2d0b7669-970a-4363-916c-8378fe9f5db9 - samples
Ontology highlight
ABSTRACT:
PROVIDER: EGAD00001010884 | EGA |
REPOSITORIES: EGA
Similar Datasets
Project description:Neoadjuvant chemotherapy can improve the survival of patients with borderline and unresectable pancreatic ductal adenocarcinoma (PDAC), however, heterogeneous responses to chemotherapy remain a significant clinical challenge. Here, we performed RNAseq (n=97) and multiplexed immunofluorescence (n=122) on chemo-naïve and post-chemotherapy (post-CTX) resected patient samples (chemoradiotherapy excluded) to define the molecular and cellular impact of neoadjuvant chemotherapy. Transcriptome analysis combined with high resolution mapping of whole tissue sections identified GATA6 (Classical), KRT17 (Basal-like) and Cytochrome P450 3A (CYP3A) co-expressing cells that were preferentially enriched in post-CTX resected samples. The persistence of GATA6Hi and KRT17Hi cells post-CTX was significantly associated with poor survival after mFOLFIRINOX (mFFX), but not gemcitabine. Analysis of organoid models derived from chemo-naïve and post-CTX samples, demonstrated that CYP3A expression is a predictor of chemotherapy response and that CYP3A-expressing drug detoxification pathways can metabolize the prodrug irinotecan, a constituent of mFFX. Taken together, these findings identify CYP3A-expressing drug-resistant cell phenotypes in residual disease that may ultimately inform adjuvant treatment selection.
| EGAS00001007143 | EGA
Project description:130 runs/ 65 samples of paired RNA-Seq data of chemo-naïve and post-chemotherapy pancreatic ductal adenocarcinoma (PDAC). The sequencing was done on Novaseq 6000 with Illumina TruSeq stranded mRNA Kit.
| EGAD00001010883 | EGA
Project description:The mechanism by which transcription factor (TF) network instructs cell-type-specific transcriptional programs to drive primitive endoderm (PrE) progenitors to commit to parietal endoderm (PE) versus visceral endoderm (VE) cell fates remains poorly understood. To address the question, we analyzed the single-cell transcriptional signatures defining PrE, PE, and VE cell states during the onset of the PE-VE lineage bifurcation. By coupling with the epigenomic comparison of active enhancers unique to PE and VE cells, we identified GATA6, SOX17, and FOXA2 as central regulators for the lineage divergence. Transcriptomic analysis of cXEN cells, an in vitro model for PE cells, after the acute depletion of GATA6 or SOX17 demonstrated that these factors induce Mycn, imparting the self-renewal properties of PE cells. Concurrently, they suppress the VE gene program, including key genes like Hnf4a and Ttr, among others. We proceeded with RNA-seq analysis on cXEN cells with FOXA2 knockout, in conjunction with GATA6 or SOX17 depletion. We found FOXA2 acts as a potent suppressor of Mycn while simultaneously activating the VE gene program. The antagonistic gene regulatory activities of GATA6/SOX17 and FOXA2 in promoting alternative cell fates, and their physical co-bindings at the enhancers provide molecular insights to the plasticity of the PrE lineage. Finally, we show that the external cue, BMP signaling, promotes the VE cell fate by activation of VE TFs and repression of PE TFs including GATA6 and SOX17. These data reveal a putative core gene regulatory module that underpins PE and VE cell fate choice.
2023-07-09 | GSE213661 | GEO
Project description:PURPOSE: To determine the impact of basal-like and classical subtypes in advanced PDAC and to explore GATA6 expression as a surrogate biomarker. EXPERIMENTAL DESIGN: Within the COMPASS trial patients proceeding to chemotherapy for advanced PDAC undergo tumour biopsy for RNA sequencing. Overall response rate (ORR) and overall survival (OS) were stratified by subtypes and according to chemotherapy received. Correlation of GATA6 with the subtypes using gene expression profiling, in situ hybridization (ISH) were explored. RESULTS: Between December 2015-May 2019, 195 patients (95%) had enough tissue for RNA sequencing; 39 (20%) were classified as basal-like and 156 (80%) as classical. RECIST response data were available for 157 patients; 29 basal-like and 128 classical where the ORR was 10% vs. 33% respectively (p=0.02). In patients with basal-like tumours treated with modified FOLFIRINOX (mFFX) (n=22) the progression rate was 60% compared to 15% in classical PDAC (p= 0.0002). Median OS in the intention to treat population (n=195) was 9.3 months for classical vs. 5.9 months for basal-like PDAC (HR 0.47 95% CI 0.32-0.69, p=0.0001). GATA6 expression by RNAseq highly correlated with the classifier (p<0.001) and ISH predicted the subtypes with sensitivity of 89% and specificity of 83%. In a multivariable analysis, GATA6 expression was prognostic (p=0.02). In exploratory analyses, basal-like tumours, could be identified by keratin 5, were more hypoxic and enriched for a T cell inflamed gene expression signature. CONCLUSIONS: The basal-like subtype is chemoresistant and can be distinguished from classical PDAC by GATA6 expression.
