Project description:Unsupervised clustering of desmoid tumors and normal mesenchymal tissues was performed using henes associated with HIF1 activity. This accurately distiguished neoplastic tissues from normal controls The study sought to identify genes differentially expressed in desmoid-type fibromatosis as opposed to normal mesenchymal tissues. We noted that beta-catenin, the central driver in desmoid-type fibromatosis, appeared to regulate HIF1 signaling in in vitro studies. Genes associated with HIF1 and angiogenesis pathways were then used to perform unsupervised clustering on desmoid tumors and normal mesenchymal tissues. The genes accurately differentiated neoplastic and normal samples.
Project description:Purpose: This study sought to identify signaling pathways that modulate β-catenin function in desmoid cells, affecting natural history and sorafenib response. Experimental Design: In vitro experiments utilized primary desmoid cell lines to examine interaction of β-catenin signaling with other pathways. Relevance of in vitro results was assessed in surgical specimens and Alliance trial A091105 correlative biopsies. Results: CTNNB1 knockdown inhibited hypoxia-regulated gene expression in vitro and reduced levels of HIF1α. Expression of hypoxia-associated genes clustered desmoids separately from normal mesenchymal tissue. ChIP-seq identified ABL1 as a β-catenin transcriptional target that modulated HIF1α protein expression and desmoid cell proliferation. Abrogation of either CTNNB1 or HIF1 inhibited the ability of desmoid cells to induce VEGFR2 phosphorylation and tube formation in endothelial cell co-cultures. Sorafenib inhibited this activity directly but also reduced HIF1α protein expression and c-Abl activity while inhibiting PDGFRβ signaling in desmoid cells. Conversely, c-Abl activity and desmoid cell proliferation were positively regulated by activation of PDGF signaling. Reduction in PDGFRβ and c-Abl phosphorylation was commonly observed in samples from patients after treatment with sorafenib; baseline samples in patients with greater drug response tended to have higher baseline PDGFRβ/c-Abl pathway activation. Conclusions: The β-catenin transcriptional target ABL1 is necessary for proliferation and maintenance of HIF1α protein expression in desmoid cells. Regulation of c-Abl activity by PDGF signaling and targeted therapies modulates desmoid cell proliferation, thereby suggesting a reason for variable biologic behavior between tumors, a mechanism for sorafenib activity in desmoids, and markers predictive of outcome in patients.
Project description:Desmoid tumors (also called deep or aggressive fibromatoses) are potentially life-threatening fibromatous lesions. Hereditary desmoid tumors arise in individuals affected by either familial adenomatous polyposis (FAP) or hereditary desmoid disease (HDD) carrying germline mutations in APC. Most non-FAP (sporadic) desmoids carry somatic mutations in the beta-catenin gene. Previous studies identified losses on 5q and 6q, and gains on 8q and 20q as recurrent genetic changes in desmoids. However, virtually all genetic changes were derived from sporadic tumors. To investigate the somatic alterations in FAP-associated desmoids and to compare them with changes occurring in sporadic tumors, we analyzed 17 FAP-associated and 38 sporadic desmoids for copy number abnormalities (CNAs) by means of array comparative genomic hybridization and multiple ligation-dependent probe amplification. Overall, the desmoids displayed only a limited number of genetic changes, occurring in 44% of cases. Common gains at 8q (7%) and 20q (5%) were almost exclusively found in sporadic tumors. Frequent common losses were observed within a 700 kb region at 5q22.2, comprising the APC gene (11%), in a 2 Mb region at 6p21.2-p21.1 (15%), and in a relatively large region at 6q15-q23.3 (20%). The FAP-associated desmoids displayed a significantly higher frequency of CNAs (59%) than the sporadic tumors (37%). As predicted by the APC germline mutations among these patients, a relatively high percentage (29%) of the FAP-associated desmoids showed loss of the APC region at 5q22.2, which was infrequently (3%) seen among sporadic tumors. Our data suggest that loss of region 6q15-q16.2 is an important event in FAP-associated as well as sporadic desmoids, most likely of relevance for desmoid tumor progression.
Project description:Desmoid tumors (also called deep or aggressive fibromatoses) are potentially life-threatening fibromatous lesions. Hereditary desmoid tumors arise in individuals affected by either familial adenomatous polyposis (FAP) or hereditary desmoid disease (HDD) carrying germline mutations in APC. Most non-FAP (sporadic) desmoids carry somatic mutations in the beta-catenin gene. Previous studies identified losses on 5q and 6q, and gains on 8q and 20q as recurrent genetic changes in desmoids. However, virtually all genetic changes were derived from sporadic tumors. To investigate the somatic alterations in FAP-associated desmoids and to compare them with changes occurring in sporadic tumors, we analyzed 17 FAP-associated and 38 sporadic desmoids for copy number abnormalities (CNAs) by means of array comparative genomic hybridization and multiple ligation-dependent probe amplification. Overall, the desmoids displayed only a limited number of genetic changes, occurring in 44% of cases. Common gains at 8q (7%) and 20q (5%) were almost exclusively found in sporadic tumors. Frequent common losses were observed within a 700 kb region at 5q22.2, comprising the APC gene (11%), in a 2 Mb region at 6p21.2-p21.1 (15%), and in a relatively large region at 6q15-q23.3 (20%). The FAP-associated desmoids displayed a significantly higher frequency of CNAs (59%) than the sporadic tumors (37%). As predicted by the APC germline mutations among these patients, a relatively high percentage (29%) of the FAP-associated desmoids showed loss of the APC region at 5q22.2, which was infrequently (3%) seen among sporadic tumors. Our data suggest that loss of region 6q15-q16.2 is an important event in FAP-associated as well as sporadic desmoids, most likely of relevance for desmoid tumor progression. Fifty-three fresh frozen tumor samples were collected at four institutes: Center for Human Genetics, University of Leuven, Belgium (21 samples); INSERM U674, Fondation Jean Dausset-CEPH, Paris, France (15 samples); Hospital for Sick Children, Toronto, Canada (13 samples); and the Italian Registry of Hereditary Colorectal Cancer (Dr. L. Bertario, 4 samples). In addition, DNA of two fresh frozen tumors, HDD-H of patient III:2 and HDD-I of patient III:6, of our hereditary desmoids disease (HDD) family10 was available (Table 1). In this family, multifocal desmoid tumors were inherited as an autosomal dominant trait, and HDD segregated with a 3' APC mutation at codon 1924. For the latter reason, they were classified as FAP tumors in this study. Three FAP tumors were derived from a family with 2 relatives in the study (D15-1 and D15-2 of a male patient and D16 of his sister). Colonic polyposis had been observed in 12 FAP patients, not in the 2 HDD-FAP patients and not in patient D15. The germline APC mutation was known in 14 of 17 FAP-associated tumors. In 28 of 38 non-FAP-associated desmoid tumors, the beta-catenin gene (CTNNB1) mutation in exon 3 was known and in 1 of 38 tumors an APC mutation was present (data not shown). The remaining tumors were characterized as FAP or non-FAP based on clinical data and positivity of tumor cells upon immunostaining for beta-catenin. DNA was extracted from the tumor samples according to standard methods.
