Project description:Increased expression of GLI1 is associated with poor prognosis for some breast cancer subtypes. A conditional transgenic GLI1 expressing mouse model, with or without heterozygous deletion of Trp53, was used to generate and study GLI1 induced mammary gland tumours. Tumour tissue was serially orthotopically transplanted for at least 10 generations in NSG mice.
Project description:Brca2(fl/fl)Trp53(fl/fl) mice were crossed with MMTV-cre mice to create mice with both alleles of Brca2 and one allele of Trp53 deleted (refered to as Brca2KO). Mature luminal, luminal progenitor and basal mammary epithelial cell populations were sorted from Brca2KO and wildtype mice. Transcriptional profiling revealed marked perturbation within the luminal Brca2KO compartment
Project description:Multiple replication abnormalities cause cells lacking BRCA2 to enter mitosis with under-replicated DNA and to activate mitotic DNA synthesis (MiDAS). However, the precise position of these MiDAS sites, as well as their origin, remains unknown. Here we labelled mitotic nascent DNA and performed high-throughput sequencing to identify at high-resolution the sites where MiDAS occurs in the absence of BRCA2. This approach revealed 150 genomic loci affected by MiDAS, which map within regions replicating during early S-phase and are therefore distinct from the aphidicolin-induced common fragile sites. Moreover, these sites largely localise near early firing origins and within genes transcribed in early S, suggesting that they stem from transcription-replication conflicts (TCRs). Inhibiting transcription with 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole (DRB) during early S-phase abrogates MiDAS. Strikingly, MiDAS sites co-localise with genomic loci where R-loops form in unchallenged conditions, suggesting that R-loop accumulation caused by BRCA2 inactivation leads to DNA lesion which are repaired by MiDAS. RAD52 is required in this process, as its abrogation in BRCA2-deficient cells reduces the rate of MiDAS and causes DNA damage accumulation in G1. Furthermore, MiDAS sites triggered by BRCA2 inactivation are hotspots for genomic rearrangement in BRCA2-mutated breast tumours. These results indicate that BRCA2 acts in early S-phase to protect TRC- and R-loop-induced DNA lesions, thereby preventing them from becoming a source of genomic instability and tumorigenesis.
Project description:To understand the overall amount of genomic instability seen in various genotypes of Brca2 (G25R) and to see where common gains and losses occur within a Trp53 heterozygous genetic background Comparing mouse tumor DNA with mouse genomic DNA
Project description:To understand the overall amount of genomic instability seen in various genotypes of Brca2 (G25R) and to see where common gains and losses occur within a Trp53 heterozygous genetic background
Project description:To analyze expression differences between Trp53 pro-and deficient as well as Atm pro- and deficient murine CLL tumors developing in the Eµ-TCL1 mouse model, we analyzed splenocytes isolated from heavily infiltrated spleens of sick mice. To investigate differences in the response to cyclophosphamide, we also analyzed splenocytes from leukemic animals that were isolated twelve hours after intraperitoneal injection of cyclophosphamide.
Project description:Succinate dehydrogenase (SDH) deficient renal cancers are a rare and understudied subtype of renal cancer. As such they represent an unmet need in kidney cancer research. Here, we seek to describe the genomics and transcriptomics of SDH deficient renal cancers by sequencing five such tumours.
Project description:Germline mutations in the BRCA2 tumour suppressor are associated with both an increased lifetime risk of developing prostate cancer (PCa) and increased risk of aggressive disease. To understand this aggression, here we profile the genomes and methylomes of localized PCa from 14 carriers of deleterious germline BRCA2 mutations (BRCA2-mutant PCa). We show that BRCA2-mutant PCa harbour increased genomic instability and a mutational profile that more closely resembles metastastic than localized disease. BRCA2-mutant PCa shows genomic and epigenomic dysregulation of the MED12L/MED12 axis, which is frequently dysregulated in metastatic castration-resistant prostate cancer (mCRPC). This dysregulation is enriched in BRCA2-mutant PCa harbouring intraductal carcinoma (IDC). Microdissection and sequencing of IDC and juxtaposed adjacent non-IDC invasive carcinoma in 10 patients demonstrates a common ancestor to both histopathologies. Overall we show that localized castration-sensitive BRCA2-mutant tumours are uniquely aggressive, due to de novo aberration in genes usually associated with metastatic disease, justifying aggressive initial treatment.
Project description:To model familial pancreatic cancer patients, we generated isogenic Brca2 deficient pancreatic cancer cell lines with CRISPR/Cas9. To investigate the changes in the transcriptome profiles upon BET inhibition, we performed RNA-seq.
