Identification of changes in gene expression after knock down of FOXL2 in patient derived immortal fallopian tube cells [CEL-Seq]
Ontology highlight
ABSTRACT: In order to identify specific events that are causatively involved in the metastatic process, we analyzed matched samples from 3 high grade serous ovarian cancer patients by RNA-seq. For each patient we examined samples representing the three cancer states: 1) primary tumor; 2) omentum metastasis (solid metastasis); 3) effusion metastasis. We identified genes differentially expressed between the various states. One of the genes found to be expressed in the primary tumor but not in the omentum or effusion metastasis is FOXL2, a transcription factor known to play a role in ovarian development and function. This change was successfully validated by RT-PCR in both the patients' samples as well as in a set of 27 independent patient samples representing the three cancer states. Knock-down of FOXL2 in patient-derived immortal fallopian tube cells lead to increased proliferation and survival. RNA-seq of the immortal fallopian tube cells after FOXL2 knock-down revealed a pro-metastatic gene expression signature. Our results suggest that FOXL2 is an important tumor suppressor and an inhibitor of ovarian cancer progression.
Project description:In order to identify specific events that are causatively involved in the metastatic process, we analyzed matched samples from 3 high grade serous ovarian cancer patients by RNA-seq. For each patient we examined samples representing the three cancer states: 1) primary tumor; 2) omentum metastasis (solid metastasis); 3) effusion metastasis. We identified genes differentially expressed between the various states. One of the genes found to be expressed in the primary tumor but not in the omentum or effusion metastasis is FOXL2, a transcription factor known to play a role in ovarian development and function. This change was successfully validated by RT-PCR in both the patients' samples as well as in a set of 27 independent patient samples representing the three cancer states. Knock-down of FOXL2 in patient-derived immortal fallopian tube cells lead to increased proliferation and survival. RNA-seq of the immortal fallopian tube cells after FOXL2 knock-down revealed a pro-metastatic gene expression signature. Our results suggest that FOXL2 is an important tumor suppressor and an inhibitor of ovarian cancer progression.
Project description:Mutations in BRCA1 and BRCA2 genes confer an increased lifetime risk for breast and ovarian cancer. Ovarian cancer risk can be decreased by risk-reducing salpingo-oophorectomy (RRSO). Studies on RRSO material have altered the paradigm of serous ovarian cancer pathogenesis. The purpose of this study was to identify candidate genes possibly involved in pathogenesis of serous ovarian cancer by carrying out a microarray analysis of differentially expressed genes in BRCA1/2- mutation positive ovarian and fallopian tube epithelium derived from RRSO surgery. Freshly frozen ovarian and fallopian tube samples from nine BRCA1/2 mutation carriers scheduled for RRSO were prospectively collected in comparison with five mutation-negative control patients undergoing salpingo-oophorectomy for benign indications. Microarray analysis of genome-wide gene expression was performed on ovarian and fallopian tube samples from BRCA1/2 and control patients. The validation of microarray data was performed by quantitative real-time polymerase chain reaction (qRT-PCR) in selected cases of RRSO samples, and also high grade serous carcinoma samples collected from patients with BRCA phenotype. From 22,733 genes, 454 transcripts were identified that were differentially expressed in BRCA1/2 mutation carriers when statistically compared to controls pooling all ovarian and fallopian tube samples together. Of these, 299 genes were statistically significantly downregulated and 155 genes were upregulated. Differentially expressed genes in BRCA1/2 samples reported here might be involved in serous ovarian carcinogenesis and provide interesting targets for further studies. Both fallopian tube and ovarian samples were collected from each BRCA1/2 mutation carrier resulting in eighteen mutation positive adnexal samples. Both fallopian tube and ovarian control samples were collected from one control patient while either ovarian or fallopian tube sample was available from four control patients, respectively, resulting in 6 adnexal control samples. High quality RNA was available from nine BRCA1/2-mutation positive ovarian and eight BRCA1/2-mutation positive fallopian tube samples and from three control ovarian and three control fallopian tube samples.
Project description:In this study, we performed miRNA profiles analysis of high-grade serous ovarian carcinoma compared to normal fallopian tube fimbria using microarray (Exiqon, Denmark) to evaluate their potential role in the pathogenesis of uterine leiomyoma. miRNA profiling analysis of the 10 samples including 5 high-grade serous ovarian carcinomas and 5 normal fallopian tube fimbria.
