Transcription profiling of human set of heterogenous ovarian tumor samples
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Jaroslav Petr Novak
PROVIDER: E-GEOD-6822 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:We have previously described differences in the expression profiles of tumors by comparing tumors of two known classes: low malignant potential versus highly malignant (invasive). This report presents an effort to discover unknown classes within a large heterogeneous set of ovarian tumors, using unsupervised learning approaches. We were able to define four classes in a set of 74 ovarian cancer tumors. Groups identified as A1 and A2 were closely related and correlated with the “invasive” pathology class while the group identified as B2 was correlated with low malignant potential tumors; group B1 consisted of a mixture of low potential and invasive samples. We selected characteristic candidate genes, which were validated by quantitative-PCR and by comparison to other published studies. Keywords: Unsupervised classification
2007-12-31 | GSE6822 | GEO
Project description:Background - The malignant potential of serous ovarian tumors, the most common ovarian tumor subtype, varies from benign to low malignant potential (LMP) tumors to frankly invasive cancers. Given the uncertainty about the relationship between these different forms, we compared their patterns of gene expression. Methods - Expression profiling was carried out on samples of 7 benign, 7 LMP and 28 invasive (moderate and poorly differentiated) serous tumors and surface epithelium of four normal whole ovaries using oligonucleotide microarrays representing over 21,000 genes. Results - We identified 311 transcripts that distinguished invasive from benign tumors, and 20 transcripts that were significantly differentially expressed between invasive and LMP tumors at p < 0.01 (with multiple testing correction). Five genes that were differentially expressed between invasive and either benign or normal tissues were validated by real time PCR in an independent panel of 46 serous tumors (4 benign, 7 LMP, 35 invasive). Overexpression of SLPI and WNT7A and down-regulation of C6orf31, PDGFRA and GLTSCR2 were measured in invasive and LMP compared with benign and normal tissues. Over-expression of WNT7A in an ovarian cancer cell line led to increased migration and invasive capacity. Conclusions - These results highlight several genes that may play an important role across the spectrum of serous ovarian tumorigenesis.
2009-07-28 | GSE17308 | GEO
Project description:PAX2: A Potential Biomarker for Low Malignant Potential Ovarian Tumors and Low-Grade Serous Ovarian Carcinomas
| PRJNA112503 | ENA
Project description:Objective: Ovarian tumors of low-malignant potential (LMP) and low-grade serous ovarian carcinomas are thought to represent different stages on a tumorigenic continuum and to develop along pathways distinct from that of high-grade serous ovarian carcinoma. Past studies have utilized gene expression profiles to support this theory. The objective of the current study was to identify new genes whose expression profiles in LMP ovarian tumors and low-grade ovarian carcinomas differ from that in high-grade ovarian carcinomas. Methods: We used RNA from 3 normal human ovarian surface epithelia (HOSE) and from 10 low-grade and 10 high-grade serous ovarian carcinoma samples to perform gene expression profiling. Using real-time reverse-transcription polymerase chain reaction (RT-PCR), we evaluated changes in PAX2 mRNA expression in cDNA created from RNA extracted from an independent set of ovarian tissue samples (7 LMP tumors and 17 low-grade and 23 high-grade serous carcinomas). We also examined PAX2 expression using Western blot analysis of protein extracted from a set of ovarian LMP and low- and high-grade carcinoma tissue samples. Additionally, we used immunohistochemistry (IHC) to validate PAX2 overexpression in a third independent set of paraffin ovarian tissue sections from 17 LMP tumors and 16 low- and 257 high-grade carcinomas. Results: Gene profiling revealed higher expression of PAX2 in low-grade than in high-grade ovarian carcinomas. Real-time RT-PCR demonstrated a statistically significant difference in median PAX2 mRNA expression, expressed as fold change, among ovarian LMP tumor (1837.38), low-grade (183.12), and high-grade (3.72) carcinoma samples (p=0.015). Western blot analysis revealed strong PAX2 expression in ovarian