title: Gene expression analysis of soft tissue sarcomas: characterization and reclassification of malignant fibrous histiocytoma.
abstract: In soft tissue sarcomas, the diagnosis of malignant fibrous histiocytoma (MFH) has been a very controversial issue, and MFH is now considered to be reclassified into pleomorphic subtypes of other sarcomas. To characterize MFH genetically, we used an oligonucleotide microarray to analyze gene expression in 105 samples from 10 types of soft tissue tumors. Spindle cell and pleomorphic sarcomas, such as dedifferentiated liposarcoma, myxofibrosarcoma, leiomyosarcoma, malignant peripheral nerve sheath tumor (MPNST), fibrosarcoma and MFH, showed similar gene expression patterns compared to other tumors. Samples from those five sarcoma types could be classified into respective clusters based on gene expression by excluding MFH samples. We calculated distances between MFH samples and other five sarcoma types (dedifferentiated liposarcoma, myxofibrosarcoma, leiomyosarcoma, MPNST and fibrosarcoma) based on differentially expressed genes and evaluated similarities. Three of the 21 MFH samples showed marked similarities to one of the five sarcoma types, which were supported by histological findings. Although most of the remaining 18 MFH samples showed little or no histological resemblance to one of the five sarcoma types, 12 of them showed moderate similarities in terms of gene expression. These results explain the heterogeneity of MFH and show that the majority of MFHs could be reclassified into pleomorphic subtypes of other sarcomas. Taken together, gene expression profiling could be a useful tool to unveil the difference in the underlying molecular backgrounds, which leads to a rational taxonomy and diagnosis of a diverse group of soft tissue sarcomas.
authors.affiliation: Cancer Transcriptome Project, National Cancer Center Research Institute, Tokyo, Japan.
authors.forename: Robert
authors.initials: R
authors.lastname: Nakayama
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nemoto
authors.forename: Hiro
authors.initials: H
authors.lastname: Takahashi
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Ohta
authors.forename: Akira
authors.initials: A
authors.lastname: Kawai
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Seki
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Yoshida
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Toyama
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ichikawa
authors.forename: Tadashi
authors.initials: T
authors.lastname: Hasegawa
mesh_terms: D016000:Cluster Analysis; D005350:Fibroma / Q000235:genetics / Q000473:pathology; D005354:Fibrosarcoma / Q000235:genetics / Q000473:pathology; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D051677:Histiocytoma, Malignant Fibrous / Q000145:classification / Q000235:genetics / Q000473:pathology; D006801:Humans; D008080:Liposarcoma / Q000235:genetics / Q000473:pathology; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012509:Sarcoma / Q000235:genetics / Q000473:pathology*; D012983:Soft Tissue Neoplasms / Q000235:genetics / Q000473:pathology*