Differential sensitivity of malignant glioma cells to methylating and chloroethylating anticancer drugs: p53 determines the switch by regulating xpc, ddb2, and DNA double-strand breaks.
These results indicate that PUMA, which is regulated under a tumor-specific expression system such as the hTERT promoter, may be better than p53 as a therapeutic tool for malignant gliomas.
Paraffin-embedded specimens of malignant gliomas from children treated in the Children's Cancer Group study CCG-945 were assessed by mutational analysis of TP53 (121 specimens) and immunohistochemical analysis of p53 (115 specimens).
We present the case of a 28-year-old man with an IDH1 and TP53 mutant high grade glioma with abnormalities in chromosomes 1 and 19 suggestive of anaplastic oligodendroglioma that rapidly progressed to widespread metastatic disease.
Furthermore, the p53 tumor suppressor, which has emerged as a key regulator of mitochondrial respiration at the expense of glycolysis, is genetically inactivated in a large proportion of HGG cases.
Here, we asked whether alterations in the p53 and RB pathways and the expression of six BCL-2 family proteins predicted acute cytotoxicity and clonogenic cell death induced by BCNU, vincristine, cytarabine, teniposide, doxorubicin, camptothecin or beta-lapachone in 12 human malignant glioma cell lines.
Additional analyses revealed that the malignant gliomas with MDM4 amplification and overexpression carried neither mutations in conserved regions of the TP53 gene nor amplification of the MDM2 gene.
However, it is difficult to treat malignant glioma with p53 gene therapy alone because of problems with resistance or a less-than-satisfactory response to the treatment.
The p53 gene is thought to function abnormally in the majority of malignant gliomas, although it has been demonstrated to be mutated in only approximately 30%.
Infection with F/K20-Adv carrying the wild-type p53 tumor suppressor gene resulted in an enhanced level of p53 protein expression and an increased incidence of F/K20-Adv in transduction efficiency for malignant glioma, providing promising tools for gene therapy.
TP53 mutations were present only in malignant gliomas, including three pGBMs and one case designated as PA with anaplastic features (with consultation opinion of pGBM).
Sinomenine Induces G1-Phase Cell Cycle Arrest and Apoptosis in Malignant Glioma Cells Via Downregulation of Sirtuin 1 and Induction of p53 Acetylation.
The P53 pathway is, therefore, disrupted in 81.8% of malignant gliomas (WHO grades III and IV), either by mutation of the p53 gene (31.8%) or by p14arf deletion (54.5%).
Our results identified oncogenic mutations in TP53 (40%), PI3KCA (15%), and ATM/MPL (5%) while none were identified in a large number of other genes commonly mutated in malignant gliomas.
Because p53-dependent apoptosis mechanisms are involved in the cytotoxic effects of irradiation and chemotherapy, we questioned whether p53 status might be associated with outcome in childhood malignant gliomas.