Showing papers by "Philippe Terrier published in 2010"

Validated prediction of clinical outcome in sarcomas and multiple types of cancer on the basis of a gene expression signature related to genome complexity

Abstract: Sarcomas are heterogeneous and aggressive mesenchymal tumors. Histological grading has so far been the best predictor for metastasis-free survival, but it has several limitations, such as moderate reproducibility and poor prognostic value for some histological types. To improve patient grading, we performed genomic and expression profiling in a training set of 183 sarcomas and established a prognostic gene expression signature, complexity index in sarcomas (CINSARC), composed of 67 genes related to mitosis and chromosome management. In a multivariate analysis, CINSARC predicts metastasis outcome in the training set and in an independent 127 sarcomas validation set. It is superior to the Federation Francaise des Centres de Lutte Contre le Cancer grading system in determining metastatic outcome for sarcoma patients. Furthermore, it also predicts outcome for gastrointestinal stromal tumors (GISTs), breast carcinomas and lymphomas. Application of the signature will permit more selective use of adjuvant therapies for people with sarcomas, leading to decreased iatrogenic morbidity and improved outcomes for such individuals.

YAP1 and VGLL3, encoding two cofactors of TEAD transcription factors, are amplified and overexpressed in a subset of soft tissue sarcomas.

Abstract: In a series of 404 adult soft tissue sarcomas, analyzed by array-CGH, we have observed in approximately 10% of them a genomic amplification of either chromosome bands 11q22 or 3p12. These two amplicons likely target the YAP1 and VGLL3 genes, respectively. Both genes encode proteins that are cofactors of the TEAD family of transcription factors. Very good correlations between amplification and expression levels were observed. Welch test analyses of transcriptome data demonstrate that tumors with amplicons share a large set of upregulated and downregulated genes. Inhibition of YAP1 and VGLL3 in cell lines with these amplifications/overexpressions leads to similar phenotypes: decrease of proliferation rate, and to a lesser extent decrease of migration properties. These data, and the fact that these amplicons are observed either in dedifferentited liposarcomas or in undifferentiated pleomorphic sarcomas, suggest that these genetics events could be involved in oncogenesis and progression of soft tissue sarcomas. © 2010 Wiley-Liss, Inc.

Molecular characterization by array comparative genomic hybridization and DNA sequencing of 194 desmoid tumors.

Abstract: Desmoid tumors are fibroblastic/myofibroblastic proliferations. Previous studies reported that CTNNB1 mutations were detected in 84% and that mutations of the APC gene were found in several cases of sporadic desmoid tumors lacking CTNNB1 mutations. Forty tumors were analyzed by comparative genomic hybridization (CGH). Karyotype and fluorescence in situ hybridization revealed a nonrandom occurrence of trisomy 8 associated with an increased risk of recurrence. We report the first molecular characterization including a large series of patients. We performed array CGH on frozen samples of 194 tumors, and we screened for APC mutations in patients without CNNTB1 mutation. A high frequency of genomically normal tumors was observed. Four relevant and recurrent alterations (loss of 6q, loss of 5q, gain of 20q, and gain of Chromosome 8) were found in 40 out of 46 tumors with chromosomal changes. Gain of Chromosomes 8 and 20 was not associated with an increased risk of recurrence. Cases with loss of 5q had a minimal common region in 5q22.5 including the APC locus. Alterations of APC, including loss of the entire locus, and CTNNB1 mutation could explain the tumorigenesis in 89% of sporadic desmoids tumors and desmoids tumors occurring in the context of Gardner's syndrome. A better understanding of the pathogenetic pathways in the initiation and progression of desmoid tumors requires studies of 8q and 20q gains, as well as of 6q and 5q losses, and study of the Wnt/beta-catenin pathway.

Constant p53 Pathway Inactivation in a Large Series of Soft Tissue Sarcomas with Complex Genetics

Abstract: Alterations of the p53 pathway are among the most frequent aberrations observed in human cancers. We have performed an exhaustive analysis of TP53, p14, p15, and p16 status in a large series of 143 soft tissue sarcomas, rare tumors accounting for around 1% of all adult cancers, with complex genetics. For this purpose, we performed genomic studies, combining sequencing, copy number assessment, and expression analyses. TP53 mutations and deletions are more frequent in leiomyosarcomas than in undifferentiated pleomorphic sarcomas. Moreover, 50% of leiomyosarcomas present TP53 biallelic inactivation, whereas most undifferentiated pleomorphic sarcomas retain one wild-type TP53 allele (87.2%). The spectrum of mutations between these two groups of sarcomas is different, particularly with a higher rate of complex mutations in undifferentiated pleomorphic sarcomas. Most tumors without TP53 alteration exhibit a deletion of p14 and/or lack of mRNA expression, suggesting that p14 loss could be an alternative genotype for direct TP53 inactivation. Nevertheless, the fact that even in tumors altered for TP53, we could not detect p14 protein suggests that other p14 functions, independent of p53, could be implicated in sarcoma oncogenesis. In addition, both p15 and p16 are frequently codeleted or transcriptionally co-inhibited with p14, essentially in tumors with two wild-type TP53 alleles. Conversely, in TP53-altered tumors, p15 and p16 are well expressed, a feature not incompatible with an oncogenic process.