Expression and Significance of p53, p16 and Rb in Primary and Secondary Glioblastomas

Objective 　To study the expression and significance of cell cycle cont rol gene-p53, p16 and Rb in glioblastomas. Methods 　To analyze the expression of p53 and p16 with RT-PCR and Western blot, and to analyze the expression of corresponding protein Rb with immunohistochemist ry( IHC) of 14 cases of primary and 16 cases of secondary glioblastomas. Results 　Non-expression of Rb protein was founded in normal brain tissue, 3 deleted in 14 (21. 4 %) primary and 2 in 16 (11. 1 %) secondary GBM with IHC. The expression of mutation p53 was higher in all secondary than primary GBM, 5 deleted of p16 expression in 14 (36. 0 %) primary GBM and only 1 in 16 (6. 25 %) secondary GBM with RT-PCR and western blot . Conclusion 　No statistical significant difference of the expression of protein Rb between primary and secondary glioblastoma. That the expression increased of cell cycle control protein p53 and the expression deleted of another cell cycle control protein p16 may be one of the major events in the progression between primary and secondary glioblastomas, they are important cell cycle control genes and may be one of the key target genes in the therapy of GBM with gene methods.