Project description:Data sets from 2 experiments using PDX derived human TNBC tissue to compare gene expression between cell subpopulations with distinct marker profiles. The first experiment describes comparison of CD184hi vs. CD184lo population, the second experiment (with a different mouse model) compares CD49f lo vs. CD49fhi as well as CD133lo vs. CD133hi. Each subpopulation shows distinct expression patterns suggestive of distinct function within breast cancer tissue.
Project description:Breast cancer is the most commonly diagnosed cancer among women. PDXs (patient-derived xenografts) are similar to cancer cell lines but differ in that they are maintained in a physiological setting as soon as they are isolated from the patient and for subsequent passages. These models are valuable for preclinical trials because PDX models have been shown to closely match their patient counterparts, both in genomic profile and response to treatment. One challenge to treatment development is tumor heterogeneity. In this study, we profiled ER+ and triple negative breast cancer PDX models using single-cell RNA-sequencing. This data may help identify populations of cells which are susceptible to certain treatments in order to improve clinical outcomes for breast cancer patients.
Project description:Breast cancer is the most commonly diagnosed cancer among women. PDXs (patient-derived xenografts) are similar to cancer cell lines but differ in that they are maintained in a physiological setting as soon as they are isolated from the patient and for subsequent passages. These models are valuable for preclinical trials because PDX models have been shown to closely match their patient counterparts, both in genomic profile and response to treatment. One challenge to treatment development is tumor heterogeneity. In this study, we profiled ER+ and triple negative breast cancer PDX models using single-cell RNA-sequencing. This data may help identify populations of cells which are susceptible to certain treatments in order to improve clinical outcomes for breast cancer patients.
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: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:Estrogen Receptor-a (ER) is the key feature in the majority of breast cancers and ER binding to the genome correlates with the Forkhead protein FOXA1 (HNF3a), but mechanistic insight is lacking. We now show that FOXA1 is the defining factor that governs differential ER-chromatin interactions. We show that almost all ER-chromatin interactions and gene expression changes are dependent on the presence of FOXA1 and that FOXA1 dictates genome-wide chromatin accessibility. Furthermore, we show that CTCF is an upstream negative regulator of FOXA1-chromatin interactions. In ER responsive breast cancer cells, the dependency on FOXA1 for tamoxifen-ER activity is absolute and in tamoxifen resistant cells, ER binding occurs independently of ligand, but in a FOXA1 dependent manner. Importantly, expression of FOXA1 in non-breast cancer cells is sufficient to alter ER binding and response to endocrine treatment. As such, FOXA1 is the primary determinant that regulates estrogen-ER activity and endocrine response in breast cancer cells and is sufficient to program ER functionality in non-breast cancer contexts. FoxA1 silenced breast cancer MCF-7 cell lines or control siRNA in the presence of Estrogen or a vehicle. MCF-7 cells were hormone-depleted for 3 d and treated with 100 nM estrogen for 6 h. There were three biological replicates for each of the four different groups.
Project description:Breast cancer is a heterogeneous disease and several distinct subtypes exist based on differential gene expression patterns. Molecular apocrine tumours were recently identified as an additional subgroup, characterised as oestrogen receptor negative and androgen receptor positive (ER_ AR+), but with an expression profile resembling ER+ luminal breast cancer. One possible explanation for the apparent incongruity is that ER gene expression programmes could be recapitulated by AR. Using a cell line model of ER_ AR+ molecular apocrine tumours (termed MDA-MB-453 cells), we map global AR binding events and find a binding profile that is similar to ER binding in breast cancer cells. We find that AR binding is a near-perfect subset of FoxA1 binding regions, a level of concordance never previously seen with a nuclear receptor. AR functionality is dependent on FoxA1, since silencing of FoxA1 inhibits AR binding, expression of the majority of the molecular apocrine gene signature and growth cell growth. These findings show that AR binds and regulates ER cis-regulatory elements in molecular apocrine tumours, resulting in a transcriptional programme reminiscent of ER-mediated transcription in luminal breast cancers.
Project description:Estrogen Receptor-a (ER) is the key feature in the majority of breast cancers and ER binding to the genome correlates with the Forkhead protein FOXA1 (HNF3a), but mechanistic insight is lacking. We now show that FOXA1 is the defining factor that governs differential ER-chromatin interactions. We show that almost all ER-chromatin interactions and gene expression changes are dependent on the presence of FOXA1 and that FOXA1 dictates genome-wide chromatin accessibility. Furthermore, we show that CTCF is an upstream negative regulator of FOXA1-chromatin interactions. In ER responsive breast cancer cells, the dependency on FOXA1 for tamoxifen-ER activity is absolute and in tamoxifen resistant cells, ER binding occurs independently of ligand, but in a FOXA1 dependent manner. Importantly, expression of FOXA1 in non-breast cancer cells is sufficient to alter ER binding and response to endocrine treatment. As such, FOXA1 is the primary determinant that regulates estrogen-ER activity and endocrine response in breast cancer cells and is sufficient to program ER functionality in non-breast cancer contexts. breast cancer MCF-7 cell lines were treaated in the presence of Estrogen, Estrogen plus Tamoxifen, Tamoxifen or a vehicle. MCF-7 cells were hormone-depleted for 3 d and treated with 100 nM estrogen or 1 microM Tamoxifen for 6 h. There were four biological replicates for each of the four different groups.