Fig. 1
Immunohistochemical analysis of human and mouse MM and embryonic mouse and human lung. ZL55-SOhigh cells were injected i.p. into NOD/SCID gamma mice and tumor cells show strong expression of CR (b; higher magnification inset in c), arrow pointing towards a strong CR-positive tumor nodule. The negative control (parallel section) is shown in (a). d) Representative example of a mouse MM showing absence of CR expression, as well as in another example of an asbestos-induced lymphocytic and granulomatous inflammation (e) of the parietal pleura. f) In the developing lung of a mouse, CR protein is already expressed in the visceral pleura at day 10 (arrows) as reported before [14]. g) Expression of CR in the mesothelial cell layer (arrows) and in scattered stromal (mesenchymal) cells of the developing human lung (arrowheads). h) Negative control on parallel section incubated without primary CR antibody. The inset shows CR-negative mesothelial cells (arrows) at 2-fold higher magnification. The few round lightly brownish-stained cells are erythrocytes, where the endogenous peroxidase activity was not completely blocked. Abbreviations: A adipose tissue; T tumor; S stroma; G granulomatous inflammation; D pleura parietalis adjacent to the diaphragm; L lung. Scale bars: A and B: 2.5 mm, C: 500 μm. D-F: 100 μm; G,H: 50 μm; insets with layer of mesothelial cells: 2-fold magnification compared to G,H