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Background: Tumor suppressor (p53) acts to integrate multiple stress signals into diverse antiproliferative responses. Its potential to transactivate or downregulate genes through apoptotic pathway in IDH-wildtype glioblastoma has never been explored., Methods: A group of twenty patients diagnosed with IDH-wildtype glioblastoma, were tested for p53 expression and NDRG2/NRF2 genes activity through protein and gene profiling assays. The connotation between these elements has been explored., Results: The mean patients' age was 64-years. All tumors were IDH-wildtype. p53 was expressed in 12 tumors and absent in 8 tumors. The activity of NDRG2 gene was downregulated in all cases. The activity of NRF2 gene was upregulated in 17 tumors and downregulated in 3 tumors. There was a significant statistical difference in PFS among tumors exhibiting different levels of p53 expression and NDRG2 gene activity [p-value= 0.025], in which 12 tumors with downregulated NDRG2 expression and positive p53 expression had earlier tumor recurrence. This statistical difference in PFS was insignificant when we compared p53 expression with NRF2 gene activity [p-value= 0.079]., Conclusions: During cell cycle arrest at G 2 phase, p53 expression in IDH-wildtype glioblastoma in elderly individuals, coupled with the downregulation of NDRG2 gene activity, led to an aberrant increase in tumor cell proliferation and accelerated tumor recurrence. However, the influence of p53 on NRF2 gene activity was found to be insignificant., Competing Interests: Declaration of Competing Interest The authors have no relevant financial or non-financial interests to disclose., (Copyright © 2024 The Authors. Published by Elsevier GmbH.. All rights reserved.)

Introduction: CD8 + T-cells and MHC-I have been detected in brain gliomas with a significant outcome. The effect of chemotherapies on the crosstalk interaction between CD8 + T-cells and MHC-I has never been explored., Material and Methods: The protein expression profiling of CD8 cytotoxic T-cells and the gene expression assay of MHC-I in 35 patients diagnosed with WHO grade 4 astrocytoma were performed. The impact of these two factors on tumor recurrence was analyzed., Results: IDH was wildtype in 13 tumors. MHC-I protein expression was absent or low in 34 tumors and dense in a single case. MHC-I gene expression was upregulated in 10 tumors and 25 tumors showed MHC-I gene downregulation. Temozolomide (TMZ) was given to 24 patients and 11 patients received TMZ plus other chemotherapies. No statistically significant association was observed between IDH mutation and CD8 + T-cells ( p = 0.383). However, this association was significant in recurrence-free interval (RFI) ( p = 0.012). IDH-wildtype tumors with highly infiltrated CD8 + T-cells or IDH-mutant tumors with low CD8 + T-cells showed late tumor recurrence. There was a statistically significant difference in RFI between tumors with different MHC-I expression and CD8 + T-cell counts after treatment with TMZ or TMZ plus ( p = 0.026)., Conclusions: No association between IDH mutation and CD8+ cytotoxic T-cell was found. IDH is directly linked to tumor recurrence regardless of CD8 + T-cells infiltration. TMZ plus other adjuvants is proved to be more effective in improving patient survival and delaying tumor recurrence, as compared to using TMZ alone. Nonetheless, none-TMZ adjuvants may increase tumor sensitization to cytotoxic T-cells more than TMZ.

Protein Arginine Methyltransferase 5 (PRMT5) is an enzyme that regulates gene expression and protein function through arginine methylation. Its association with isocitrate dehydrogenase (IDH) mutation in Grade-4 astrocytoma was rarely investigated. Our aim was to aim to explore the association between IDH mutation and PRMT5 and its effect on tumor recurrence. A retrospective cohort of 34 patients with Grade 4 astrocytoma has been tested for PRMT5 expression using protein and gene expression arrays. The impact of IDH-mutation and PRMT5 expression on tumor recurrence was explored. IDH-wildtype was detected in 13 tumors. PRMT5 protein was highly expressed in 30 tumors and the expression was low in four tumors. PRMT5 gene expression was upregulated in 33 tumors and downregulated in a single tumor case. Tumors with different PRMT5 gene expressions and IDH mutation were found to have a significant statistical difference in recurrence-free interval (RFI) (p-value<0.001). IDH-wildtype glioblastoma with upregulated PRMT5 gene or protein expression showed earlier tumor recurrence compared to IDH-mutant Grade 4 astrocytoma with upregulated PRMT5 expression. The association between IDH mutation and PRMT5 in IDH-mutant Grade 4 astrocytoma or IDH-wildtype glioblastoma is indirectly bidirectional. PRMT5 upregulation in glioblastoma can lead to increased cell proliferation and tumor regrowth. [ABSTRACT FROM AUTHOR]