The mutational landscape of endometrial cancer

An Overview of Artificial Intelligence in Gynaecological Pathology Diagnostics

Background: The advent of artificial intelligence (AI) has revolutionised many fields in healthcare. More recently, it has garnered interest in terms of its potential applications in histopathology, where algorithms are increasingly being explored as adjunct technologies that can support pathologists in diagnosis, molecular typing and prognostication. While many research endeavours have focused on solid tumours, gynaecological malignancies have nevertheless been relatively overlooked. The aim of this review was therefore to provide a summary of the status quo in the field of AI in gynaecological pathology by encompassing malignancies throughout the entirety of the female reproductive tract rather than focusing on individual cancers. Methods: This narrative/scoping review explores the potential application of AI in whole slide image analysis in gynaecological histopathology, drawing on both findings from the research setting (where such technologies largely remain confined), and highlights any findings and/or applications identified and developed in other cancers that could be translated to this arena. Results: A particular focus is given to ovarian, endometrial, cervical and vulval/vaginal tumours. This review discusses different algorithms, their performance and potential applications. Conclusions: The effective application of AI tools is only possible through multidisciplinary co-operation and training.

The Application of Liquid Biopsy for the Development and Validation of a Non-Invasive Screening and Diagnosis Test for Endometrial Premalignant and Malignant Lesions: A Prospective Innovative Pilot Study

Background/Objectives: Endometrial cancer (EC) is a common malignancy in developed countries, with incidence closely linked to lifestyle factors and genetic predispositions, notably Lynch syndrome. Traditional biopsy methods for diagnosis and monitoring are invasive. This study aims to develop and validate a non-invasive diagnostic method for EC using liquid biopsy, specifically examining circulating tumor DNA (ctDNA) for its potential in early detection and disease monitoring. Methods: A cohort of 63 patients with EC or atypical endometrial hyperplasia (AEH) was recruited from the Gynecological Unit of the Azienda Ospedaliera Universitaria Federico II. Plasma samples were processed to extract ctDNA, which was sequenced and analyzed for mutations. Matched tumor tissue and germline DNA were also examined to confirm mutation concordance and assess potential genetic predispositions. Results: Pathogenic mutations were identified in plasma ctDNA in 59 out of 63 cases (93%), with a 65% concordance between plasma ctDNA mutations and those found in solid tumor samples. Key mutations in genes such as PTEN, PIK3R1, and KMT2C were significantly associated with a higher tumor grade and advanced stage disease, such as myometrial infiltration. Conclusions: Liquid biopsy shows promise as a minimally invasive diagnostic and monitoring tool for EC, offering real-time insights into tumor biology. The high mutation concordance between the plasma ctDNA and tumor tissue underscores the potential of a liquid biopsy in managing EC, particularly for patients at risk of recurrence. Further longitudinal studies are needed to establish ctDNA as a standard tool in EC diagnosis and monitoring.

Genomic Landscape of ctDNA and Real-World Outcomes in Advanced Endometrial Cancer

PURPOSE

ctDNA is a novel technique extensively studied in solid tumors, although not currently well defined in endometrial cancer.

EXPERIMENTAL DESIGN

A de-identified retrospective analysis of 1,988 patients with advanced/recurrent endometrial cancer was performed. In addition, an analysis of a real-world evidence cohort was completed (n = 1,266). Patients underwent ctDNA testing using Guardant360 during routine clinical care. The objective was to describe and assess molecular landscape using ctDNA.

RESULTS

Among 1,988 ctDNA samples, at least one somatic alteration was detected in 91.6% (n = 1,821). Most frequently altered genes were TP53 (64%), PIK3CA (29%), PTEN (25%), ARID1A (20%), and KRAS (14%). Overall, 18.5% had amplifications, with the majority identified in CCNE1 (40.9%), PIK3CA (22%), and EGFR (19.3%). From the real-world evidence cohort, those with TP53 mutations had a worse overall survival (OS) versus those without TP53 mutations (P = 0.02) and those with TP53 comutations had an inferior OS in comparison with TP53-mutated only (P = 0.016). Amongst these, patients with a PIK3CA comutation (P = 0.012) and CCNE1 amplification (P = 0.01) had an inferior OS compared with those with only TP53 mutations. Fifty-seven patients with newly diagnosed endometrial cancer had at least two serial ctDNA samples showing evolution in detected variants compared with baseline samples, with TP53 being the most frequent change.

CONCLUSIONS

This study is one of the largest cohorts of ctDNA currently reported in endometrial cancer. The presence of TP53 mutation and other comutations detected by ctDNA have a negative effect on outcomes. This report suggests that ctDNA analysis is feasible and could become a useful biomarker for endometrial cancer.

