Pyrosequencing Analysis of MGMT Promoter Methylation in Meningioma

Unlocking the secrets: the power of methylation-based cfDNA detection of tissue damage in organ systems

BACKGROUND

Detecting organ and tissue damage is essential for early diagnosis, treatment decisions, and monitoring disease progression. Methylation-based assays offer a promising approach, as DNA methylation patterns can change in response to tissue damage. These assays have potential applications in early detection, monitoring disease progression, evaluating treatment efficacy, and assessing organ viability for transplantation. cfDNA released into the bloodstream upon tissue or organ injury can serve as a biomarker for damage. The epigenetic state of cfDNA, including DNA methylation patterns, can provide insights into the extent of tissue and organ damage.

CONTENT

Firstly, this review highlights DNA methylation as an extensively studied epigenetic modification that plays a pivotal role in processes such as cell growth, differentiation, and disease development. It then presents a variety of highly precise 5-mC methylation detection techniques that serve as powerful tools for gaining profound insights into epigenetic alterations linked with tissue damage. Subsequently, the review delves into the mechanisms underlying DNA methylation changes in organ and tissue damage, encompassing inflammation, oxidative stress, and DNA damage repair mechanisms. Next, it addresses the current research status of cfDNA methylation in the detection of specific organ tissues and organ damage. Finally, it provides an overview of the multiple steps involved in identifying specific methylation markers associated with tissue and organ damage for clinical trials. This review will explore the mechanisms and current state of research on cfDNA methylation-based assay detecting organ and tissue damage, the underlying mechanisms, and potential applications in clinical practice.

DNA methylation meningioma biomarkers: attributes and limitations

Meningioma, one of the most common primary central nervous system tumors, are classified into three grades by the World Health Organization (WHO) based on histopathology. The gold-standard treatment, surgical resection, is hampered by issues such as incomplete resection in some cases and a high recurrence rate. Alongside genetic alterations, DNA methylation, plays a crucial role in progression of meningiomas in the occurrence and development of meningiomas. The epigenetic landscape of meningioma is instrumental in refining tumor classification, identifying robust molecular markers, determining prognosis, guiding treatment selection, and innovating new therapeutic strategies. Existing classifications lack comprehensive accuracy, and effective therapies are limited. Methylated DNA markers, exhibiting differential characteristics across varying meningioma grades, serve as invaluable diagnostic tools. Particularly, combinatorial methylated markers offer insights into meningioma pathogenesis, tissue origin, subtype classification, and clinical outcomes. This review integrates current research to highlight some of the most promising DNA and promoter methylation markers employed in meningioma diagnostics. Despite their promise, the development and application of DNA methylation biomarkers for meningioma diagnosis and treatment are still in their infancy, with only a handful of DNA methylation inhibitors currently clinically employed for meningioma treatment. Future studies are essential to validate these markers and ascertain their clinical utility. Combinatorial methylated DNA markers for meningiomas have broad implications for understanding tumor development and progression, signaling a paradigm shift in therapeutic strategies for meningiomas.

The Epigenetic Landscape of Meningiomas

Epigenetic changes have been found to be increasingly important in tumor development and progression. These alterations can be present in tumors such as meningiomas in the absence of any gene mutations and alter gene expression without affecting the sequence of the DNA itself. Some examples of these alterations that have been studied in meningiomas include DNA methylation, microRNA interaction, histone packaging, and chromatin restructuring. In this chapter we will describe in detail each of these mechanisms of epigenetic modification in meningiomas and their prognostic significance.

[The DNA methylation profiling in the study and treatment of patients with meningiomas of the craniovertebral junction]

The paper presents the experience of using DNA methylation status in patients with meningiomas of the craniovertebral junction area in a neurosurgical clinic. A clinical case of combined treatment of a patient with meningioma of the craniovertebral junction and the choice of tactics based on the result of DNA methylation analysis of meningioma are described.

Evaluation of a procaspase-3 activator with hydroxyurea or temozolomide against high-grade meningioma in cell culture and canine cancer patients

BACKGROUND

High-grade meningioma is an aggressive type of brain cancer that is often recalcitrant to surgery and radiotherapy, leading to poor overall survival. Currently, there are no FDA-approved drugs for meningioma, highlighting the need for new therapeutic options, but development is challenging due to the lack of predictive preclinical models.

METHODS

To leverage the known overexpression of procaspase-3 in meningioma, PAC-1, a blood-brain barrier penetrant procaspase-3 activator, was evaluated for its ability to induce apoptosis in meningioma cells. To enhance the effects of PAC-1, combinations with either hydroxyurea or temozolomide were explored in cell culture. Both combinations were further investigated in small groups of canine meningioma patients and assessed by MRI, and the novel apoptosis tracer, [18F]C-SNAT4, was evaluated in patients treated with PAC-1 + HU.

RESULTS

In meningioma cell lines in culture, PAC-1 + HU are synergistic while PAC-1 + TMZ show additive-to-synergistic effects. In canine meningioma patients, PAC-1 + HU led to stabilization of disease and no change in apoptosis within the tumor, whereas PAC-1 + TMZ reduced tumor burden in all three canine patients treated.

CONCLUSIONS

Our results suggest PAC-1 + TMZ as a potentially efficacious combination for the treatment of human meningioma, and also demonstrate the utility of including pet dogs with meningioma as a means to assess anticancer strategies for this common brain tumor.

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.

A Reappraisal of Superficial Pleomorphic Liposarcoma

OBJECTIVES

Superficial pleomorphic liposarcoma (PL) has a favorable prognosis compared to deeply seated PL. Given developments in the classification of lipomatous neoplasms, we reappraised a series of cases.

METHODS

Retrospective clinicopathologic evaluation and genome-wide single-nucleotide polymorphism (SNP) microarray studies were performed for cases previously designated superficial PL.

RESULTS

Four cases were identified (age, 48-70 years). Two were dermally confined, whereas two were superficial subcutaneous; no recurrences or metastases were reported. Tumors demonstrated pleomorphic spindled morphology with variable cellularity. Multivacuolated atypical lipoblasts were focal in 3 and abundant in 1. Dermal tumors demonstrated atypical cells within sclerotic collagen. Genome-wide SNP microarray studies revealed consistent gains and losses, including losses at the 13q14.2 locus encompassing RB1 and DLEU2 and deletion/disruption of the TP53 locus. Although subcutaneous examples showed genomic changes similar to deep PL, the dermal examples showed fewer genetic alterations, including changes reported in the spectrum of atypical spindle cell/pleomorphic lipomatous tumors (ASPLT). All lacked MDM2 amplification.

CONCLUSIONS

Careful integration of histologic and genetic features may improve classification of lipomatous neoplasms with atypia, allowing reclassification of some superficial PL as ASPLT.

Epigenetic IVD Tests for Personalized Precision Medicine in Cancer

Epigenetic alterations play a key role in the initiation and progression of cancer. Therefore, it is possible to use epigenetic marks as biomarkers for predictive and precision medicine in cancer. Precision medicine is poised to impact clinical practice, patients, and healthcare systems. The objective of this review is to provide an overview of the epigenetic testing landscape in cancer by examining commercially available epigenetic-based in vitro diagnostic tests for colon, breast, cervical, glioblastoma, lung cancers, and for cancers of unknown origin. We compile current commercial epigenetic tests based on epigenetic biomarkers (i.e., DNA methylation, miRNAs, and histones) that can actually be implemented into clinical practice.