a series of immunohistochemical markers that are clinically useful in discriminating chRCC and oncocytoma.
Project description:[original title] Genomic expression and single-nucleotide polymorphism profiling discriminates chromophobe renal cell carcinoma and oncocytoma. Background : Chromophobe renal cell carcinoma (chRCC) and renal oncocytoma are two distinct but closely related entities with strong morphologic and genetic similarities. While chRCC is a malignant tumor, oncocytoma is usually regarded as a benign entity. The overlapping characteristics are best explained by a common cellular origin, and the biologic differences between chRCC and oncocytoma are therefore of considerable interest in terms of carcinogenesis, diagnosis and clinical management. Previous studies have been relatively limited in terms of examining the differences between oncocytoma and chromophobe RCC. Methods : Gene expression profiling using the Affymetrix HGU133Plus2 platform was applied on chRCC (n=15) and oncocytoma specimens (n=15). Supervised analysis was applied to identify a discriminatory gene signature, as well as differentially expressed genes. Immunohistochemical validation was performed in an independent set of tumors. Results : A novel 14 probe-set signature was developed to classify the tumors internally with 93% accuracy, and this was successfully validated on an external data-set with 94% accuracy. Parafibromin, aquaporin 6, and synaptogyrin 3 were novel immunohistochemical markers effectively discriminating the two pathologic entities. Conclusion : Gene expression profiles and pathway analysis effectively distinguish chRCC from oncocytoma. We have generated a novel transcript predictor that is able to discriminate between the two entities accurately, and which has been validated both in an internal and an independent data-set, implying generalizability. We have identified a series of immunohistochemical markers that are clinically useful in discriminating chRCC and oncocytoma. 30 mRNA profiling samples (15 chromophobe RCC, 15 oncocytoma)
Project description:We profiled DNA methylation in fresh-frozen oncocytoma and chRCC tumors and tumor-adjacent adjacent normal tissue to identify a signature of differentially methylated CpG sites that robustly distinguish oncocytoma from chRCC. DNA methylation profiles were generated for renal oncocytomas (n=12), primary kidney chromophobes (chRCC) (n=8) and primary kidney clear cell carcinomas (ccRCC) (n=2). Also profiled were three oncocytic neoplasms of unclear pathological diagnosis, including two masses described as hybrid oncocytic/chromophobe type (n=2), and one mass described as hybrid oncocytic renal neoplasm. Also profiled were histologically normal adjacent kidney parenchyma tissue (NKP) from a subset of these patients, including NKP from oncocytoma (n=7), chRCC (n=5), ccRCC (n=1), hybrid oncocytic/chromophobe type (n=1), and hybrid oncocytic renal neoplasm (n=1) bearing kidneys (combined n=15 NKP).
Project description:This study aims to compare gene expression profiles of chromophobe renal cell carcinoma (RCC) and benign oncocytoma, aiming at identifying differentially expressed genes.
Project description:Chromosomal abnormalities, such as structural and numerical abnormalities, are a common occurrence in cancer. The close association of homologous chromosomes during interphase, a phenomenon termed somatic chromosome pairing, has been observed in cancerous cells, but the functional consequences of somatic pairing have not been established. Gene expression profiling studies revealed that somatic pairing of chromosome 19 is a recurrent chromosomal abnormality in renal oncocytoma, a neoplasia of the adult kidney. Somatic pairing was associated with significant disruption of gene expression within the paired regions and resulted in the deregulation of the prolyl-hydroxylase EGLN2, a key protein that regulates the oxygen-dependent degradation of hypoxia-inducible factor (HIF). Overexpression of EGLN2 in renal oncocytoma increased ubiquitin-mediated destruction of HIF and concomitantly suppressed the expression of several HIF-target genes, including the pro-death BNIP3L gene. The transcriptional changes that are associated with somatic pairing of chromosome 19 mimic the transcriptional changes that occur following DNA amplification. Therefore, in addition to numerical and structural chromosomal abnormalities, alterations in chromosomal spatial dynamics should be considered as genomic events that are associated with tumorigenesis. The identification of EGLN2 as a significantly deregulated gene that maps within the paired chromosome region directly implicates defects in the oxygen-sensing network to the biology of renal oncocytoma. Keywords: Gene expression profiling, SNP analysis, renal, tumor Oncocytoma and Chromophobe RCC samples - expression profiling and SNP chip analysis
Project description:This study aims to compare gene expression profiles of chromophobe renal cell carcinoma (RCC) and benign oncocytoma, aiming at identifying differentially expressed genes. Experiment Overall Design: Nine cases each of chromophobe RCC and oncocytoma were analyzed by oligonucleotide microarray. Candidate genes that showed consistent differential expression were validated by RT-PCR using 25 fresh-frozen and 15 formalin-fixed paraffin-embedded tumor samples. Immunohistochemical analysis was also performed for two selected gene products, Claudin 8 and MAL2.
Project description:The proteome of clinical tissue samples diagnosed with chromophobe renal cell carcinomas (chRCC) and renal oncocytomas (RO) were evaluated to establish a potential discriminative biomarker panel of proteins for these two tumors subtypes.
Project description:Renal cell carcinoma is the most common neoplasm of the adult kidney. A few subtypes of RCC include papillary RCC (pRCC), chromophobe RCC (chRCC) and the benign oncocytoma tumor. In some cases, distinguishing between the RCC subyptes is difficult. We performed a mircroRNA (miRNA) microarray to determine differential miRNA expression between pRCC, chRCC, and oncocytoma. We performed a miRNA microarray on 10 tumor samples of each papillary renal cell carcinoma (pRCC), chromophobe renal cell carcinoma (chRCC), and oncocytoma.
Project description:Renal cell carcinoma is the most common neoplasm of the adult kidney. A few subtypes of RCC include papillary RCC (pRCC), chromophobe RCC (chRCC) and the benign oncocytoma tumor. In some cases, distinguishing between the RCC subyptes is difficult. We performed a mircroRNA (miRNA) microarray to determine differential miRNA expression between pRCC, chRCC, and oncocytoma.