Detection of driver mutations and genomic signatures in endometrial cancers using artificial intelligence algorithms

Analyzed endometrial cancer (EC) genomes have allowed for the identification of molecular signatures, which enable the classification, and sometimes prognostication, of these cancers. Artificial intelligence algorithms have facilitated the partitioning of mutations into driver and passenger based on a variety of parameters, including gene function and frequency of mutation. Here, we undertook an evaluation of EC cancer genomes deposited on the Catalogue of Somatic Mutations in Cancers (COSMIC), with the goal to classify all mutations as either driver or passenger. Our analysis showed that approximately 2.5% of all mutations are driver and cause cellular transformation and immortalization. We also characterized nucleotide level mutation signatures, gross chromosomal re-arrangements, and gene expression profiles. We observed that endometrial cancers show distinct nucleotide substitution and chromosomal re-arrangement signatures compared to other cancers. We also identified high expression levels of the CLDN18 claudin gene, which is involved in growth, survival, metastasis and proliferation. We then used in silico protein structure analysis to examine the effect of certain previously uncharacterized driver mutations on protein structure. We found that certain mutations in CTNNB1 and TP53 increase protein stability, which may contribute to cellular transformation. While our analysis retrieved previously classified mutations and genomic alterations, which is to be expected, this study also identified new signatures. Additionally, we show that artificial intelligence algorithms can be effectively leveraged to accurately predict key drivers of cancer. This analysis will expand our understanding of ECs and improve the molecular toolbox for classification, diagnosis, or potential treatment of these cancers.

Targeting DNA Damage Repair and Immune Checkpoint Proteins for Optimizing the Treatment of Endometrial Cancer

The dependence of cancer cells on the DNA damage response (DDR) pathway for the repair of endogenous- or exogenous-factor-induced DNA damage has been extensively studied in various cancer types, including endometrial cancer (EC). Targeting one or more DNA damage repair protein with small molecules has shown encouraging treatment efficacy in preclinical and clinical models. However, the genes coding for DDR factors are rarely mutated in EC, limiting the utility of DDR inhibitors in this disease. In the current review, we recapitulate the functional role of the DNA repair system in the development and progression of cancer. Importantly, we discuss strategies that target DDR proteins, including PARP, CHK1 and WEE1, as monotherapies or in combination with cytotoxic agents in the treatment of EC and highlight the compounds currently being evaluated for their efficacy in EC in clinic. Recent studies indicate that the application of DNA damage agents in cancer cells leads to the activation of innate and adaptive immune responses; targeting immune checkpoint proteins could overcome the immune suppressive environment in tumors. We further summarize recently revolutionized immunotherapies that have been completed or are now being evaluated for their efficacy in advanced EC and propose future directions for the development of DDR-based cancer therapeutics in the treatment of EC.

Fluorescence in situ hybridization test for detection of endometrial carcinoma cells by non-invasive vaginal swab

Endometrial cancer (EC) is the most common gynaecological malignancy with increasing incidence in developed countries. As gold standard, hysteroscopy confirms only 30% of suspected ECs. The detection of EC cells in the vagina by fluorescence in situ hybridization (FISH) after a smear test could reduce invasive procedures in the future. Using array-based comparative genome hybridization (aCGH) on 65 endometrial carcinomas, most frequently imbalanced regions of the tumour genome were identified. Bacterial artificial chromosomes were used to generate FISH-probes homologue to these human regions. The FISH test was hybridized on swabs specimens collected from the vaginal cavity. Samples from six patients without EC were selected as a negative control and on 13 patients with known EC as a positive control. To distinguish between benign and EC cases, the cut-off value has been defined. A first validation of this EC-FISH Test was performed with swabs from 41 patients with suspected EC. The most common genomic imbalances in EC are around the CTNNB1, FBXW7 and APC genes. The cut-off is defined at 32% of analysed cells without diploid signal pattern. This differs significantly between the positive and negative controls (p < 0.001). In a first validation cohort of 41 patients with suspected EC, the EC-FISH Test distinguishes patients with and without EC with a sensitivity of 91% and a specificity of 83%. The negative predictive value is 96%. This is the first report of a non-invasive EC-FISH Test to predict EC in women with suspected EC.

