Reduced expression of PDCD5 is associated with high-grade astrocytic gliomas

Programmed cell death 5 (PDCD5) is a novel apoptosis-promoting protein. Recently, a decreased expression of PDCD5 has been found in several types of human tumors. However, the expression level of PDCD5 in human gliomas has not been investigated. In the present study, we examined the expression of PDCD5 in 88 human glioma samples at both mRNA and protein levels by RT-PCR, Western blotting and immunohistochemistry. We found that 53.3% (16/30) of the glioma samples had a reduced expression of PDCD5 mRNA and 70.5% (62/88) had a reduced expression of the PDCD5 protein as compared to normal brain tissue. Furthermore, we studied the correlation of the expression level of PDCD5 with the clinicopathological grade and survival of patients with astrocytomas. Although longitudinal studies of a cohort of patients with astrocytoma revealed that PDCD5 expression was not able to predict clinical outcome (p>0.05), a decreased expression of PDCD5 correlated significantly with high-grade astrocytomas (p<0.001). In conclusion, our data suggest that reduced PDCD5 expression may contribute to the pathogenesis of human gliomas.