DNA methylome analyses implicate fallopian tube as the tissue of origin for high grade serous ovarian cancer
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE81228 | GEO | 2016/05/10
SECONDARY ACCESSION(S): PRJNA321008
REPOSITORIES: GEO
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Project description:UnlabelledHigh-grade serous ovarian cancer (HGSC) is the most common and lethal form of epithelial ovarian cancer (EOC). Two distinct tissues have been suggested as the tissue of origin: ovarian surface epithelia (OSE) and fallopian tube epithelia (FTE). We hypothesized that the DNA methylome of HGSC should more closely resemble the methylome of its tissue of origin. To this end, we profiled HGSC (n = 10), and patient-matched OSE and FTE (n = 5) primary fresh-frozen tissues, and analyzed the DNA methylome using Illumina 450K arrays (n = 20) and Agilent Sure Select methyl-seq (n = 7). Methylomes were compared using statistical analyses of differentially methylated CpG sites (DMC) and differentially methylated regions (DMR). In addition, methylation was evaluated within a variety of different genomic contexts, including CpG island shores and Homeobox (HOX) genes, due to their roles in tissue specification. Publicly available HGSC methylome data (n = 628) were interrogated to provide additional comparisons with FTE and OSE for validation. These analyses revealed that HGSC and FTE methylomes are significantly and consistently more highly conserved than are HGSC and OSE. Pearson correlations and hierarchal clustering of genes, promoters, CpG islands, CpG island shores, and HOX genes all revealed increased relatedness of HGSC and FTE methylomes. Thus, these findings reveal that the landscape of FTE more closely resembles HGSC, the most common and deadly EOC subtype.ImplicationsDNA methylome analyses support the hypothesis that HGSC arise from the fallopian tube and that due to its tissue-specificity and biochemical stability, interrogation of the methylome may be a valuable approach to examine cell/tissue lineage in cancer. Mol Cancer Res; 14(9); 787-94. ©2016 AACR.
| S-EPMC5025356 | biostudies-literature
Project description:The cell and tissue of origin of high grade serous ovarian cancer (HGSC) is controversial. While the disease was traditionally assumed to arise from the ovarian surface epithelium (OSE), recent work supports an alternative model implicating the fallopian tube fimbriae epithelium (FTE). We used comparative DNA methylome analyses as a means to test these two competing models, hypothesizing that the HGSC methylome should more closely resemble its tissue of origin. Using two separate analysis methods, analysis within distinct genomic contexts, and validation studies using large-scale publically available HGSC methylome data, we consistently observed that the DNA methylome of HGSC more closely resembles FTE than OSE. These data support the FTE origin model, and suggest DNA methylome analysis as a useful approach to examine cell/tissue lineage origin in cancer. HGSC is the most common and lethal form of epithelial ovarian cancer (EOC). Two distinct tissues have been hypothesized as the tissue of origin of HGSC: OSE and FTE. We hypothesized that the DNA methylome of HGSC would more closely resemble the methylome of its tissue of origin. To test this, we profiled HGSC (n=10), OSE (n=7), and FTE (n=7) primary fresh-frozen tissues, and analyzed DNA methylome using Illumina 450K arrays (n=24) and Agilent Sure Select methyl-seq (n=7). We compared methylomes using statistical analyses of differentially methylated CpG sites (DMC) and differentially methylated regions (DMR), and methylation within a variety of different genomic contexts, including CpG island shores. We also analyzed methylation specifically at Homeobox (HOX) genes, due to their role in tissue specification. We used publically available HGSC methylome data (n=628) to provide additional comparison with FTE and OSE and potential validation. This analysis revealed that HGSC and FTE methylomes were significantly and consistently more highly conserved than were HGSC and OSE. Pearson correlations and hierarchal clustering of genes, promoters, CpG islands, CpG island shores, and HOX genes all revealed the increased relatedness of HGSC and FTE methylomes. In addition, two different large data sets of publically-available HGSC methylome data confirmed these relationships. In summary, our findings support the FTE origin model for HGSC, the most common and deadly EOC subtype. Due to its tissue-specificity and biochemical stability, interrogation of the DNA methylome appears to be a valuable approach to examine cell/tissue lineage in cancer.