Endometrial Cancer Following Levonorgestrel-Releasing Intrauterine System Insertion in Young Women with Atypical Hyperplasia: Two Case Reports and Literature Review

Levonorgestrel-releasing intrauterine system (LNG-IUS) insertion is the first-line treatment for atypical hyperplasia (AH) in young women who wish to retain their fertility. However, the procedure is not always effective, and may allow AH to progress to endometrioid endometrial cancer (EEC). Two young women with AH who wished to preserve their fertility developed EEC following 52-mg LNG-IUS in insertion at our institution. One was a 34-year-old woman diagnosed with endometrial cancer 2 years after LNG-IUS insertion. The second was a 30-year-old woman diagnosed 17 months after LNG-IUS insertion. Proactive molecular risk classification for endometrial cancer (ProMisE) classification revealed that the first and second patients had p53-abnormal (p53abn) EEC and mismatch repair deficient (MMR-d) EEC, respectively. MMR-d and p 53abn were frequently observed in both AH and EEC specimens. Studies suggest that MMR-d and p53abn are predictors of the occurrence adverse effects after fertility-preserving treatment for EEC. AH is a precursor of EEC. Therefore, p53 and mismatch repair (MMR) mutation may be used to identify women with AH who will not likely benefit from progestin therapy. Molecular assays in women with AH will likely be useful for identifying novel predictive biomarkers of progestin resistance and to improve the safety of conservative treatment. Combined assessment of progesterone receptor (PR) with these predictive molecular markers may improve the predictive ability.

Discovery of Dual TAF1-ATR Inhibitors and Ligand-Induced Structural Changes of the TAF1 Tandem Bromodomain

Bromodomains regulate chromatin remodeling and gene transcription through recognition of acetylated lysines on histones and other proteins. Bromodomain-containing protein TAF1, a subunit of general transcription factor TFIID, initiates preinitiation complex formation and cellular transcription. TAF1 serves as a cofactor for certain oncogenic transcription factors and is implicated in regulating the p53 tumor suppressor. Therefore, TAF1 is a potential target to develop small molecule therapeutics for diseases arising from dysregulated transcription, such as cancer. Here, we report the ATR kinase inhibitor AZD6738 (Ceralasertib) and analogues thereof as bona fide inhibitors of TAF1. Crystallographic and small-angle X-ray scattering studies established that newly identified and previously reported inhibitors stabilize distinct structural states of the TAF1 tandem bromodomain through "open-closed" transitions and dimerization. Combined with functional studies on p53 signaling in cancer cell lines, the data provide new insights into the feasibility and challenges of TAF1 inhibitors as chemical probes and therapeutics.

Endometrial polyps are non-neoplastic but harbor epithelial mutations in endometrial cancer drivers at low allelic frequencies

Endometrial polyps (EMPs) are common exophytic masses associated with abnormal uterine bleeding and infertility. Unlike normal endometrium, which is cyclically shed, EMPs persist over ovulatory cycles and after the menopause. Despite their usual classification as benign entities, EMPs are paradoxically associated with endometrial carcinomas of diverse histologic subtypes, which frequently arise within EMPs. The etiology and potential origins of EMPs as clonally-derived neoplasms are uncertain, but previous investigations suggested that EMPs are neoplasms of stromal origin driven by recurring chromosomal rearrangements. To better define benign EMPs at the molecular genetic level, we analyzed individual EMPs from 31 women who underwent hysterectomy for benign indications. The 31 EMPs were subjected to comprehensive genomic profiling by exome sequencing of a large panel of tumor-related genes including oncogenes, tumor suppressors, and chromosomal translocation partners. There were no recurring chromosomal rearrangements, and copy-number analyses did not reveal evidence of significant chromosome-level events. Surprisingly, there was a high incidence of single nucleotide variants corresponding to classic oncogenic drivers (i.e., definitive cancer drivers). The spectrum of known oncogenic driver events matched that of endometrial cancers more closely than any other common cancer. Further analyses including laser-capture microdissection showed that these mutations were present in the epithelial compartment at low allelic frequencies. These results establish a link between EMPs and the acquisition of endometrial cancer driver mutations. Based on these findings, we propose a model where the association between EMPs and endometrial cancer is explained by the age-related accumulation of endometrial cancer drivers in a protected environment that-unlike normal endometrium-is not subject to cyclical shedding.

Comparative transcriptome analysis between patient and endometrial cancer cell lines to determine common signaling pathways and markers linked to cancer progression

The rising incidence and mortality of endometrial cancer (EC) in the United States calls for an improved understanding of the disease's progression. Current methodologies for diagnosis and treatment rely on the use of cell lines as models for tumor biology. However, due to inherent heterogeneity and differential growing environments between cell lines and tumors, these comparative studies have found little parallels in molecular signatures. As a consequence, the development and discovery of preclinical models and reliable drug targets are delayed. In this study, we established transcriptome parallels between cell lines and tumors from The Cancer Genome Atlas (TCGA) with the use of optimized normalization methods. We identified genes and signaling pathways associated with regulating the transformation and progression of EC. Specifically, the LXR/RXR activation, neuroprotective role for THOP1 in Alzheimer's disease, and glutamate receptor signaling pathways were observed to be mostly downregulated in advanced cancer stage. While some of these highlighted markers and signaling pathways are commonly found in the central nervous system (CNS), our results suggest a novel function of these genes in the periphery. Finally, our study underscores the value of implementing appropriate normalization methods in comparative studies to improve the identification of accurate and reliable markers.

