Spatial integration of protein and chromosomal states reveals early copy number changes and genotype-associated immune neighborhoods in serous ovarian cancer evolution.

to investigate the frequency of the types of fallopian tubal secretory cell expansion (SCE) in diseases of the reproductive organs and to determine the immunophenotype and biological role of the cells in the early stages of the pathogenesis of high-grade ovarian serous carcinomas (HGOSC). The investigation enrolled 287 patients with extraovarian diseases and ovarian serous tumors varying in grade, whose fallopian tubes were morphologically and immunohistochemically examined using p53, Ki-67, PAX2, Bcl-2, beta-catenin, and ALDH1 markers. The material was statistically processed applying the Mann-Whitney test and χ2 test. The rate of secretory cell proliferation (SCP) (more than 10 consecutive secretory cells) and that of secretory cell overgrowth (SCO) (more than 30 consecutive secretory cells) increase with age in all investigated reproductive system diseases. The rate of SCP in the corpus fimbriatum of the patients with HGOSC was 5.9 times higher than that in those with extraovarian disease (p<0.01); when comparing the same patient groups, that of SCO was 3.4 times higher (p<0.05). The immunohistochemical characteristics of the investigated lesions (in scores) were as follows: PAX2 was expressed in the intact epithelium (2.8), in SCP (1.3), in SCO (1.2), in serous tubal intraepithelial carcinoma (STIC) (1.0), and in HGOSC (0.9); Bcl-2 was in the intact epithelium (2.2), in SCP (2.1), STIC (0.9), and in HGOSC (0.6), β-catenin was in the intact epithelium (0.5), in SCP (2.85), in SCO (2.95), in STIC (0.6), and in HGOSC (0.5); ALDH1 was in the intact epithelium (0.5), in SCP (2.91), in SCO (2.92), in STIC (1.2), and in HGOSC (0.6). There were statistically significant differences with a 95% confidence interval (p<0.05) for: 1) PAX2 between the intact epithelium and pathology (fallopian tube lesions and HGOSC); 2) Bcl-2 between the intact epithelium and SCE (SCP and SCO) and between SCE and HGOSC; 3) beta-catenin between the intact epithelium and SCE (SCP and SCO) and between SCE and HGOSC; 4) ALDH1 between the intact epithelium and SCE, between and SCE and STIC, and between STIC and HGOSC. SCE was shown to be an independent intraepithelial lesion. The incidence of this abnormality increased with age and significantly differed in the patients with fallopian tubal lesions in extraovarian diseases from that in those with malignant ovarian serous tumors (by 5.3 times), while these groups showed a three-fold difference in SCO. Thus, SCP may serve as a more sensitive marker for the early stages of the pathogenesis of ovarian serous carcinoma. The studied types of SCE demonstrated multiple molecular events (loss of PAX2 expression and increased Bcl-2, beta-catenin, and ALDH1 expressions), some of which underwent considerable changes, by increasing the severity of a pathological process (loss of ALDH1, and beta-catenin, and bcl-2 expressions). Thus, therapeutic exposure in the early stages of pathogenesis may have a few points of application and just several molecules can serve as independent markers for early pathological changes in the fallopian tubal epithelium.

