Project description:Round cell component is a resk factor associated with metastasis and poor prognosis in myxoid liposarcoma. To identify microRNAs which play a role in the malignancy of round cell component, we performed microRNA microarray analysis and compared the miRNA expression profilings between myxoid and round cell component.
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: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:miR-135b expression is higher in myxoid liposarcoma cell lines than in adipose-derived mesenchymal cell line, as well as in myxoid liposarcoma tumors than in adjacent normal prostate tissues.To further investigate the molecular mechanisms regulated by miR-135b, we performed mRNA microarray analysis of cell cultures from myxoid liposarcoma cell line after transfections with miR-135b mimic or negative control.
Project description:Soft tissue sarcomas are aggressive mesenchymal cancers that affect more than 10,600 new patients per year in the US, about 40% of whom will die of their disease. Soft tissue sarcomas exhibit remarkable histologic diversity, with more than 50 recognized subtypes, but our knowledge of their genomic alterations is limited. Here we describe the results of an integrative analysis of DNA sequence, copy number, and mRNA expression in 207 samples encompassing seven major subtypes. Genes mutated in more than 5% of samples within a subtype were KIT (in gastrointestinal stromal cell tumors, or GISTs), TP53 (pleomorphic liposarcomas), PIK3CA (myxoid/round-cell liposarcoma), and NF1 (both myxofibrosarcoma and pleomorphic liposarcoma). We show evidence that PIK3CA mutations, found in 18% of myxoid/round-cell liposarcomas, activate AKT in vivo and are associated with poor outcomes. Point mutations in the tumor suppressor gene NF1 were discovered in both myxofibrosarcomas and pleomorphic liposarcomas, while genomic deletions were observed in all subtypes at varying frequencies. Finally, we found that short hairpin RNA-based knockdown of a subset of genes that are amplified in dedifferentiated liposarcoma, including CDK4 and YEATS4, decreased cell proliferation. Our study yields the most detailed map of molecular alterations across diverse sarcoma subtypes to date and provides potential subtype-specific targets for therapy.
Project description:Soft tissue sarcomas are aggressive mesenchymal cancers that affect more than 10,600 new patients per year in the US, about 40% of whom will die of their disease. Soft tissue sarcomas exhibit remarkable histologic diversity, with more than 50 recognized subtypes, but our knowledge of their genomic alterations is limited. Here we describe the results of an integrative analysis of DNA sequence, copy number, and mRNA expression in 207 samples encompassing seven major subtypes. Genes mutated in more than 5% of samples within a subtype were KIT (in gastrointestinal stromal cell tumors, or GISTs), TP53 (pleomorphic liposarcomas), PIK3CA (myxoid/round-cell liposarcoma), and NF1 (both myxofibrosarcoma and pleomorphic liposarcoma). We show evidence that PIK3CA mutations, found in 18% of myxoid/round-cell liposarcomas, activate AKT in vivo and are associated with poor outcomes. Point mutations in the tumor suppressor gene NF1 were discovered in both myxofibrosarcomas and pleomorphic liposarcomas, while genomic deletions were observed in all subtypes at varying frequencies. Finally, we found that short hairpin RNA-based knockdown of a subset of genes that are amplified in dedifferentiated liposarcoma, including CDK4 and YEATS4, decreased cell proliferation. Our study yields the most detailed map of molecular alterations across diverse sarcoma subtypes to date and provides potential subtype-specific targets for therapy.