Temozolomide in malignant glioma

Enzyme-Instructed Host-Guest Assembly/Disassembly for Biomedical Applications

Compared with the normal assembly/disassembly approaches, enzyme-instructed host-guest assembly/disassembly strategies due to their superior biocompatibility and specificity for specific substrates, can more effectively and precisely release molecules at lesions for reflecting in vivo biological events. Specifically, due to the over-expression of enzymes in specific tissues, the assembly/disassembly processes can directly occur on the pathological sites (or regions of interest), thus these enzyme-instructed processes are widely and effectively used for disease treatment or precise bioimaging. Based on it, we introduce the concept and major strategies of enzyme-instructed host-guest assembly/disassembly, illustrate their importance in the diagnosis and treatment of diseases, and review their advances in biomedical applications. Further, the challenges of these strategies in the clinic and future tendencies are also prospected.

Local delivery of doxorubicin prodrug via lipid nanocapsule-based hydrogel for the treatment of glioblastoma

Glioblastoma (GBM) recurrences appear in most cases around the resection cavity borders and arise from residual GBM cells that cannot be removed by surgery. Here, we propose a novel treatment that combines the advantages of nanomedicine and local drug delivery to target these infiltrating GBM cells. We developed an injectable lipid nanocapsule (LNC)-based formulation loaded with lauroyl-doxorubicin prodrug (DOXC12). Firstly, we demonstrated the efficacy of intratumoral administration of DOXC12 in GL261 GBM-bearing mice, which extended mouse survival. Then, we formulated an injectable hydrogel by mixing the appropriate amount of prodrug with the lipophilic components of LNC. We optimized the hydrogel by incorporating cytidine-C16 (CytC16) to achieve a mechanical stiffness adapted for an application in the brain post-surgery (DOXC12-LNCCL). DOXC12-LNCCL exhibited high DOXC12 encapsulation efficiency (95%) and a size of approximately 60 nm with sustained drug release for over 1 month in vitro. DOXC12-LNCCL exhibited enhanced cytotoxicity compared to free DOXC12 (IC50 of 349 and 86 nM, respectively) on GL261 GBM cells and prevented the growth of GL261 spheroids cultured on organotypic brain slices. In vivo, post-surgical treatment with DOXC12-LNCCL significantly improved the survival of GL261-bearing mice. The combination of this local treatment with the systemic administration of anti-inflammatory drug ibuprofen further delayed the onset of recurrences. In conclusion, our study presents a promising therapeutic approach for the treatment of GBM. By targeting residual GBM cells and reducing the inflammation post-surgery, we present a new strategy to delay the onset of recurrences in the gap period between surgery and standard of care therapy.

Iron Oxide Nanoparticles Decorated with Functional Peptides for a Targeted siRNA Delivery to Glioma Cells

Glioma is a deadly form of brain cancer, and the difficulty of treating glioma is exacerbated by the chemotherapeutic resistance developed in the tumor cells over the time of treatment. siRNA can be used to silence the gene responsible for the increased resistance, and sensitize the glioma cells to drugs. Here, iron oxide nanoparticles functionalized with peptides (NP-CTX-R₁₀) were used to deliver siRNA to silence O6-methylguanine-DNA methyltransferase (MGMT) to sensitize tumor cells to alkylating drug, Temozolomide (TMZ). The NP-CTX-R₁₀ could complex with siRNA through electrostatic interactions and was able to deliver the siRNA to different glioma cells. The targeting ligand chlorotoxin and cell penetrating peptide polyarginine (R₁₀) enhanced the transfection capability of siRNA to a level comparable to commercially available Lipofectamine. The NP-siRNA was able to achieve up to 90% gene silencing. Glioma cells transfected with NP-siRNA targeting MGMT showed significantly elevated sensitivity to TMZ treatment. This nanoparticle formulation demonstrates the ability to protect siRNA from degradation and to efficiently deliver the siRNA to induce therapeutic gene knockdown.

Radiotherapy-drug combinations in the treatment of glioblastoma: a brief review

Glioblastoma (GBM) accounts for over 50% of gliomas and carries the worst prognosis of all solid tumors. Owing to the limited local control afforded by surgery alone, efficacious adjuvant treatments such as radiotherapy (RT) and chemotherapy are fundamental in achieving durable disease control. The best clinical outcomes are achieved with tri-modality treatment consisting of surgery, RT and systemic therapy. While RT-chemotherapy combination regimens are well established in oncology, this approach was largely unsuccessful in GBM until the introduction of temozolomide. The success of this combination has stimulated the search for other candidate drugs for concomitant use with RT in GBM. This review seeks to collate the current evidence for these agents and synthesize possible future directions for the field.

