Comprehensive analyses of somatic TP53 mutation in tumors with variable mutant allele frequency
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ABSTRACT:
PROVIDER: EGAS00001002200 | EGA |
REPOSITORIES: EGA
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Project description:Low-grade ovarian serous carcinomas are believed to arise via an adenoma-serous borderline tumor-serous carcinoma sequence. In this study, we found that advanced-stage, low-grade ovarian serous carcinomas both with and without adjacent serous borderline tumor shared similar regions of loss of heterozygosity. We then analyzed 91 ovarian tumor samples for mutations in TP53, BRAF, and KRAS. TP53 mutations were not detected in any serous borderline tumors (n = 30) or low-grade serous carcinomas (n = 43) but were found in 73% of high-grade serous carcinomas (n = 18). BRAF (n = 9) or KRAS (n = 5) mutation was detected in 47% of serous borderline tumors, but among the low-grade serous carcinomas (39 stage III, 2 stage II, and 2 stage I), only one (2%) had a BRAF mutation and eight (19%) had a KRAS mutation. The low frequency of BRAF mutations in advanced-stage, low-grade serous carcinomas, which contrasts with previous findings, suggests that aggressive, low-grade serous carcinomas are more likely derived from serous borderline tumors without BRAF mutation. In addition, advanced-stage, low-grade carcinoma patients with BRAF or KRAS mutation have a better apparent clinical outcome. However, further investigation is needed. Low-grade ovarian serous carcinomas are believed to arise via an adenoma-serous borderline tumor-serous carcinoma sequence. In this study, we found that advanced-stage, low-grade ovarian serous carcinomas both with and without adjacent serous borderline tumor shared similar regions of loss of heterozygosity. We then analyzed 91 ovarian tumor samples for mutations in TP53, BRAF, and KRAS. TP53 mutations were not detected in any serous borderline tumors (n = 30) or low-grade serous carcinomas (n = 43) but were found in 73% of high-grade serous carcinomas (n = 18). BRAF (n = 9) or KRAS (n = 5) mutation was detected in 47% of serous borderline tumors, but among the low-grade serous carcinomas (39 stage III, 2 stage II, and 2 stage I), only one (2%) had a BRAF mutation and eight (19%) had a KRAS mutation. The low frequency of BRAF mutations in advanced-stage, low-grade serous carcinomas, which contrasts with previous findings, suggests that aggressive, low-grade serous carcinomas are more likely derived from serous borderline tumors without BRAF mutation. In addition, advanced-stage, low-grade carcinoma patients with BRAF or KRAS mutation have a better apparent clinical outcome. However, further investigation is needed. Gene expression analysis was performed on five serous borderline tumors with BRAF mutation and five serous borderline tumors without BRAF mutation randomly. RNA was extracted from microdissected tumor cells. Expression profiling was carried out with Affymetrix GeneChip Human Genome U133 Plus 2.0 arrays
2011-03-04 | E-GEOD-27659 | biostudies-arrayexpress
Project description:Low-grade ovarian serous carcinomas are believed to arise via an adenoma-serous borderline tumor-serous carcinoma sequence. In this study, we found that advanced-stage, low-grade ovarian serous carcinomas both with and without adjacent serous borderline tumor shared similar regions of loss of heterozygosity. We then analyzed 91 ovarian tumor samples for mutations in TP53, BRAF, and KRAS. TP53 mutations were not detected in any serous borderline tumors (n = 30) or low-grade serous carcinomas (n = 43) but were found in 73% of high-grade serous carcinomas (n = 18). BRAF (n = 9) or KRAS (n = 5) mutation was detected in 47% of serous borderline tumors, but among the low-grade serous carcinomas (39 stage III, 2 stage II, and 2 stage I), only one (2%) had a BRAF mutation and eight (19%) had a KRAS mutation. The low frequency of BRAF mutations in advanced-stage, low-grade serous carcinomas, which contrasts with previous findings, suggests that aggressive, low-grade serous carcinomas are more likely derived from serous borderline tumors without BRAF mutation. In addition, advanced-stage, low-grade carcinoma patients with BRAF or KRAS mutation have a better apparent clinical outcome. However, further investigation is needed. Low-grade ovarian serous carcinomas are believed to arise via an adenoma-serous borderline tumor-serous carcinoma sequence. In this study, we found that advanced-stage, low-grade ovarian serous carcinomas both with and without adjacent serous borderline tumor shared similar regions of loss of heterozygosity. We then analyzed 91 ovarian tumor samples for mutations in TP53, BRAF, and KRAS. TP53 mutations were not detected in any serous borderline tumors (n = 30) or low-grade serous carcinomas (n = 43) but were found in 73% of high-grade serous carcinomas (n = 18). BRAF (n = 9) or KRAS (n = 5) mutation was detected in 47% of serous borderline tumors, but among the low-grade serous carcinomas (39 stage III, 2 stage II, and 2 stage I), only one (2%) had a BRAF mutation and eight (19%) had a KRAS mutation. The low frequency of BRAF mutations in advanced-stage, low-grade serous carcinomas, which contrasts with previous findings, suggests that aggressive, low-grade serous carcinomas are more likely derived from serous borderline tumors without BRAF mutation. In addition, advanced-stage, low-grade carcinoma patients with BRAF or KRAS mutation have a better apparent clinical outcome. However, further investigation is needed.