Introduction: Despite the clear genetic evidence linking serous tubal intraepithelial carcinoma (STIC) and high-grade serous ovarian carcinoma (HGSOC), the specific conditions and events that promote the progression of STIC lesions into invasive disease remain poorly understood. Method: As a critical initial step, we have assembled a cohort of incidental p53 signatures, STIC lesions, and STIC with concurrent HGSOC. We have performed extensive multi-modal analysis using multiplexed tissue imaging and spatial transcriptomics that identify features of the immune system that play a vital role in the early steps of HGSOC development. We have processed 43 specimens using highly multiplexed tissue imaging at single-cell resolution (cyclic immunofluorescence, CyCIF), and 35 specimens for micro-regional spatial transcriptomics using the GeoMx (Whole Transcriptome, Nanostring) on over 450 pathologist-annotated regions of interest. Results: Our data suggests an immune-cold environment and T-cell dysfunction in STIC lesions, including incidental STIC. One of the significant immune populations identified was CD103+ tissue-resident memory T cells (TRM). In incidental p53 signatures, activation of TRM was rare, similar to FT, which may indicate the absence of sensing “tumor antigen” by these TRM. CyCIF analysis also revealed that most incidental STIC lesions (7/9 cases) overexpress major histocompatibility complex (MHC) class I compared to the normal epithelium, especially both HLA complex, HLA-A and HLA-E. Most STICs showed extensive intra-lesion heterogeneity, with some STICs remaining HLA-A and HLA-E negative. Incidental p53 signatures, on the other hand, were mostly HLA-A and HLA-E negative and, when positive, had only a few cells expressing HLA. We hypothesized that there might be a natural selection of HLA-E-positive clones as STICs progress to HGSOC. Consistent with this, HGSOC showed further overexpression of HLA-E. However, HLA-E heterogeneity was still observed in the invasive tumor, with both positive and negative clones co-existing. Geomx data suggested that the interferon signaling pathway is upregulated in the epithelial of HLA-E positive STIC and cancer clones compared to HLA-E negative clones. In turn, both HLA-A and HLA-E might be overexpressed in the epithelial of HLA-E-positive STICs. Overall, we showed that the response in interferon (IFN) α and γ, NF-KB, and IL-6-induced STAT-3 pathways were upregulated in both STIC lesions and carcinoma. The role of these pathways, especially STAT-3 pathway, has been shown in other aneuploid cancers in promoting immune escape, cell proliferation and migration, chemoresistance and inhibiting apoptosis. We have shown the co-localization of cGAS and BAF, a marker for micronuclei rupture, by super-resolution 3D imaging to confirm one of the mechanisms of IFN activation. Conclusion: Taken together, these data may indicate chromosomal instability is one of the mechanisms that is driving the IFN-signaling pathway and, hence, a potential selective advantage for HLA-E-positive clones in tumorigenesis, leading to inhibiting NK cell surveillance followed by reducing T cell infiltration. Citation Format: Tanjina Kader, Jia-Ren Lin, Shannon Coy, Clemens Hug, Yu-An Chen, Roxanne J. Pelletier, Mariana Leon, John Lee, Yi-Lin Xu, Clarence Yapp, Natalie Shih, Gabriel Mingo, Euihye Jung, Srishti Rathore, Judith Agudo, Charles Drescher, Peter K. Sorger, Ronny Drapkin, Sandro Santagata. Multimodal spatial profiling reveals the emergence of an immune suppressive microenvironment at the initial stages of high-grade serous ovarian cancer development [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB311.

Serous tubal intraepithelial carcinomas (STICs) have been documented in high-grade serous ovarian carcinomas (HGSOCs). However, the rate of association between STICs and HGSOCs and, therefore, the fraction of HGSOCs that are likely to have originated from the fallopian tube (FT), has remained unclear. To appraise the literature describing the association between STICs and established HGSOCs. Ovid MEDLINE and EMBASE were searched. Studies were included if they evaluated the frequency of STICs in HGSOCs, and were published in an English peer-reviewed journal. Appropriate studies were evaluated for their compliance with the 'Strengthening and Reporting of Observational Studies in Epidemiology (STROBE)' criteria. Ten articles met the study selection criteria. The reported coexistence between STICs and HGSOCs ranged from 11% to 61% (mean: 31%, 95% CI: 17-46%). STICs were rarely found in other gynaecological cancers. Small sample size, lack of objective criteria to identify STICs and the retrospective nature of the studies contributed to the variability in reporting the rate of the association. STICs were identified commonly in the FTs of women with HGSOC. Finding the true rate of association between STICs and HGSOCs will require further investigations. While there is evidence that a fraction of HGSOCs arise from the FTs, an accurate estimate of that fraction remains to be determined. The lack of an accurate estimate of the association makes it difficult to evaluate the potential magnitude of reduction of HGSOCs following prophylactic salpingectomy. A systematic review of the incidence of STICs in HGSOCs identifies significant methodological inconsistencies.

