title: Expression and diagnostic relevance of heat shock protein 90 and signal transducer and activator of transcription 3 in malignant pheochromocytoma.
abstract: BACKGROUND
  Malignant pheochromocytoma (PCC) is a rare catecholamine producing tumour with a poor prognosis. For many years predicting PCC behaviour has remained a highly difficult task. The aim of this study was to evaluate heat shock protein 90 (HSP90) and signal transducer and activator of transcription 3 (STAT3) as tissue-based markers to predict malignant PCC.
  
  
  METHODS
  Ninety-two sporadic PCC patients were enrolled. We compared the expression of HSP90 and STAT3 by immunohistochemistry of benign versus malignant PCCs. In addition, in 17 snap frozen PCC and in 7 healthy adrenal tissues, we investigated the expression of HSP90 and STAT3 by means of western immunoblot.
  
  
  RESULTS
  Positive staining for HSP90 was observed in 22.37% (95% CI 13.00% to 31.74%) of the benign and 66.67% (95% CI 44.89% to 88.45%) of the malignant cases. Similarly, STAT3 staining was seen in 26.32% (95% CI 16.42% to 36.22%) of the benign versus 83.33% (95% CI 66.11% to 100.55%) of the malignant cases. Using HSP90 and STAT3 combined, the positive predictive value of malignancy was signiﬁcantly increased to 0.70 (95% CI 0.45 to 0.86). Besides, logistic regression analysis showed that HSP90 (OR=3.667, p=0.039) and STAT3 (OR=9.474, p=0.002) were independently associated with malignant PCC.
  
  
  CONCLUSIONS
  This study has conﬁrmed that malignant PCC overexpress HSP90 and STAT3, and the combination of HSP90 and STAT3 can be used as helpful diagnostic markers to distinguish malignant from benign PCCs.
authors: Department of Urology, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.
authors: Yunze
authors: Y
authors: Xu
authors: Yicheng
authors: Y
authors: Qi
authors: Wenbin
authors: W
authors: Rui
authors: Yu
authors: Y
authors: Zhu
authors: Chongyu
authors: C
authors: Zhang
authors: Juping
authors: J
authors: Zhao
authors: Qing
authors: Q
authors: Wei
authors: Yuxuan
authors: Y
authors: Wu
authors: Zhoujun
authors: Z
authors: Shen
authors: Guang
authors: G
authors: Ning
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000737:chemistry* / Q000473:pathology; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D015153:Blotting, Western; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D005260:Female; D018841:HSP90 Heat-Shock Proteins / Q000032:analysis*; D006801:Humans; D007150:Immunohistochemistry; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D010673:Pheochromocytoma / Q000737:chemistry* / Q000473:pathology; D011237:Predictive Value of Tests; D011379:Prognosis; D050796:STAT3 Transcription Factor / Q000032:analysis*; D015854:Up-Regulation
chemical_list: D014408:Biomarkers, Tumor; D018841:HSP90 Heat-Shock Proteins; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human