Maintenance of WT1 expression in tumor cells is associated with a good prognosis in malignant glioma patients treated with WT1 peptide vaccine immunotherapy

We have previously revealed the overexpression of Wilms' tumor gene 1 (WT1) in malignant glioma and developed WT1 peptide vaccine cancer immunotherapy. A phase II clinical trial indicated the clinical efficacy of the WT1 peptide vaccine for recurrent malignant glioma. Here, we aimed to investigate the immunological microenvironment in glioma tissues before and after WT1 peptide vaccine treatment. Paired tissue samples were obtained from 20 malignant glioma patients who had received the WT1 peptide vaccine for > 3 months and experienced tumor progression, confirmed radiographically and/or clinically, during vaccination. We discovered that the expression of WT1 and HLA class I antigens in the tumor cells significantly decreased after vaccination. Maintenance of WT1 expression, which is the target molecule of immunotherapy, in tumor cells during the vaccination period was significantly associated with a longer progression-free and overall survival. A high expression of HLA class I antigens and low CD4⁺/CD8⁺ tumor-infiltrating lymphocytes (TIL) ratio in pre-vaccination specimens, were also associated with a good prognosis. No statistically significant difference existed in the number of infiltrating CD3⁺ or CD8⁺ T cells between the pre- and post-vaccination specimens, whereas the number of infiltrating CD4⁺ T cells significantly decreased in the post-vaccination specimens. This study provides insight into the mechanisms of intra-tumoral immune reaction/escape during WT1 peptide vaccine treatment and suggests potential clinical strategies for cancer immunotherapy.

Diagnosis and Individualized Treatment of Secondary Central Nervous System Lymphoma: A Case Report

Non-Hodgkin lymphoma can disseminate to the central nervous system at initiation of treatment for systemic lymphoma or spread during the relapse of systematic lymphoma with CNS involvement, which is defined as secondary central nervous system lymphoma (SCNSL). The incidence of SCNSL depends on the pathological type of lymphoma and is especially high in aggressive lymphoma. SCNSL has a poor prognosis because of the lack of effective treatment regimens. This article presents a rare case of SCNSL; an individualized treatment regimen was designed according to the genetic analyses of the patient tumor and included a Bruton's tyrosine kinase (BTK) inhibitor. After six cycles of treatment and another two cycles of rituximab, most lesions lost their metabolic activity. However, in the final stage of treatment, our patient unfortunately suffered from respiratory failure, which revealed that we should pay attention to Pneumocystis jirovecii pneumonia during ibrutinib treatment.

BRCA1 Protein Expression Predicts Survival in Glioblastoma Patients from an NRG Oncology RTOG Cohort

PURPOSE

Glioblastoma, the most common malignant brain tumor, was associated with a median survival of <1 year in the pre-temozolomide (TMZ) era. Despite advances in molecular and genetic profiling studies identifying several predictive biomarkers, none has been translated into routine clinical use. Our aim was to investigate the prognostic significance of a panel of diverse cellular molecular markers of tumor formation and growth in an annotated glioblastoma tissue microarray (TMA).

METHODS AND MATERIALS

A TMA composed of archived glioblastoma tumors from patients treated with surgery, radiation, and non-TMZ chemother-apy, was provided by RTOG. RAD51, BRCA-1, phosphatase and tensin homolog tumor suppressor gene (PTEN), and miRNA-210 expression levels were assessed using quantitative in situ hybridization and automated quantitative protein analysis. The objectives of this analysis were to determine the association of each biomarker with overall survival (OS), using the Cox proportional hazard model. Event-time distributions were estimated using the Kaplan-Meier method and compared by the log-rank test.

RESULTS

A cohort of 66 patients was included in this study. Among the 4 biomarkers assessed, only BRCA1 expression had a statistically significant correlation with survival. From univariate analysis, patients with low BRCA1 protein expression showed a favorable outcome for OS (p = 0.04; hazard ratio = 0.56) in comparison with high expressors, with a median survival time of 18.9 versus 4.8 months.

CONCLUSIONS

BRCA1 protein expression was an important survival predictor in our cohort of glioblastoma patients. This result may imply that low BRCA1 in the tumor and the consequent low level of DNA repair cause vulnerability of the cancer cells to treatment.

