To this aim, 21 invasive urothelial cell carcinomas of the renal pelvis and 27 high-grade renal cell carcinomas (8 renal cell carcinomas with sarcomatoid dedifferentiation and 5 type 1 and 7 type 2 papillary renal cell carcinomas as well as 7 collecting duct carcinomas) were stained with antibodies directed against protein gene product 9.5, CD10, vimentin, CEA, p63, CK5/6, CK7, CK20, PAX2, PAX8, CD117 (c-Kit), AE1/3, α-methyl CoA racemase, actin, and desmin.
In summary, we identified PAX2 as a regulator of L1-CAM and ADAM10, which play crucial roles in the progression of various cancers including renal cell carcinoma and the downregulation of ADAM10 maybe an earlier step in renal cancer development as it seems to be involved in processes of EMT.
Immunohistochemically, tumor cells of clear cell papillary RCC were diffusely positive for PAX2 and cytokeratin 7, but negative for CD10, RCC Ma, and AMACR.
In contrast to earlier published data, Xp11 translocation RCC frequently expressed renal transcription factors PAX8 (16/21 cases) and PAX2 (14/21 cases), whereas only 1 of 21 cases focally expressed MiTF and only 5 of 21 overexpressed p21.
Although immunohistochemical expression of PAX-2 has been described in a variety of primary renal cell carcinoma (RCC) subtypes and in metastatic RCC, its specificity as a marker of renal lineage in a metastatic setting has not been fully evaluated.
Aquaporin-1 and PAX-2 expression was found to correlate with nuclear grading for clear cell renal cell carcinomas but not for papillary renal cell carcinomas.
In contrast, only two of the nine kidney specimens from patients without renal cell carcinoma expressed Pax-2 mRNA, indicating that expression of this protein is significantly higher in renal cell carcinoma (P < 0.01).
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.
These data indicate that Pax-2 gene function is required for proliferation, as well as differentiation during embryonic development, and suggest a novel therapy for RCC.