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Cells Aug 2022Glioblastoma (GBM) is the most common and highly lethal type of brain tumor, with poor survival despite advances in understanding its complexity. After current standard... (Review)
Review
Glioblastoma (GBM) is the most common and highly lethal type of brain tumor, with poor survival despite advances in understanding its complexity. After current standard therapeutic treatment, including tumor resection, radiotherapy and concomitant chemotherapy with temozolomide, the median overall survival of patients with this type of tumor is less than 15 months. Thus, there is an urgent need for new insights into GBM molecular characteristics and progress in targeted therapy in order to improve clinical outcomes. The literature data revealed that a number of different signaling pathways are dysregulated in GBM. In this review, we intended to summarize and discuss current literature data and therapeutic modalities focused on targeting dysregulated signaling pathways in GBM. A better understanding of opportunities for targeting signaling pathways that influences malignant behavior of GBM cells might open the way for the development of novel GBM-targeted therapies.
Topics: Brain Neoplasms; Glioblastoma; Humans; Signal Transduction; Temozolomide
PubMed: 36010607
DOI: 10.3390/cells11162530 -
Discovery Medicine Feb 2017Checkpoint inhibitors, like ipilimumab, nivolumab, and pembrolizumab, have provided a breakthrough in cancer immunotherapy, such as in the treatment of melanoma and... (Review)
Review
Checkpoint inhibitors, like ipilimumab, nivolumab, and pembrolizumab, have provided a breakthrough in cancer immunotherapy, such as in the treatment of melanoma and colorectal and lung cancer. The close relationship between the number of mutations (mutational load) and the response to checkpoint immunotherapy has been convincingly demonstrated in these cancers. Hypermutations in tumors are caused by environmental factors, like UV radiations or cigarette smoking, or by germinal mutations affecting genes of the Mismatch Repair (MMR) machinery, as in the Lynch syndrome. In the context of a high mutational load, a number of neoantigens become visible to the immune system, creating the basis for effective T cell responses. In low- and high-grade gliomas, the most frequent brain tumors, germinal MMR defects are rare; however, hypermutations associated with mutations or decreased expression of MMR genes are rather frequent, occurring in 20-60% of the tumors at recurrence after alkylating chemotherapy with temozolomide. Ongoing clinical trials and genomic investigations will clarify if temozolomide-induced hypermutations, which usually occur in the presence of methylation of the methylguanine methyltransferase gene (MGMT), will be effectively targeted by immunotherapy with checkpoint inhibitors or dendritic cell immunotherapy, thus improving the survival expectations for patients affected by these tumors.
Topics: Animals; Antineoplastic Agents, Alkylating; Dacarbazine; Glioma; Humans; Immunotherapy; Mutation; Temozolomide
PubMed: 28371614
DOI: No ID Found -
Current Oncology (Toronto, Ont.) Feb 2023Outcomes for patients with high-grade glioma remain poor. Temozolomide (TMZ) is the only drug approved for first-line treatment of glioblastoma multiforme, the most... (Review)
Review
Outcomes for patients with high-grade glioma remain poor. Temozolomide (TMZ) is the only drug approved for first-line treatment of glioblastoma multiforme, the most aggressive form of glioma. Chronotherapy highlights the potential benefit of timed TMZ administration. This is based on pre-clinical studies of enhanced TMZ-induced glioma cytotoxicity dependent on circadian, oscillating expression of key genes involved in apoptosis, DNA damage repair, and cell-cycle mediated cell death. The current systematic review's primary aim was to evaluate the efficacy and toxicity of TMZ chronotherapy. A systemic review of literature following PRISMA guidelines looking at clinical outcomes on TMZ chronotherapy on gliomas was performed. The search in the English language included three databases (PubMed, EMBASE, and Cochrane) and five conferences from 1946 to April 2022. Two independent reviewers undertook screening, data extraction, and risk-of-bias assessment. A descriptive analysis was conducted due to limited data. Of the 269 articles screened, two unique studies were eligible and underwent abstraction for survival and toxicity findings. Both studies-one a retrospective cohort study (n = 166) and the other a prospective randomized feasibility study (n = 35)-were conducted by the same academic group and suggested a trend for improved overall survival, but possibly increased toxicity when TMZ was administered in the morning (vs. evening). There was limited evidence suggesting possible therapeutic value from administering TMZ in the morning, which may be consistent with the pre-clinical observations of the importance of the timing of TMZ administration in vitro. Larger, pragmatic, prospective randomized controlled trials are needed to ascertain the value of TMZ chronotherapy to provide optimized and equitable care for this population.