Systematic Next Generation Sequencing is feasible in clinical practice and identifies opportunities for targeted therapy in women with uterine cancer: Results from a prospective cohort study

BACKGROUND

Both incidence and mortality of uterine cancer are on the rise and mortality is higher for African American women. The aim of our study was to evaluate how Next Generation Sequencing (NGS) may facilitate identification of and intervention for treatment disparities when integrated into clinical workflows.

RESULTS

Our cohort included 159 uterine cancer patients with recurrent/progressive and newly diagnosed advanced stage and/or high-risk histology. The most common tumor histological subtypes included EEC (n = 67), SEC (n = 34), UCS (n = 20), and mixed (n = 14). Black patients were most likely to present with aggressive histology: (SEC, 34.0%) and carcinosarcoma (UCS, 14.0%). The four most common mutations across all subtypes were TP53, PIK3CA, PTEN, and ARID1A. There was racial disparity between Black versus non-Black patients who were initiated on targeted therapy (28.2% vs. 38.2%, respectively) and clinical trial (15% vs. 22.6%, respectively). Compared to non-Black patients, Black patients had a significantly higher percentage TP53 mutations (p < 0.05) and a significantly lower percentage ARID1A mutations (p < 0.05).

CONCLUSIONS

NGS for uterine malignancies provides actionable information for targetable mutations and/or clinical trial enrollment in most patients; further investigation is necessary to identify potentially modifiable factors contributing to current disparities that may improve targeted therapy uptake and clinical trial participation.

Serial genomic analysis of endometrium supports the existence of histologically indistinct endometrial cancer precursors

The endometrium is unique as an accessible anatomic location that can be repeatedly biopsied and where diagnostic biopsies do not extirpate neoplastic lesions. We exploited these features to retrospectively characterize serial genomic alterations along the precancer/cancer continuum in individual women. Cases were selected based on (1) endometrial cancer diagnosis/hysterectomy and (2) preceding serial endometrial biopsies including for some patients an early biopsy before a precancer histologic diagnosis. A comprehensive panel was designed for endometrial cancer genes. Formalin‐fixed, paraffin‐embedded specimens for each cancer, preceding biopsies, and matched germline samples were subjected to barcoded high‐throughput sequencing to identify mutations and track their origin and allelic frequency progression. In total, 92 samples from 21 patients were analyzed, providing an opportunity for new insights into early endometrial cancer progression. Definitive invasive endometrial cancers exhibited expected mutational spectra, and canonical driver mutations were detectable in preceding biopsies. Notably, ≥1 cancer mutations were detected prior to the histopathologic diagnosis of an endometrial precancer in the majority of patients. In 18/21 cases, ≥1 mutations were confirmed by abnormal protein levels or subcellular localization by immunohistochemistry, confirming genomic data and providing unique views of histologic correlates. In 19 control endometria, mutation counts were lower, with a lack of canonical endometrial cancer hotspot mutations. Our study documents the existence of endometrial lesions that are histologically indistinct but are bona fide endometrial cancer precursors. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

Profilin-1 is dysregulated in endometroid (type I) endometrial cancer promoting cell proliferation and inhibiting pro-inflammatory cytokine production

Endometrial cancer (EC) is the most common gynaecological malignancy. Alarmingly its incidence and mortality rate is increasing particularly in younger women of reproductive age. Despite this, there are limited treatment options for EC. Profilin-1 (PFN1) regulates tumorigenesis in numerous cancers, but the role of PFN1 in EC has not been investigated. We hypothesized that PFN1 would have altered expression in EC and contribute to the development of EC. We quantified PFN1 in type 1 EC and benign/normal endometrium by RT-qPCR and IHC. The effect of silencing PFN1 on cell adhesion and proliferation was investigated using 2 EC cell lines (HEC1A and AN3CA). The effect of recombinant PFN1 (100 μM) on pro-inflammatory cytokine gene expression was investigated using THP1 monocyte cell line. PFN1 immunolocalized to glandular epithelial cells, vascular endothelial cells and leukocytes in the stromal compartment of normal endometrium and EC. PFN1 immunostaining intensity was significantly elevated in grade (G)I EC compared to normal endometrium, GI-II and GIII EC. In endometrial epithelial cancer cells alone, PFN1 immunostaining intensity was significantly reduced in GII and III EC compared to normal endometrium and GI EC. The stromal compartment of EC had strong PFN1 expression compared to benign and normal endometrium. Silencing PFN1 in the AN3CA endometrial epithelial cancer cell line significantly enhanced cell adhesion and proliferation. PFN1 treatment significantly down-regulated TNFα and IL1β mRNA expression by THP1 cells. This study demonstrated that whilst PFN1 production is retained in the stromal compartment of EC, PFN1 production is lost in endometrial epithelial cancer cells with increasing cancer grade. PFN1 may play a role in the tumorigenesis of EC. Loss of PFN1 in GII and GIII endometrial epithelial cancer cells associated with sustained PFN1 by infiltrating immune cells may promote EC tumorigenesis due to increased endometrial epithelial cancer cell proliferation coupled with a pro-tolerance tumor microenvironment.