2016-05-10 | GSE81224 | GEO
Project description:The cell and tissue of origin of high grade serous ovarian cancer (HGSC) is controversial. While the disease was traditionally assumed to arise from the ovarian surface epithelium (OSE), recent work supports an alternative model implicating the fallopian tube fimbriae epithelium (FTE). We used comparative DNA methylome analyses as a means to test these two competing models, hypothesizing that the HGSC methylome should more closely resemble its tissue of origin. Using two separate analysis methods, analysis within distinct genomic contexts, and validation studies using large-scale publically available HGSC methylome data, we consistently observed that the DNA methylome of HGSC more closely resembles FTE than OSE. These data support the FTE origin model, and suggest DNA methylome analysis as a useful approach to examine cell/tissue lineage origin in cancer. HGSC is the most common and lethal form of epithelial ovarian cancer (EOC). Two distinct tissues have been hypothesized as the tissue of origin of HGSC: OSE and FTE. We hypothesized that the DNA methylome of HGSC would more closely resemble the methylome of its tissue of origin. To test this, we profiled HGSC (n=10), OSE (n=7), and FTE (n=7) primary fresh-frozen tissues, and analyzed DNA methylome using Illumina 450K arrays (n=24) and Agilent Sure Select methyl-seq (n=7). We compared methylomes using statistical analyses of differentially methylated CpG sites (DMC) and differentially methylated regions (DMR), and methylation within a variety of different genomic contexts, including CpG island shores. We also analyzed methylation specifically at Homeobox (HOX) genes, due to their role in tissue specification. We used publically available HGSC methylome data (n=628) to provide additional comparison with FTE and OSE and potential validation. This analysis revealed that HGSC and FTE methylomes were significantly and consistently more highly conserved than were HGSC and OSE. Pearson correlations and hierarchal clustering of genes, promoters, CpG islands, CpG island shores, and HOX genes all revealed the increased relatedness of HGSC and FTE methylomes. In addition, two different large data sets of publically-available HGSC methylome data confirmed these relationships. In summary, our findings support the FTE origin model for HGSC, the most common and deadly EOC subtype. Due to its tissue-specificity and biochemical stability, interrogation of the DNA methylome appears to be a valuable approach to examine cell/tissue lineage in cancer.
2016-05-10 | GSE81227 | GEO
Project description:High-grade serous ovarian carcinoma (HGSOC) is a lethal disease for which improved screening and treatment strategies are urgently needed. Progress in these areas is impeded by our poor understanding of HGSOC pathogenesis. Most ovarian cancer research is based on the hypothesis that HGSOC arises from ovarian surface epithelial cells. However, recent studies suggest that >50% of high-grade serous carcinomas involving the ovary likely arise from fallopian tube epithelium. Therefore, limiting HGSOC research to modeling based on ovarian surface epithelium alone is inadequate. To address the need for a fallopian tube-based model of HGSOC, we have developed a system for studying human fallopian tube secretory epithelial cell (FTSEC) transformation. Our model is based on (i) immortalization of FTSECs isolated from primary samples of normal, nondiseased human fallopian tubes, (ii) transformation of FTSECs with defined genetic elements, and (iii) xenograft-based tumorigenic assays. We use our model to show that FTSECs immortalized with human telomerase reverse transcriptase (hTERT) plus SV40 large T and small T antigens are transformed by either oncogenic Ras (H-Ras(V12)) or c-Myc expression, leading to increased proliferation, clonogenicity, and anchorage-independent growth. Additionally, we demonstrate that FTSECs remain susceptible to c-Myc-mediated transformation in the absence of viral oncoproteins, by replacing SV40 large T and small T antigens with sh-p53, mutant CDK4 (CDK4(R24C)), and sh-PP2A-B56?. Importantly, all transformed FTSECs gave rise to high-grade Müllerian carcinomas that were grossly, histologically, immunophenotypically, and genomically similar to human HGSOC. With this model, we will now be able to assess the transformative effects of specific genetic alterations on FTSECs in order to characterize their respective roles in HGSOC development.
| S-EPMC3088633 | biostudies-literature
Project description:High-grade serous ovarian carcinoma (HGSOC) is the most frequent type of ovarian cancer and has a poor outcome. It has been proposed that fallopian tube cancers may be precursors of HGSOC but evolutionary evidence for this hypothesis has been limited. Here, we perform whole-exome sequence and copy number analyses of laser capture microdissected fallopian tube lesions (p53 signatures, serous tubal intraepithelial carcinomas (STICs), and fallopian tube carcinomas), ovarian cancers, and metastases from nine patients. The majority of tumor-specific alterations in ovarian cancers were present in STICs, including those affecting TP53, BRCA1, BRCA2 or PTEN. Evolutionary analyses reveal that p53 signatures and STICs are precursors of ovarian carcinoma and identify a window of 7 years between development of a STIC and initiation of ovarian carcinoma, with metastases following rapidly thereafter. Our results provide insights into the etiology of ovarian cancer and have implications for prevention, early detection and therapeutic intervention of this disease.
| S-EPMC5653668 | biostudies-literature
Project description:The cell-of-origin of high grade serous ovarian carcinoma (HGSOC) remains controversial, with fallopian tube epithelium (FTE) and ovarian surface epithelium (OSE) both considered candidates. Here, by using genetically engineered mouse models and organoids, we assessed the tumor-forming properties of FTE and OSE harboring the same oncogenic abnormalities. Combined RB family inactivation and Tp53 mutation in Pax8 + FTE caused Serous Tubal Intraepithelial Carcinoma (STIC), which metastasized rapidly to the ovarian surface. These events were recapitulated by orthotopic injection of mutant FTE organoids. Engineering the same genetic lesions into Lgr5 + OSE or OSE-derived organoids also caused metastatic HGSOC, although with longer latency and lower penetrance. FTE- and OSE-derived tumors had distinct transcriptomes, and comparative transcriptomics and genomics suggest that human HGSOC arises from both cell types. Finally, FTE- and OSE-derived organoids exhibited differential chemosensitivity. Our results comport with a dualistic origin for HGSOC and suggest that the cell-of-origin might influence therapeutic response.
