Expression of NCRs ligands on human prostate cancer.

<p>(a,b) NKp30-Ig and NKp46D2-Ig specifically bind to human prostate cell lines. PC3/<i>Luc</i> (a) and DU145 (b) cell lines were stained with NKp30-Ig, NKp46D2-Ig or control CD99-Ig, followed by PE-conjugated mouse anti-human IgG1 antibody. Grey histograms represent the background staining by the control CD99-Ig fusion protein and the black empty histograms represent the staining by either NKp30-Ig or NKp46D2-Ig, as indicated in the top of each histogram. This figure represents one experiment out of three performed. (c) Immunohistochemical staining of primary human prostate adenocarcinoma and benign prostate hyperplasia (BPH) by NKp30-Ig and NKp46D2-Ig. Cuts from formalin-fixed and paraffin-embedded human prostate adenocarcinoma (upper panel) and BPH (lower panel) were antigen-retrieved by microwave-citrate treatment. Slides were then stained with NKp30-Ig, negative control CD99-Ig or NKp46D2-Ig, followed by biotinylated-goat-anti-human-Fc and avidin-biotin HRP complex. Substrate for HRP was AEC (red color) and slides were counter-stained with Hematoxylin. Figure shows a representative staining at X400 magnification. Arrow in NKp30-Ig staining of adenocarcinoma (top left panel) points to a representative membrane staining. Staining intensity for top left and top right panels is considered as 2 (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0002150#s2" target="_blank">Methods</a>). (d) Expression of NKp30 and NKp46 ligands is abundant on malignant prostate tumors. Cuts from different patients suffering from benign (<i>n</i> = 8) or malignant (<i>n</i> = 9) prostate tumors were prepared and stained as above. Staining was performed in triplicates. Analysis of staining intensity (0-3) and percentage of stained tumor cells was performed by two pathologists. Positive staining was defined when staining intensity was above 1 and encompassed at least 50% of the cells, as described in ‘<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0002150#s2" target="_blank">material and methods</a>’.