Abstract
BACKGROUND
The principal components of the interleukin‐1 (IL‐1) family are two secreted factors (IL‐1α and IL‐1β), two transmembrane receptors (IL‐1RI [biologically active] and IL‐1RII [inert receptor]), and a natural antagonist receptor of IL‐1 function (IL‐1Ra). Changes in the expression pattern of these IL‐1 members have been reported to be related to disease progression. The objective of the current study was to evaluate these changes in prostatic tissue by means of immunohistochemistry and Western blot analysis.
METHODS
Immunohistochemical and Western blot analyses were performed in 20 normal samples, 35 samples of benign prostatic hyperplasia (BPH) and 27 samples from patients with prostate carcinoma (PC).
RESULTS
In normal prostate samples, immunoreactions to IL‐1β and IL‐1RI were positive, whereas there were no immunoreactions observed to IL‐1α, IL‐1RII, or IL‐1Ra. In BPH, in addition to immunoreactions to IL‐1β and IL‐1RI, immunoreactions to IL‐1α, IL‐1RII, and IL‐1Ra were observed in many samples. In samples of PC with low Gleason grade, most tumors had positive immunoreactions to IL‐1α and IL‐1RI. In samples of PC with high Gleason grade, immunoreactions were seen only to IL‐1α, IL‐1RI, and IL‐1RII.
CONCLUSIONS
The current results suggested that high expression levels of IL‐1α and IL1‐RI in epithelial cells in BPH and PC samples were involved in cell proliferation and that the loss of immunoexpression of IL‐1β and IL‐1Ra was a characteristic feature of PC compared with normal prostate samples and BPH. Because this loss is progressive up to a complete absence of immunoexpression in PC of high Gleason grade, the evaluation of IL‐1β and IL‐1Ra in PC may be significant in assessing for malignancy. Cancer 2004;100:1388–96. © 2004 American Cancer Society.