Vinyl and Alkynyl Triazenes: Synthesis, Reactivity, and Applications

Aromatic compounds containing triazenyl groups (N₃ RR') have a profound impact on synthetic organic and medicinal chemistry. In contrast, the chemistry of vinyl and alkynyl triazenes was a largely uncharted territory until recently. The situation has changed over the last five years, and it has become apparent that vinyl and alkynyl triazenes are highly interesting compounds with a unique reactivity. The electron-donating properties of the triazenyl group provide alkynyl triazenes with an ynamide-like reactivity, which can be exploited in reactions of the triple bond. Vinyl triazenes, on the other hand, can be used for electrophilic vinylation reactions. The foundation for this new triazene chemistry are synthetic pathways which allow preparing vinyl and alkynyl triazenes in few steps from readily available starting materials. In this Minireview, we summarize recent developments in this area.

Design, Synthesis, and Preliminary Studies of Spiro-isoxazoline-peroxides against Human Cytomegalovirus and Glioblastoma ∥

The association between glioblastoma (GBM) and human cytomegalovirus (HCMV) infection has been the intensely debated topic over the decades for developing new therapeutic options. In this regard, the peroxides from natural and synthetic sources served as potential antiviral and anticancer agents in the past. Herein, a concise and efficient strategy has been demonstrated to access a novel class of peroxides containing a spiro-isoxazoline to primarily investigate the biological activities. The synthetic compounds were evaluated for in vitro antiviral and antiproliferative activity against HCMV and glioblastoma cell line (GBM6), respectively. While compound 13m showed moderate anti-CMV activity (IC₅₀ = 19 μM), surprisingly, an independent biological assay for compound 13m revealed its antiproliferative activity against the human glioblastoma cell line (GBM6) with an IC₅₀ of 10 μM. Hence, the unification of an isoxazoline and peroxide heterocycles could be a potential direction to initiate the HCMV-GBM drug discovery program.

An adherent tissue-inspired hydrogel delivery vehicle utilised in primary human glioma models

A physical hydrogel cross-linked via the host-guest interactions of cucurbit[8]uril and utilised as an implantable drug-delivery vehicle for the brain is described herein. Constructed from hyaluronic acid, this hydrogel is biocompatible and has a high water content of 98%. The mechanical properties have been characterised by rheology and compared with the modulus of human brain tissue demonstrating the production of a soft material that can be moulded into the cavity it is implanted into following surgical resection. Furthermore, effective delivery of therapeutic compounds and antibodies to primary human glioblastoma cell lines is showcased by a variety of in vitro and ex vivo viability and immunocytochemistry based assays.

NEO212 Inhibits Migration and Invasion of Glioma Stem Cells

Glioblastoma multiforme is a malignant brain tumor noted for its extensive vascularity, aggressiveness, and highly invasive nature, suggesting that cell migration plays an important role in tumor progression. The poor prognosis in GBM is associated with a high rate of tumor recurrence, and resistance to the standard of care chemotherapy, temozolomide (TMZ). The novel compound NEO212, a conjugate of TMZ and perillyl alcohol (POH), has proven to be 10-fold more cytotoxic to glioma stem cells (GSC) than TMZ, and is active against TMZ-resistant tumor cells. In this study, we show that NEO212 decreases migration and invasion of primary cultures of patient-derived GSCs, in both mesenchymal USC02 and proneural USC04 populations. The mechanism by which NEO212 reduces migration and invasion appears to be independent of its DNA alkylating effects, which cause cytotoxicity during the first hours of treatment, and is associated with a decrease in the FAK/Src signaling pathway, an effect not exhibited by TMZ. NEO212 also decreases the production of matrix metalloproteinases MMP2 and MMP9, crucial for GSC invasion. Gene expression analysis of epithelial and mesenchymal markers suggests that NEO212 increases the expression of epithelial-like characteristics, suggesting a reversion of the epithelial-to-mesenchymal transition process. Furthermore, in an in vivo orthotopic glioma model, NEO212 decreases tumor progression by reducing invasion of GSCs, thereby increasing survival time of mice. These studies indicate that NEO212, in addition to cytotoxicity, can effectively reduce migration and invasion in GSCs, thus exhibiting significant clinical value in the reduction of invasion and malignant glioma progression. Mol Cancer Ther; 17(3); 625-37. ©2018 AACR.

Hybrid Gd3+/cisplatin cross-linked polymer nanoparticles enhance platinum accumulation and formation of DNA adducts in glioblastoma cell lines

New hybrid nanoparticles permitted MRI monitoring of a cisplatin infusion while enhancing drug accumulation and DNA adduct formation in glioblastoma cells.

