Prognostic significance of downregulated expression of programmed cell death 5 in chondrosarcoma.

Background And Objectives: Programmed Cell Death 5 (PDCD5) is a novel apoptosis-related gene and deregulation of PDCD5 is involved in tumorigenicity. This study was designed to investigate the expression level of PDCD5 and to clarify its clinical significance in chondrosarcoma.

Methods: The mRNA and protein levels of PDCD5 in chondrosarcoma and matched corresponding non-tumor tissues were evaluated by real-time PCR and Western blot, respectively. The expression of PDCD5 protein was investigated by immunohistochemistry assays in chondrosarcoma, and its association with clinicopathologic factors and overall survival was also analyzed.

Results: The mRNA and protein levels of PDCD5 were significantly decreased in chondrosarcoma compared with corresponding non-tumor tissues. Low expression of PDCD5 protein was 61.8% (21/34) in chondrosarcomas, as compared 12.5% (1/8) in normal bones, as well as compared 23.5% (4/17) in benign cartilage tumors. PDCD5 expression was correlated with anatomical location and histological grade. The survival rate of patients with low-PDCD5 tumors was lower than that of patients with high-PDCD5 tumors. Multivariate analysis revealed that the downregulated expression of PDCD5 was an independent prognostic factor for overall survival.

Conclusions: PDCD5 is downregulated in chondrosarcoma and might be an independent prognostic factor for overall survival of chondrosarcoma patients.