Project description:To characterize Homologous recombination deficiency (BRCAness) in triple-negative breast cancer PDX models genomic signature was utilized. After normalization using ChAS we obtained absolute copy number profiles using the GAP software (Popova et al, Genome Biol, 2009). The number of Large-scale State Transitions (LSTs) was used to annotate PDX as BRCAness or not (Popova et al, Cancer Res 2012).
Project description:To characterize Homologous recombination deficiency (BRCAness) in triple-negative breast cancer PDX models genomic signature was utilized. After normalization using Genotyping Console we obtained absolute copy number profiles using the GAP software (Popova et al, Genome Biol, 2009). The number of Large-scale State Transitions (LSTs) was used to annotate PDX as BRCAness or not (Popova et al, Cancer Res 2012).
Project description:Engraftment of primary pancreas ductal adenocarcinomas (PDAC) in mice to generate patient derived xenograft (PDX) models is a promising platform to for biological and therapeutic studies in this disease. However, these models are still incompletely characterized. Here, we measured the impact of the murine environment on the gene expression of the engrafted human tumoral cells. We have analyzed gene expression profiles from 35 new PDX models and compared them with previously published microarray data from PDAC and hepatocellular carcinoma (HCC). Our results showed that PDX models derived from PDAC, or HCC, were clearly different to the cell lines derived from the same cancer tissues. Indeed, PDAC- and HCC-derived cell lines are indistinguishable one from the other based in their gene expression profiles. In contrast, the transcriptomes of PDAC and HCC PDX models are clearly different and more similar to their original tumor than to PDX models from the other tumor type. Interestingly, the main differences between pancreatic PDX models and human PDAC is the expression of genes involved in pathways related with extracellular matrix interactions and cell cycle regulation likely reflecting the adaptations of the tumors to the new environment. Furthermore, most of these differences are detected in the first passages after the tumor engraftment, indicating early phases of the adaptation process. In conclusion, different from conventional cancer cell lines, PDX models of PDAC retain similar gene expression profiles of PDAC. Expression changes are mainly related to genes involved in stromal pathways likely reflecting the adaptation to new environments. We also provide evidence of the stability of gene expression patterns over subsequent passages. We have analyzed gene expression profiles from 35 new PDX models and compared them with previously published in GEO microarray data. We used PDX models, primary tumors and cell lines from PDAC and hepatocellular carcinoma. All these public data were re-process in order to compare with our 35 samples
Project description:Developing animal models representating the cancer biology of advanced prostate cancer patients is challenging but essential for delivering individualized medical therapies. In an effort to develop patient derived xenograft (PDX) models, we took the metastatic site tissue from the rib lesion twice (ie, before and after enzalutamide treatment) over a twelve week period and implanted subcutaneously and under the renal capsule in immuno-deficient mice. To characterize and compare the genome and transcriptome landscapes of patient tumor tissues and the corresponding PDX models, we performed whole exome and transcriptome sequencing for metastatic tumor tissue as well as its derived PDXs. We demonstrated the feasibility of developping PDX models from patient who developed castrate-resistant prostate cancer. Our data suggested PDX models preserve the patient’s genomic and transcriptomic alterations in high fidelity, as illustrated by somatic mutation, copy number variation, gene fusion and gene expression. RNA sequencing of prostate cancer tumor tissue and derived xenograft using Illumina HiSeq 2000.
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