Figure 4

In situ detection of ZIP1 mRNA and zinc levels in normal and malignant glands. Panel A. Representative ZIP1 mRNA in Prostate Sections . Sections (inserts 1,2) from two prostate cancer subjects are shown with low magnification. Blue arrows point to acini with normal glandular epithelium that exhibit ZIP1 mRNA. White arrows point to adenocarcinomatous glands in which ZIP1 expression is not demonstrable. Insert 3 is a higher magnification of a section from a cancer patient to show more detail. Blue arrows point to acini with normal glandular epithelium. Red arrows point to malignant glands. Green arrows point to stromal (fibromuscular) tissue. The malignant epithelial cells exhibit a complete absence of detectable ZIP1 mRNA in the glandular epithelium. The normal glandular epithelium exhibits ZIP1 expression; and no ZIP1 expression in the stroma. Normal acini marked 'a' show uniform ZIP1 mRNA expression in the glandular epithelium. Advanced adenocarcinomatous glands marked as 'b" show uniform absence of ZIP1 mRNA. Developing early stage adenocarcinomatous glands marked 'c' show a progression of normal ZIP1 expressing cells and malignant cells that lost the expression of ZIP1. Panel B. Representative Zinc Levels in Prostate Sections. High zinc is represented by Newport Green yellow stain and low zinc is represented by TSQ red stain. The malignant region of the peripheral zone shows a significant depletion of zinc in the malignant glandular epithelium as exhibited by the red staining (white arrows). The depletion of zinc is evident in early differentiated malignant glands as represented by combinations of red and yellow staining in the glandular epithelial cells. As malignancy advances to the undifferentiated stage, the zinc is further depleted as represented by the dominant red stain and no yellow stain in the glandular epithelium of the adenocarcinomatous glands. The depletion of zinc in the malignant glandular region results in the surrounding stroma showing a higher zinc level (green stain) than the glandular epithelium. In contrast, the normal peripheral zone glands exhibit high zinc levels as represented by the uniform yellow stain and absence of red stain in the glandular epithelium. The stroma surrounding the glands exhibits a lower zinc level as shown by the red stain.