High-grade serous “ovarian” carcinoma (HGSC), the most lethal gynecologic cancer, typically presents at advanced stages owing to lack of symptoms in early-stage disease. Additionally, no effective screening strategies exist. Despite the misnomer, most HGSC arise from fallopian tube epithelium (FTE). Better understanding early steps in pathogenesis of serous tubal intraepithelial carcinoma (STIC) and cell of origin for HGSC will inform early detection strategies and lead to new insights for effective screening approaches. HGSC and STIC are characterized by TP53 mutation and chromosomal instability. Earlier lesions in the FTE, such as “p53 signatures, ” benign lesions harboring TP53 mutation, are less well understood. We aimed to study STIC, p53 signatures, and the benign FT at the single cell and spatial level, considering not only epithelial and lesional cells but also the surrounding stromal and immune microenvironment. We employed single-cell RNA sequencing (scRNA-seq) in combination with single-nuclei RNA sequencing using 10x flex and single-cell spatial transcriptomics (scST), on formalin-fixed paraffin-embedded (FFPE) tissues to analyze normal and neoplastic fallopian tubes. scST data from 84 fields of view representing 8 patients (5 benign, 3 STIC) were used to define epithelial subtypes within the FTE, considering both gene expression profiles and spatial distributions correlating to histopathological findings. Furthermore, scRNA-seq data from fresh non-neoplastic FT and FFPE STIC samples were integrated to construct comprehensive atlases. The epithelial subtypes within the scST data were mapped on to the integrated atlas using gene module scores.Seven distinct epithelial subtypes were identified, with transcriptional diversity linked to HGSC precursors. Subtype-specific gene expression profiles were linked to histological features, revealing cellular heterogeneity in normal epithelium in contrast to clonal expansions and STIC. In the microenvironment, we found epithelial subtype-specific stromal and immune interactions. Furthermore, four subclusters of macrophages were identified with distinct expression programs; some subtypes were only abundant in association with STIC. We implemented scST in clinical FT samples including STIC, and integrated ST features with a large atlas of scRNA-seq data to refine single cell characterization of benign FT, p53 signatures, and STIC. Our spatially informed analyses recognized distinct subsets of epithelial, immune, and stromal cells that change over the course of STIC/HGSC development. Additionally, the trajectory of epithelial subtypes demonstrates the most likely epithelial cell subtype from which STIC may form. Our integrated FT atlas provides a critical resource for others seeking to understand early events in HGSC pathogenesis, advancing early detection and therapeutic strategies. Citation Format: Sahar Nasr, Jacob Gutierrez, Caleb lareau, Brooke Howitt. Single cell and spatial mapping of the fallopian tube with insight into origin of high grade serous carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 5000.

CCNE1 amplification and centrosome number abnormality in serous tubal intraepithelial carcinoma: further evidence supporting its role as a precursor of ovarian high-grade serous carcinoma

&lt;div&gt;AbstractPurpose:&lt;p&gt;The current paradigm in the development of high-grade serous ovarian carcinoma (HGSC) proposes that the majority of HGSCs arise from precursor serous tubal intraepithelial carcinoma (STIC) lesions of the fallopian tube. Here we survey genome-wide methylation in HGSC precursor lesions to identify genomic regions that exhibit high-specificity differential hypermethylation for potential use as biomarkers for detecting STIC and HGSC at stages when curative intervention likely remains feasible.&lt;/p&gt;Experimental Design:&lt;p&gt;We first identified quality control criteria for performing reliable methylomic analysis of DNA-limited tubal precursor lesions with the Illumina Infinium MethylationEPIC array. We then used this platform to compare genome-wide methylation among 12 STICs with paired adjacent-normal epithelia, one p53 signature lesion and two samples of concurrent HGSC. The resulting methylomic data were analyzed by unsupervised hierarchical clustering and multidimensional analysis. Regions of high-confidence STIC-specific differential hypermethylation were identified using selective bioinformatic criteria and compared with published MethylationEPIC data from 23 HGSC tumors and 11 healthy fallopian tube mucosae.&lt;/p&gt;Results:&lt;p&gt;Unsupervised analysis showed that STICs largely clustered with HGSCs, but were clearly distinct from adjacent-normal fallopian tube epithelia. Forty-two genomic regions exhibited high-confidence STIC-specific differential hypermethylation, of which 17 (40.5%) directly overlapped with HGSC-specific differentially methylated regions. Methylation at these shared loci was able to completely distinguish STIC and HGSC samples from normal and adjacent-normal specimens.&lt;/p&gt;Conclusions:&lt;p&gt;Our results suggest that most STICs are epigenetically similar to HGSCs and share regions of differential hypermethylation that warrant further evaluation for potential use as biomarkers for early detection of ovarian HGSC.&lt;/p&gt;&lt;p&gt;&lt;i&gt;See related commentary by Ishak and De Carvalho, p. 6083&lt;/i&gt;&lt;/p&gt;&lt;/div&gt;

