Prognostic value of TP53 expression and MGMT methylation in glioblastoma patients treated with temozolomide combined with other chemotherapies.

OBJECTIVE: To assess the recurrence interval and predictive significance of TP53 expression and O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation in glioblastomas treated with radiotherapy and combined chemotherapies, including temozolomide, lomustine, procarbazine and bevacizumab. METHOD: We reviewed the clinical outcomes of 52 totally resected glioblastoma patients, who received conventional radiotherapy and temozolomide with other chemotherapeutic agents. Correlation of TP53 expression and MGMT promotor methylation with recurrence interval was analyzed using Kaplan Meier estimates. RESULTS: No significant association was found between MGMT promotor methylation and TP53 expression in glioblastomas (P-value = 0.158). Patients with non-methylated MGMT who received temozolomide chemotherapy with other chemotherapeutic agents showed significantly later recurrence (P-value = 0.007) compared with patients with non-methylated MGMT who received temozolomide alone. No significant difference was found in recurrence interval among glioblastoma patients with methylated MGMT who received temozolomide alone or with other chemotherapies (P-value = 0.667). Moreover, patients with non-TP53-expressing tumors who received temozolomide with other chemotherapies had significantly later recurrence (P-value = 0.04) compared with patients who received temozolomide alone. CONCLUSION: Totally resected glioblastoma patients, with non-methylated MGMT or non-TP53-expressing tumors treated with radiotherapy and combined chemotherapies had a reduced chance of tumor recurrence and a more favorable outcome. Furthermore, both MGMT and TP53 are independent prognostic factors for glioblastoma.

The interplay mechanism between IDH mutation, MGMT-promoter methylation, and PRMT5 activity in the progression of grade 4 astrocytoma: unraveling the complex triad theory.

Background: The dysregulation of Isocitrate dehydrogenase (IDH) and the subsequent production of 2-Hydroxyglutrate (2HG) may alter the expression of epigenetic proteins in Grade 4 astrocytoma. The interplay mechanism between IDH, O-6-methylguanine-DNA methyltransferase (MGMT)-promoter methylation, and protein methyltransferase proteins-5 (PRMT5) activity, with tumor progression has never been described. Methods: A retrospective cohort of 34 patients with G4 astrocytoma is classified into IDH-mutant and IDH-wildtype tumors. Both groups were tested for MGMT-promoter methylation and PRMT5 through methylation-specific and gene expression PCR analysis. Inter-cohort statistical significance was evaluated. Results: Both IDH-mutant WHO grade 4 astrocytomas (n = 22, 64.7%) and IDH-wildtype glioblastomas (n = 12, 35.3%) had upregulated PRMT5 gene expression except in one case. Out of the 22 IDH-mutant tumors, 10 (45.5%) tumors showed MGMT-promoter methylation and 12 (54.5%) tumors had unmethylated MGMT. All IDH-wildtype tumors had unmethylated MGMT. There was a statistically significant relationship between MGMT-promoter methylation and IDH in G4 astrocytoma (p-value = 0.006). Statistically significant differences in progression-free survival (PFS) were also observed among all G4 astrocytomas that expressed PRMT5 and received either temozolomide (TMZ) or TMZ plus other chemotherapies, regardless of their IDH or MGMT-methylation status (p-value=0.0014). Specifically, IDH-mutant tumors that had upregulated PRMT5 activity and MGMT-promoter methylation, who received only TMZ, have exhibited longer PFS. Conclusions: The relationship between PRMT5, MGMT-promoter, and IDH is not tri-directional. However, accumulation of D2-hydroxyglutarate (2-HG), which partially activates 2-OG-dependent deoxygenase, may not affect their activities. In IDH-wildtype glioblastomas, the 2HG-2OG pathway is typically inactive, leading to PRMT5 upregulation. TMZ alone, compared to TMZ-plus, can increase PFS in upregulated PRMT5 tumors. Thus, using a PRMT5 inhibitor in G4 astrocytomas may help in tumor regression.

Outcomes of central nervous system tuberculosis in Saudi Arabia: a multi-center study.

OBJECTIVES: Central nervous system tuberculosis (TB) (CNS-TB) can occur in several forms, including intracranial tuberculoma, tuberculous brain abscess, TB meningitis (TBM), and spinal TB. Early treatment can save lives and prevent severe neurological complications. This study aimed to describe the characteristics and post-treatment outcomes of patients with CNS-TB and identify factors associated with poor outcomes. To the best of our knowledge, this is the largest CNS-TB study till date published in Saudi Arabia. METHODS: This retrospective cohort study included all patients diagnosed with CNS-TB in three tertiary centers in Saudi Arabia (King Abdulaziz Medical City in Jeddah, King Abdulaziz Medical City in Riyadh, and Al-Noor Specialist Hospital in Makkah) between 2009 and 2019. Data of patients' demographics, co-morbidities, presenting symptoms, type of CNS-TB, medical and surgical treatments, and outcome after completion of treatment were obtained from medical records. Treatment outcomes were categorized using the modified Rankin Scale for neurological disability. RESULTS: A total of 140 participants were included in this study from 2009 to 2019. Good outcomes were achieved in approximately 65% of cases, whereas 35% had poor outcomes based on the modified Rankin Scale. Glasgow Coma Scale score ≤10 at presentation and TBM/tuberculoma were significantly associated with poor outcomes. Moreover, the use of corticosteroids, more than three anti-TB medications, and surgical interventions were not significantly associated with good or poor outcomes. DISCUSSION: CNS-TB is associated with a high burden of long-term neurological morbidity. Early detection and treatment are crucial to prevent serious complications and decrease morbidity and mortality.