Project description:The mechanisms underlying oncogenesis in desmoid-type fibromatosis are poorly understood. This project sought to understand how β-catenin may function to promote desmoid formation and how external signaling by PDGFRβ modulates this activity. To examine this question, RNA-seq was performed on CTNNB1 knock-downs. Gene set enrichment analysis suggested that the oncogene controlled HIF1 and angiogenesis pathways; expression of related genes accurately differentiated desmoids analyzed by U133A array from normal mesenchymal tissues. We identified c-ABL as a direct transcriptional target of β-catenin that promoted HIF1α expression in desmoid cells. We also noted that c-ABL activity was enhanced by PDGFRβ. PDGFRβ enhanced desmoid cell proliferation and c-ABL was necessary for desmoid proliferation. To identify potential markers of PDGFRβ/c-ABL activity in vivo, we assessed RNA-seq of desmoid cells treated with PDGF-BB. ERG1 transcription was highly upregulate and IHC of ERG1 was subsequently used to assess outcomes in desmoid patients with biopsies available for testing.
Project description:The mechanisms underlying oncogenesis in desmoid-type fibromatosis are poorly understood. This project sought to understand how β-catenin may function to promote desmoid formation and how external signaling by PDGFRβ modulates this activity. To examine this question, RNA-seq was performed on CTNNB1 knock-downs. Gene set enrichment analysis suggested that the oncogene controlled HIF1 and angiogenesis pathways; expression of related genes accurately differentiated desmoids analyzed by U133A array from normal mesenchymal tissues. We identified c-ABL as a direct transcriptional target of β-catenin that promoted HIF1α expression in desmoid cells. We also noted that c-ABL activity was enhanced by PDGFRβ. PDGFRβ enhanced desmoid cell proliferation and c-ABL was necessary for desmoid proliferation. To identify potential markers of PDGFRβ/c-ABL activity in vivo, we assessed RNA-seq of desmoid cells treated with PDGF-BB. ERG1 transcription was highly upregulate and IHC of ERG1 was subsequently used to assess outcomes in desmoid patients with biopsies available for testing.
Project description:One of the main problems in managing desmoids tumors is their locoregional aggressiveness and their high ability to recur after initial treatment. In our work, with the goal to identify molecular markers that can predict Progression-Free Survival, gene-expression screening was conducted on 128 available independent untreated primary desmoid tumors using cDNA microarray. By analyzing expression profiles, we have identified, for the first time, a gene expression signature that is able to predict Progression-Free Survival. This molecular signature identified two groups with clearly distinct Progression-Free Survival in the two sets of subjects. Patients in good prognostic group had achieved a progression-free 2-year survival rate of 86% while patients in poor prognostic group had a progression-free 2-year survival rate of 44%. 128 available independent untreated primary desmoid tumors
Project description:Ctcf heterozygous knockout mice are susceptible to neoplasia in a broad range of tissues, including lymphoma, endometrial cancer, and non-small cell lung cancer. Retention of the wild type Ctcf allele in these tumors establishes CTCF as a haploinsufficient tumor suppressor gene. Both human tumors and normal murine tissues with CTCF disruption are characterized by genome-wide differences in DNA methylation relative to CTCF wild type tissues, indicating even modest disruption of CTCF broadly destabilizes DNA methylation in vivo. This cross species functional analysis identifies CTCF as a commonly mutated tumor suppressor gene and establishes a central role for DNA methylation stability in tumor suppression. RRBS sequencing of transgenic Ctcf heterozygous mice and wild-type litter mate whole lung tissue.
Project description:Desmoid tumors (DTs) are rare mesenchymal monoclonal lesions that have a high risk of local recurrence but lack metastatic potential. Since the Notch pathway appears to be important in the carcinogenesis of several tumor types, in the past few years γ-secretase inhibitors (GSIs) have emerged as a potential therapeutic treatment by inhibiting cancer cell Notch signaling through NICD cleavage blockade. To investigate the antitumor effect of PF-03084014, a γ-secretase inhibitor, in DT models, cells treated with PF-03084014 were characterized by gene array analysis. Three cell strains of Desmoid tumors (Desm14, Desm27 and Desm39b) were subjected to either no treatment (control, called G-0) or treatment with 10μM of PF-03084014 (called G-10). The regimen for each treatment was ~8 days and ~30 days; multiple group comparison