SETMAR Shorter Isoform: A New Prognostic Factor in Glioblastoma

Are we better together? Addressing a combined treatment of pitavastatin and temozolomide for brain cancer

Pitavastatin is commonly prescribed to treat hypercholesterolemia through the regulation of cholesterol biosynthesis. Interestingly, it has also demonstrated a great potential for treating brain tumors, although the detailed cytotoxic mechanism, particularly in glioblastoma, remains incompletely understood. This work explores the activity of pitavastatin in 2D and 3D glioblastoma models, in an attempt to provide a more representative and robust overview of its anticancer potential in glioblastoma. The results show that not only is pitavastatin 10-1000 times-fold more effective in reducing tumoral metabolic activity than temozolomide, but also demonstrate a synergistic activity with this alkylating drug. In addition, low micromolar concentrations of this statin strongly impair the growth and the invasion ability of multicellular tumor spheroids. The obtained qRT-PCR and proteomics data highlight the modulation of cell death via apoptosis (BAX/BCL2, CASP9) and autophagy (BECN1, BNIP3, BNIP3L and LC3B), as well as an epithelial to mesenchymal transition blockage (HTRA1, SERPINE1, WNT5A, ALDH3B1 and EPHA2) and remodeling of the extracellular matrix (VCAN, SERPINE1 and TGFBI). Overall, these results lay the foundation for further investigations on the potential combinatory clinical treatment with temozolomide.

Epigenetic Modifiers: Exploring the Roles of Histone Methyltransferases and Demethylases in Cancer and Neurodegeneration

Histone methyltransferases (HMTs) and histone demethylases (HDMs) are critical enzymes that regulate chromatin dynamics and gene expression through the addition and removal of methyl groups on histone proteins. HMTs, such as PRC2 and SETD2, are involved in the trimethylation of histone H3 at lysine 27 and lysine 36, influencing gene silencing and activation. Dysregulation of these enzymes often leads to abnormal gene expression and contributes to tumorigenesis. In contrast, HDMs including KDM7A and KDM2A reverse these methylation marks, and their dysfunction can drive disease progression. In cancer, the aberrant activity of specific HMTs and HDMs can lead to the silencing of tumor suppressor genes or the activation of oncogenes, facilitating tumor progression and resistance to therapy. Conversely, in neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD), disruptions in histone methylation dynamics are associated with neuronal loss, altered gene expression, and disease progression. We aimed to comprehend the odd activity of HMTs and HDMs and how they contribute to disease pathogenesis, highlighting their potential as therapeutic targets. By advancing our understanding of these epigenetic regulators, this review provides new insights into their roles in cancer and neurodegenerative diseases, offering a foundation for future research.

Unite and Conquer: Association of Two G-Quadruplex Aptamers Provides Antiproliferative and Antimigration Activity for Cells from High-Grade Glioma Patients

Background: High-grade gliomas remain a virtually incurable form of brain cancer. Current therapies are unable to completely eradicate the tumor, and the tumor cells that survive chemotherapy or radiation therapy often become more aggressive and resistant to further treatment, leading to inevitable relapses. While the antiproliferative effects of new therapeutic molecules are typically the primary focus of research, less attention is given to their influence on tumor cell migratory activity, which can play a significant role in recurrence. A potential solution may lie in the synergistic effects of multiple drugs on the tumor. Objectives: In this study, we investigated the effect of combined exposure to bi-(AID-1-T), an anti-proliferative aptamer, and its analog bi-(AID-1-C), on the migratory activity of human GBM cells. Results: We examined the effects of various sequences of adding bi-(AID-1-T) and bi-(AID-1-C) on five human GBM cell cultures. Our findings indicate that certain sequences significantly reduced the ability of tumor cells to migrate and proliferate. Additionally, the expression of Nestin, PARP1, L1CAM, Caveolin-1, and c-Myc was downregulated in human GBM cells that survived exposure, suggesting that the treatment had a persistent antitumor effect on these cells.

A Case of Long-Term Survival After Glioblastoma, IDH-Wild Type

INTRODUCTION

Glioblastoma is a uniformly lethal primary central nervous system neoplasm. Despite the increased understanding of its pathophysiology and treatment advancements, median overall survival for patients with glioblastoma, IDH-wild type remains 14 to 21 months from diagnosis.

