Project description:Advanced breast cancer is characterised by enhanced tumour adaptability to therapeutic pressure and the metastatic microenvironment. Transcriptome differences in three ER positive (ER+) cell models are uncovered through this RNA-seq analysis of MCF7 (endocrine sensitive), LY2 (endocrine resistant) and T347 (derived from an ER-positive, treatment resistant brain metastatic patient tumour) cells.
Project description:We investigated the global microRNA expression patterns in normal pancreas, pancreatic endocrine tumours and acinar carcinomas to evaluate their involvement in transformation and malignant progression of these tumour types.
Project description:Advanced breast cancer is characterised by enhanced tumour adaptability to therapeutic pressure and the metastatic microenvironment. Targeting epi-transcriptomic modulators may reverse cellular adaptability, offering new therapeutic strategies to treat metastatic disease. This study looks into the dynamic adaptations that occur in cancer cells in response to therapeutic pressure and metastatic evolution by profiling mRNA epi-transcriptomic modifications in models of disease progression. ER positive (ER+) cell models were used to represent progressive breast cancer, MCF7 (endocrine sensitive), LY2 (endocrine resistant) and T347 (derived from an ER-positive, treatment resistant brain metastatic patient tumour) cells. MeRIP sequencing was undertaken to determine genome-wide RNA methylated regions.
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: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.
Project description:Advanced breast cancer is characterised by enhanced tumour adaptability to therapeutic pressure and the metastatic microenvironment. Transcriptome differences in 14 primary breast tumour samples (n = 14 samples) are uncovered through this comparative RNA-seq analysis of patients that responded well to therapy (n = 7) and patients who had disease recurrence on endocrine treatment (n = 7). RNA sequencing data is deposited as log2 transformed median-of-ratios (DESeq2) normalised counts gene expression values (44934 genes IDs; n = 14 tumour samples).
Project description:Inactivating mutations in the MEN1 gene predisposing to the multiple endocrine neoplasia type 1 (MEN1) syndrome can also cause sporadic pancreatic endocrine tumors. MEN1 encodes menin, a subunit of MLL1/MLL2-containing histone methyltransferase complexes that trimethylate histone H3 at lysine 4 (H3K4me3). The importance of menin-dependent H3K4me3 in normal and transformed pancreatic endocrine cells is unclear. To study the role of menin-dependent H3K4me3, we performed in vitro differentiation of wild-type as well as menin-null mouse embryonic stem cells (mESCs) into pancreatic islet-like endocrine cells (PILECs). Gene expression analysis and genome-wide H3K4me3 ChIP-Seq profiling in wild-type and menin-null mESCs and PILECs revealed menin-dependent H3K4me3 at the imprinted Dlk1-Meg3 locus in mESCs, and all four Hox loci in differentiated PILECs. Specific and significant loss of H3K4me3 and gene expression was observed for genes within the imprinted Dlk1-Meg3 locus in menin-null mESCs and the Hox loci in menin-null PILECs. Given that the reduced expression of genes within the DLK1-MEG3 locus and the HOX loci is associated with MEN1-like sporadic tumors, our data suggests a possible role for menin-dependent H3K4me3 at these genes in the initiation and progression of sporadic pancreatic endocrine tumors. Furthermore, our investigation also demonstrates that menin-null mESCs can be differentiated in vitro into islet-like endocrine cells, underscoring the utility of menin-null mESC-derived specialized cell types for genome-wide high-throughput studies. Genome-wide mapping of H3K4me3 and microarray gene expression profiling in TC-1 wild-type (WT) mESCs, menin-null (Men1-ko) mESCs (3.2N), pancreatic islet-like endocrine cells (PILECs) derived from WT mESCs, and PILECs derived from Men1-ko mESCs.
Project description:Endoderm cells undergo a sequence of fate choices to generate insulin-secreting M-NM-2 cells. Studies of chromatin transitions during this process have been limited to the pancreatic progenitor stage that can be reconstituted from stem cells in vitro, with a gap in understanding the induction of endocrine cells. To address this, we established conditions for isolating endoderm cells, pancreatic progenitors, and endocrine cells from different staged embryos and performed genome wide analysis of the H3K27me3 mark of the repressive Polycomb complex. During the transition from endoderm to pancreas progenitors and during the transition from pancreas progenitors to endocrine cells, genes that lose the H3K27me3 mark typically encode transcriptional regulators, whereas genes that acquire the mark typically are involved in cell biology morphogenesis. Precocious depletion of the EZH2, a H3K27 methylase, at the pancreas progenitor stage enhanced the production of endocrine cells, leading to a later increase in pancreatic beta cells. Similarly, pharmacologic inhibition of EZH2 in embryonic pancreatic tissue explants and human embryonic stem cell cultures led to an increase in endocrine progenitors in vitro. These findings reveal a repeating target gene pattern in H3K27me3 dynamics and provide a means to modulate M-NM-2 cell development from stem cells. Analyzed five FACS-sorted tissues in early mouse embryo; for each tissue we sequenced H3K27me3 and input; no replicates
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.