Differential expression of SLPI in prostate cancer and benign prostate tissue

【Objective】To study the expression of SLPI in different prostate tissue and its clinical significance.【Methods】We analyzed SLPI mRNA expression in normal prostate epithelia,benign prostatic hyperplasia (BPH) epithelia,prostate cancer and prostate cancer cell lines by using semi-quantitative reverse transcription polymerase chain reaction (RT-PCR).Western blot examination showed protein expression of SLPI in benign prostate epithelia and prostate cancer cell lines.We examined SLPI and SLPI protein expression by immunohistochemistry in 20 nor-mal prostate tissues,50 BPH tissues and 103 prostate cancers.【Results】Semi-quantitative PCR examination rev-eled that the mRNA level of SLPI was significantly decreased in prostate cancers compared with that in benign prostate epithelial cells (P 0.01).SLPI protein was down-regulate in prostate cancer cell lines compared to benign prostate epithelial cells.Immunohistochemical expression of SLPI was observed in prostate epithelial cells,whereas little or no staining was observed in prostate cancer.SLPI protein expression was detected in 10 of 20 (50%) normal prostate samples,26 of 50 (52%) BPH samples and 1 of 103 (1%) prostate cancer samples.The difference between the 3 groups were significant.【Conclusions 】 SLPI may play an important role in progression of prostate cancercells.The function of SLPI in prostate should be further studied.