Genomic Profiling of Uterine Aspirates and cfDNA as an Integrative Liquid Biopsy Strategy in Endometrial Cancer

The incidence and mortality of endometrial cancer (EC) have risen in recent years, hence more precise management is needed. Therefore, we combined different types of liquid biopsies to better characterize the genetic landscape of EC in a non-invasive and dynamic manner. Uterine aspirates (UAs) from 60 patients with EC were obtained during surgery and analyzed by next-generation sequencing (NGS). Blood samples, collected at surgery, were used for cell-free DNA (cfDNA) and circulating tumor cell (CTC) analyses. Finally, personalized therapies were tested in patient-derived xenografts (PDXs) generated from the UAs. NGS analyses revealed the presence of genetic alterations in 93% of the tumors. Circulating tumor DNA (ctDNA) was present in 41.2% of cases, mainly in patients with high-risk tumors, thus indicating a clear association with a more aggressive disease. Accordingly, the results obtained during the post-surgery follow-up indicated the presence of ctDNA in three patients with progressive disease. Moreover, 38.9% of patients were positive for CTCs at surgery. Finally, the efficacy of targeted therapies based on the UA-specific mutational landscape was demonstrated in PDX models. Our study indicates the potential clinical applicability of a personalized strategy based on a combination of different liquid biopsies to characterize and monitor tumor evolution, and to identify targeted therapies.

A 73-gene proliferative transcriptomic signature predicts uterine serous carcinoma patient survival and response to primary therapy

OBJECTIVES

To develop a transcriptomic signature capable of predicting overall survival (OS) for uterine serous carcinoma (USC).

METHODS

RNAseq data for 58 USC patients were obtained from TCGA. Expression of 73 candidate genes was measured for 67 Augusta University (AU) samples using NanoString technology.

RESULTS

Analysis of the TCGA RNAseq data identified 73 genes that individually predict prognosis for USC patients and an elastic net model with all 73 genes (USC73) distinguishes a good OS group with low USC73 score from a poor OS group with high USC73 score (5-year OS = 83.3% and 13.3% respectively, HR = 40.1; p = 3 × 10^-8). This finding was validated in the independent AU cohort (HR = 4.3; p = 0.0004). The poor prognosis group with high USC73 score consists of 37.9% and 32.8% of patients in the TCGA and AU cohort respectively. USC73 score and pathologic stage independently contribute to OS and together provide the best prognostic value. Early stage, low USC73 patients have the best prognosis (5-year OS = 85.1% in the combined dataset), while advanced stage, high USC73 patients have the worst prognosis (5-year OS = 6.4%, HR = 30.5, p = 1.2 × 10^-12). Consistent with the observed poor survival, primary cell cultures from high USC73 patients had higher proliferation rate and cell cycle progression; and high USC73 patients had lower rates of complete response to standard therapy.

CONCLUSIONS

The USC73 transcriptomic signature and stage independently predict OS of USC patients and the best prediction is achieved using USC73 and stage. USC73 may also serve as a therapeutic biomarker to guide patient care.

Long non-coding RNAs and endometrial cancer

Endometrial cancer (EC) is one of the most common gynecologic malignancies. In spite of the advance in chemotherapy, radiotherapy or surgical techniques for EC in recent years, the survival rate of advanced stage EC patients remains unsatisfactory. Long non-coding RNAs (lncRNAs) are known as transcripts longer than 200 nucleotides exhibiting no or limited protein-coding potential. Growing evidence suggested lncRNAs may be a critical class of pervasive genes involved in cancer progression. However, the function and biological relevance between lncRNAs and EC remain not yet fully understood. Accumulating evidence has indicated that lncRNAs are dysregulated in EC, and closely related to tumorigenesis, metastasis and chemoresistance. In this review, we summarize the known regulation and functional roles of lncRNAs in EC. Besides, we will discuss the potential of lncRNAs as diagnostic biomarkers and therapeutic targets in EC.