Topics: Humans; Temozolomide; Retrospective Studies; Prospective Studies; Brain Neoplasms; Glioma; Chronotherapy; Randomized Controlled Trials as Topic
PubMed: 36826108
DOI: 10.3390/curroncol30020147 -
Current Oncology (Toronto, Ont.) May 2022Glioblastomas with multiple foci at presentation (mGBMs) account for 2-35% of all GBMs. mGBMs have limited existing data and no standardized treatment. This study aims... (Review)
Review
Glioblastomas with multiple foci at presentation (mGBMs) account for 2-35% of all GBMs. mGBMs have limited existing data and no standardized treatment. This study aims to determine their incidence, demographic and clinical features, outcome, and prognostic factors in terms of overall survival. We performed a monocentric retrospective study, reviewing patients treated at the Istituto Oncologico Veneto. Inclusion criteria were: new diagnosis of GBM and presence of multiple lesions on pre-treatment MRI. ECOG PS was used to evaluate clinical condition, RANO criteria for radiological assessment, and CTCAE v5.0 for treatment-related adverse events. The incidence of newly diagnosed mGBM was 7.2% and the study population consisted of 98 patients. Median age was 63 years, M:F ratio of 1.8:1, and a surgical approach was undertaken in 73 patients (mostly partial resection). MGMT was methylated in 47.5%, and 82 patients received active oncological treatment (65.9% radiotherapy plus temozolomide (RT + TMZ)). The disease control rate with RT + TMZ was 63%. Median OS of the entire study population was 10.2 months (95% CI 6.6-13.8), and median PFS was 4.2 months (95% CI 3.2-5.2). The ECOG PS, the extent of resection, and the RT + TMZ were significant prognostic factors in the univariate analysis for OS, but only the RT + TMZ was a significant independent OS predictor in the multivariate analysis (HR = 3.1, 95% IC 1.3-7.7, = 0.014). The incidence of mGBM is not rare. RT + TMZ is confirmed to be an independent prognostic factor for survival and a safe and effective treatment. When feasible, RT + TMZ should be considered as a possible first-line treatment. The role of the extent of resection is still unclear.
Topics: Antineoplastic Agents, Alkylating; Brain Neoplasms; Dacarbazine; Humans; Middle Aged; Retrospective Studies; Temozolomide
PubMed: 35621670
DOI: 10.3390/curroncol29050280 -
Cells Dec 2022Glioblastoma, a grade IV astrocytoma, is regarded as the most aggressive primary brain tumour with an overall median survival of 16.0 months following the standard... (Review)
Review
Glioblastoma, a grade IV astrocytoma, is regarded as the most aggressive primary brain tumour with an overall median survival of 16.0 months following the standard treatment regimen of surgical resection, followed by radiotherapy and chemotherapy with temozolomide. Despite such intensive treatment, the tumour almost invariably recurs. This poor prognosis has most commonly been attributed to the initiation, propagation, and differentiation of cancer stem cells. Despite the unprecedented advances in biomedical research over the last decade, the current in vitro models are limited at preserving the inter- and intra-tumoural heterogeneity of primary tumours. The ability to understand and manipulate complex cancers such as glioblastoma requires disease models to be clinically and translationally relevant and encompass the cellular heterogeneity of such cancers. Therefore, brain cancer research models need to aim to recapitulate glioblastoma stem cell function, whilst remaining amenable for analysis. Fortunately, the recent development of 3D cultures has overcome some of these challenges, and cerebral organoids are emerging as cutting-edge tools in glioblastoma research. The opportunity to generate cerebral organoids via induced pluripotent stem cells, and to perform co-cultures with patient-derived cancer stem cells (GLICO model), has enabled the analysis of cancer development in a context that better mimics brain tissue architecture. In this article, we review the recent literature on the use of patient-derived glioblastoma organoid models and their applicability for drug screening, as well as provide a potential workflow for screening using the GLICO model. The proposed workflow is practical for use in most laboratories with accessible materials and equipment, a good first pass, and no animal work required. This workflow is also amenable for analysis, with separate measures of invasion, growth, and viability.
