Correlation of Cav-1 mRNA, S100A4 mRNA and CD31 expression with prostate cancer tumor metastasis and patient survival rate

Abstract

Objective To explore the expression of Cav-1 mRNA,S100A4 mRNA and CD31 in prostate cancer (PCa) and their correlation with tumor metastasis and patient survival rate. Methods PCa specimens (n =42) and adjacent tissue specimens ( n =12 ) from radical prostatectomy were obtained from January 2004 to May 2006.The mean age of patient was 71.6 ± 7.6 years ( range 58 - 86 years).According to Gleason scores,prostatectomy specimens were stratified into≤6 (n =17),7 (n =12) and ≥8( n =13 ) groups.Patients were classified as clinical stage T1 ( n =16),stage T2 ( n =9 ),stage T3 ( n =11 )and stage T4 (n =6).Patients were divided into PCa with bone metastasis (n =8 ) and PCa without bone metastasis ( n =34).Preoperative PSA levels of the patients were stratified into three groups: ＜ 4 ( n =4)μg/L,4-10 (n=10)μg/Land ＞10 μg/L (n=28).12 adjacent tissues 1 -2 cm away from tumor or another lobe of prostate were microscopically verified without cancer cells and were tested for comparison.The expression of Cav-1 mRNA and S100A4 mRNA were detected by Situ hybridization in 42 PCa specimens and 12 adjacent tissues and using CD31 for marking vascular endothelial cells,the tumor microvascular density (MVD) was counted.The correlation of Cav-1 mRNA,S100A4 mRNA and CD31 expression was analyzed in combination.with clinical and pathological fcatures including Gleason score,TNM staging,PSA values and bone metastasis. Results The positive expression rate of Cav-1 mRNA in PCa was 35.7％ ( 15/42),while it was 0％ (0/12) in controls,P ＜0.05.The positive expression rate of S100A4 mRNA in PCa was 47.6％ (20/42),while it was 8.3％ (1/12) in controls,P ＜0.05.The positive expression rate of Cav-1 mRNA in PCa was positively correlated with Gleason score,TNM stage and bone metastasis.The positive expression rate of S100A4 mRNA in PCa was positively correlated with TNM stage and bone metastasis.The average MVD in patients of negative expression of Cav-1 mRNA was (62.8 ± 10.4)/mm2,and the average -MVD in patients of positive expression of Cav-1 mRNA was (83.5 ±6.7 )/mm2,P ＜ 0.05.While the average MVD in patients of negative expression of S100A4 mRNA was (63.3 ± 12.0)/mm2,and the average MVD in patients of positive expression of S100A4 mRNA was (77.9 ± 11.0)/mm2,P ＜ 0.05.The 5-year survival rate in patients with positive Cav-1 mRNA expression was significantly lower than that of with negative expression (46.7％ versus 85.2％,P ＜ 0.05 ),while the 5-year survival rate in the patients with positive expression of S100A4 mRNA was significantly lower than that of with negative expression (50.0％ versus 90.9％,P ＜ 0.05 ). Conclusions The positive Cav-1 mRNA and S100A4 mRNA expression,increased MVD are positively correlated with PCa progression and bone metastasis. Furthermore,Cav-1 and S100A4 in PCa may promote angiogenesis and cause tumor cells to bone metastases,which can reduce survival rate of patients. Key words: Prostate cancer; Caveolin-1; S100A4; Situ hybridization