Project description:A significant proportion of patients with oestrogen receptor (ER) positive breast cancers (BC) develop resistance to endocrine treatments (ET) and relapse with metastatic disease. Bone is the most common metastatic site in ER+ patients, however bone metastases are technically challenging to biopsy and analyse. Difficulties concern both tumour tissue acquisition and techniques for analysis and RNA extractions. Patient-derived xenografts (PDX) of BC bone metastases have not been reported yet. For the first time we established PDX models from bone metastatic biopsies of patients progressing on ET and treated by vertebroplasty. PDX models were analysed at genomic level to identify new therapeutic targets associated with endocrine resistance in the metastatic setting. Identification of chromosomic alterations in bone metastasis derived PDX.
Project description:End-stage breast cancers are clonally heterogeneous and harbor many poorly-understood treatment resistance mechanisms. We therefore established multiple Patient-Derived-Xenograft (PDX) models to study genomic events driving advanced disease. Comparative whole-genome sequencing of paired primary tumors and their PDX models demonstrated that PDX retain the vast majority of the structural variations and copy number aberrations seen within the originating tumor, and with high fidelity. Variant allele fractions (VAF) were preserved, even for rare mutations. Clonal representation is therefore a transplantable phenotype, indicating that genomic heterogeneity can be regulated in a tumor-autonomous mechanism, indifferent to host immune status. Mutations and gene rearrangements were documented in the ESR1 gene in three of five sequenced luminal PDX/progenitor tumor pairs (amplification, point mutation and translocation), and were associated with clinical endocrine response phenotypes, differential PDX estradiol responsiveness and all induced estradiol-independent growth in standard cell lines. PDX models are therefore a significant new tool for fundamental studies on the molecular basis for resistance to endocrine treatment in advanced breast cancer. reference x sample
Project description:A significant proportion of patients with oestrogen receptor (ER) positive breast cancers (BC) develop resistance to endocrine treatments (ET) and relapse with metastatic disease. Bone is the most common metastatic site in ER+ patients, however bone metastases are technically challenging to biopsy and analyse. Difficulties concern both tumour tissue acquisition and techniques for analysis and RNA extractions. Patient-derived xenografts (PDX) of BC bone metastases have not been reported yet. For the first time we established PDX models from bone metastatic biopsies of patients progressing on ET and treated by vertebroplasty. PDX models were analysed at transcriptomic level and compared to patient’s early primary tumours to identify new therapeutic targets associated with endocrine resistance in the metastatic setting. Identification of activated signalling pathways in bone metastasis by comparative transcriptomic analyses of the bone metastasis derived PDX compared to the patients' primary breast tumor.
Project description:Glioblastomas (GBM) are the most common primary CNS tumor. GBMs often recur as highly aggressive, intractable, therapy resistant tumors. Key molecular regulators of acquired radiation resistance in recurrent GBM are largely unknown with a dearth of accurate pre-clinical models. To address this, we generated eight GBM patient-derived xenograft (PDX) models of acquired radiation-therapy selected (RTS) resistance compared with same-patient, treatment naïve (RTU) PDX. A novel bioinformatics pipeline analyzed phenotypic, transcriptomic and kinomic alterations, identifying long non-coding RNAs (lncRNAs) and targetable, PDX-specific kinases. We observed differential transcriptional enrichment of DNA damage repair (DDR) pathways in our RTS models. Multiple molecular routes to acquired radiation-resistance were revealed in our models including PDX-specific kinases that we validated with targeted small molecule inhibitors (SMIs). We identified 184, mostly novel, lncRNAs differentially regulated between RTU and RTS PDX. Several of these lncRNAs were associated with transcriptional changes in DDR, cell cycle progression, stemness, and chromatin remodeling pathways. This study identifies lncRNAs as potential key regulators in recurrent GBM and therapy resistance. We also demonstrate that SMIs aimed at lncRNA-related signaling pathways may represent a novel therapeutic approach for recurrent GBM tumors.
Project description:<p>Resistance to endocrine treatments and CDK4/6 inhibitors is considered a near-inevitability in most patients with estrogen receptor positive breast cancers (ER+ BC). By genomic and metabolomics analyses of patients’ tumours, metastasis-derived patient-derived xenografts (PDX) and isogenic cell lines we demonstrate that a fraction of metastatic ER + BC is highly reliant on oxidative phosphorylation (OXPHOS). Treatment by the OXPHOS inhibitor IACS-010759 strongly inhibits tumour growth in multiple endocrine and palbociclib resistant PDX. Mutations in the PIK3CA/AKT1 genes are significantly associated with response to IACS-010759. At the metabolic level, in vivo response to IACS-010759 is associated with decreased levels of metabolites of the glutathione, glycogen and pentose phosphate pathways in treated tumours. In vitro, endocrine and palbociclib resistant cells show increased OXPHOS dependency and increased ROS levels upon IACS-010759 treatment. Finally, in ER+ BC patients, high expression of OXPHOS associated genes predict poor prognosis. In conclusion, these results identify OXPHOS as a promising target for treatment resistant ER+ BC patients.Insert information here such as publication abstract</p>
Project description:We recently demonstrated that a human Notch1-specific neutralizing antibody (OMP52M51) was very effective in T-ALL patient derived xenografts (PDX) bearing NOTCH1/FBW7 mutations. However, we observed development of acquired resistance following long-term administration of the antibody and used PDX models to investigate this phenomenon. We analyzed expression profiles to identify genes and pathways modulated in mice treated until progression or acute treated with a neutralizing antibody against Notch1.
Project description:Acquired resistance to endocrine therapy occurs with high frequency in patients with luminal breast cancer (LBC). We report here the establishment of four patient-derived xenograft models of LBC with acquired resistance in vivo to tamoxifen and estrogen deprivation. CEL files represent expresison data generated from 5 replicates (independent mice) of the following tumor models: HBCx22 (parental), HBCx22 TamR (tamoxifen-resistant), HBCx22 OvaR (ovariectomy-resistant), HBCx34 (parental), HBCx34 TamR (tamoxifen-resistant), HBCx34 OvaR (ovariectomy-resistant)
Project description:End-stage breast cancers are clonally heterogeneous and harbor many poorly-understood treatment resistance mechanisms. We therefore established multiple Patient-Derived-Xenograft (PDX) models to study genomic events driving advanced disease. Comparative whole-genome sequencing of paired primary tumors and their PDX models demonstrated that PDX retain the vast majority of the structural variations and copy number aberrations seen within the originating tumor, and with high fidelity. Variant allele fractions (VAF) were preserved, even for rare mutations. Clonal representation is therefore a transplantable phenotype, indicating that genomic heterogeneity can be regulated in a tumor-autonomous mechanism, indifferent to host immune status. Mutations and gene rearrangements were documented in the ESR1 gene in three of five sequenced luminal PDX/progenitor tumor pairs (amplification, point mutation and translocation), and were associated with clinical endocrine response phenotypes, differential PDX estradiol responsiveness and all induced estradiol-independent growth in standard cell lines. PDX models are therefore a significant new tool for fundamental studies on the molecular basis for resistance to endocrine treatment in advanced breast cancer.
Project description:Acquired resistance to endocrine therapy occurs with high frequency in patients with luminal breast cancer (LBC). We report here the establishment of four patient-derived xenograft models of LBC with acquired resistance in vivo to tamoxifen and estrogen deprivation.
2014-07-09 | GSE55561 | GEO
Project description:Effect of Vistusertib alone of in combination with fulvestrant in human breast cancer PDX models of acquired endocrine resistance