Project description:Mutations in BRCA1 and BRCA2 genes confer an increased lifetime risk for breast and ovarian cancer. Ovarian cancer risk can be decreased by risk-reducing salpingo-oophorectomy (RRSO). Studies on RRSO material have altered the paradigm of serous ovarian cancer pathogenesis. The purpose of this study was to identify candidate genes possibly involved in pathogenesis of serous ovarian cancer by carrying out a microarray analysis of differentially expressed genes in BRCA1/2- mutation positive ovarian and fallopian tube epithelium derived from RRSO surgery. Freshly frozen ovarian and fallopian tube samples from nine BRCA1/2 mutation carriers scheduled for RRSO were prospectively collected in comparison with five mutation-negative control patients undergoing salpingo-oophorectomy for benign indications. Microarray analysis of genome-wide gene expression was performed on ovarian and fallopian tube samples from BRCA1/2 and control patients. The validation of microarray data was performed by quantitative real-time polymerase chain reaction (qRT-PCR) in selected cases of RRSO samples, and also high grade serous carcinoma samples collected from patients with BRCA phenotype. From 22,733 genes, 454 transcripts were identified that were differentially expressed in BRCA1/2 mutation carriers when statistically compared to controls pooling all ovarian and fallopian tube samples together. Of these, 299 genes were statistically significantly downregulated and 155 genes were upregulated. Differentially expressed genes in BRCA1/2 samples reported here might be involved in serous ovarian carcinogenesis and provide interesting targets for further studies.
Project description:Ovarian cancer has a clear predilection for metastasis to the omentum, but the underlying mechanisms involved in ovarian cancer spread are not well understood. Here, we used a parabiosis model that demonstrates preferential hematogenous metastasis of ovarian cancer to the omentum. Our studies revealed that the ErbB3-neuregulin1 (NRG1) axis is a dominant pathway responsible for hematogenous omental metastasis. Elevated levels of ErbB3 in ovarian cancer cells and NRG1 in the omentum allowed for tumor cell localization and growth in the omentum. Depletion of ErbB3 in ovarian cancer substantially impaired omental metastasis. Our results highlight hematogenous metastasis as a previously under-recognized mode of ovarian cancer metastasis. These findings have implications for designing new strategies aimed at preventing and treating ovarian cancer metastasis.
Project description:We analysed the extracellular matrix (ECM) landscape of fresh, healthy tissues from human fallopian tube (FT), fimbria (FB, the tissue of origin of serous tubal intraepithelial lesions) and ovarian tissue (OV). The aim was to identify differentially expressed matrix proteins between FB and FT or OV which may promote the neoplastic transformation of serous tubal intraepithelial lesions (STICs) into high-grade serous ovarian cancer, HGSOC, and metastasis from the FB to the OV.
Project description:Fallopian tube epithelium is the tissue-of-origin of most high grade serous papillary ovarian carcinoma. This tumor has been exensively investigated and sequenced but expression profiling data of normal fallopian tube epithelial cells is still rare. This project compares the miRNA profiles of high grade serous papillary ovarian tumors (FFPE and fresh frozen) to that of normal unmatched epithelial cells from resected fallopian tubes.
Project description:Most epithelial ovarian cancers are thought to arise from different cells in the ovarian or fallopian tube epithelium. We hypothesized that these distinct cells-of-origin may play a role in determining ovarian tumor phenotype and also could inform the molecular classification of ovarian cancer. To test this hypothesis, we developed new methods to isolate and culture paired normal human ovarian (OV) and fallopian tube (FT) epithelial cells from multiple donors without cancer and identified a cell-of-origin gene expression signature that distinguished these cell types within the same patient. Application of the OV versus FT cell-of-origin gene signature to gene expression profiles of primary ovarian cancers permitted identification of distinct OV and FT-like subgroups among these cancers. Importantly, the normal FT-like tumor classification correlated with a significantly worse disease-free survival. This work describes a new experimental method for culture of normal human OV and FT epithelial cells from the same patient. These findings provide new evidence that cell-of-origin is an important source of ovarian tumor heterogeneity and the associated differences in tumor phenotype. We analyzed 12 samples from two donor patients and established cultures of both ovarian epithelium and fallopian tube epithelium (hTERT immortalized), each with 3 replicates (different culture passages).
Project description:High-grade serous ovarian cancer (HGSOC) progresses to advanced stages without symptoms and the 5-year survival rate is a dismal 30%. Recent studies of ovaries and oviducts in patients with BRCA mutations revealed that premalignant HGSC is found almost exclusively in the fallopian tube. To validate this notion, we cloned and transformed the fallopian tube stem cells (FTSC). We demonstrated that the tumors derived from the transformed fallopian tube stem cells (FTSCt) share the similar histological and molecular feature of high-grade serous cancer. In addition, a whole-genome transcriptome analysis comparing between FTSC, immortalized fallopian tube stem cells (FTSCi), and FTSCt showing a clear molecular progression, which is mimicked by the gene expression comparison between laser captured normal oviducts and HGSOC ( cancer and paired normal samples from 10 patients).
Project description:Comparison of gene expression profiling among high-grade ovarian epithelial cancer, ovarian epithelium and fallopian tube which might indicate the origin and carcinogenesis of ovarian cancer