title: Dysadherin expression as a significant prognostic factor and as a determinant of histologic features in synovial sarcoma: special reference to its inverse relationship with E-cadherin expression.
abstract: Dysadherin is a cancer-associated cell membrane glycoprotein, which down-regulates E-cadherin and promotes metastasis. Synovial sarcoma is a very rare mesenchymal tumor that exhibits an epithelial profile. To confirm the diagnosis of synovial sarcoma, we evaluated several immunohistochemical markers, or detected SYT-SSX fusion gene transcript. We studied the clinicopathologic features in 92 synovial sarcoma patients and also assessed the immunohistochemical expression of dysadherin and E-cadherin to examine their possible association with histologic subtype and biologic behavior. Moreover, among 30 patients, for whom frozen materials were available, dysadherin mRNA expression was examined by reverse transcription-polymerase chain reaction and real-time quantitative reverse transcription-polymerase chain reaction analysis. Dysadherin-positive expression was significantly correlated with E-cadherin-reduced expression (P=0.0004). Dysadherin-positive immunostaining was diffusely observed in the membranes of tumor cells in 30/68 (44%) patients with monophasic fibrous type and in 1/2 (50%) patients with poorly differentiated type. However, in biphasic tumors, dysadherin expression in the fibrous component was not diffusely observed, but often sporadically or focally observed [20/22 (91%) patients]. In addition, dysadherin mRNA expression in monophasic fibrous type was significantly higher than in biphasic type (P=0.0079). Synovial sarcoma patients with dysadherin expression survived for a significantly shorter time than those without dysadherin expression (P=0.0006). Patients with combined dysadherin-positive expression and E-cadherin-reduced expression had a significantly worse prognosis than those with other combinations of dysadherin and E-cadherin expression (P=0.0007). SYT-SSX fusion gene transcript was detected in 39 patients. In our series, SYT-SSX fusion type was found to have no correlation with histologic subtype, prognosis, or dysadherin expression. In multivariate analysis, dysadherin immunopositivity (P=0.0411) was an independent adverse prognostic factor, in addition to a high MIB-1 labeling index (> or =10%). We conclude that E-cadherin dysfunction by dysadherin is associated with reduced E-cadherin expression and morphologic change from epithelioid to spindle phenotype. Dysadherin expression is considered to be one of the determinants of histologic subtype in synovial sarcoma. Moreover, dysadherin expression is an excellent and independent prognostic indicator.
authors.affiliation: Department of Anatomic Pathology, Pathological Sciences, Graduate School of Medical Sciences, Kyushu University, Maidashi 3-1-1, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Teiyu
authors.initials: T
authors.lastname: Izumi
authors.forename: Yoshinao
authors.initials: Y
authors.lastname: Oda
authors.forename: Tadashi
authors.initials: T
authors.lastname: Hasegawa
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Nakanishi
authors.forename: Akira
authors.initials: A
authors.lastname: Kawai
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sonobe
authors.forename: Tomonari
authors.initials: T
authors.lastname: Takahira
authors.forename: Chikashi
authors.initials: C
authors.lastname: Kobayashi
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Sadafumi
authors.initials: S
authors.lastname: Tamiya
authors.forename: Setsuo
authors.initials: S
authors.lastname: Hirohashi
authors.forename: Yukihide
authors.initials: Y
authors.lastname: Iwamoto
authors.forename: Masazumi
authors.initials: M
authors.lastname: Tsuneyoshi
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D015820:Cadherins / Q000378:metabolism*; D018450:Disease Progression; D005121:Extremities; D005260:Female; D015870:Gene Expression; D006801:Humans; D007124:Immunoenzyme Techniques; D007473:Ion Channels; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D008840:Microfilament Proteins; D008940:Mitotic Index; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000378:metabolism; D011379:Prognosis; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013584:Sarcoma, Synovial / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D012983:Soft Tissue Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor; D015820:Cadherins; C451410:FXYD5 protein, human; D007473:Ion Channels; D008562:Membrane Glycoproteins; D008840:Microfilament Proteins; D009363:Neoplasm Proteins; D015514:Oncogene Proteins, Fusion; D012333:RNA, Messenger; C116512:SYT-SSX fusion protein