In normal rat kidney, Gal-3 is expressed in distal tubular epithelial cells.
Immunohistochemistry was performed using a modification of the avidin-biotin peroxidase complex technique with a monoclonal antibody against Gal-3 (dilution 1:250; Novocastra/Vector Laboratories, Burlingame, California).
The Gal-3 expression in tumors was correlated with histologic types, tumor stage, and nuclear grade.
In 21 normal renal tissues, Gal-3 was expressed in collecting ducts, intermediate thin ducts, and distal tubules (Figure 1, A).
Overall, positive expression of Gal-3 was observed in 92 of 217 renal neoplasms (42.
Twenty-two of 23 oncocytomas (96%) demonstrated strong expression of Gal-3 (Figure 1, B).
Nineteen of 21 chromophobe RCCs (90%) expressed Gal-3 (Figure 1, C).
5%) showed positive cytoplasmic Gal-3 expression (Figure 1, D).
Expression pattern of Gal-3 in conventional RCC was variable.
Four of 10 clear cell RCCs (40%), 1 of 6 papillary RCCs (17%), and all oncocytomas (4 of 4; 100%) and chromophobe (4 of 4; 100%) RCCs showed cytoplasmic and/or nuclear staining for Gal-3.