&lt;div&gt;AbstractPurpose:&lt;p&gt;The current paradigm in the development of high-grade serous ovarian carcinoma (HGSC) proposes that the majority of HGSCs arise from precursor serous tubal intraepithelial carcinoma (STIC) lesions of the fallopian tube. Here we survey genome-wide methylation in HGSC precursor lesions to identify genomic regions that exhibit high-specificity differential hypermethylation for potential use as biomarkers for detecting STIC and HGSC at stages when curative intervention likely remains feasible.&lt;/p&gt;Experimental Design:&lt;p&gt;We first identified quality control criteria for performing reliable methylomic analysis of DNA-limited tubal precursor lesions with the Illumina Infinium MethylationEPIC array. We then used this platform to compare genome-wide methylation among 12 STICs with paired adjacent-normal epithelia, one p53 signature lesion and two samples of concurrent HGSC. The resulting methylomic data were analyzed by unsupervised hierarchical clustering and multidimensional analysis. Regions of high-confidence STIC-specific differential hypermethylation were identified using selective bioinformatic criteria and compared with published MethylationEPIC data from 23 HGSC tumors and 11 healthy fallopian tube mucosae.&lt;/p&gt;Results:&lt;p&gt;Unsupervised analysis showed that STICs largely clustered with HGSCs, but were clearly distinct from adjacent-normal fallopian tube epithelia. Forty-two genomic regions exhibited high-confidence STIC-specific differential hypermethylation, of which 17 (40.5%) directly overlapped with HGSC-specific differentially methylated regions. Methylation at these shared loci was able to completely distinguish STIC and HGSC samples from normal and adjacent-normal specimens.&lt;/p&gt;Conclusions:&lt;p&gt;Our results suggest that most STICs are epigenetically similar to HGSCs and share regions of differential hypermethylation that warrant further evaluation for potential use as biomarkers for early detection of ovarian HGSC.&lt;/p&gt;&lt;p&gt;&lt;i&gt;See related commentary by Ishak and De Carvalho, p. 6083&lt;/i&gt;&lt;/p&gt;&lt;/div&gt;

