Differential expression of S100A2 and S100A4 during progression of human prostate adenocareinoma

Purpose : To establish the clinical significance of calcium binding proteins S10OA2 and S10OA4 during progression of human prostate adenocarcinoma. Patients and Methods: Expression pattern of S10OA2 and S10OA4 was determined in normal human prostate epithelial cells (NHPE); virally transformed prostate epithelial cells (PZ-HPV-7); several human prostate carcinoma cells (22Rv1, DU145, LNCaP, and PC3); tissue samples obtained during transuretheral prostatic resection from patients with benign prostate hyperplasia (BPH), prostatitis, and adenocarcinorna; and paraffin-embedded sections from pair-matched benign and cancer specimens of different tumor grade. Results : High constitutive protein expression of S10OA2 was observed in NHPE and PZ-HPV-7 cells, whereas its complete absence was observed in 22Rv1, DU145, LNCaP, and PC3 cells. Tissue samples of BPH and prostatitis exhibited higher mRNA and protein levels of S10OA2 than lowgrade cancer (Gleason score less than or equal to 6), whereas a complete loss was observed in high-grade cancer specimens (Gleason score > 6). Immunohistochernical analysis further confirmed high levels of S10OA2 in benign tissues and a progressive loss with increasing tumor grade. The protein level of S100A4 was significantly higher in all carcinoma cells compared with NHPE and PZ-HPV-7 cells. The mRNA and protein level of S100A4 was significantly higher in high-grade cancer specimens compared with BPH, prostatitis, and lowgrade cancer. The high levels of S100A4 observed in cancer tissue correlated with increasing tumor grade. Conclusion: Loss of S10OA2 and increased expression of S100A4 may be an important event during progression of prostate cancer in humans. (C) 2003 by American Society of Clinical Oncology.