Comment in Response to "Temozolomide in Glioblastoma Therapy: Role of Apoptosis, Senescence and Autophagy etc. by B. Kaina"

Use of surface-modified porous silicon nanoparticles to deliver temozolomide with enhanced pharmacokinetic and therapeutic efficacy for intracranial glioblastoma in mice

Glioblastoma (GBM) is one of the most common and fatal primary brain tumors, with a 5-year survival rate of 7.2%. The standard treatment for GBM involves surgical resection followed by chemoradiotherapy, and temozolomide (TMZ) is currently the only approved chemotherapeutic agent for the treatment of GBM. However, hydrolytic instability and insufficient drug accumulation are major challenges that limit the effectiveness of TMZ chemotherapy. To overcome these limitations, we have developed a drug delivery platform utilizing porous silicon nanoparticles (pSiNPs) to improve the stability and blood-brain barrier penetration of TMZ. The pSiNPs are synthesized via electrochemical etching and functionalized with octadecane. The octadecyl-modified pSiNP (pSiNP-C18) demonstrates the superiority of loading efficiency, in vivo stability, and brain accumulation of TMZ. Treatment of intracranial tumor-bearing mice with TMZ-loaded pSiNP-C18 results in a decreased tumor burden and a corresponding increase in survival compared with equivalent free-drug dosing. Furthermore, the mice treated with TMZ-loaded nanoparticles do not exhibit in vivo toxicity, thus underscoring the preclinical potential of the pSiNP-based platform for the delivery of therapeutic agents to gliomas.

Special Issue: Principal Challenges in the Adjuvant Treatment of Glioblastoma

Despite advances in local treatments, such as supramaximal resection (even in eloquent locations [...].

Critical View of Novel Treatment Strategies for Glioblastoma: Failure and Success of Resistance Mechanisms by Glioblastoma Cells

According to the invasive nature of glioblastoma, which is the most common form of malignant brain tumor, the standard care by surgery, chemo- and radiotherapy is particularly challenging. The presence of glioblastoma stem cells (GSCs) and the surrounding tumor microenvironment protects glioblastoma from recognition by the immune system. Conventional therapy concepts have failed to completely remove glioblastoma cells, which is one major drawback in clinical management of the disease. The use of small molecule inhibitors, immunomodulators, immunotherapy, including peptide and mRNA vaccines, and virotherapy came into focus for the treatment of glioblastoma. Although novel strategies underline the benefit for anti-tumor effectiveness, serious challenges need to be overcome to successfully manage tumorigenesis, indicating the significance of developing new strategies. Therefore, we provide insights into the application of different medications in combination to boost the host immune system to interfere with immune evasion of glioblastoma cells which are promising prerequisites for therapeutic approaches to treat glioblastoma patients.

B4GalT1 Regulates Apoptosis and Autophagy of Glioblastoma In Vitro and In Vivo

Our study was designed to investigate the role of B4GalT1 in glioblastoma, in vitro and in vivo, to detect whether B4GalT1 knockdown could regulate the development of glioblastoma, and further observe the relationship between B4GalT1 knockdown and the apoptosis and autophagy of glioblastoma. To begin, we looked at TCGA and GEPIA systems to predict the potential function of B4GalT1. Western blot and RT-PCR were used to analyze the expression, or mRNA level, of B4GalT1 at different tissue or cell lines. Next, the occurrence and development of glioblastoma, in vitro and in vivo, was observed by using B4GalT1 knocked down by lentivirus. Finally, the apoptosis and autophagy of glioblastoma was observed in vitro and in vivo. Results show that B4GalT1 was a highly variable gene, and GEPIA and TCGA systems show B4GalT1 expression in GBM tumor tissue was higher than in normal tissue. Pair-wise gene correlation analysis revealed a probable relationship between B4GalT1 and autophagy related proteins. The B4GalT1 expression and mRNA level were increased in tumor cells, or U87 cells. B4GalT1 knocked down by lentivirus could inhibit glioblastoma development, in vitro and in vivo, by reducing tumor weight and volume, increasing survival, and weakening tumor cells proliferation, migration, invasion. B4GalT1 knockdown could increase apoptosis and autophagy of glioblastoma in vitro and in vivo. Our study demonstrates that B4GalT1 may be able to regulate apoptosis and autophagy of glioblastoma. Bax, Bcl-2, cleaved caspase-3, Beclin-1, and LC3 s may be the downstream target factors of B4GalT1 in apoptosis and autophagy, which may provide a new strategy to reduce glioblastoma development by regulating apoptosis and autophagy.

Considering the Experimental use of Temozolomide in Glioblastoma Research

Temozolomide (TMZ) currently remains the only chemotherapeutic component in the approved treatment scheme for Glioblastoma (GB), the most common primary brain tumour with a dismal patient's survival prognosis of only ~15 months. While frequently described as an alkylating agent that causes DNA damage and thus-ultimately-cell death, a recent debate has been initiated to re-evaluate the therapeutic role of TMZ in GB. Here, we discuss the experimental use of TMZ and highlight how it differs from its clinical role. Four areas could be identified in which the experimental data is particularly limited in its translational potential: 1. transferring clinical dosing and scheduling to an experimental system and vice versa; 2. the different use of (non-inert) solvent in clinic and laboratory; 3. the limitations of established GB cell lines which only poorly mimic GB tumours; and 4. the limitations of animal models lacking an immune response. Discussing these limitations in a broader biomedical context, we offer suggestions as to how to improve transferability of data. Finally, we highlight an underexplored function of TMZ in modulating the immune system, as an example of where the aforementioned limitations impede the progression of our knowledge.