LMP and low-grade carcinoma samples but no PAX2 protein expression in high-grade carcinomas. On IHC, more LMP tumor and low-grade carcinoma samples expressed moderate to high levels of PAX2 than did high-grade ovarian carcinoma samples. The numbers of samples with strong nuclear staining was significantly higher for ovarian LMP tumors (10 of 17, p<0.001) and low-grade serous carcinomas (10 of 16, p<0.001) than for high-grade carcinomas (27 of 257). Discussion: Our identification and validation of higher PAX2 expression in ovarian LMP tumors and low-grade serous carcinomas than in high-grade carcinomas supports the two-tiered hypothesis that the first two are on a continuum and are distinct from high-grade ovarian carcinomas. PAX2 may represent a potential biomarker and future therapeutic target for individualizing chemotherapy for ovarian LMP tumors and low-grade carcinomas in the future. Experiment Overall Design: We used RNA from 3 normal human ovarian surface epithelia (HOSE) and from 10 low-grade and 10 high-grade serous ovarian carcinoma samples to perform gene expression profiling. Using real-time reverse-transcription polymerase chain reaction (RT-PCR), we evaluated changes in PAX2 mRNA expression in cDNA created from RNA extracted from an independent set of ovarian tissue samples (7 LMP tumors and 17 low-grade and 23 high-grade serous carcinomas). We also examined PAX2 expression using Western blot analysis of protein extracted from a set of ovarian LMP and low- and high-grade carcinoma tissue samples. Additionally, we used immunohistochemistry (IHC) to validate PAX2 overexpression in a third independent set of paraffin ovarian tissue sections from 17 LMP tumors and 16 low- and 257 high-grade carcinomas.
2009-06-08 | E-GEOD-14001 | biostudies-arrayexpress
Project description:Objective: Ovarian tumors of low-malignant potential (LMP) and low-grade serous ovarian carcinomas are thought to represent different stages on a tumorigenic continuum and to develop along pathways distinct from that of high-grade serous ovarian carcinoma. Past studies have utilized gene expression profiles to support this theory. The objective of the current study was to identify new genes whose expression profiles in LMP ovarian tumors and low-grade ovarian carcinomas differ from that in high-grade ovarian carcinomas. Methods: We used RNA from 3 normal human ovarian surface epithelia (HOSE) and from 10 low-grade and 10 high-grade serous ovarian carcinoma samples to perform gene expression profiling. Using real-time reverse-transcription polymerase chain reaction (RT-PCR), we evaluated changes in PAX2 mRNA expression in cDNA created from RNA extracted from an independent set of ovarian tissue samples (7 LMP tumors and 17 low-grade and 23 high-grade serous carcinomas). We also examined PAX2 expression using Western blot analysis of protein extracted from a set of ovarian LMP and low- and high-grade carcinoma tissue samples. Additionally, we used immunohistochemistry (IHC) to validate PAX2 overexpression in a third independent set of paraffin ovarian tissue sections from 17 LMP tumors and 16 low- and 257 high-grade carcinomas. Results: Gene profiling revealed higher expression of PAX2 in low-grade than in high-grade ovarian carcinomas. Real-time RT-PCR demonstrated a statistically significant difference in median PAX2 mRNA expression, expressed as fold change, among ovarian LMP tumor (1837.38), low-grade (183.12), and high-grade (3.72) carcinoma samples (p=0.015). Western blot analysis revealed strong PAX2 expression in ovarian LMP and low-grade carcinoma samples but no PAX2 protein expression in high-grade carcinomas. On IHC, more LMP tumor and low-grade carcinoma samples expressed moderate to high levels of PAX2 than did high-grade ovarian carcinoma samples. The numbers of samples with strong nuclear staining was significantly higher for ovarian LMP tumors (10 of 17, p<0.001) and low-grade serous carcinomas (10 of 16, p<0.001) than for high-grade carcinomas (27 of 257). Discussion: Our identification and validation of higher PAX2 expression in ovarian LMP tumors and low-grade serous carcinomas than in high-grade carcinomas supports the two-tiered hypothesis that the first two are on a continuum and are distinct from high-grade ovarian carcinomas. PAX2 may represent a potential biomarker and future therapeutic target for individualizing chemotherapy for ovarian LMP tumors and low-grade carcinomas in the future.
