bms-754807 and Glioma

High-grade glioma (HGG) is highly resistant to therapy, prompting us to investigate the contribution of insulin-like growth factor receptor (IGF-1R), linked with radioresistance in other cancers. IGF-1R immunohistochemistry in 305 adult HGG (aHGG) and 103 paediatric/young adult HGG (pHGG) cases revealed significant association with adverse survival in pHGG, with median survival of 13.5 vs 29 months for pHGGs with moderate/strong vs negative/weak IGF-1R (p = 0.011). Secondly, we tested IGF-1R inhibitor BMS-754807 in HGG cells, finding minimal radiosensitisation of 2/3 aHGG cell lines (dose enhancement ratios DERs < 1.60 at 2-8 Gy), and greater radiosensitisation of 2/2 pHGG cell lines (DERs ≤ 4.16). BMS-754807 did not influence radiation-induced apoptosis but perturbed the DNA damage response with altered induction/resolution of γH2AX, 53BP1 and RAD51 foci. These data indicate that IGF-1R promotes radioresistance in pHGG, potentially contributing to the association of IGF-1R with adverse outcome and suggesting IGF-1R as a candidate treatment target in pHGG.

Topics: Brain Neoplasms; Cell Line, Tumor; DNA Damage; Glioma; Humans; Immunohistochemistry; Neoplasm Grading; Pyrazoles; Radiation Tolerance; Receptor, IGF Type 1; Signal Transduction; Tissue Array Analysis; Triazines

Diffuse intrinsic pontine gliomas (DIPGs) represent a particularly lethal type of pediatric brain cancer with no effective therapeutic options. Our laboratory has previously reported the development of genetically engineered DIPG mouse models using the RCAS/tv-a system, including a model driven by PDGF-B, H3.3K27M, and p53 loss. These models can serve as a platform in which to test novel therapeutics prior to the initiation of human clinical trials. In this study, an in vitro high-throughput drug screen as part of the DIPG preclinical consortium using cell-lines derived from our DIPG models identified BMS-754807 as a drug of interest in DIPG. BMS-754807 is a potent and reversible small molecule multi-kinase inhibitor with many targets including IGF-1R, IR, MET, TRKA, TRKB, AURKA, AURKB. In vitro evaluation showed significant cytotoxic effects with an IC50 of 0.13 μM, significant inhibition of proliferation at a concentration of 1.5 μM, as well as inhibition of AKT activation. Interestingly, IGF-1R signaling was absent in serum-free cultures from the PDGF-B; H3.3K27M; p53 deficient model suggesting that the antitumor activity of BMS-754807 in this model is independent of IGF-1R. In vivo, systemic administration of BMS-754807 to DIPG-bearing mice did not prolong survival. Pharmacokinetic analysis demonstrated that tumor tissue drug concentrations of BMS-754807 were well below the identified IC50, suggesting that inadequate drug delivery may limit in vivo efficacy. In summary, an unbiased in vitro drug screen identified BMS-754807 as a potential therapeutic agent in DIPG, but BMS-754807 treatment in vivo by systemic delivery did not significantly prolong survival of DIPG-bearing mice.

Topics: Animals; Antineoplastic Agents; Brain Stem Neoplasms; Disease Models, Animal; Glioma; High-Throughput Screening Assays; Mice; Mice, Inbred C57BL; Pyrazoles; Survival Rate; Triazines