title: Prognostic significance of Id-1 and its association with EGFR in renal cell cancer.
abstract: OBJECTIVE
  Epidermal growth factor receptor (EGFR) is suggested as one of the positive regulators in the invasive progression of renal cell cancer (RCC). Recently, Id-1 (inhibitor of differentiation or DNA binding), a helix-loop-helix transcription factor, has been identified as one of the key factors in the EGFR signalling pathway. The aim of this study was to investigate the significance of Id-1 expression in renal cell cancer and to study its relationship with EGFR.
  
  
  RESULTS
  Id-1 and EGFR expression was examined in tissue microarray (TMA) samples of 107 RCC and 32 normal kidney specimens by immunohistochemistry. Relative Id-1 and EGFR protein expression was quantified by estimating the staining intensity on a four-grade scale. We found that while negative to weak expression of Id-1 and EGFR was observed in non-malignant kidney tissues, most RCCs showed significant positive Id-1 and EGFR expression in tumour cells. In addition, Id-1 immunostaining intensity was positively associated with increased tumour staging, grading and EGFR expression.
  
  
  CONCLUSIONS
  Overexpression of Id-1 is a novel marker for advanced RCC which is positively correlated with EGFR expression. Our results suggest that Id-1 may play an important role in the development of RCC and indicate that Id-1 is a potential marker of patients with a poor prognosis.
authors: Cancer Biology Group, Department of Anatomy, Faculty of Medicine, University of Hong Kong, Hong Kong.
authors: X
authors: X
authors: Li
authors: Z
authors: Z
authors: Zhang
authors: D
authors: D
authors: Xin
authors: C W
authors: CW
authors: Chua
authors: Y C
authors: YC
authors: Wong
authors: S C L
authors: SC
authors: Leung
authors: Y
authors: Y
authors: Na
authors: X
authors: X
authors: Wang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000378:metabolism* / Q000473:pathology; D066246:ErbB Receptors / Q000502:physiology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D051798:Inhibitor of Differentiation Protein 1 / Q000096:biosynthesis*; D007668:Kidney / Q000378:metabolism / Q000473:pathology; D007680:Kidney Neoplasms / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D012016:Reference Values; D046888:Tissue Array Analysis
chemical_list: D051798:Inhibitor of Differentiation Protein 1; D066246:ErbB Receptors