| EGAD00001006081 | EGA
Project description:BACKGROUND: Malignant pleural mesothelioma (MPM) is difficult to distinguish from reactive mesothelial proliferations (RMPs). MicroRNAs (miRNAs) are small non-coding RNA-strands (~22 nucleotides) that post-transcriptionally regulate gene-expression. Studies have shown that miRNAs are potential diagnostic markers in other cancers; however, it is uncertain whether miRNAs are useful biomarkers for differentiating MPM from RMP. OBJECTIVE: To identify differentially expressed microRNAs which can aid in the diagnostics of MPM. METHODS: We screened with a quantitative RT-PCR (RT-qPCR)-based platform the expression of 742 miRNAs in formalin-fixed paraffin-embedded (FFPE) preoperative diagnostic biopsies, surgically resected MPM-specimens previously treated with chemotherapy, and corresponding non-neoplastic pleura (NNP) from 5 patients. RESULTS: By comparing the change in microRNA expression in patient-matched tissue samples, we identify 14 miRNAs which exhibit statistically significant deregulation between sample groups. CONCLUSION: Based on this initial screening of miRNA expression, we have identified 14 miRNAs which are potential diagnostic biomarkers and may aid in diffferentiating RMP from MPM. qPCR microRNA expression profiling. MicroRNA expression in surgical tissue samples and presurgery diagnostic biopsies of malignant pleural mesotheliomas was compared to corresponding patient-matched non-neoplastic pleura. Patient-matched diagnostic biopsies from still chemotherapy-naïve patients were included to test for chemotherapy-induced changes in microRNA expression.
2014-01-25 | E-GEOD-54394 | biostudies-arrayexpress
Project description:When locally advanced breast cancer is treated with neoadjuvant chemotherapy, the recurrence risk is significantly higher if no complete pathologic response is achieved. Identification of the underlying resistance mechanisms is essential to select treatments with maximal efficacy and minimal toxicity. Here we employed gene expression profiles derived from 317 HER2-negative treatment-naïve breast cancer biopsies of patients who underwent neoadjuvant chemotherapy, deep whole exome and RNA-sequencing profiles of 22 matched pre- and post-treatment tumors, and treatment outcome data to identify biomarkers of response and resistance mechanisms. Molecular profiling of treatment-naïve breast cancer samples revealed that expression levels of proliferation, immune response and extracellular matrix (ECM) organization combined predict response to chemotherapy. Triple negative patients with high proliferation, high immune response and low ECM expression had a significantly better treatment response and survival benefit (HR 0.29, 95% CI 0.10-0.85; p=0.02), while in ER+ patients the opposite was seen (HR 4.73, 95% CI 1.51-14.8; 0=0.008). The characterization of paired pre-and post-treatment samples revealed that aberrations of known cancer genes were either only present in the pre-treatment sample (CDKN1B) or in the post-treatment sample(TP53, APC, CTNNB1). Proliferation-associated genes were frequently down-regulated in post-treatment ER+ tumors, but not in triple negative tumors. Genes involved in ECM were upregulated in the majority of post-chemotherapy samples. Genomic and transcriptomic differences between pre- and post-chemotherapy samples are common and may reveal potential mechanisms of therapy resistance. Our results show a wide range of distinct, but related mechanisms, with a prominent role for proliferation- and ECM-related genes.
| EGAS00001005876 | EGA
Project description:In adult K14Î?NLef1 mouse, the overexpression of â??NLef1, a Ã?-catenin dominat negative, in basal keratinocytes leads to the conversion of hair follicles into multilayered epithelial cysts and ectopic sebaceous gland. â??NLef1 transcriptional activity led to Gata6 overexpression in the pilosebaceous unit in transgenic mice. To uncover direct target genes of Gata6 we performed ChIP-Seq experiments in primary mouse keratinocytes. Examination of Gata6 genomic targets in mouse primary keratinocytes
2017-05-16 | E-GEOD-62607 | biostudies-arrayexpress
Project description:This study includes treatment-naïve fresh tissue sample from 4 HGSOC patients.
| EGAD00001006984 | EGA
Project description:Our data suggest that neoadjuvant chemotherapy enhances anti-cancer responses of T cells in peritoneal metastases of patients with high-grade serous ovarian cancer but does not decrease levels of immune checkpoint molecules, providing a rationale for sequential chemo-immunotherapy. tRNA was isolated from 35 omental tissue samples of HGSOC metastases either pre or post NACT treatment. RNASeq was performed on poly-A selected mRNA fragments, 100 b.p paired end, and strand specific, on average 40 million reads per sample.
2016-07-27 | E-GEOD-71340 | biostudies-arrayexpress
Project description:Chemo-resistance is the major cause of death in advanced prostate cancer (PCa), especially in metastatic PCa (mPCa). However, the molecular mechanisms behind chemo-resistance of PCa have not been clarified so far. Here we found GADD45B was significantly low expressed in metastasis PCa and it could promote chemotherapy sensitivity. So we further constructed GADD45B overexpressed cell line to investigate the possible mechanism.
2021-07-01 | E-MTAB-10704 | biostudies-arrayexpress