The effect of p53 on the activity of NRF2 and NDRG2 genes through apoptotic pathway in IDH-wildtype glioblastoma.

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 G2 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.

Epidemiological distribution of primary central nervous system tumors in the Western Province of Saudi Arabia: a local registry from neuroscience-affiliated centers.

OBJECTIVES: Central nervous system (CNS) tumors are a major and growing global healthcare challenge. Western Saudi Arabia has an inconsistent data registry; therefore, the epidemiology of CNS tumors is unclear across the country. This study is aimed to assemble the epidemiological matrix of CNS tumors in the Western Province of Saudi Arabia. METHODS: A retrospective analysis was performed using clinical data obtained from 3 neuroscience centers in Western Saudi Arabia in the period 2014-2019. The sample size included 663 adult and pediatric cases from the local and expatriate populations diagnosed with CNS tumors. The distributions of age, sex, clinical presentation, tumor location, type of surgery, histological subtype, genetic characteristics, and recurrence rate were explored. RESULTS: The analysis included 500 adult cases and 163 pediatric cases up to 18 years of age with a male-to-female ratio of 1.16. The mean age at diagnosis was 38.0±22.6 years. The supratentorium was the most common location (n=515, 77.7%). Most patients presented with headache (n=298, 44.9%), followed by a focal neurological deficit (19.9%). The most common primary CNS tumor was glioblastoma (n=234, 35.3%), followed by meningioma (n=100, 15.1%). The recurrence rate after surgery was estimated to be 40.9% among all CNS tumors. CONCLUSIONS: This is the first tumor registry of Western Province of Saudi Arabia that describes the distribution of primary CNS tumors and highlights their epidemiological matrix. Several incidence trends in terms of histological type, age group, sex, location, and recurrence were determined, and some genetic characteristics were recognized.

The Impact of IDH1 Mutation and MGMT Promoter Methylation on Recurrence-Free Interval in Glioblastoma Patients Treated With Radiotherapy and Chemotherapeutic Agents.

The aim of this study is to investigate the relationship between isocitrate dehydrogenase-1 (IDH1) mutation and O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation with recurrence-free interval in glioblastoma patients treated with chemoradiotherapies. Clinical data were collected from 82 patients with totally resected glioblastoma and treated with adjuvant therapies from 2014 to 2019. IDH1 mutation was assessed by immunohistochemistry and MGMT promoter methylation was assessed by different sequencing methods. IDH1 mutation was present in 32 cases and 50 cases were IDH1 wildtype; 54 and 28 patients had unmethylated and methylated MGMT promoter, respectively, Of the 82 patients, 62 patients received chemoradiotherapy while 20 patients only received radiation. Approximately, 61% of patients had a tumor recurrence after 1 year, and 39% showed a recurrence before 1 year of treatment. There was no significant relationship between IDH1 mutation and MGMT promoter methylation (p-value = 0.972). Patients with IDH1 mutation and their age <50 years showed a significant difference in recurrence-free interval (p-value = 0.014). Difference in recurrence-free interval was also statistically observed in patients with unmethylated MGMT promoter and treated with chemoradiotherapies (p-value = 0.031), by which they showed a late tumor recurrence (p-value = 0.016). This revealed that IDH1 mutation and MGMT methylation are independent prognostic factors in glioblastoma. Although IDH1-mutant glioblastomas showed late tumor recurrence in patients less than 50 years old, the type of treatment modalities may not show additional beneficial outcome. Patients with unmethylated MGMT and IDH1 mutation, treated with different chemoradiotherapies, showed a late tumor recurrence.

Sensitivity Assessment of Wilms Tumor Gene (WT1) Expression in Glioblastoma using qPCR and Immunohistochemistry and its Association with IDH1 Mutation and Recurrence Interval.

PURPOSE: Wilms tumor 1 (WT1) gene has recently shown a role in gliomagenesis, making it a potential immunotherapy target in glioblastomas. We aimed to investigate the most sensitive method to detect WT1 expression in glioblastoma and explore the relationship between WT1 expression, IDH1 mutation and recurrence interval. PATIENTS AND METHODS: Clinical data were collected from 44 patients with glioblastomas, treated with adjuvant therapies. WT1 expression was assessed in all cases using immunohistochemistry (IHC), while its gene expression was assessed in 13 clustered samples using polymerase chain reaction (qPCR). IDH1 mutation was assessed using IHC. The sensitivity between IHC and RT-qPCR was examined. Kaplan-Meier curves were used to compare the recurrence-free interval (RFI) between IDH1 and WT1 expression groups. RESULTS: IDH1wildtype was found in 26 cases (59.1%) and the remaining 18 cases (40.9%) were IDH1mutant. Through IHC, WT1 was overexpressed in 32 cases (72.7%), partially expressed in 9 cases (20.5%) and not expressed in only 3 cases. For the 13 cases tested by qPCR, 6 cases showed WT1 upregulation and 7 cases showed WT1 downregulation. There was no significant difference in WT1 expression among cases with different RNA concentrations regardless the testing method (p-value >0.05). However, the difference between IHC and qPCR was significant. IDH1mutant cases with WT1 overexpression showed significant difference in RFI (p-value =0.048). CONCLUSION: Parallel testing for WT1 expression using IHC and qPCR is not reliable. However, IHC provides more accurate results. Moreover, IDH1mutant glioblastomas with WT1 overexpression are associated with late RFI particularly if temozolomide with additional chemotherapies are used.