INTRODUCTION Serous tubal intra-epithelial carcinoma (STIC) in the fallopian tube has been proposed as a putative precursor of ovarian high-grade serous carcinoma (HGSC)[1,2]. Association of STIC and HGSCs is seen in ∼50% of cases, and in ∼15% of women undergoing prophylactic removal of fallopian tubes. Clonal STIC-HGSC relationship is suggested by shared TP53 mutations and overexpression[3]. To further investigate the relationship, we applied genome-wide sequencing of same-patient STIC, HGSC and normal tube DNAs isolated from FFPE tumor specimens of 4 ovarian cancer patients. Here we report extended patterns of somatic alterations shared between STIC and HGSC and identify the affected homeostatic pathways. METHODS We established the STIC-HGSC co-occurrence by pathological evaluation and immunohistochemistry for TP53 and MKI67 positivity. Overlapping TP53 mutations were determined by Sanger sequencing. DNA was isolated from STIC, HGSC and normal tissue areas of paraffin sections, with laser-capture microdissection and whole-genome DNA amplification employed for STICs due to the small cellular content. 250 ng of DNA was converted to sequencing libraries (Kapa Biosystems kit) and exome enrichment done by SeqCap EZ System, Nimblegen, Roche. Exomes were sequenced on Illumina HiSeq2500 at ∼100x coverage in 100-bp paired-end run. Somatic mutations were analyzed by MuTect and FreeBayes callers to determine unique as well as overlapping STIC and HGSC alterations. RESULTS Deep sequencing expanded the number of shared STIC-HGSC mutations to 20-55 per patient. ETV5, LPAR4, MTOR, and PAK3 genes harbored recurrent mutations in HGSCs, and the shared STIC-HGSC mutations involved genes acting in the pathways of response to stress, regulation of apoptosis, autophagy, RAS and small GTPase-mediated signaling, and actin cytoskeleton organization (e.g. MTOR, NF1, BECN1, ARHGEF18, RASA1, PREX2, TTN). Our findings were corroborated for 80 STIC-HGSC-shared gene mutants by the cBioportal/The Cancer Genome Atlas data on ovarian serous carcinoma. CONCLUSIONS The broad patterns of somatic alterations shared by STIC and HGSC document a clonal relationship of these neoplastic lesions and possible origins of ovarian carcinomas in the tubal epithelium. We propose that our genome-wide strategy, once reproduced in a higher patient number, may facilitate future development of approaches to HGSC screening, treatment and prevention. ACKNOWLEDGMENTS IARC Regular Budget; IARC Postdoctoral Fellowship Program (supported by the European Commission FP7 Marie Curie Actions COFUND). NYU Genome Technology Center (supported in part by NIH/NCI P30CA016087). We thank Dr E. Kuhn for assistance with pathology evaluations. REFERENCES 1. Li HX, et al. Int J Clin Exp Pathol. 2014 Feb 15;7(3):848-57. 2. Kurman RJ. Ann Oncol. 2013 Dec;24 Suppl 10:x16-21. 3. Kuhn E, et al. J Pathol. 2012 Feb;226(3):421-6. Citation Format: Yan Song, Maude Ardin, Vincent Cahais, Christine Carreira, Reetta Holmila, Stephanie Villar, Xavier Castells, Maxime Vallee, Adriana Heguy, Pierre-Paul Bringuier, Qin Guo, Xun Zhang, Jiri Zavadil. Genome-wide analysis of somatic mutations shared by co-occurring ovarian high-grade serous carcinomas and serous tubal intraepithelial carcinomas. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3884. doi:10.1158/1538-7445.AM2015-3884

High grade serous ovarian carcinoma (HGSC) without identifiable serous tubal intraepithelial carcinoma (STIC) within the fallopian tube (FT) occurs in approximately 50% of patients. The objective of this study was to use a multisite tumor sampling approach to study HGSC with and without STIC. RNAseq analysis of HGSC samples collected from multiple sites e.g. ovary, FT and peritoneum, revealed moderate levels of intrapatient heterogeneity in gene expression that could influence molecular profiles. Mixed‐model ANOVA analysis of gene expression in tumor samples from patients with multiple tumor sites (n = 13) and patients with a single site tumor sample (n = 11) to compare HGSC‐STIC to HGSC‐NOSTIC identified neurotensin (NTS) as significantly higher (> two‐fold change, False Discovery Rate (FDR) < 0.10) in HGSC‐STIC. This data was validated using publicly available RNA‐Seq datasets. Concordance between higher NTS gene expression and NTS peptide levels in HGSC‐STIC samples was demonstrated by immunohistochemistry. To determine the role of NTS in HGSC, five ovarian cancer (OvCa) cell lines were screened for expression of NTS and its receptors, NTSR1 and NTSR3. Increased expression of NTS and NSTR1 was observed in several of the OvCa cells, whereas the NTSR3 receptor was lower in all OvCa cells, compared to immortalized FT epithelial cells. Treatment with NTSR1 inhibitor (SR48692) decreased cell proliferation, but increased cell migration in OvCa cells. The effects of SR48692 were receptor mediated, since transient RNAi knockdown of NTSR1 mimicked the migratory effects and knockdown of NTSR3 mimicked the anti‐proliferative effects. Further, knockdown of NTSR1 or NTSR3 was associated with acquisition of distinct morphological phenotypes, epithelial or mesenchymal, respectively. Taken together, our results reveal a difference in a biologically active pathway between HGSC with and without STIC. Furthermore, we identify neurotensin signaling as an important pathway involved in cell proliferation and epithelial–mesenchymal transition in HGSC‐STIC which warrants further study as a potential therapeutic target. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

