Evolution of core archetypal phenotypes in high-grade serous ovarian cancer (HGSOC)
Ontology highlight
ABSTRACT: 24 malignant fluid samples were collected from 9 high-grade ovarian cancer patients at various time points over the course of chemotherapy. Additionally, an independent cohort of 8 malignant fluid samples were collected from pre-treatment patients and 7 samples from post-treatment patients. Single-cell RNA sequencing (scRNA-seq) was performed using 10X or iCell8 technologies.
Project description:We measured gene expression in single-cell RNA sequencing samples from patients with high-grade serous ovarian cancer (HGSOC), for a study on improving HGSOC subtype definition by taking into account varying cell type proportions within tumors.
Project description:Tumor cells were isolated from solid tumors or ascites from HGSOC patients and enriched for EpCAM expression by antibody magnetic beads (affinity)-based methods and large RNAs (> 200 nt) sequenced (50 bp paired ends) after rRNA depletion (RiboZero). Expression differences between patients with miliary and non-miliary peritoneal tumor spreading were used for a search for new targeted therapies and for biological annotion.
Project description:The epigenome offers an additional facet of cancer that can help categorize patients into those at risk of disease, recurrence, or treatment failure. We conducted a retrospective, nested, case-control study of advanced and recurrent high-grade serous ovarian cancer (HGSOC) patients in which we assessed epigenome-wide association using Illumina methylationEPIC arrays to characterize DNA methylation status and RNAseq to evaluate gene expression. Comparing HGSOC tumors with normal fallopian tube tissues we observe global hypomethylation but with skewing towards hypermethylation when interrogating gene promoters. In total, 5,852 gene interrogating probes revealed significantly different methylation. Within HGSOC, 57 probes highlighting 17 genes displayed significant differential DNA methylation between primary and recurrent disease. Between optimal vs suboptimal surgical outcomes 99 probes displayed significantly different methylation but only 29 genes showed an inverse correlation between methylation status and gene expression. Overall, differentially methylated genes point to several pathways including RAS as well as hippo signaling in normal vs primary HGSOC; valine, leucine, and isoleucine degradation and endocytosis in primary vs recurrent HGSOC; and pathways containing immune driver genes in optimal vs suboptimal surgical outcomes. Thus, differential DNA methylation identified numerous genes that could serve as potential biomarkers and/or therapeutic targets in HGSOC.
Project description:Introduction/ Background: The epigenome represents and adds another facet of complexity to cancer that needs to be understood to categorize patients into those at risk of disease, recurrence, or treatment failure. Our goal is to compare DNA methylation status between controls vs HGSOC, and relate it with clinical outcomes. Methodology: A retrospective review of our institution’s advanced/ recurrent HGSOC patients yielded 99 cases with good quality DNA and RNA. 12 normal fallopian tubes were also collected and used as controls. Infinium Illumina methylationEPIC was used to characterize DNA methylation status and RNA seq to evaluate gene expression. T- tests were used to compare methylation patterns between controls vs HGSOC, primary vs recurrent, and optimal vs suboptimal surgical outcomes. Spearman’s rank correlation was used to evaluate association between degree of methylation and expression of identified genes. Validation of our findings used the cancer genome atlas (TCGA) database followed by C-statistics to assess degree of agreement. Results: Out of 66,069 methylation probes that interrogate known genes, 5,852 probes were significantly different between normal and HGSOC. This includes genes that are enriched in several pathways such as the RAS signaling pathway. A similar analysis of the TCGA database showed 2,075 differentially methylated probes. 1,891 probes were significant in both datasets giving a 70.1% degree of agreement. When comparing differential DNA methylation between primary and recurrent disease, there were 57 probes which represent 17 genes that were significantly different. When comparing optimal vs suboptimal surgical outcomes, 99 probes were significantly different wherein 29 genes show expected inverse correlation between methylation status and gene expression. Conclusions: There are significant differences in methylation patterns between HGSOC and fallopian tubes, primary vs recurrent tissues, and optimal vs sub-optimal surgical outcomes. Cataloging these phenomena in a well characterized clinical population will aid in determining groupings for precision medicine treatment cohorts in the future.
Project description:We investigated whether biomarker analysis in endobronchial epithelial lining fluid (ELF) collected by bronchoscopic microsampling may be useful for a definitive preoperative diagnosis. Therefore we compared ELF samples close to nodule and from the contralateral site from patients with malignant or benign diagnosis.
Project description:We investigated whether biomarker analysis in endobronchial epithelial lining fluid (ELF) collected by bronchoscopic microsampling may be useful for a definitive preoperative diagnosis. Therefore we compared ELF samples close to nodule and from the contralateral site from patients with malignant or benign diagnosis.
Project description:We have sequenced ovarian tumors in several different ways: 1) poly-A captured scRNA-seq, 2) poly-A captured pooled scRNA-seq in pools of 4 samples each 3) Bulk RNA-seq on ribo-depleted tumor chunks 4) Bulk RNA-seq on poly-A captured dissociated cells 5) Bulk RNA-seq on ribo-depleted dissociated cells
Project description:The goal of the study was to further delineate the molecular signatures associated with high-grade serous ovarian cancer in order to develop validated clinically useful prognostic signatures with the potential to guide therapy decisions. Fresh frozen samples were prospectively collected from a series of 174 consecutive women with high-grade serous ovarian, primary peritonial, or fallopian tube cancer who underwent surgery by a gynecologic oncologist at Mayo Clinic betweern 1994 and 2005. All patients received postoperative chemotherapy with a platinum agent, and 75% received a taxane. All patients signed an Institutional Review Board approved consent for bio-banking, clinical data extraction and molecular analysis. Median follow-up time was 35 months (range, 1-202 months). Fourteen patients (8%) were included in the TCGA study.