Diagnostic investigations of DKK-1 and PDCD5 expression levels as independent prognostic markers of human chondrosarcoma

Abstract

In this study, we investigated the expression levels of Dickkopf-1 (DKK-1) and programmed cell death 5 (PDCD5) by using quantitative real-time PCR and immunohistochemistry in patients with chondrosarcoma. The DKK-1 mRNA levels were significantly higher in chondrosarcoma when compared with the corresponding nontumor tissues (mean ± SD: 4.23 ± 1.54; 1.54 ± 0.87; P = 0.001). PDCD5 mRNA levels were remarkably deceased in tumor tissues when compared with corresponding nontumor tissues (mean ± SD: 1.94 ± 0.73; 5.42 ± 1.73; P = 0.001). The high and moderate DKK-1 expressions were observed for 60% of chondrosarcoma samples in comparison with 27.5% of corresponding nontumor tissues (P = 0.001). Moreover, low expression of PDCD5 was found in 67.5% of the tumor tissues when compared with the nontumor tissues (32.5%; P = 0.002). The results of this study showed that high DKK-1 expression levels were strongly related to MSTS stage (P = 0.011) and the advancement of histological grade (P < 0.001). Furthermore, the PDCD5 expression levels were correlated with histological grade (P < 0.001), MSTS stage (P = 0.016), and distant metastasis (P = 0.001). Kaplan-Meier survival and log-rank survival showed that patients with high DKK-1 levels and low PDCD5 levels were correlated with shorter overall survival (log-rank test P < 0.001). PDCD5 levels, histological grade, and tumor stage were independent predictors of overall survival. In conclusion, DKK-1 and PDCD5 can be independent predictors of overall survival in patients suffering from chondrosarcoma. © 2016 IUBMB Life, 68(7):597–601, 2016.