To study the morphologic changes of fallopian tubal epithelium in patients with ovarian serous epithelial tumors and to explore the relationship between the tubal epithelial changes and tumorigenesis of serous ovarian carcinoma. The fallopian tubes in 79 cases of high-grade serous ovarian carcinoma, 12 cases of low-grade serous ovarian carcinoma, 16 cases of serous borderline ovarian tumor and 11 cases of non-ovarian benign tumors were serially examined under light microscope. Immunohistochemical study with EnVision method was used to detect the expression of p53 and bcl-2 protein in the fallopian tubal epithelium in all cases. The occurrences of secretory cell outgrowth (SCOUT), p53 signature, serous tubal intraepithelial carcinoma (STIC) and serous invasive carcinoma were analyzed. SCOUT in tubal epithelium was observed in 60.8% (48/79) of the high-grade serous carcinoma group, 4/12 of the low-grade serous carcinoma group, 3/16 of the serous borderline tumor group and 2/11 of the non-ovarian benign tumor group (P = 0.001). P53 signature, STIC and serous invasive carcinoma occurred only in the fallopian tubal epithelium of patients with high-grade serous ovarian carcinoma, with the positive rates being 29.1% (23/79), 15.2% (12/79) and 44.3% (35/79), respectively. Of the 23 cases with p53 signature, 17 cases had solitary lesion and 6 cases involved more than two sites. A total of 33 p53 signature positive foci were found, with 22 foci located at fimbria and 11 at ampulla. Bcl-2 expression was demonstrated in 90.9% of those foci (30/33). Of the 12 patients with STIC, 7 cases were solitary and 5 cases involved more than two sites. A total of 18 STIC foci were found, with 16 foci located at fimbria and 2 at ampulla. All of them were positive for bcl-2. SCOUT is found in fallopian tubal epithelium in patients with serous ovarian epithelial tumors, especially high-grade serious carcinoma. On the other hand, p53 signature, STIC and invasive serous carcinoma of tubal epithelium are observed only in patients with high-grade serous ovarian carcinoma, with a predilection of fimbrial involvement. Correlation exists between SCOUT, p53 signature, STIC and high-grade serous ovarian carcinomas. Bcl-2 and p53 immunostaining is helpful for demonstrating such lesions.

The current paradigm in the development of high-grade serous ovarian carcinoma (HGSC) proposes that the majority of HGSCs arise from precursor serous tubal intraepithelial carcinoma (STIC) lesions of the fallopian tube. Here we survey genome-wide methylation in HGSC precursor lesions to identify genomic regions that exhibit high-specificity differential hypermethylation for potential use as biomarkers for detecting STIC and HGSC at stages when curative intervention likely remains feasible. We first identified quality control criteria for performing reliable methylomic analysis of DNA-limited tubal precursor lesions with the Illumina Infinium MethylationEPIC array. We then used this platform to compare genome-wide methylation among 12 STICs with paired adjacent-normal epithelia, one p53 signature lesion and two samples of concurrent HGSC. The resulting methylomic data were analyzed by unsupervised hierarchical clustering and multidimensional analysis. Regions of high-confidence STIC-specific differential hypermethylation were identified using selective bioinformatic criteria and compared with published MethylationEPIC data from 23 HGSC tumors and 11 healthy fallopian tube mucosae. Unsupervised analysis showed that STICs largely clustered with HGSCs, but were clearly distinct from adjacent-normal fallopian tube epithelia. Forty-two genomic regions exhibited high-confidence STIC-specific differential hypermethylation, of which 17 (40.5%) directly overlapped with HGSC-specific differentially methylated regions. Methylation at these shared loci was able to completely distinguish STIC and HGSC samples from normal and adjacent-normal specimens. Our results suggest that most STICs are epigenetically similar to HGSCs and share regions of differential hypermethylation that warrant further evaluation for potential use as biomarkers for early detection of ovarian HGSC.See related commentary by Ishak and De Carvalho, p. 6083.

