title: Clinical relevance of peroxisome proliferator-activated receptor-gamma expression in myxoid liposarcoma.
abstract: Peroxisome proliferator-activated receptor gamma (PPARγ) is a ligand-activated transcription factor that belongs to the nuclear hormone receptor superfamily. PPARγ is essential in adipocyte differentiation from precursor cells. Its antitumorigenic effects are reported in certain malignancies; however, its effects in liposarcoma are unclear.
  
  
  
  We analyzed PPARγ expression using immunohistochemistry (IHC) in 46 patients with myxoid liposarcoma [MLS; median age, 47 years (range, 14-90 years) and mean follow-up period, 91 months (range, 13-358 months)]. PPARγ mRNA expression levels were measured by quantitative reverse transcription polymerase chain reaction. Further, we evaluated the correlation of PPARγ expression with clinical outcomes.
  
  
  
  We found that the metastasis-free survival rate was significantly higher in lower PPARγ expressers [34 patients with labeling index (LI) <50 %] than in higher expressers (12 patients with LI ≥50 %; p = 0.01). Cox multivariate analysis revealed that a higher PPARγ level was an independent predictor of metastasis (relative risk = 6.945, p = 0.026). Furthermore, using 28 fresh MLS specimens, we confirmed an increased PPARγ mRNA expression level in the higher LI group (p = 0.001).
  
  
  
  In this study, higher PPARγ expression in MLS was a risk factor associated with distant metastasis; therefore, it would be a novel prognostic marker for MLS. Further analyses will help to understand the correlation between PPARγ expression and tumor malignancy in liposarcoma.
authors.affiliation: Department of Orthopaedic Surgery, Kanazawa University Graduate School of Medical Sciences, 13-1 Takara-machi, Kanazawa, 920-8641, Japan. a_take@med.kanazawa-u.ac.jp.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Takeuchi
authors.affiliation: Department of Orthopaedic Surgery, Kanazawa University Graduate School of Medical Sciences, 13-1 Takara-machi, Kanazawa, 920-8641, Japan.
authors.forename: Norio
authors.initials: N
authors.lastname: Yamamoto
authors.affiliation: Department of Orthopaedic Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, 602-8566, Japan.
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Shirai
authors.affiliation: Department of Orthopaedic Surgery, Kanazawa University Graduate School of Medical Sciences, 13-1 Takara-machi, Kanazawa, 920-8641, Japan.
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Hayashi
authors.affiliation: Department of Orthopaedic Surgery, Kanazawa University Graduate School of Medical Sciences, 13-1 Takara-machi, Kanazawa, 920-8641, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Miwa
authors.affiliation: Department of Biochemistry and Molecular Vascular Biology, Kanazawa University Graduate School of Medical Sciences, 13-1 Takara-machi, Kanazawa, 920-8640, Japan.
authors.forename: Seiichi
authors.initials: S
authors.lastname: Munesue
authors.affiliation: Department of Biochemistry and Molecular Vascular Biology, Kanazawa University Graduate School of Medical Sciences, 13-1 Takara-machi, Kanazawa, 920-8640, Japan.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Yamamoto
authors.affiliation: Department of Orthopaedic Surgery, Kanazawa University Graduate School of Medical Sciences, 13-1 Takara-machi, Kanazawa, 920-8641, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tsuchiya
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D018208:Liposarcoma, Myxoid / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D047495:PPAR gamma / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012307:Risk Factors; D012983:Soft Tissue Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D015996:Survival Rate; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D047495:PPAR gamma; D012333:RNA, Messenger
keywords: Immunohistochemistry; Myxoid liposarcoma; PCR; Peroxisome proliferator-activated receptor gamma; Prognostic marker