PIK3CA Mutations in Diffuse Gliomas: An Update on Molecular Stratification, Prognosis, Recurrence, and Aggressiveness

CRISPR/Cas9-mediated knockout strategies for enhancing immunotherapy in breast cancer

Breast cancer, a prevalent disease with significant mortality rates, often presents treatment challenges due to its complex genetic makeup. This review explores the potential of combining Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) gene knockout strategies with immunotherapeutic approaches to enhance breast cancer treatment. The CRISPR/Cas9 system, renowned for its precision in inducing genetic alterations, can target and eliminate specific cancer cells, thereby minimizing off-target effects. Concurrently, immunotherapy, which leverages the immune system's power to combat cancer, has shown promise in treating breast cancer. By integrating these two strategies, we can potentially augment the effectiveness of immunotherapies by knocking out genes that enable cancer cells to evade the immune system. However, safety considerations, such as off-target effects and immune responses, necessitate careful evaluation. Current research endeavors aim to optimize these strategies and ascertain the most effective methods to stimulate the immune response. This review provides novel insights into the integration of CRISPR/Cas9-mediated knockout strategies and immunotherapy, a promising avenue that could revolutionize breast cancer treatment as our understanding of the immune system's interplay with cancer deepens.

Molecular biology and novel therapeutics for IDH mutant gliomas: The new era of IDH inhibitors

Gliomas with Isocitrate dehydrogenase (IDH) mutation represent a discrete category of primary brain tumors with distinct and unique characteristics, behaviors, and clinical disease outcomes. IDH mutations lead to aberrant high-level production of the oncometabolite D-2-hydroxyglutarate (D-2HG), which act as a competitive inhibitor of enzymes regulating epigenetics, signaling pathways, metabolism, and various other processes. This review summarizes the significance of IDH mutations, resulting upregulation of D-2HG and the associated molecular pathways in gliomagenesis. With the recent finding of clinically effective IDH inhibitors in these gliomas, this article offers a comprehensive overview of the new era of innovative therapeutic approaches based on mechanistic rationales, encompassing both completed and ongoing clinical trials targeting gliomas with IDH mutations.

Deciphering Glioblastoma: Fundamental and Novel Insights into the Biology and Therapeutic Strategies of Gliomas

Gliomas constitute a diverse and complex array of tumors within the central nervous system (CNS), characterized by a wide range of prognostic outcomes and responses to therapeutic interventions. This literature review endeavors to conduct a thorough investigation of gliomas, with a particular emphasis on glioblastoma (GBM), beginning with their classification and epidemiological characteristics, evaluating their relative importance within the CNS tumor spectrum. We examine the immunological context of gliomas, unveiling the intricate immune environment and its ramifications for disease progression and therapeutic strategies. Moreover, we accentuate critical developments in understanding tumor behavior, focusing on recent research breakthroughs in treatment responses and the elucidation of cellular signaling pathways. Analyzing the most novel transcriptomic studies, we investigate the variations in gene expression patterns in glioma cells, assessing the prognostic and therapeutic implications of these genetic alterations. Furthermore, the role of epigenetic modifications in the pathogenesis of gliomas is underscored, suggesting that such changes are fundamental to tumor evolution and possible therapeutic advancements. In the end, this comparative oncological analysis situates GBM within the wider context of neoplasms, delineating both distinct and shared characteristics with other types of tumors.

Genetic profiling of rat gliomas and cardiac schwannomas from life-time radiofrequency radiation exposure study using a targeted next-generation sequencing gene panel

The cancer hazard associated with lifetime exposure to radiofrequency radiation (RFR) was examined in Sprague Dawley (SD) rats at the Ramazzini Institute (RI), Italy. There were increased incidences of gliomas and cardiac schwannomas. The translational relevance of these rare rat tumors for human disease is poorly understood. We examined the genetic alterations in RFR-derived rat tumors through molecular characterization of important cancer genes relevant for human gliomagenesis. A targeted next-generation sequencing (NGS) panel was designed for rats based on the top 23 orthologous human glioma-related genes. Single-nucleotide variants (SNVs) and small insertion and deletions (indels) were characterized in the rat gliomas and cardiac schwannomas. Translational relevance of these genetic alterations in rat tumors to human disease was determined through comparison with the Catalogue of Somatic Mutations in Cancer (COSMIC) database. These data suggest that rat gliomas resulting from life-time exposure to RFR histologically resemble low grade human gliomas but surprisingly no mutations were detected in rat gliomas that had homology to the human IDH1 p.R132 or IDH2 p.R172 suggesting that rat gliomas are primarily wild-type for IDH hotspot mutations implicated in human gliomas. The rat gliomas appear to share some genetic alterations with IDH1 wildtype human gliomas and rat cardiac schwannomas also harbor mutations in some of the queried cancer genes. These data demonstrate that targeted NGS panels based on tumor specific orthologous human cancer driver genes are an important tool to examine the translational relevance of rodent tumors resulting from chronic/life-time rodent bioassays.