Somatic mutation of TP53 is the most common molecular genetic alteration in high grade serous carcinoma (HGSC) of the ovary, occurring in more than 95% of cases. As serous tubal intraepithelial carcinomas (STICs) have been proposed to be the most likely precursor of HGSC, we undertook a study to determine whether STICs harbor TP53 mutations as well. Mutations of TP53 have been reported in STICs and associated HGSC but that study was limited to 5 cases. We therefore performed TP53 mutational analysis in a larger series of STICs and concurrent HGSCs and correlated the mutational status with p53 immunoreactivity. Formalin-fixed paraffin-embedded tissue specimens were obtained from 18 HGSCs with concurrent STICs; 8 of them contained two discrete STICs. Approximately 1,000 cells from STIC and normal-appearing fallopian tubal epithelium were laser-capture microdissected, while HGSCs were manually microdissected. Genomic DNA was extracted, PCR amplified and sequenced. TP53 mutations were analyzed from exons 4 to 8. Immunohistochemistry (IHC) for p53 was performed in all the cases. TP53 mutations were detected in 15 (83.3%) of 18 HGSCs. Importantly, TP53 mutations were not detected in the corresponding FTE samples from the same patients, confirming they are somatic mutations in HGSCs. STIC and associated HGSC shared identical TP53 mutations in 15 (93.8%) of 16 patients including 7 who had two STICs. The discordant case showed TP53 mutation in the HGSC but not in two separate concurrent STICs. By IHC, all the cases demonstrated the same pattern of p53 immunoreactivity (either all positive or completely negative) except the case with wild-type TP53 in the STIC and mutant TP53 in the HGSC. By IHC the STIC was p53 negative and the HGSC p53 positive. The three TP53 wild-type HGSCs and their associated STICs exhibited undetectable nuclear p53 by IHC. In contrast, four p53-negative HGSCs contained mutant TP53 with either a deletion or an insertion mutation. Our findings provide cogent evidence that TP53 mutations occur in most STICs, and that both STIC and concurrent HGSC share the identical TP53 mutations in the majority of cases. Future molecular genetic studies are necessary to delineate the clonal relationship and tumor progression from STIC to HGSC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 221. doi:10.1158/1538-7445.AM2011-221

Outcome and Management of Serous Tubal Intraepithelial Carcinoma Following Opportunistic Salpingectomy: Systematic Review and Meta-Analysis