2009-05-31 | GSE14001 | GEO
Project description:Serous borderline tumours (SBOT) are a challenging group of ovarian tumours positioned between benign and malignant disease. We have profiled the DNA methylomes of 12 low grade serous carcinoma (LGSC), 19 SBOT and 16 benign serous tumours (BST) across 27,578 CpG sites to further characterise the epigenomic relationship between these subtypes of ovarian tumours. Unsupervised hierarchical clustering of DNA methylation levels showed that LGSC differ distinctly from BST, however, not from SBOT. Gene ontology analysis of genes showing differential methylation at linked CpG sites between LGSC and BST revealed significant enrichment of gene groups associated with cell adhesion, cell-cell signalling and the extracellular region consistent with a more invasive phenotype of LGSC as compared to BST. Consensus clustering highlighted differences between SBOT methylomes and returned subgroups with malignant-like or benign-like methylation profiles. Furthermore, a two loci DNA methylation signature can distinguish between these SBOT subgroups with benign-like and malignant-like methylation characteristics. Our findings indicate striking similarities between SBOT and LGSC methylomes which supports a common origin and the view that LGSC may arise from SBOT. A subgroup of SBOT can be classified into tumours with a benign-like or a malignant-like methylation profile which may help in identifying tumours more likely to progress into LGSC. Array-based methylation profiling was performed using the Infinium HumanMethylation27 BeadChip in 12 low grade serous carcinoma, 19 serous borderline tumours and 16 benign serous tumours. The reproducibility of the Infinium HumanMethylation27 BeadChips was evaluated using four biological replicates of the high grade serous ovarian cancer cell line PEO1. Differential methylation cutoff was estimated from four biological replicates by bootstrap resampling and set at Δβ ≥ 0.25 corresponding to a FDR ≤ 0.09.
2012-12-31 | E-GEOD-40105 | biostudies-arrayexpress
Project description:Low-grade serous ovarian carcinomas are typically Ras-pathway mutated, TP53 wild-type, have limited chromosomal aberration, and are frequently associated with borderline tumors. By contrast, high-grade serous ovarian carcinoma lack Ras-pathway mutations, are invariably TP53 mutated, show widespread genomic change, and are commonly BRCA-pathway disrupted. We sought to identify differences in genomic copy number changes between co-existing borderline and invasive components of serous carcinoma. Paired co-existing borderline and invasive tumor components of ovarian serous carcinoma were sampled and profiled from tumors from 7 patients
2014-10-01 | E-GEOD-57279 | biostudies-arrayexpress
Project description:Low-grade serous ovarian carcinomas are typically Ras-pathway mutated, TP53 wild-type, have limited chromosomal aberration, and are frequently associated with borderline tumors. By contrast, high-grade serous ovarian carcinoma lack Ras-pathway mutations, are invariably TP53 mutated, show widespread genomic change, and are commonly BRCA-pathway disrupted. We sought to identify differentially expressed genes between co-existing borderline and invasive components of serous carcinoma. Paired co-existing borderline and invasive tumor components were profiled from tumors from 7 patients
2014-10-01 | E-GEOD-56443 | biostudies-arrayexpress
Project description:Distinction between serous tumors of low malignant potential and serous carcinomas
| PRJNA92877 | ENA
Project description:Low-grade serous ovarian carcinomas are typically Ras-pathway mutated, TP53 wild-type, have limited chromosomal aberration, and are frequently associated with borderline tumors. By contrast, high-grade serous ovarian carcinoma lack Ras-pathway mutations, are invariably TP53 mutated, show widespread genomic change, and are commonly BRCA-pathway disrupted.We sought to identify differences in genomic copy number changes between co-existing borderline and invasive components of serous carcinoma. Paired co-existing borderline and invasive tumor components were sampled and profiled from formalin-fixed paraffin embedded tumors from 6 patients
2014-10-01 | E-GEOD-57276 | biostudies-arrayexpress