Novel Immunotherapeutics for the Treatment of Glioblastoma: The Last Decade of Research

Physiological Imaging Methods for Evaluating Response to Immunotherapies in Glioblastomas

Glioblastoma (GBM) is the most malignant brain tumor in adults, with a dismal prognosis despite aggressive multi-modal therapy. Immunotherapy is currently being evaluated as an alternate treatment modality for recurrent GBMs in clinical trials. These immunotherapeutic approaches harness the patient's immune response to fight and eliminate tumor cells. Standard MR imaging is not adequate for response assessment to immunotherapy in GBM patients even after using refined response assessment criteria secondary to amplified immune response. Thus, there is an urgent need for the development of effective and alternative neuroimaging techniques for accurate response assessment. To this end, some groups have reported the potential of diffusion and perfusion MR imaging and amino acid-based positron emission tomography techniques in evaluating treatment response to different immunotherapeutic regimens in GBMs. The main goal of these techniques is to provide definitive metrics of treatment response at earlier time points for making informed decisions on future therapeutic interventions. This review provides an overview of available immunotherapeutic approaches used to treat GBMs. It discusses the limitations of conventional imaging and potential utilities of physiologic imaging techniques in the response assessment to immunotherapies. It also describes challenges associated with these imaging methods and potential solutions to avoid them.

Pathogenetic Features and Current Management of Glioblastoma

Glioblastoma (GBM) is the most common form of primary malignant brain tumor with a devastatingly poor prognosis. The disease does not discriminate, affecting adults and children of both sexes, and has an average overall survival of 12-15 months, despite advances in diagnosis and rigorous treatment with chemotherapy, radiation therapy, and surgical resection. In addition, most survivors will eventually experience tumor recurrence that only imparts survival of a few months. GBM is highly heterogenous, invasive, vascularized, and almost always inaccessible for treatment. Based on all these outstanding obstacles, there have been tremendous efforts to develop alternative treatment options that allow for more efficient targeting of the tumor including small molecule drugs and immunotherapies. A number of other strategies in development include therapies based on nanoparticles, light, extracellular vesicles, and micro-RNA, and vessel co-option. Advances in these potential approaches shed a promising outlook on the future of GBM treatment. In this review, we briefly discuss the current understanding of adult GBM's pathogenetic features that promote treatment resistance. We also outline novel and promising targeted agents currently under development for GBM patients during the last few years with their current clinical status.

Anti-seizure medication is not associated with an increased risk to develop cancer in epilepsy patients

Objective

Whether anti-seizure medication (ASM) increases the risk for cancer has been debated for decades. While for some ASM, a carcinoma-promoting effect has been suspected, carcinoma-protective effects have been shown for other ASM. However, the issue remains unresolved as data from preclinical and clinical studies have been inconsistent and contradictory.

Methods

We collected anonymous patient data from practice neurologists throughout Germany between 2009 and 2018 using the IMS Disease Analyzer database (QuintilesIMS, Frankfurt, Germany). People with epilepsy (PWE) with an initial cancer diagnosis and antiepileptic therapy prior to the index date were 1:1 matched with a control group of PWE without cancer according to age, gender, index year, Charlson Comorbidity Index, and treating physician. For both groups, the risk to develop cancer under treatment with different ASMs was analyzed using three different models (ever use vs. never use (I), effect per one (II) and per five therapy years (III).

Results

A total of 3152 PWE were included (each group, n = 1,576; age = 67.3 ± 14.0 years). The risk to develop cancer was not significantly elevated for any ASM. Carbamazepine was associated with a decreased cancer risk (OR Model I: 0.699, p < .0001, OR Model II: 0.952, p = .4878, OR Model III: 0.758, p < .0004).

Significance

Our findings suggest that ASM use does not increase the risk of cancer in epilepsy patients.

Supplementary Information

The online version of this article (10.1007/s00415-020-10379-4) contains supplementary material, which is available to authorized users.

MicroRNA-142-3p inhibits proliferation and induces apoptosis by targeting the high-mobility group box 1 via the Wnt/β-catenin signaling pathway in glioma

BACKGROUND

Glioma is one of the most common brain tumors. Copious microRNAs have been identified as critical regulators in the development of glioma. MicroRNA-142-3p (miR-142-3p) has been reported as a tumor suppressor in some malignancies. However, the roles and molecular mechanisms of miR-142-3p in the development of glioma are poorly defined.

METHODS

An RT-qPCR assay was carried out to detect expressions of miR-142-3p and high-mobility group box 1 (HMGB1) mRNA. A bioinformatic analysis and a luciferase reporter assay were used to explore the interaction between miR-142-3p and HMGB1 3'UTR. A Western blot assay was performed to examine protein expression of HMGB1, c-myc, cleaved caspase-3, and β-catenin. Cell proliferative ability was assessed by an MTS assay. The cell apoptotic rate was measured using flow cytometry via the double-staining of Annexin V-FITC and propidium iodide (PI).

RESULTS

MiR-142-3p expression was remarkably reduced in glioma tissues. Mechanical analyses showed that HMGB1 was a target of miR-142-3p. Functional investigations revealed that miR-142-3p suppressed proliferation and induced apoptosis by targeting HMGB1 in glioma cells. Moreover, miR-142-3p inactivated Wnt/β-catenin signaling and activated caspase-3 signaling by targeting HMGB1 in glioma cells.

CONCLUSION

MiR-142-3p inhibits proliferation and induces apoptosis by targeting HMGB1 via the Wnt/β-catenin signaling pathway in glioma cells, providing a deep exploration into the roles and molecular basis of miR-142-3p in the proliferation and apoptosis of glioma cells and highlighting the therapeutical values of miR-142-3p and HMGB1 for glioma.