2011-03-04 | GSE27659 | GEO
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 differences in genomic copy number changes in borderline and invasive components of serous carcinoma. Borderline and invasive tumor components were profiled from patients with LGSC
2014-10-01 | E-GEOD-57270 | biostudies-arrayexpress
Project description:Genome-wide copy number variation was measured in TP53 mutation negative ovarian tumours. Analysis described in "Driver mutations in TP53 are ubiquitous in high grade serous carcinoma of the ovary" (Ahmed et al., 2010)
2010-03-04 | GSE19416 | GEO
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:The functional status of the tumor repressor protein (TP53 or TRP53) is a defining feature of ovarian cancer. Mutant or null alleles of TP53 are expressed in greater than 90% of all high-grade serous adenocarcinomas. Wild type TP53 is elevated in low-grade serous adenocarcinomas in women and in our Pten/Kras/Amhr2-Cre mutant mouse model. Disruption of the Trp53 gene in this mouse model did not lead to high-grade ovarian cancer but did increase expression of estrogen receptor alpha (ERalpha; ESR1) and markedly enhanced the responsiveness of these cells to estrogen. Specifically, when Trp53 positive and Trp53 null mutant mice were treated with estradiol or vehicle, only the Trp53 null and Esr1 positive tumors respond vigorously to estradiol in vivo and exhibit features characteristic of high-grade type ovarian cancer: invasive growth into the ovarian stroma, rampant metastases to the peritoneal cavity and signs of genomic instability. Estrogen promoted and progesterone suppressed the growth of Trp53 null ovarian tumors and tumor cells injected intraperitoneally (IP), subcutaneously (SC) or when grown in matrigel. Exposure of the Trp53 depleted cells to estrogen also has a profound impact on the tumor microenvironment and immune-related events. These results led to the new paradigm that TRP53 status is related to the susceptibility of transformed ovarian surface epithelial (OSE) cells to estradiol-induced metastases and genomic instability. This novel finding is relevant not only for women during their reproductive years but also for women on hormone (estradiol) replacement therapies. A direct comparison of ovarian surface epithelia cells from two different genotype mice
2014-03-21 | E-GEOD-51095 | 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 were sampled and profiled from formalin-fixed paraffin embedded tumors from 6 patients
2014-10-01 | E-GEOD-57276 | biostudies-arrayexpress
Project description:High-grade serous ovarian cancer is the most aggressive histological type of epithelial ovarian cancer, which is characterized by a high frequency of somatic TP53 mutations. To provide a better understanding of the molecular mechanisms involved in the pathogenesis of these cancers and to develop a risk classification system, we conducted profiling of the copy number alterations present in these tumors. Thirty patients who were diagnosed as high-grade serous ovarian cancer were recruited in this study. Affymetrix SNP array were performed according to the manufacturer's directions on DNA extracted from high-grade serous ovarian cancer tissues or peripheral blood samples. The Japanese Serous Ovarian Cancer Study Group
2015-09-05 | E-GEOD-61237 | biostudies-arrayexpress
Project description:Epithelial ovarian cancer is morphologically and clinically heterogeneous. Transcriptional profiling has revealed molecular subtypes (referred to as M-bM-^@M-^\C-signaturesM-bM-^@M-^]) that correlate to biological as well as clinical features. We aimed to determine gene expression differences between malignant, benign and borderline serous ovarian tumors, and to investigate similarities to the intrinsic molecular subtypes of breast cancer. Global gene expression profiling was performed using Illumina's HT12 Bead Arrays and applied to 59 fresh-frozen ovarian tumors. SAM analysis revealed enrichment of cell cycel processes among the malignant tumors, in line with malignant tumors being highly proliferative. The borderline tumors were split between the malignant and benign tumor clusters, indicating that borderline tumors have both malignant and benign features. Furthermore, nearest centroid classification was performed applying previously published gene profiles for the ovarian cancer C-signatures and the intrinsic breast cancer subtypes, respectively, and showed significant correlations between the malignant serous tumors and the highly aggressive C1, C2 and C4 ovarian cancer signatures, and the basal-like breast cancer subtype. The benign and borderline serous tumors together were significantly correlated to the normal-like breast cancer subtype and the ovarian cancer C3 signature. The borderline tumors, on the other hand, correlated significantly to the Luminal A breast cancer subtype. These findings remained when analyzed in a large, independent dataset. The data in this study link the transcriptional profiles of serous ovarian cancer to the intrinsic molecular subtypes of breast cancer, in line with the shared clinical and molecular features between high-grade serous ovarian cancer and basal-like breast cancer, including an aggressive phenotype, frequent TP53 mutations and a high degree of genomic instability, and suggest that biomarkers and targeted therapies may overlap between these subsets of ovarian and breast cancers. Finally, the link between benign and borderline ovarian cancer and luminal breast cancer may indicate endocrine responsiveness in a subset of ovarian cancers. Total RNA obtained from serous ovarian adenocarcinomas, adenomas and borderline tumors. Gene expression profiling using Illumina's HT12 v4 bead arrays. Application of ovarian cancer molecular subtypes and intrinsic breast cancer subtypes using nearest centroid classification. KRAS and BRAF mutation analyses in the malignant and borderline tumors.
2014-08-15 | E-GEOD-57477 | biostudies-arrayexpress