Malignant glioma-primitive neuroectodermal tumor recurring as PNET-like only subdural collection: Case report

Background

Histologic variants of conventional glioblastoma are rare clinical entities. In recent years, an aggressive variant termed malignant glioma with primitive neuroectodermal tumor components (MG-PNET) has been described in adults. In addition to the rarity of supratentorial primitive neuroectdoermal tumors (sPNET) in adults, MG-PNET can present with unique radiographic features.

Case Description

We report the case of a 42-year-old male who presented with headaches and vision changes. Magnetic resonance imaging (MRI) of the brain revealed a large right frontal lesion. He underwent craniotomy with pathology demonstrating glioblastoma WHO grade IV, with primitive neuroectodermal tumor-like components (MG-PNET). Seven weeks later the patient represented with worsening headaches and left-hand weakness. MRI brain revealed a diffusion restricting subdural collection overlying the prior craniotomy site. Biopsy revealed PNET-like recurrence of the previously treated MG-PNET.

Conclusion

In addition to histologic deviation, MG-PNET can present with variable radiographic findings on MRI and a clinical course distinctive from traditional glioblastoma. The hypercellular nature of this lesion can present as a diffusion-restricting lesion.

Enhancement of temozolomide stability by loading in chitosan-carboxylated polylactide-based nanoparticles

In the presented work, amphiphilic nanoparticles based on chitosan and carboxy-enriched polylactic acid have been prepared to improve the stability of the pro-drug temozolomide in physiological media by encapsulation. The carrier, with a diameter in the range of 150-180 nm, was able to accommodate up to 800 μg of temozolomide per mg of polymer. The obtained formulation showed good stability in physiological condition and preparation media up to 1 month. Temozolomide loaded inside the carrier exhibited greater stability than the free drug, in particular in simulated physiological solution at pH 7.4 where the hydrolysis in the inactive metabolite was clearly delayed. CS-SPLA nanoparticles demonstrated a pH-dependent TMZ release kinetics with the opportunity to increase or decrease the rate. Mass spectroscopy, UV-Vis analysis, and in vitro cell tests confirmed the improvement in temozolomide stability and effectiveness when loaded into the polymeric carrier, in comparison with the free drug.

Primitive Neuroectodermal Tumor with Glioblastoma Multiforme Components in an Adult: A Collision Tumor

We report a rare case of a central nervous system collision tumor in a 40-year-old woman. Histopathological examination of her large temporal tumor revealed two different components making up the tumor tissue. The predominant component of the tumor was found to be a primitive neuroectodermal tumor. The other component was glioblastoma multiforme. Both of these tumors carry a poor prognosis, and primitive neuroectodermal tumors are extremely uncommon in adults. Central nervous system neoplasms with the combined features of both primitive neuroectodermal tumor and malignant glioma are very rare and represent a diagnostic and treatment predicament. The patient underwent surgical resection, radiation therapy, and chemotherapy targeting both the primitive neuroectodermal tumor and glioblastoma. Our patient has been fortunate in not showing any sign of recurrence and will celebrate the third anniversary since her diagnosis this January.

Glioblastoma patients in Slovenia from 1997 to 2008

BACKGROUND

Glioblastoma is the most common primary brain tumour. It has a poor prognosis despite some advances in treatment that have been achieved over the last ten years. In Slovenia, 50 to 60 glioblastoma patients are diagnosed each year. In order to establish whether the current treatment options have any influence on the survival of the Slovenian glioblastoma patients, their data in the period from the beginning of the year 1997 to the end of the year 2008 have been analysed.

PATIENTS AND METHODS

All patients treated at the Institute of Oncology Ljubljana from 1997 to 2008 were included in the retrospective study. Demographics, treatment details, and survival time after the diagnosis were collected and statistically analysed for the group as a whole and for subgroups.

RESULTS

From 1997 to 2008, 527 adult patients were diagnosed with glioblastoma and referred to the Institute of Oncology for further treatment. Their median age was 59 years (from 20 to 85) and all but one had the diagnosis confirmed by a pathologist. Gross total resection was reported by surgeons in 261 (49.5%) patients; good functional status (WHO 0 or 1) after surgery was observed in 336 (63.7%) patients, radiotherapy was performed in 422 (80.1%) patients, in 317 (75.1%) of them with radical intent, and 198 (62.5 %) of those received some form of systemic treatment (usually temozolomide). The median survival of all patients amounted to 9.7 months. There was no difference in median survival of all patients or of all treated patients before or after the chemo-radiotherapy era. However, the overall survival of patients treated with radical intent was significantly better (11.4 months; p < 0.05). A better survival was also noticed in radically treated patients who received additional temozolomide therapy (11.4 vs. 13.1 months; p = 0.014). The longer survival was associated with a younger age and a good performance status as well as with a more extensive tumour resection. In patients treated with radical intent, having a good performance status, and receiving radiotherapy and additional temozolomide therapy, the survival was significantly longer, based on multivariate analysis.

