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:In contrast to epithelial derived carcinomas that arise in most human organs, ovarian surface epithelial cells become more rather than less differentiated as the malignancy progresses. To test the hypothesis that ovarian surface epithelial cells retain properties of relatively uncommitted pluripotent cells until undergoing neoplastic transformation, we conducted gene expression profiling analysis (Affymetrix, U133 Plus 2.0) of 12 ovarian surface epithelial cells and 12 laser capture microdissected serous papillary ovarian cances. We find that over 2000 genes are significantly differentially expressed between the surface epithelial and cancer samples. Network analysis implicates key signaling pathways and pathway interactions in ovarian cancer development. Genes previously associated with adult stem cell maintenance are expressed in ovarian surface epithelial cells and significantly down-regulated in ovarian cancer cells. Our results indicate that the surface of the ovary is an adult stem cell niche and that deregulation of genes involved in maintaining the quiescence of ovarian surface epithelial cells is instrumental in the initiation and development of ovarian cancer.
Project description:Low grade serous ovarian cancer (LGSC) is a rare subtype of ovarian cancer, characterized by a slow growth rate, resistance to current treatment regimens, multiple recurrences and poor survival. LGSC arise from serous borderline tumor (SBT), however the mechanism of transformation is poorly understood. To better understand the biology of serous ovarian tumors, we performed whole proteome profiling of LGSC, SBT and the more common high grade serous (HGSC) ovarian tumors. Proteins associated with the tumor microenvironment were differentially expressed between LGSC and SBT or HGSC. In particular, fibroblast activation protein (FAP), a protein expressed in cancer associated fibroblasts, is abundantly expressed in LGSC. Furthermore, Tregs and M2 macrophages are more abundant in the stroma of LGSC compared to SBT. Together these data suggest that the tumor microenvironment provides a supportive environment for LGSC tumorigenesis and progression, and that targeting the tumor microenvironment of LGSC may be a viable therapeutic strategy.
Project description:High-grade serous ovarian cancer is the most aggressive histological type of epithelial ovarian cancer, which is characterized by a high frequency of somatic TP53 mutations. To provide a better understanding of the molecular mechanisms involved in the pathogenesis of these cancers and to develop a risk classification system, we conducted profiling of the copy number alterations present in these tumors. Thirty patients who were diagnosed as high-grade serous ovarian cancer were recruited in this study. Affymetrix SNP array were performed according to the manufacturer's directions on DNA extracted from high-grade serous ovarian cancer tissues or peripheral blood samples. The Japanese Serous Ovarian Cancer Study Group
Project description:Recent evidence suggests that ovarian high-grade serous carcinoma (HGSC) originates from the epithelium of the fallopian tube. However, most mouse models are based on the previous prevailing view that ovarian cancer develops from the transformation of the ovarian surface epithelium. Here, we report the extensive histological and molecular characterization of the mogp-TAg transgenic mouse, which expresses the SV40 large T-antigen (TAg) under the control of the mouse müllerian-specific Ovgp-1 promoter. Histologic analysis of the fallopian tubes of mogp-TAg mice identified a variety of neoplastic lesions analogous to those described as precursors to ovarian HGSC. We identified areas of normal appearing p53-positive epithelium that are similar to “p53 signatures” in the human fallopian tube. More advanced proliferative lesions with nuclear atypia and epithelial stratification were also identified that were morphologically and immunohistochemically reminiscent of human serous tubal intraepithelial carcinoma (STIC), a potential precursor of ovarian HGSC. Beside these noninvasive precursor lesions, we also identified invasive adenocarcinoma in the ovary of 56% of the mice. Microarray analysis revealed several genes differentially expressed between the fallopian tube of mogp-TAg and WT C57BL/6. One of these genes, Top2a, which encodes topoisomerase II-alpha, was shown by immunohistochemistry to be concurrently expressed with elevated p53 and specifically elevated in mouse STICs, but not in surrounding tissues. TOP2A protein was also found elevated in human STICs, low-grade, and high-grade serous carcinoma. The mouse model reported here displays a progression from normal tubal epithelium to invasive HGSC in the ovary, and therefore closely simulates the current emerging model of human ovarian HGSC pathogenesis. This mouse therefore has the potential to be a very useful new model for elucidating the mechanisms of serous ovarian tumorigenesis, as well as for developing novel approaches for the prevention, diagnosis, and therapy of this disease. Keywords: transgenic mouse model, ovarian cancer, fallopian tube, intraepithelial carcinoma 6 mouse fallopian tubes (FT) were analyzed with experimental repeats; 3 wildtype C57BL6 mice (FT) and 3 transgenic mogp-TAg (FT), with one set of each at 7, 8 and 9 weeks of age.
