Li X, Zhang Z, Xin D, Chua C W, Wong Y C, Leung S C L, Na Y, Wang X
Cancer Biology Group, Department of Anatomy, Faculty of Medicine, University of Hong Kong, Hong Kong.
Histopathology. 2007 Mar;50(4):484-90. doi: 10.1111/j.1365-2559.2007.02637.x.
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.
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.
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.
表皮生长因子受体（EGFR）被认为是肾细胞癌（RCC）侵袭进展的正调控因子之一。最近，一种螺旋-环-螺旋转录因子Id-1（分化或DNA结合抑制因子）已被确定为EGFR信号通路中的关键因子之一。本研究的目的是探讨Id-1在肾细胞癌中的表达意义，并研究其与EGFR的关系。
采用免疫组织化学方法检测了107例肾细胞癌组织芯片（TMA）样本和32例正常肾组织样本中Id-1和EGFR的表达。通过四级评分法估计染色强度，对Id-1和EGFR蛋白的相对表达进行定量。我们发现，在非恶性肾组织中观察到Id-1和EGFR呈阴性至弱表达，而大多数肾细胞癌肿瘤细胞中Id-1和EGFR呈显著阳性表达。此外，Id-1免疫染色强度与肿瘤分期、分级及EGFR表达增加呈正相关。
Id-1的过表达是晚期肾细胞癌的一个新标志物，与EGFR表达呈正相关。我们的结果表明，Id-1可能在肾细胞癌的发生发展中起重要作用，并提示Id-1是预后不良患者的一个潜在标志物。