CASE REPORT

We present the case of a 48-year-old female who presented with a focal seizure and was found to have a right frontal lobe mass on the brain magnetic resonance imaging. She underwent gross total resection and received a histological diagnosis of glioblastoma. She received radiotherapy and 6 cycles of carmustine (BCNU). Seventeen months later, she developed left hemiparesis. Imaging was concerning for tumor progression, and she was treated with 1 cycle of mechlorethamine, vincristine (oncovin), procarbazine, and prednisone (MOPP). Subsequent surveillance imaging demonstrated a therapeutic response. Twenty-seven years after her glioblastoma diagnosis, she developed status epilepticus and died from respiratory failure. Neuropathology on autopsy demonstrated extensive treatment-related changes but no evidence of recurrent glioblastoma. Genomic testing performed over 30 years after her original diagnosis revealed a profile diagnostic of glioblastoma, IDH-wild type per 2021 World Health Organization criteria.

CONCLUSIONS

This patient is one of the longest-known survivors of glioblastoma, IDH-wild type, with pathologic confirmation of glioblastoma at the time of her resection and no evidence of residual disease 26 years after her last treatment. She presented with multiple factors associated with long-term glioblastoma survivorship, including female sex, young age, high Karnofsky score, and multimodal therapy. This case shows that long-term survival after glioblastoma diagnosis is possible and likely mediated through a combination of individual, tumor, and treatment factors.

Investigating the Expression Pattern of the SETMAR Gene Transcript Variants in Childhood Acute Leukemia: Revisiting an Old Gene

BACKGROUND

The chimeric enzyme SETMAR (or Metnase) has been associated with several DNA processes, including DNA damage repair through the non-homologous joining pathway and suppression of chromosomal translocation in mouse fibroblasts. SETMAR overexpression has been reported in certain cancers suggesting that it might contribute to the establishment or progression of these cancers. In leukemia, the SETMAR gene transcript variants have not been widely studied. Therefore, this study aimed to quantify 3 predominant SETMAR variants in 2 types of childhood acute leukemia, acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL).

METHODS

In this study, using reverse transcription-quantitative polymerase chain reaction (RT-qPCR), the relative expression of 3 SETMAR transcript variants (Var 1, Var 2, and Var A) were evaluated in the bone marrow samples collected from 30 newly diagnosed patients with AML, 65 newly diagnosed patients with ALL, and 15 healthy individuals.

RESULTS

The expression of SETMAR variants 1 and A were significantly higher in AML patients compared with controls ( P =0.02, and P =0.009, respectively). Variant A expression was significantly higher in ALL compared with controls ( P =0.003). When comparing the expression in translocation-positive and negative subgroups, the expression of variant 1 was significantly higher in translocation-positive ALL patients ( P =0.03). The variants' distribution patterns differed concerning translocation status ( P =0.041), as variants 1 and A were dominant in the translocation-positive ALL group, and variant 2 was more prevalent in translocation-negative ones.

CONCLUSIONS

According to the results, SETMAR showed increased expression in pediatric acute leukemia's bone marrow samples, indicating a role for this molecule in leukemia pathogenesis. As this is the first report of SETMAR expression in pediatric leukemias, further studies are needed to investigate the causality of this association.

SETMAR, a case of primate co-opted genes: towards new perspectives

BACKGROUND

We carry out a review of the history and biological activities of one domesticated gene in higher primates, SETMAR, by discussing current controversies. Our purpose is to open a new outlook that will serve as a framework for future work about SETMAR, possibly in the field of cognition development.

MAIN BODY

What is newly important about SETMAR can be summarized as follows: (1) the whole protein sequence is under strong purifying pressure; (2) its role is to strengthen existing biological functions rather than to provide new ones; (3) it displays a tissue-specific pattern of expression, at least for the alternative-splicing it undergoes. Studies reported here demonstrate that SETMAR protein(s) may be involved in essential networks regulating replication, transcription and translation. Moreover, during embryogenesis, SETMAR appears to contribute to brain development.

SHORT CONCLUSION

Our review underlines for the first time that SETMAR directly interacts with genes involved in brain functions related to vocalization and vocal learning. These findings pave the way for future works regarding SETMAR and the development of cognitive abilities in higher primates.