Recent developments in the study of epithelial ovarian cancer have called into question the traditional views regarding the site of tumor initiation. Histopathologic studies and genomic analyses suggest that extra-ovarian sites, like the fallopian tube (FT) epithelium, may harbor the coveted cell of origin and could therefore contribute significantly to the development of high-grade serous ovarian carcinoma (HGSOC). Our ability to validate these emerging genomic and pathologic observations and characterize the early transformation events of HGSOC hinges on the development of novel model systems. The tubal hypothesis of serous tumorigenesis has led us to develop a number of experimental platforms. These platforms provide us with a unique view into the susceptibilities of the FT epithelium to neoplastic transformation and provide a vehicle to query the contribution of any given genetic alteration to tumor development in vitro and in vivo. These models include the ex-vivo bioanalytical platform of benign FT epithelium, the in vitro FT secretory cell transformation model, a series of patient-derived primary tumor xenograft (PDX) models that retain the phenotypic and genotypic properties of the original patient tumors, and a genetically-engineered mouse model (GEMM) that specifically targets the FT epithelium in vivo. Our GEM model specifically targets the Müllerian secretory cell. It uses the Pax8 promoter to drive expression of the Cre recombinase in the fallopian tube (FT) secretory cells. Pax8 is a lineage marker for the Müllerian system. It is necessary for the development of the female reproductive tract and its expression is retained in the adult FT secretory cell and in nearly all HGSOCs. By crossing our Pax8-Cre deletor mouse with mice carrying floxed alleles of BRCA genes, TP53 (or mutant) and/or PTEN, we could specifically manipulate the expression of these genes in the FT secretory cell. Using this approach, in collaboration with the laboratory of Daniela Dinulescu, we showed that HGSOC can originate in secretory cell of the FT and also established that serous tubal intraepithelial carcinoma (STIC) is the precursor lesion to high-grade serous ovarian and peritoneal carcinomas. Importantly, the tumors that arise in this model not only look like high-grade serous carcinomas but they also retain the genomic complexity that is a hallmark of human HGSOC. In addition to providing mechanistic insight into the origin and pathogenesis of HGSC, this model provides a platform to explore HGSOC sensitivity to novel therapeutic strategies and to develop better detection strategies for early tumor diagnosis in high-risk women. Citation Format: Ronny Drapkin. Discovering the distal fallopian tube as the origin for high-grade serous ovarian cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: From Concept to Clinic; Sep 18-21, 2013; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2013;19(19 Suppl):Abstract nr IA5.

&lt;div&gt;Abstract&lt;p&gt;The initial molecular events that lead to malignant transformation of the fimbria of the fallopian tube (FT) through high-grade serous ovarian carcinoma (HGSC) remain poorly understood. In this study, we report that increased expression of signal transducer and activator of transcription 3 (&lt;i&gt;pSTAT3 Tyr705&lt;/i&gt;) and suppression or loss of protein inhibitor of activated STAT3 (&lt;i&gt;PIAS3&lt;/i&gt;) in FT likely drive HGSC. We evaluated human tissues-benign normal FT, tubal-peritoneal junction (TPJ), p53 signature FT tissue, tubal intraepithelial lesion in transition (TILT), serous tubal intraepithelial carcinoma (STIC) without ovarian cancer, and HGSC for expression of &lt;i&gt;STAT3/PIAS3&lt;/i&gt; (compared with their known &lt;i&gt;TP53&lt;/i&gt; signature) and their target proliferation genes. We observed constitutive activation of &lt;i&gt;STAT3&lt;/i&gt; and low levels or loss of &lt;i&gt;PIAS3&lt;/i&gt; in the TPJ, p53 signature, TILT, and STIC through advanced stage IV (HGSC) tissues. Elevated expression of &lt;i&gt;pSTAT3 Tyr705&lt;/i&gt; and decreased levels of &lt;i&gt;PIAS3&lt;/i&gt; appeared as early as TPJ and the trend continued until very advanced stage HGSC (compared with high &lt;i&gt;PIAS3&lt;/i&gt; and low &lt;i&gt;pSTAT3&lt;/i&gt; expression in normal benign FT). Exogenous expression of &lt;i&gt;STAT3&lt;/i&gt; in FT cells mediated translocation of &lt;i&gt;pSTAT3&lt;/i&gt; and &lt;i&gt;c-Myc&lt;/i&gt; into the nucleus. &lt;i&gt;In vivo&lt;/i&gt; experiments demonstrated that overexpression of &lt;i&gt;STAT3&lt;/i&gt; in FT secretory epithelial cells promoted tumor progression and metastasis, mimicking the clinical disease observed in patients with HGSC. Thus, we conclude that the &lt;i&gt;STAT3&lt;/i&gt; pathway plays a role in the development and progression of HGSC from its earliest premalignant states.&lt;/p&gt;&lt;p&gt;&lt;b&gt;Significance:&lt;/b&gt; Concomitant gain of pSTAT3 Tyr705 and loss of PIAS3 appear critical for initiation and development of high-grade serous carcinoma. &lt;i&gt;Cancer Res; 78(7); 1739–50. ©2018 AACR&lt;/i&gt;.&lt;/p&gt;&lt;/div&gt;