Data-driven prioritization and preclinical evaluation of therapeutic targets in glioblastoma

Abstract

Background Patients with glioblastoma (GBM) have a dismal prognosis, and there is an unmet need for new therapeutic options. This study aims to identify new therapeutic targets in GBM. Methods mRNA expression data of patient-derived GBM (n = 1,279) and normal brain tissue (n = 46) samples were collected from GEO and TCGA. Functional genomic mRNA (FGmRNA) profiling was applied to capture the downstream effects of genomic alterations on gene expression levels. Next, class comparison between GBM and normal brain tissue was performed. Significantly upregulated genes in GBM were further prioritized based on 1) known interactions with anti-neoplastic drugs, 2) current drug development status in humans, and 3) association with biologic pathways known to be involved in GBM. Antineoplastic agents against prioritized targets were validated in vitro and in vivo. Results We identified 712 significantly upregulated genes in GBM compared to normal brain tissue, of which 27 have a known interactions with antineoplastic agents. 17 out of the 27 genes, including EGFR and VEGFA, have been clinically evaluated in GBM with limited efficacy. For the remaining ten genes, RRM2, MAPK9 (JNK2, SAPK1a), and XIAP play a role in GBM development. We demonstrated for the MAPK9 inhibitor RGB-286638 a viability loss in multiple GBM cell culture models. Although no overall survival benefit was observed in vivo, there were indications that RGB-286638 may delay tumor growth. Conclusions The MAPK9 inhibitor RGB-286638 showed promising in vitro results. Furthermore, in vivo target engagement studies and combination therapies with this compound warrant further exploration.

MAPK9 is Correlated with a Poor Prognosis and Tumor Progression in Glioma

“…The results of western blotting and immunohistochemistry showed that MAPK9 ex-pression in glioma tissue was obviously higher than that in normal tissue. This finding is in agreement with the observations of Cyrillo G et al [17] using the MAPK9 inhibitor RGB-286638; these studies demonstrated decreased viability in multiple cell culture models of GBM, and there was some evidence that RGB-286638 can retard tumor growth.…”

“…Using tumor specimens from 18 proneural and 12 mesenchymal highgrade glioma patients, Kim et al [16] compared the expression of 349 kinase-encoding genes in primary cultures of glioma stem cells in a genome-wide expression study and found that the MAPK9 gene was significantly upregulated in mesenchymal tumor specimens. Recent studies have found that the MAPK9 inhibitor RGB-286638 causes loss of activity in a variety of basement membrane cell culture models and that RGB-286638 may retard tumor growth [17].…”

Radio-sensitizing effect of MEK inhibition in glioblastoma in vitro and in vivo

“…In vivo validation 6-8 weeks old female athymic nude mice were obtained via Envigo and housed according to guidelines and regulations of the VU University (AVD114002017841, protocol #841-NCH-19-10). After one week of acclimatization, 0.5 x 10 6 GBM8 cells which stably express Fire y Luciferase (Fluc) and mCherry, were stereotactically injected into the striatum (coordinates relative to the bregma; x-2mm; y0.5mm; z-3mm) as previously described (12,30,31). Mice received the following analgesia; at least 24h pre-and postoperative carprofen (0.067 mg/mL) via their drinking water, half an hour before the intracranial surgery subcutaneous injection of Buprenorphine (0.05 mg/kg), and a droplet of Lidocaine (5 mg/mL) was applied onto and spread over the exposed periosteum as local analgesia.…”

“…injection of 150 uL D-luciferin (Gold Biotechnology, St. Louis, MO, USA). Tumor engraftment was measured on day 6, mice with incomplete tumor engraftment (< 10 4 RLU) were excluded (6 out of 48, including two arms of an independent study (30)). Mice were strati ed into four treatment groups each containing 7 mice based on their Fluc activity by distributing the maximal dynamic range over all groups; Vehicle (PBS; 200 uL/day), PD0325901 (5 mg/kg/day), radiotherapy (2 Gy/day) and PD0325901/radiotherapy (5 mg/kg/day and 2 Gy/day).…”