Topics: Humans; Glioblastoma; Neoplasm Recurrence, Local; Temozolomide; Brain Neoplasms; Organoids
PubMed: 36611949
DOI: 10.3390/cells12010153 -
Neuro-oncology Apr 2023
Topics: Humans; Temozolomide; Methotrexate; Dacarbazine; Lymphoma; Brain
PubMed: 36655502
DOI: 10.1093/neuonc/noad015 -
Developmental Neuroscience 2023Glioblastoma (GBM), the most common and lethal primary brain tumor in adults, requires multi-treatment intervention which unfortunately barely shifts the needle in... (Review)
Review
Glioblastoma (GBM), the most common and lethal primary brain tumor in adults, requires multi-treatment intervention which unfortunately barely shifts the needle in overall survival. The treatment options after diagnosis and surgical resection (if possible) include irradiation, temozolomide (TMZ) chemotherapy, and now tumor treating fields (TTFields). TTFields are electric fields delivered locoregionally to the head/tumor via a wearable medical device (Optune®). Overall, the concomitant treatment of TTFields and TMZ target tumor cells but spare normal cell types in the brain. Here, we examine whether primary cilia, microtubule-based "antennas" found on both normal brain cells and GBM cells, play specific roles in sensitizing tumor cells to treatment. We discuss evidence supporting GBM cilia being exploited by tumor cells to promote their growth and treatment resistance. We review how primary cilia on normal brain and GBM cells are affected by GBM treatments as monotherapy or concomitant modalities. We also focus on latest findings indicating a differential regulation of GBM ciliogenesis by TTFields and TMZ. Future studies await arrival of intracranial TTFields models to determine if GBM cilia carry a prognostic capacity.
Topics: Adult; Humans; Cilia; Brain; Temozolomide
PubMed: 38630257
DOI: 10.1159/000529193 -
Advanced Science (Weinheim,... Jan 2023Glioblastoma (GBM) is the most aggressive type of cancer. Its current first-line postsurgery regimens are radiotherapy and temozolomide (TMZ) chemotherapy, both of which...
Glioblastoma (GBM) is the most aggressive type of cancer. Its current first-line postsurgery regimens are radiotherapy and temozolomide (TMZ) chemotherapy, both of which are DNA damage-inducing therapies but show very limited efficacy and a high risk of resistance. There is an urgent need to develop novel agents to sensitize GBM to DNA-damaging treatments. Here it is found that the triterpene compound stellettin B (STELB) greatly enhances the sensitivity of GBM to ionizing radiation and TMZ in vitro and in vivo. Mechanistically, STELB inhibits the expression of homologous recombination repair (HR) factors BRCA1/2 and RAD51 by promoting the degradation of PI3Kα through the ubiquitin-proteasome pathway; and the induced HR deficiency then leads to augmented DNA damage and cell death. It is further demonstrated that STELB has the potential to rapidly penetrate the blood-brain barrier to exert anti-GBM effects in the brain, based on zebrafish and nude mouse orthotopic xenograft tumor models. The study provides strong evidence that STELB represents a promising drug candidate to improve GBM therapy in combination with DNA-damaging treatments.
Topics: Animals; Mice; Humans; Glioblastoma; Recombinational DNA Repair; Dacarbazine; Phosphatidylinositol 3-Kinases; Antineoplastic Agents, Alkylating; Zebrafish; Drug Resistance, Neoplasm; Brain Neoplasms; Temozolomide; Triterpenes; DNA Damage
PubMed: 36453577
DOI: 10.1002/advs.202205529 -
Clinics (Sao Paulo, Brazil) 2012Temozolomide is an alkylating agent used in the treatment of gliomas and, more recently, aggressive pituitary adenomas and carcinomas. Temozolomide methylates DNA and,... (Review)
Review
Temozolomide is an alkylating agent used in the treatment of gliomas and, more recently, aggressive pituitary adenomas and carcinomas. Temozolomide methylates DNA and, thereby, has antitumor effects. O6-methylguanine-DNA methyltransferase, a DNA repair enzyme, removes the alkylating adducts that are induced by temozolomide, thereby counteracting its effects. A Medline search for all of the available publications regarding the use of temozolomide for the treatment of pituitary tumors was performed. To date, 46 cases of adenohypophysial tumors that were treated with temozolomide, including 30 adenomas and 16 carcinomas, have been reported. Eighteen of the 30 (60%) adenomas and 11 of the 16 (69%) carcinomas responded favorably to treatment. One patient with multiple endocrine neoplasia type 1 and an aggressive prolactin-producing adenoma was also treated and demonstrated a good response. No significant complications have been attributed to temozolomide therapy. Thus, temozolomide is an effective treatment for the majority of aggressive adenomas and carcinomas. Evidence indicates that there is an inverse correlation between levels of O6-methylguanine-DNA methyltransferase immunoexpression and therapeutic response. Alternatively, high-level O6-methylguanine-DNA methyltransferase immunoexpression correlates with an unfavorable response. Here, we review the use of temozolomide for treating pituitary neoplasms.
Topics: Adenoma; Antineoplastic Agents, Alkylating; Carcinoma; Dacarbazine; Humans; Pituitary Neoplasms; Temozolomide
PubMed: 22584716
DOI: 10.6061/clinics/2012(sup01)20 -
Neuro-oncology Nov 2021
Topics: Antineoplastic Agents, Alkylating; Dacarbazine; Glioblastoma; Humans; Temozolomide
PubMed: 34347098
DOI: 10.1093/neuonc/noab186