CONCLUSIONS

We observed a gradual increase in the survival of glioblastoma patients who were treated with radical intent over the last ten years. Good functional surgery, advances in radiotherapy and addition of temozolomide all contributed to this increase. Though the increased survival seems to be more pronounced in certain subgroups, we have still not been able to exactly define them. Further research, especially in tumour biology and genetics is needed.

A conceptually new treatment approach for relapsed glioblastoma: coordinated undermining of survival paths with nine repurposed drugs (CUSP9) by the International Initiative for Accelerated Improvement of Glioblastoma Care

To improve prognosis in recurrent glioblastoma we developed a treatment protocol based on a combination of drugs not traditionally thought of as cytotoxic chemotherapy agents but that have a robust history of being well-tolerated and are already marketed and used for other non-cancer indications. Focus was on adding drugs which met these criteria: a) were pharmacologically well characterized, b) had low likelihood of adding to patient side effect burden, c) had evidence for interfering with a recognized, well-characterized growth promoting element of glioblastoma, and d) were coordinated, as an ensemble had reasonable likelihood of concerted activity against key biological features of glioblastoma growth. We found nine drugs meeting these criteria and propose adding them to continuous low dose temozolomide, a currently accepted treatment for relapsed glioblastoma, in patients with recurrent disease after primary treatment with the Stupp Protocol. The nine adjuvant drug regimen, Coordinated Undermining of Survival Paths, CUSP9, then are aprepitant, artesunate, auranofin, captopril, copper gluconate, disulfiram, ketoconazole, nelfinavir, sertraline, to be added to continuous low dose temozolomide. We discuss each drug in turn and the specific rationale for use- how each drug is expected to retard glioblastoma growth and undermine glioblastoma's compensatory mechanisms engaged during temozolomide treatment. The risks of pharmacological interactions and why we believe this drug mix will increase both quality of life and overall survival are reviewed.

Signal transduction molecule patterns indicating potential glioblastoma therapy approaches

PURPOSE

The expression of an array of signaling molecules, along with the assessment of real-time cell proliferation, has been performed in U87 glioma cell line and in patients' glioblastoma established cell cultures in order to provide a better understanding of cellular and molecular events involved in glioblastoma pathogenesis. Experimental therapy was performed using a phosphatidylinositol-3'-kinase (PI3K) inhibitor.

PATIENTS AND METHODS

xMAP technology was employed to assess expression levels of several signal transduction molecules and real-time xCELLigence platform for cell behavior.

RESULTS

PI3K inhibition induced the most significant effects on global signaling pathways in patient-derived cell cultures, especially on members of the mitogen-activated protein-kinase family, P70S6 serine-threonine kinase, and cAMP response element-binding protein expression and further prevented tumor cell proliferation.

CONCLUSION

The PI3K pathway might be a prime target for glioblastoma treatment.

Radiotherapy and temozolomide in anaplastic astrocytoma: a retrospective multicenter study by the Central Nervous System Study Group of AIRO (Italian Association of Radiation Oncology)

Although the evidence for the benefit of adding temozolomide (TMZ) to radiotherapy (RT) is limited to glioblastoma patients, there is currently a trend toward treating anaplastic astrocytomas (AAs) with combined RT + TMZ. The aim of the present study was to describe the patterns of care of patients affected by AA and, particularly, to compare the outcome of patients treated exclusively with RT with those treated with RT + TMZ. Data of 295 newly diagnosed AAs treated with postoperative RT ± TMZ in the period from 2002 to 2007 were reviewed. More than 75% of patients underwent a surgical removal. All the patients had postoperative RT; 86.1% of them were treated with 3D-conformal RT (3D-CRT). Sixty-seven percent of the entire group received postoperative chemotherapy with TMZ (n = 198). One-hundred sixty-six patients received both concomitant and sequential TMZ. Prescription of postoperative TMZ increased in the most recent period (2005-2007). One- and 4-year survival rates were 70.2% and 28.6%, respectively. No statistically significant improvement in survival was observed with the addition of TMZ to RT (P = .59). Multivariate analysis showed the statistical significance of age, presence of seizures, Recursive Partitioning Analysis classes I-III, extent of surgical removal, and 3D-CRT. Changes in the care of AA over the past years are documented. Currently there is not evidence to justify the addition of TMZ to postoperative RT for patients with newly diagnosed AA outside a clinical trial. Results of prospective and randomized trials are needed.