Pax-2 expression in adult renal tumors

Hum Pathol. 2001 Mar;32(3):282-7. doi: 10.1053/hupa.2001.22753.


To assess the expression of the homeogene Pax-2 in adult renal cell carcinomas, we did a retrospective immunohistochemical analysis of 56 frozen tumor samples representing all major histologic subtypes of renal tumors. There were 33 conventional renal cell carcinomas (58.9%), 12 papillary renal cell carcinomas (21.4%), 4 chromophobe cell renal carcinomas, 4 urothelial cell renal carcinomas, and 3 oncocytomas. Forty-five tumors (62.5%) were localized, and 21 tumors had extrarenal involvement. Eight patients (14%) had metastatic disease at the end of the follow-up. We searched for relationships between Pax-2 expression and nuclear grading, TNM staging, Ki-67 proliferation index, expression of transforming growth factor-beta1 (TGF-beta 1), an in vitro down-regulator of Pax-2 expression, and finally cytogenetic abnormalities. All histologic subtypes expressed Pax-2 protein, except urothelial renal carcinomas. The highest expression was in papillary renal cell carcinomas. In this subtype, all tumors and 83.3% +/- 12.3% of tumor cells were immunoreactive for Pax-2. All but 2 conventional renal cell carcinomas expressed Pax-2, but with 26.3% +/- 29.6% of immunoreactive cells (P <.001). Pax-2 expression was not correlated with nuclear grading (P =.6), tumor size (P =.3), and TGF-beta 1 expression (P =.1). Nevertheless, Pax-2 expression correlated with the Ki-67 proliferation index only for the conventional histologic subtype (P =.03). In this histologic subtype, Pax-2 expression was higher in patients with metastatic disease than in those without (P =.02). Pax-2 expression was not associated with specific cytogenetic abnormalities like trisomy 7 (P =.1), 3p deletion (P =.5), and hyperdiploidy (P =.2). TGF-beta 1 expression, positive in 33 tumors (59%), was not correlated with either Pax-2 expression (P =.1) or current prognostic factors such as nuclear grading (P =.2). Interestingly, we also observed an expression of TGF-beta RI and TGF-beta RII in the tumors with high nuclear grading (P =.005). We conclude that Pax-2 protein is expressed in all major histologic subtypes of renal cell carcinomas. The pattern of expression differs between these subtypes. Pax-2 expression in conventional renal cell carcinomas is correlated with the proliferation index and is significantly higher in patients with metastatic disease. HUM PATHOL 32:282-287.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoma, Oxyphilic / chemistry
  • Adenoma, Oxyphilic / genetics
  • Adenoma, Oxyphilic / pathology
  • Adult
  • Aged
  • Aged, 80 and over
  • Carcinoma, Papillary / chemistry
  • Carcinoma, Papillary / genetics
  • Carcinoma, Papillary / pathology
  • Carcinoma, Renal Cell / chemistry
  • Carcinoma, Renal Cell / genetics
  • Carcinoma, Renal Cell / pathology
  • Cell Division
  • Cell Nucleus / pathology
  • Chromosome Aberrations
  • Cryopreservation
  • Cytogenetic Analysis
  • DNA-Binding Proteins / analysis*
  • Female
  • Humans
  • Immunohistochemistry
  • Ki-67 Antigen / analysis
  • Kidney Neoplasms / chemistry*
  • Kidney Neoplasms / genetics
  • Kidney Neoplasms / pathology
  • Male
  • Middle Aged
  • Neoplasm Metastasis
  • PAX2 Transcription Factor
  • Retrospective Studies
  • Transcription Factors / analysis*
  • Transforming Growth Factor beta / analysis


  • DNA-Binding Proteins
  • Ki-67 Antigen
  • PAX2 Transcription Factor
  • PAX2 protein, human
  • Transcription Factors
  • Transforming Growth Factor beta