Expression of Snail, Insulin-like mRNA-binding Protein3 and Aldehyde Dehydrogenase 1 as Diagnostic Markers in Clear Cell, Papillary, and Chromophobe Variants of Renal Cell Carcinoma

Renal cell carcinoma (RCC) is the most prevalent malignancy of kidney. Snail is a zinc-finger transcription factor, associated with advanced tumor stage and poor prognosis of RCC. Insulin-like mRNA-binding protein3 (IMP3) immunopositivity predicts metastatic progression and patients’ survival in RCC. Aldehyde dehydrogenase 1 (ALDH1) is a stem cell marker, expressed in many different solid tumors of bladder, pancreas, colon, and kidney. The present study aimed to assess the diagnostic value of Snail, IMP3, and ALDH1 expression in clear cell, papillary, and chromophobe variants of RCC.
This retrospective study included 50 tissue blocks of RCC cases (35 clear cells, along with 11 papillary and four chromphobe carcinomas). Immunohistochemical staining was evaluated using antibody against Snail, IMP3, and ALDH1 in all the cases.
Snail was observed to be 74.3% in clear cell RCC and 18.2% in papillary, but negatively expressed in all chromophobe carcinomas. IMP3 was expressed in 72.7% of papillary carcinomas and 28.6% of clear cell RCC; it was totally expressed in all chromophobe carcinomas. ALDH1 was expressed in 94.2% of clear cell RCC, 54.6% of papillary carcinomas, and 50% of chromophobe carcinomas. Snail, IMP3, and ALDH1 were found to be associated with advanced tumor stage and high grade; accordingly, they could be considered as poor markers for RCC patients.
ALDH1 is a good sensitive marker for diagnosis of RCC, especially for clear cell type, while IMP3 is a good marker for diagnosis of chromophobe carcinoma and Snail can be used for diagnosis of clear cell carcinoma.