Restoration of microRNA-29c in type I endometrioid cancer reduced endometrial cancer cell growth

Endometrial cancer is the most common gynaecological cancer worldwide, and the prognosis of patients with advanced disease remains poor. MicroRNAs (miRs) are dysregulated in endometrial cancer. miRs-29-a, -b and -c expression levels are downregulated in endometrial cancer; however, a specific role for miR-29c and its target genes remain to be elucidated. The aim of the present study was to determine the functional effect of restoring miR-29c expression in endometrial cancer cell lines and to identify miR-29c targets involved in cancer progression. miR-29c expression in human endometrial tumour grades 1-3 and benign tissue as well as in the endometrial cancer cell lines Ishikawa, HEC1A and AN3CA were analysed using reverse transcriptase-quantitative PCR (RT-qPCR). The cell lines were transfected with miR-29c mimic, miR-29c inhibitor or scrambled control. xCELLigence real-time cell monitoring analysed proliferation and migration, and flow cytometry was used to analyse apoptosis and cell cycle. The expression of miR-29c target genes in transfected cell lines was analysed using RT-qPCR. miR-29c was downregulated in grade 1-3 endometrial cancer samples compared with benign endometrium. miR-29c was reduced in Ishikawa and AN3CA cells, but not in HEC1A cell lines compared with non-cancerous primary human endometrial epithelial cells. Overexpression of miR-29c variably reduced proliferation, increased apoptosis and reduced the expression levels of miR-29c target genes, including cell division cycle 42, HMG-box transcription factor 1, integrin subunit β 1, MCL1 apoptosis regulator BCL2 family member, MDM2 proto-oncogene, serum/glucocorticoid regulated kinase 1, sirtuin 1 and vascular endothelial growth factor A, across the three cell lines investigated. Inhibition of miR-29c in HEC1A cells increased proliferation and collagen type IV α 1 chain expression. The re-introduction of miR-29c to endometrial cancer cell lines reduced proliferation, increased apoptosis and reduced miR-29c target gene expression in vitro. The present results suggested that miR-29c may be a potential therapeutic target for endometrial cancer.

The resistance of esophageal cancer cells to paclitaxel can be reduced by the knockdown of long noncoding RNA DDX11-AS1 through TAF1/TOP2A inhibition

Esophageal cancer (EC) is one of the most common malignancies in the world. The currently used chemotherapeutic drug for the treatment of EC is paclitaxel (PTX), the efficacy of which is affected by the development of drug resistance. The present study aims to define the role of the long noncoding RNA (lncRNA) DDX11-AS1 in the progression of EC with the involvement of PTX-resistant EC cells. First, EC and adjacent normal tissue samples were collected from 82 patients with EC, after which the expression levels of DDX11-AS1, TOP2A and TAF1 were determined. The results showed that DDX11-AS1, TOP2A and TAF1 were highly expressed in EC tissues, and there was a positive correlation between the expression levels of DDX11-AS1 and TOP2A. A PTX-resistant EC cell line was constructed. Next, we evaluated the effects of DDX11-AS1 and TOP2A on the resistance of EC cells to PTX, and the regulatory relationships between DDX11-AS1, TOP2A and TAF1 were investigated. DDX11-AS1 could promote TOP2A transcription via TAF1, and the knockdown of TOP2A or DDX11-AS1 could increase the sensitivity of EC cells to PTX. The effect of DDX11-AS1 on the growth of PTX-inhibited tumors was confirmed using a tumor formation assay in nude mice. It was verified that knocking down DDX11-AS1 reduced the expression level of TOP2A and inhibited tumor growth. In conclusion, our findings suggest that DDX11-AS1 knockdown results in reduced resistance of EC cells to PTX by inhibiting TOP2A transcription via TAF1. Therefore, DDX11-AS1 knockdown could be a promising therapeutic strategy for EC.

Crosstalk between PKCα and PI3K/AKT Signaling Is Tumor Suppressive in the Endometrium

Protein kinase C (PKC) isozymes are commonly recognized as oncoproteins based on their activation by tumor-promoting phorbol esters. However, accumulating evidence indicates that PKCs can be inhibitory in some cancers, with recent findings propelling a shift in focus to understanding tumor suppressive functions of these enzymes. Here, we report that PKCα acts as a tumor suppressor in PI3K/AKT-driven endometrial cancer. Transcriptional suppression of PKCα is observed in human endometrial tumors in association with aggressive disease and poor prognosis. In murine models, loss of PKCα is rate limiting for endometrial tumor initiation. PKCα tumor suppression involves PP2A-family-dependent inactivation of AKT, which can occur even in the context of genetic hyperactivation of PI3K/AKT signaling by coincident mutations in PTEN, PIK3CA, and/or PIK3R1. Together, our data point to PKCα as a crucial tumor suppressor in the endometrium, with deregulation of a PKCα→PP2A/PP2A-like phosphatase signaling axis contributing to robust AKT activation and enhanced endometrial tumorigenesis.