An expanded role for surgery in grade 3 1p/19q co-deleted oligodendroglioma

Background

Grade 3 1p/19q co-deleted oligodendroglioma is an uncommon primary CNS tumor with a high rate of progression and recurrence. This study examines the benefit of surgery after progression and identifies predictors of survival.

Methods

This is a single-institution retrospective cohort study of consecutive adult patients with anaplastic or grade 3 1p/19q co-deleted oligodendroglioma diagnosed between 2001 and 2020.

Results

Eighty patients with 1p/19q co-deleted grade 3 oligodendroglioma were included. The median age was 47 years (interquartile range 38-56) and 38.8% were women. All patients underwent surgery, including gross total resection (GTR) for 26.3% of patients, subtotal resection (STR) for 70.0% of patients, and biopsy for 3.8% of patients. Forty-three cases (53.8%) progressed at a median of 5.6 years, and the median overall survival (OS) was 14.1 years. Among 43 cases of progression or recurrence, 21 (48.8%) underwent another resection. Patients who underwent a second operation had improved OS (P = .041) and survival after progression/recurrence (P = .012), but similar time to subsequent progression as patients who did not have repeat surgery (P = .50). Predictors of mortality at initial diagnosis included a preoperative Karnofsky Performance Status (KPS) under 80 (hazard ratio [HR] 5.4; 95% CI 1.5-19.2), an STR or biopsy rather than GTR (HR 4.1; 95% CI 1.2-14.2), and a persistent postoperative neurologic deficit (HR 4.0; 95% CI 1.2-14.1).

Conclusions

Repeat surgery is associated with increased survival, but not time to subsequent progression for progressing or recurrent 1p/19q co-deleted grade 3 oligodendrogliomas recur. Mortality is associated with a preoperative KPS under 80, lack of GTR, and persistent postoperative neurologic deficits after the initial surgery.

Oncogenic potential of PIK3CD in glioblastoma is exerted through cytoskeletal proteins PAK3 and PLEK2

The Class I_A phosphoinositide-3-kinase catalytic isoforms p110α, p110β, and p110δ have been implicated to play vital but overlapping roles in various cancers, including glioblastoma (GBM). We have previously shown that PIK3CD, encoding p110δ, is highly expressed in multiple glioma cell lines and involved in glioma cell migration and invasion. Based on the RNA sequencing data from The Cancer Genome Atlas (TCGA) database, we found the level of PIK3CD expression is significantly higher in GBM than WHO grade II and III gliomas and is closely related to poor survival. To further dissect the oncogenic roles of PIK3CD in glioma progression, we employed CRISPR/Cas9 to completely abrogate its expression in the GBM cell line U87-MG and have successfully isolated two knockout clones with different gene modifications. As expected, the knockout clones exhibited significantly lower migration and invasion capabilities when compared with their parental cells. Interestingly, knockout of PIK3CD also dramatically reduced the colony formation ability of the knockout cells. Further study revealed that PIK3CD deficiency could negate tumorigenesis in nude mice. To determine the downstream effect of PIK3CD depletion, we performed RT² profiler PCR array of selected gene sets and found that knockout of PIK3CD impaired the activity of p-21 activated kinase 3 (PAK3) and pleckstrin 2 (PLEK2), molecules involved in cancer cell migration and proliferation. This explains why the glioma cells without the PIK3CD expression exhibited weaker oncogenic features. Further, RNAseq analysis of parent and knockout clones revealed that this interaction might happen through axonogenesis signaling pathway. Taken together, we demonstrated that PIK3CD could be a potential prognostic factor and therapeutic target for GBM patients.