Prognostic significance of Id-1 and its association with EGFR in renal cell cancer.
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.
Li
X
X
Cancer Biology Group, Department of Anatomy, Faculty of Medicine, University of Hong Kong, Hong Kong.
Zhang
Z
Z
Xin
D
D
Chua
C W
CW
Wong
Y C
YC
Leung
S C L
SC
Na
Y
Y
Wang
X
X
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
D051798:Inhibitor of Differentiation Protein 1; D066246:ErbB Receptors