Overexpression of HOMER2 predicts better outcome in low-grade endometrioid endometrial adenocarcinoma

We have previously shown that HOMER2 (Homer scaffolding protein 2), a protein coding gene, was highly expressed in low grade (LG) endometrioid adenocarcinoma (EAC) of the uterus. The role of HOMER2 in endometrial cancer (EC) is widely unknown; therefore, the aim of this study was to determine the expression and the predictive value of HOMER2 protein expression in series of patients with EC. HOMER2 protein expression was detected on paraffin-embedded tissues from 336 cases using immunohistochemistry (IHC). Tumours were categorised in two groups; group 1 (EAC, FIGO grade 1 and 2; n = 191) and group 2 (all other subtypes including grade 3 EAC; n = 145). Statistical analysis was performed to evaluate associations between HOMER2 protein expression and pathological parameters (histological type, grade, stage, lymphovascular invasion, myometrial depth of invasion) and patient outcome [progression-free survival (PFS) and cancer-specific survival (CSS)]. HOMER2 was significantly overexpressed in group 1 compared to group 2 cancers (67% versus 30%; p < 0.001) and with low tumour grade (p < 0.001). In group 1, HOMER2 overexpression was an independent prognostic factor for improved CSS (adjusted-hazard ratio 0.28; 95% confidence interval 0.08-0.96; p = 0.042). HOMER2 expression was not associated with survival in group 2 (p > 0.05). This is the first study of HOMER2 protein expression in EC. We speculate that HOMER2 may be involved in tumourigenesis of endometrioid uterine tumours and suggest that HOMER2 should be studied further for potential clinical and therapeutic applications.

Endometrial cancer cells exhibit high expression of p110β and its selective inhibition induces variable responses on PI3K signaling, cell survival and proliferation

PTEN loss and constitutive activation of the class I phosphoinositide 3-kinase (PI3K) pathway are key drivers of endometrial tumorigenesis. In some cancer types, PTEN-deficient tumors are reliant on class I PI3K p110β (encoded by PIK3CB) activity but little is known about this contribution in endometrial tumorigenesis. In this study, we find that p110β is overexpressed in a panel of 7 endometrial cancer cell lines compared to non-transformed cells. Furthermore, in 234 clinically annotated patient samples, PIK3CB mRNA levels increase significantly in the early phase of tumorigenesis from precursors to low grade primary malignant lesions whereas PIK3CA levels are higher in non-endometrioid compared to endometrioid primary tumors. While high levels of either PIK3CA or PIK3CB associate with poor prognosis, only elevated PIK3CB mRNA levels correlate with a high cell cycle signature score in clinical samples. In cancer cell lines, p110α inhibition reduces cell viability by inducing cell death in PIK3CA mutant cells while p110β inhibition delayed proliferation in PTEN-deficient cells, but not in WT cells. Taken together, our findings suggest that PIK3CB/p110β contributes to some of the pleiotropic functions of PI3K in endometrial cancer, particularly in the early steps by contributing to cell proliferation.

Molecular Pathology: Predictive, Prognostic, and Diagnostic Markers in Uterine Tumors

This article focuses on the diagnostic, prognostic, and predictive molecular biomarkers in uterine malignancies, in the context of morphologic diagnoses. The histologic classification of endometrial carcinomas is reviewed first, followed by the description and molecular classification of endometrial epithelial malignancies in the context of histologic classification. Taken together, the molecular and histologic classifications help clinicians to approach troublesome areas encountered in clinical practice and evaluate the utility of molecular alterations in the diagnosis and subclassification of endometrial carcinomas. Putative prognostic markers are reviewed. The use of molecular alterations and surrogate immunohistochemistry as prognostic and predictive markers is also discussed.

Chondroitin sulfate proteoglycan protein is stimulated by interleukin 11 and promotes endometrial epithelial cancer cell proliferation and migration

Endometrial cancer is the most common gynecological cancer. We identified interleukin 11 (IL11) as a critical mediator of endometrial tumourigenesis and demonstrated that IL11 regulates chondroitin sulfate proteoglycan (CSPG4) in human placental trophoblasts. CSPG4 is a cell membrane protein overexpressed in numerous human cancers, although its role in endometrial cancer has not been investigated. We examined CSPG4 expression and localization in primary human type I endometrioid grade (G) 1-3 tumours by qPCR and immunohistochemistry and determined whether IL11 stimulated CSPG4. IL11 upregulated CSPG4 mRNA in HEC1A (G2-derived endometrial epithelial cancer cell line) cells. IL11 administration to BALB/c nude mice enhanced HEC1A xenograft tumour growth and increased CSPG4 protein in tumours. CSPG4 mRNA was unchanged between human G1-3 endometrial cancer and control tissues. CSPG4 protein levels were elevated in the epithelium of G2 and G3 endometrial cancer and in the tumour-associated stroma of G3 tumour tissues compared to proliferative phase or post-menopausal endometrium. CSPG4 knockdown by siRNA reduced HEC1A proliferation and migration in vitro and reduced gene expression of the key epithelial-to-mesenchymal transition (EMT) regulator SNAIL. Our data suggest that CSPG4 inhibition may impair endometrial cancer progression by reducing cancer cell proliferation, migration and potentially EMT.

