Levels of pSTAT3, PDCD4 and IL-6 in human prostate specimens.

<p><b>(A, B)</b> Immunohistochemistry studies were performed to determine the levels of pSTAT3 in formalin-fixed paraffin embedded prostate tumor specimens, as compared to adjacent normal prostate specimen. Diaminobenzidine tetrahydrochloride (DAB) staining revealed high expression of pSTAT3 <b>(B)</b> as dark-brown labeling in epithelial cells of tumor samples (marked by red arrows) while low expression was observed in paired perinormal prostate tissues <b>(A)</b>. In contrast, high expression of PDCD4 was observed in perinormal prostate tissues (as evidenced by dark-brown labeling, indicated by yellow arrows) <b>(C)</b>, as compared to prostate tumors <b>(D)</b>. Immunolabling of prostate tumor revealed high expression of IL-6 <b>(F)</b>, compared to perinormal prostate specimens. Representative images show immunohistochemical studies performed in four different specimens obtained from three different patients. Pictures magnification is 400x. Scale bar is 20 μm.