Project description:Identification of differential gene regulation pattern in human liposarcoma The FUS-CHOP fusion protein has been found to be instrumental for specific oncogenic processes in liposarcoma, but its ability to induce metastasis and the underlying mechanisms by which this can be achieved remain unknown. In order to dissect its functional role in this context, we stably overexpressed this protein in SW872 liposarcoma and HT1080 fibrosarcoma cell lines, and were able to demonstrate that forced expression of FUS-CHOP significantly increases migration and invasion, as well as enhance lung and liver metastasis in the in vivo chicken chorioallantoic membrane (CAM) model, that is proliferation independent. Additionally, FUS-CHOP enhances the expression of matrix-metalloproteinases -2 and -9, and transactivates their promoters in vitro. Mutational analysis showed that C/EBP-β- (-769/-755), NF-κB (-525/-516) and CREB/AP-1 (-218/-207) sites were important for MMP-2, and NF-κB (-604/-598), AP-1 (-539/-532) and AP-1 (-81/-72) for MMP-9 transactivation. Moreover, a direct in vivo interaction of FUS-CHOP was observed in case of the MMP-2 promoter within region (-769/-207). siRNA data revealed that MMP-2 expression is essential in the FUS-CHOP induced metastatic phenotype. MMP-2-mRNA and protein expression correlated significantly with FUS-CHOP positivity in 31 resected patient liposarcoma tissues. We have for the first time provided substantial evidence for the FUS-CHOP oncoprotein as an inducer of metastasis that is due to the transcriptional induction of specific tumor-associated proteases. Insights gained from this study not only support a deeper understanding of the mechanistic properties of FUS-CHOP, but also open up new avenues for targeted therapy. 3 liposarcoma tumor samples, 3 corresponding normal samples, one sample replicated
Project description:Identification of differential gene regulation pattern in human liposarcoma The FUS-CHOP fusion protein has been found to be instrumental for specific oncogenic processes in liposarcoma, but its ability to induce metastasis and the underlying mechanisms by which this can be achieved remain unknown. In order to dissect its functional role in this context, we stably overexpressed this protein in SW872 liposarcoma and HT1080 fibrosarcoma cell lines, and were able to demonstrate that forced expression of FUS-CHOP significantly increases migration and invasion, as well as enhance lung and liver metastasis in the in vivo chicken chorioallantoic membrane (CAM) model, that is proliferation independent. Additionally, FUS-CHOP enhances the expression of matrix-metalloproteinases -2 and -9, and transactivates their promoters in vitro. Mutational analysis showed that C/EBP-β- (-769/-755), NF-κB (-525/-516) and CREB/AP-1 (-218/-207) sites were important for MMP-2, and NF-κB (-604/-598), AP-1 (-539/-532) and AP-1 (-81/-72) for MMP-9 transactivation. Moreover, a direct in vivo interaction of FUS-CHOP was observed in case of the MMP-2 promoter within region (-769/-207). siRNA data revealed that MMP-2 expression is essential in the FUS-CHOP induced metastatic phenotype. MMP-2-mRNA and protein expression correlated significantly with FUS-CHOP positivity in 31 resected patient liposarcoma tissues. We have for the first time provided substantial evidence for the FUS-CHOP oncoprotein as an inducer of metastasis that is due to the transcriptional induction of specific tumor-associated proteases. Insights gained from this study not only support a deeper understanding of the mechanistic properties of FUS-CHOP, but also open up new avenues for targeted therapy.
Project description:We identified novel protein-protein interactions between FUS-CHOP, a fusion oncoprotein that drives myxoid liposarcoma, and SNF2H, the ATPase subunit of the imitation switch (ISWI) chromatin remodeling complex. We used antibodies for FUS-CHOP, SNF2H, and H3K27ac to profile localization of these proteins and histones marks on chromatin in human MLPS cell lines and show that colocalization of FUS-CHOP and SNF2H occurs at new enhancers marked by H3K27ac.
Project description:FUS-CHOP and EWS-CHOP balanced translocations characterize myxoid liposarcoma which encompasses myxoid (ML) and round cell (RC) variants initially believed to be distinct diseases. Currently, myxoid and RC liposarcoma are regarded to represent the well differentiated and the poorly differentiated ends, respectively, within spectrum of myxoid liposarcoma where the fusion proteins blocking lipogenic differentiation play a role in tumor initiation while molecular determinants associated to progression to RC remain poorly understood. Activation of AKT pathway sustained by PIK3CA and PTEN mutations and growth factor receptor signalling such as RET and IGF1R have been recently correlated with the increasing of aggressiveness and RC. Aim of the present study is to elucidate molecular events involved in driving round cell progression analyzing two small series of MLS selected to be representative of the two end of the gamut: the pure myxoid (0% of RC component) and RC with high cellular component (≥80%). The validation series (INT-B) consisted of cryopreserved samples obtained from 12 patients. Six cases were pure myxoid and six were pure RC. The diagnoses were confirmed by means of FISH analysis, which revealed CHOP rearrangement, or by RT-PCR searching for the transcript type. Different molecular variants of the fusion transcript have been described by Powers MP et al. (Mod Pathol. 2010).
