Project description:We devised a high-throughput, cell-based assay to identify novel therapeutic compounds to treat Group3 medulloblastoma (G3 MB). Mouse G3 MBs, grown as neurospheres, were screened against a library of approximately 7,000 compounds including FDA-approved drugs. We identified two FDA-approved drugs, pemetrexed and gemcitabine that preferentially inhibited tumor proliferation in vitro compared to control neurospheres, and substantially inhibited tumor proliferation in vivo. When combined, the two drugs significantly increased survival P7 Trp53-/-, Cdkn2c-/- neurospheres and MYC mouse cells were compared treated and untreated with drugs pemetrexed+gemcitabine
Project description:We devised a high-throughput, cell-based assay to identify novel therapeutic compounds to treat Group3 medulloblastoma (G3 MB). Mouse G3 MBs, grown as neurospheres, were screened against a library of approximately 7,000 compounds including FDA-approved drugs. We identified two FDA-approved drugs, pemetrexed and gemcitabine that preferentially inhibited tumor proliferation in vitro compared to control neurospheres, and substantially inhibited tumor proliferation in vivo. When combined, the two drugs significantly increased survival
Project description:We examined the transformation susceptibility of different cerebellar stem/progenitors by developing several new Group3 medulloblastoma murine models using orthotopic transplantation and in utero electroporation (EP)-based in vivo gene transfer with Cre/LoxP-mediated conditional Myc gene activation and loss of Trp53 function. We used microarrays to compared the transcriptome of these novel Group3 medulloblastoma mouse models and CPC mouse models to existing mouse models of medulloblastoma subgroups and used cross-species analysis to compare these models to human medulloblastoma subgroups
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.
Project description:To test the effects of uracil DNA glycosylase (UNG) loss on the formation of double strand breaks (DSBs) by the anti-cancer agent pemetrexed, we performed ChIP-seq for serine 139-phosphorylated H2AX (gammaH2AX), a marker of DSBs, in human cells wild-type or deficient for UNG in combination with pemetrexed treatment. UNG deficiency results in an increase in DSBs upon pemetrexed treatment, and we found that pemetrexed treatment induces DSBs at different genomic locations in UNG wild-type and knockout cells. Similar results were observed upon cisplatin treatment of UNG wild-type and knockout cells, and the genomic locations of DSBs were distinct between pemetrexed-treated and cisplatin-treated samples. Taken together, our results suggst differential mechanisms for DSB formation in UNG-competent and UNG-deficient cells. The genomic distribution of gammaH2AX in UNG WT and KO cells treated with pemetrexed or cisplatin was determined by ChIP-seq
Project description:In this study, we evaluate the therapeutic potential of combining osimertinib with pemetrexed and clarify the underlying molecular mechanisms in order to establish novel therapeutic strategies for EGFR-mutant NSCLC. We found that the combination of osimertinib and pemetrexed could induce strong apoptotic activity and enhance anti-tumor effects compared to monotherapy in two NSCLC cell lines harboring an EGFR mutation. In addition, we have identified PLK1 as a therapeutic target for combination therapy and as a promising treatment target for overcoming resistance to osimertinib in EGFR-mutated NSCLC patients.
Project description:To test the effects of uracil DNA glycosylase (UNG) loss on the formation of double strand breaks (DSBs) by the anti-cancer agent pemetrexed, we performed ChIP-seq for serine 139-phosphorylated H2AX (gammaH2AX), a marker of DSBs, in human cells wild-type or deficient for UNG in combination with pemetrexed treatment. UNG deficiency results in an increase in DSBs upon pemetrexed treatment, and we found that pemetrexed treatment induces DSBs at different genomic locations in UNG wild-type and knockout cells. Similar results were observed upon cisplatin treatment of UNG wild-type and knockout cells, and the genomic locations of DSBs were distinct between pemetrexed-treated and cisplatin-treated samples. Taken together, our results suggest differential mechanisms for DSB formation in UNG-competent and UNG-deficient cells.
Project description:Group3 Medulloblastoma is a highly malignant pediatric brain tumor and despite patients harboring different genetic alterations they are treated with similar therapies. Here, we perform an in-vivo Patient-Specific screen and we identify Otx2 and c-Myc as strong inducers of Group3 Medulloblastoma. We demonstrate that the chromatin modifier Smarca4, also mutated in human patients, is able to reduce Otx2/c-Myc tumorigenic activity in-vivo. Furthermore, Otx2/c-Myc co-overexpression in human cerebellar organoids generates Medulloblastoma-like organoids that induce brain cancer in mice with a DNA methylation signature similar to human Group3 MB. Finally, inhibition of histone methyltransferases reduces Otx2/c-Myc tumorigenesis in ex-vivo culture and in human cerebellar organoids. Therefore, understanding the role of different altered genes in Medulloblastoma patients will be of great importance to develop new personalized therapies.
Project description:Translational research is commonly performed in the C57B6/J mouse strain, chosen for its genetic homogeneity and phenotypic uniformity. Here, we evaluate the suitability of the white-footed deer mouse (Peromyscus leucopus) as a model organism for aging research, offering a comparative analysis against C57B6/J and diversity outbred (DO) Mus musculus strains. Our study includes comparisons of body composition, skeletal muscle function, and cardiovascular parameters, shedding light on potential applications and limitations of P. leucopus in aging studies. Notably, P. leucopus exhibits distinct body composition characteristics, emphasizing reduced muscle force exertion and a unique metabolism, particularly in fat mass. Cardiovascular assessments showed changes in arterial stiffness, challenging conventional assumptions and highlighting the need for a nuanced interpretation of aging-related phenotypes. Our study also highlights inherent challenges associated with maintaining and phenotyping P. leucopus cohorts. Behavioral considerations, including anxiety-induced responses during handling and phenotyping assessment, pose obstacles in acquiring meaningful data. Moreover, the unique anatomy of P. leucopus necessitates careful adaptation of protocols designed for Mus musculus. While showcasing potential benefits, further extensive analyses across broader age ranges and larger cohorts are necessary to establish the reliability of P. leucopus as a robust and translatable model for aging studies.