Frequent loss of PDCD4 expression in human glioma: Possible role in the tumorigenesis of glioma

Programmed cell death 4 (PDCD4) was recently identified as a novel tumor suppressor gene. The loss of PDCD4 expression was found in several types of human cancer cell lines. To date, however, the status of PDCD4 expression in human glioma tissue is not known. In the present study, the expression of PDCD4 in 30 glioma samples was determined at both mRNA and protein levels by means of RT-PCR, Western blotting, and immunohistochemistry. Herein, we demonstrate, for the first time, that 47% (14/30) of glioma samples lost the expression of PDCD4 mRNA, and 77% (23/30) of glioma samples lacked the PDCD4 protein expression, whereas adjacent normal glial tissues expressed high levels of PDCD4 mRNA and protein. Furthermore, the loss of PDCD4 expression does not significantly correlate with the pathological and clinical features of the glioma. Our new data suggest that the loss of PDCD4 expression is a frequent event in human glioma and may partially contribute to the development of the tumor.