Project description:FUS-CHOP and EWS-CHOP balanced translocations characterize myxoid liposarcoma which encompasses myxoid (ML) and round cell (RC) variants initially believed to be distinct diseases. Currently, myxoid and RC liposarcoma are regarded to represent the well differentiated and the poorly differentiated ends, respectively, within spectrum of myxoid liposarcoma where the fusion proteins blocking lipogenic differentiation play a role in tumor initiation while molecular determinants associated to progression to RC remain poorly understood. Activation of AKT pathway sustained by PIK3CA and PTEN mutations and growth factor receptor signalling such as RET and IGF1R have been recently correlated with the increasing of aggressiveness and RC. Aim of the present study is to elucidate molecular events involved in driving round cell progression analyzing two small series of MLS selected to be representative of the two end of the gamut: the pure myxoid (0% of RC component) and RC with high cellular component (≥80%). The training series (INT-A) was made up of formalin-fixed paraffin embedded samples obtained from 12 patients. The diagnoses were confirmed by means of FISH analysis, which revealed CHOP rearrangement, or by RT-PCR searching for the transcript type. Different molecular variants of the fusion transcript have been described by Powers MP et al. (Mod Pathol. 2010).
Project description:Transcriptional profiling of patient-derived xenograft models of myxoid liposarcoma with either FUS-CHOP type I, named as ML017, or FUS-CHOP type III, named as ML006. Both ML017 and ML006 are responsive to trabectedin treatment, while model ML017/ET has aquired resistance to the drug. Samples are either under untreated conditions, or treated either with trabectedin or pioglitazone or both.
Project description:FUS-CHOP and EWS-CHOP balanced translocations characterize myxoid liposarcoma which encompasses myxoid (ML) and round cell (RC) variants initially believed to be distinct diseases. Currently, myxoid and RC liposarcoma are regarded to represent the well differentiated and the poorly differentiated ends, respectively, within spectrum of myxoid liposarcoma where the fusion proteins blocking lipogenic differentiation play a role in tumor initiation while molecular determinants associated to progression to RC remain poorly understood. Activation of AKT pathway sustained by PIK3CA and PTEN mutations and growth factor receptor signalling such as RET and IGF1R have been recently correlated with the increasing of aggressiveness and RC. Aim of the present study is to elucidate molecular events involved in driving round cell progression analyzing two small series of MLS selected to be representative of the two end of the gamut: the pure myxoid (0% of RC component) and RC with high cellular component (≥80%).
Project description:FUS-CHOP and EWS-CHOP balanced translocations characterize myxoid liposarcoma which encompasses myxoid (ML) and round cell (RC) variants initially believed to be distinct diseases. Currently, myxoid and RC liposarcoma are regarded to represent the well differentiated and the poorly differentiated ends, respectively, within spectrum of myxoid liposarcoma where the fusion proteins blocking lipogenic differentiation play a role in tumor initiation while molecular determinants associated to progression to RC remain poorly understood. Activation of AKT pathway sustained by PIK3CA and PTEN mutations and growth factor receptor signalling such as RET and IGF1R have been recently correlated with the increasing of aggressiveness and RC. Aim of the present study is to elucidate molecular events involved in driving round cell progression analyzing two small series of MLS selected to be representative of the two end of the gamut: the pure myxoid (0% of RC component) and RC with high cellular component (≥80%).
Project description:The TLS-CHOP fusion protein is found in the majority of human myxoid liposarcomas (MLS), and is thought to have oncogenic functions. Until now, however, the molecular function of TLS-CHOP for oncogenesis is still elusive. In this report, we have revealed that knockdown of TLS-CHOP by specific siRNA in MLS-derived cell lines inhibits cell growth and leads to cell death. Thus, TLS-CHOP may be a promising therapeutic target for MLS treatment. Thus we explored the target genes of TLS-CHOP influence cell-proliferation or cell death with microarray. We compared the whole mRNA profiles of cells treated with TLS-CHOP siRNA or control oligo in two myxoid liposarcoma cell-line.
Project description:Although different sarcomas have been modeled in mice upon expression of fusion oncogenes in MSCs, sarcomagenesis has not been successfully modeled in human MSCs (hMSCs). We report that FUS-CHOP, a hallmark fusion gene in mixoid liposarcoma (MLS), has an instructive role in lineage commitment, and its expression in hMSC sequentially immortalized/transformed with up to 5 oncogenic hits (p53 and Rb deficiency, hTERT over-expression, c-myc stabilization and H-RASv12 mutation) drives the formation of serially transplantable MLS. This is the first model of sarcoma based on the expression of a sarcoma-associated fusion protein in hMSC, and allowed us to unravel the differentiation processes and signaling pathways altered in the MLS-initiating cells. This study will contribute to test novel therapeutic approaches, and constitutes a proof-of-concept to employ hMSCs as target cell for modeling other fusion gene-associated human sarcomas. Wild type (MSC-0H) or transformed (MSC-5H) BM-hMSCs were transduced with concentrated viral particles expressing either pRRL-EF1?-PGK-GFP (empty vector; GFP) or pRRL-EF1?-FUS-CHOP-PGK-GFP (FUSCHOP expressing vector; FC) in order to generate MSC-0H-GFP, MSC-0H-FC, MSC-5H-GFP and MSC-5H-FC cell lines. MSC-0H-GFP and MSC-0H-FC cells did not develop tumors, meanwhile MSC-5H-GFP cells gave rise to undifferentiated sarcomas and MSC-5H-FC originated mixoid liposarcoma tumors when inoculated into immunedeficient mice. Several cell lines were derived from tumors developed from MSC-5H-GFP (T-5H-GFP-1 to -3 cell lines) and MSC-5H-FC (T-5H-FC-1 to -3 cell lines) cells. Gene expression analysis was performed using MSC-0H, MSC-5H and T-5H cell lines and lists of differentially expressed genes were created by comparing the gene expression profiles of MSC-0H-FC, MSC-5H-FC and T-5H-FC cell types to the control MSC-0H-GFP cells.