Expression of interleukin‐8 gene in radical prostatectomy specimens is associated with advanced pathologic stage

Abstract

BACKGROUND We previously reported that relative expression of E‐cadherin, matrix metalloproteinases (MMPs)‐2 and ‐9, and vascular endothelial growth factor (VEGF)/vascular permeability factor in radical prostatectomy specimens (RP) can distinguish organ‐confined cancers from advanced prostate cancers. Here, we evaluate the expression of interleukin‐8 (IL‐8) and basic fibroblast growth factor (bFGF), two other genes involved in angiogenesis and metastasis, in RP specimens. METHODS The expression level of IL‐8 and bFGF mRNA in the invasive edge of 41 prostate cancers of different stages was determined using a rapid colorimetric in situ hybridization (ISH) technique. Gene expression levels of IL‐8 and bFGF were correlated with the Gleason score and pathologic stage to ascertain their relationship to prostate cancer progression. RESULTS The expression of IL‐8 and bFGF genes was detected by ISH in histologically normal prostate gland epithelium as well as in glands with foci of cancer. Increased mRNA expression of IL‐8 was associated with both the Gleason score and pathologic stage of tumors and distinguished organ‐confined from non‐confined tumors (P = 0.002). In contrast, the expression of bFGF mRNA did not correlate with the Gleason score or pathologic stage. CONCLUSIONS Overexpression of Il‐8 mRNA, but not bFGF mRNA, in RP specimens is directly associated with progression of prostate cancer.