Project description:Laboratory mice comprise an inexpensive and expeditious model organism for preclinical vaccine testing; however, vaccine immunogenicity often fails to adequately translate to humans. Recent reports indicate that reconstituting physiologic microbial experience to specific pathogen free (SPF) mice induces durable immunological changes that better recapitulate the human immune system. We examined the impact of microbial experience on responses to vaccination after cohousing laboratory mice with pet store mice. We demonstrate that human transcriptional responses to influenza vaccination are better recapitulated in cohoused mice. Induction of humoral responses by vaccination was dampened in cohoused mice and resulted in poor control upon challenge. Additionally, the establishment of protective heterosubtypic T cell immunity was compromised in cohoused mice. In summary, SPF mice exaggerated both humoral and T cell protection induced by influenza vaccines compared to cohoused mice, suggesting that reconstituting microbial experience in laboratory mice through cohousing may better inform preclinical vaccine testing.
Project description:The pediatric preclinical testing program previously demonstrated activity of eribulin in osteosarcoma patient-derived xenograft (PDX) models. The phase 2 trial in patients with relapsed osteosarcoma failed to meet response endpoints. Eribulin was evaluated in the original and an expanded set of PDX models and tested at multiple dose levels and schedules to evaluate dose-response. Maximal response was observed at the highest dose, consistent with prior results. The alternative schedule generated similar responses. We demonstrate steep dose-response for eribulin in osteosarcoma PDX models, implying that any deviation from achievement of effective concentrations may have a significant impact on activity.
Project description:IntroductionWEE1 is a serine kinase central to the G2 checkpoint. Inhibition of WEE1 can lead to cell death by permitting cell-cycle progression despite unrepaired DNA damage. AZD1775 is a WEE1 inhibitor that is in clinical development for children and adults with cancer.MethodsAZD1775 was tested using a dose of 120 mg/kg administered orally for days 1 to 5. Irinotecan was administered intraperitoneally at a dose of 2.5 mg/kg for days 1 to 5 (one hour after AZD1775 when used in combination). AZD1775 and irinotecan were studied alone and in combination in neuroblastoma (n = 3), osteosarcoma (n = 4), and Wilms tumor (n = 3) xenografts.ResultsAZD1775 as a single agent showed little activity. Irinotecan induced objective responses in two neuroblastoma lines (PRs), and two Wilms tumor models (CR and PR). The combination of AZD1775 + irinotecan-induced objective responses in two neuroblastoma lines (PR and CR) and all three Wilms tumor lines (CR and 2 PRs). The objective response measure improved compared with single-agent treatment for one neuroblastoma (PR to CR), two osteosarcoma (PD1 to PD2), and one Wilms tumor (PD2 to PR) xenograft lines. Of note, the combination yielded CR (n = 1) and PR (n = 2) in all the Wilms tumor lines. The event-free survival was significantly longer for the combination compared with single-agent irinotecan in all models tested. The magnitude of the increase was greatest in osteosarcoma and Wilms tumor xenografts.ConclusionsAZD1775 potentiates the effects of irinotecan across most of the xenograft lines tested, with effect size appearing to vary across tumor panels.
Project description:BackgroundRegorafenib is a small molecule multikinase inhibitor that inhibits multiple kinases including BRAF, KIT, PDGFRB, RAF, RET, and VEGFR1-3.ProceduresThe in vivo anticancer effects of regorafenib were assessed in a panel of six osteosarcoma models, three rhabdomyosarcoma models, and one Ewing sarcoma model.ResultsRegorafenib induced modest inhibition of tumor growth in the models evaluated.ConclusionThe overall pattern of response to regorafenib appears similar to that of the kinase inhibitor sorafenib, with pronounced slowing of tumor growth in some models, limited to the period of agent administration, being the primary treatment effect.
Project description:Pediatric ependymoma has relatively low frequencies of DNA mutations, which suggest that epigenetics may drive tumors. However, the epigenetic mechanisms for recurrent ependymoma are still poorly understood. Here, we performed longitudinal and comprehensive DNA methylation and gene expression analysis for recurrent pediatric ependymoma tumors from 10 patients, total 46 DNA methylomes (including primary tumors and matched recurrent tumors; normal pediatric brain tissues and PDOX tumors). Both RELA and PFA tumors maintained the subtype DNA methylation signatures during repeated relapses. We further identified the potential DNA methylation predictors, drivers and boosters and their potential regulated genes for recurrent ependymoma tumors. Increased DNA methylation levels within H3K4me1 enriched regions indicates disturbed functions of LSD1 gene in recurrent ependymoma tumors. Combining novel LSD1 inhibitor SYC-836 with radiation (XRT) significantly prolonged animal survival times in PDOX models of recurrent PFA ependymoma. Our PDOX models provide a unique platform for preclinical testing drugs and development of new therapy for pediatric recurrent ependymoma.