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 is one of the most deadly cancers accounting for only 3% of diagnosed cancers, but is the fifth leading cause of cancer deaths among woman; however, the progression of ovarian cancer is poorly understood. To study and further understand the early events that lead to epithelial derived ovarian cancer, we previously developed a cell model of progressive ovarian cancer. Mouse ovarian surface epithelial (MOSE) cells have undergone spontaneous transformation in cell culture and represent pre-neoplastic, non-tumorigenic to an aggressive malignant phenotype. Microarray analysis was performed with RNA isolated from different stages of MOSE cells to examine changes in gene expression as MOSE cells transition from a pre-neoplastic to a malignant state. RNA was isolated from MOSE early cell representing a pre-neoplastic, non-malignant stage, MOSE Intermediate cells representing a noeplastic, pre-invasive state, and MOSE Late cells representing a malignant, invasive stage. Three biological replicates were used to take into account variations within the heterogeneous cultures.
Project description:Epithelial ovarian cancer is morphologically and clinically heterogeneous. Transcriptional profiling has revealed molecular subtypes (referred to as M-bM-^@M-^\C-signaturesM-bM-^@M-^]) that correlate to biological as well as clinical features. We aimed to determine gene expression differences between malignant, benign and borderline serous ovarian tumors, and to investigate similarities to the intrinsic molecular subtypes of breast cancer. Global gene expression profiling was performed using Illumina's HT12 Bead Arrays and applied to 59 fresh-frozen ovarian tumors. SAM analysis revealed enrichment of cell cycel processes among the malignant tumors, in line with malignant tumors being highly proliferative. The borderline tumors were split between the malignant and benign tumor clusters, indicating that borderline tumors have both malignant and benign features. Furthermore, nearest centroid classification was performed applying previously published gene profiles for the ovarian cancer C-signatures and the intrinsic breast cancer subtypes, respectively, and showed significant correlations between the malignant serous tumors and the highly aggressive C1, C2 and C4 ovarian cancer signatures, and the basal-like breast cancer subtype. The benign and borderline serous tumors together were significantly correlated to the normal-like breast cancer subtype and the ovarian cancer C3 signature. The borderline tumors, on the other hand, correlated significantly to the Luminal A breast cancer subtype. These findings remained when analyzed in a large, independent dataset. The data in this study link the transcriptional profiles of serous ovarian cancer to the intrinsic molecular subtypes of breast cancer, in line with the shared clinical and molecular features between high-grade serous ovarian cancer and basal-like breast cancer, including an aggressive phenotype, frequent TP53 mutations and a high degree of genomic instability, and suggest that biomarkers and targeted therapies may overlap between these subsets of ovarian and breast cancers. Finally, the link between benign and borderline ovarian cancer and luminal breast cancer may indicate endocrine responsiveness in a subset of ovarian cancers. Total RNA obtained from serous ovarian adenocarcinomas, adenomas and borderline tumors. Gene expression profiling using Illumina's HT12 v4 bead arrays. Application of ovarian cancer molecular subtypes and intrinsic breast cancer subtypes using nearest centroid classification. KRAS and BRAF mutation analyses in the malignant and borderline tumors.