| S-EPMC6879755 | biostudies-literature
Project description:DNA methylome analyses implicate fallopian tube as the tissue of origin for high grade serous ovarian cancer
| PRJNA321008 | ENA
Project description:Although ovarian cancer is the most lethal gynecologic malignancy in women, little is known about how the cancer initiates and metastasizes. In the last decade, new evidence has challenged the dogma that the ovary is the main source of this cancer. The fallopian tube has been proposed instead as the primary origin of high-grade serous ovarian cancer, the subtype causing 70% of ovarian cancer deaths. By conditionally deleting Dicer, an essential gene for microRNA synthesis, and Pten, a key negative regulator of the PI3K pathway, we show that high-grade serous carcinomas arise from the fallopian tube in mice. In these Dicer-Pten double-knockout mice, primary fallopian tube tumors spread to engulf the ovary and then aggressively metastasize throughout the abdominal cavity, causing ascites and killing 100% of the mice by 13 mo. Besides the clinical resemblance to human serous cancers, these fallopian tube cancers highly express genes that are known to be up-regulated in human serous ovarian cancers, also demonstrating molecular similarities. Although ovariectomized mice continue to develop high-grade serous cancers, removal of the fallopian tube at an early age prevents cancer formation--confirming the fallopian tube origin of the cancer. Intriguingly, the primary carcinomas are first observed in the stroma of the fallopian tube, suggesting that these epithelial cancers have a mesenchymal origin. Thus, this mouse model demonstrates a paradigm for the origin and initiation of high-grade serous ovarian carcinomas, the most common and deadliest ovarian cancer.
| S-EPMC3309733 | biostudies-literature
Project description:The fallopian tube epithelium (FTE) is one of the progenitor populations for high-grade serous ovarian cancer (HGSC). Loss of PAX2 is the earliest known molecular aberration in the FTE occurring in serous carcinogenesis followed by a mutation in p53. Pathological studies report consistent loss of PAX2 in benign lesions as well as serous tumors. In the current study, the combined loss of PAX2 and expression of the R273H p53 mutant protein in murine oviductal epithelial (MOE) cells enhanced proliferation and growth in soft agar in vitro but was insufficient to drive tumorigenesis in vivo. A serially passaged model was generated to investigate the role of aging, but was also insufficient to drive tumorigenesis. These models recapitulate early benign lesions and suggest that a latency period exists between loss of PAX2, p53 mutation and tumor formation. Stathmin and fut8 were identified as downstream targets regulated by loss of PAX2 and mutation of p53 in MOE cells. Re-expression of PAX2 in PAX2-null human HGSC cells reduced cell survival via apoptosis. Phosphatase and tensin homolog (PTEN)shRNA negatively regulated PAX2 expression and stable re-expression of PAX2 in MOE:PTENshRNA cells significantly reduced proliferation and peritoneal tumor formation in athymic nude mice. PAX2 was determined to be a direct transcriptional target that was activated by wild-type p53, whereas mutant p53 inhibited PAX2 transcription in MOE cells. A small molecule screen using the proximal PAX2 promoter driving luciferase identified four small molecules that were able to enhance PAX2 mRNA expression in MOE cells. PAX2 re-expression in HGSC cells and PTEN-deficient oviductal tumors may have the potential to induce apoptosis. In summary, mutant p53 and PTEN loss negatively regulated PAX2 and PAX2 re-expression in HGSC cells induced cell death.
| S-EPMC5581540 | biostudies-literature
Project description:Fallopian tube secretory epithelial cells (FTSECs) have been suggested to be the source of high-grade serous ovarian carcinoma (HGSOC). Although several genetic alterations are known to be involved in HGSOC development, the minimal requirements remain unclear. We aimed to identify oncogenic mutations indispensable for HGSOC development in a stepwise model, using immortalized FTSECs. FTSECs were isolated from clinical samples and immortalized by overexpression of cyclin D1, CDK4R24C, and hTERT. Oncogenic mutations in the p53, c-Myc, and RAS/PI3K pathways were mimicked by lentiviral transduction. We found two distinct patterns of gene alteration essential for HGSOC development: p53/KRAS/AKT and p53/KRAS/c-Myc. Dominant-negative p53, alone or combined with oncogenic KRAS (KRASV12), constitutively active AKT (CA-AKT), and c-Myc, did not induce tumorigenesis in immortalized cells; however, overexpression of CA-AKT or c-Myc, along with dominant-negative p53 and KRASV12, conferred tumorigenic potential. Transformed FTSECs formed tumors in nude mice that were grossly, histologically, and immunohistochemically similar to human HGSOCs. Interestingly, mice harboring tumors with c-Myc amplifications displayed extensive metastases, consistent with the increased dissemination in their human counterparts. Thus, aberrant p53/KRASV12/c-Myc or p53/KRASV12/PI3K-AKT signaling was the minimum requirement for FTSEC carcinogenesis. The model based on this evidence could shed light on the early stages of HGSOC development.
| S-EPMC5849158 | biostudies-literature