Genetic analysis of uterine aspirates improves the diagnostic value and captures the intra-tumor heterogeneity of endometrial cancers

Endometrial cancer is the most common cancer of the female genital tract in developed countries. Although the majority of endometrial cancers are diagnosed at early stages and the 5-year overall survival is around 80%, early detection of these tumors is crucial to improve the survival of patients given that the advanced tumors are associated with a poor outcome. Furthermore, correct assessment of the pre-clinical diagnosis is decisive to guide the surgical treatment and management of the patient. In this sense, the potential of targeted genetic sequencing of uterine aspirates has been assessed as a pre-operative tool to obtain reliable information regarding the mutational profile of a given tumor, even in samples that are not histologically classifiable. A total of 83 paired samples were sequenced (uterine aspirates and hysterectomy specimens), including 62 endometrioid and non-endometrioid tumors, 10 cases of atypical hyperplasia and 11 non-cancerous endometrial disorders. Even though diagnosing endometrial cancer based exclusively on genetic alterations is currently unfeasible, mutations were mainly found in uterine aspirates from malignant disorders, suggesting its potential in the near future for supporting the standard histologic diagnosis. Moreover, this approach provides the first evidence of the high intra-tumor genetic heterogeneity associated with endometrial cancer, evident when multiple regions of tumors are analyzed from an individual hysterectomy. Notably, the genetic analysis of uterine aspirates captures this heterogeneity, solving the potential problem of incomplete genetic characterization when a single tumor biopsy is analyzed.

Lean Body Weight and Metformin Are Insufficient to Prevent Endometrial Hyperplasia in Mice Harboring Inactivating Mutations in PTEN

OBJECTIVES

Obesity is a major risk factor for endometrial cancer. We evaluated whether obesity exacerbates progression of endometrial hyperplasia (EH) using the PRCre/+ PTENflox/+ mouse model and examined if the type 2 diabetes drug, metformin, could prevent EH.

METHODS

Twenty obese (PRCre/+ PTENflox/+) mice were maintained on a high-fat diet, while 20 lean mice ate a matching low-fat diet. Ten mice from each group received metformin (1,000 mg/day) in drinking water. Mice were euthanized at 26 weeks. Uterine tissue was scored for degree of EH. Immunohistochemical staining for Ki67 was used to evaluate cellular proliferation. Markers of PI3K/AKT/mTOR activity were evaluated by immunohistochemistry using activation-specific antibodies. Serum adiponectin was quantified by ELISA.

RESULTS

Obesity had no effect on the extent of EH in (PRCre/+ PTENflox/+) mice. While metformin significantly altered circulating adiponectin levels in obese and lean animals, it had no effect on EH. There were no differences in endometrial proliferation as measured by Ki67 staining. Neither obesity nor metformin altered PI3K/AKT/mTOR activity in these animals.

CONCLUSIONS

Weight and metformin did not affect the severity of EH resulting from PTEN inactivation. Alternative mouse models of early endometrial cancer are required for preclinical cancer prevention studies.

Long non-coding RNA profiling links subgroup classification of endometrioid endometrial carcinomas with trithorax and polycomb complex aberrations

BACKGROUND

Integrative analysis of endometrioid endometrial carcinoma (EEC) using multiple platforms has distinguished four molecular subgroups. However, the landscape of expressed long non-coding RNAs (lncRNA) and their role in charting EEC subgroups and determining clinical aggressiveness remain largely unknown.

RESULTS

Using stringent criteria, we identified 1,931 expressed lncRNAs and predicted potential drivers through integrative analysis. Unsupervised clustering of lncRNA expression revealed three robust categories: basal-like, luminal-like and CTNNB1-enriched subgroups. Basal-like subgroup was enriched for aggressive tumors with higher pathological grade (p < 0.0001), TNM stage (p = 0.01), and somatic mutations in trithorax-group genes (MLL, MLL2 and MLL3); and it overexpressed polycomb genes EZH2 and CBX2. In contrast to the luminal-like subgroup, progesterone (PGR) and estrogen receptor (ESR1) genes were highly down-regulated in the EEC basal-like subgroup. Consistent with its enrichment for CTNNB1 mutations (69%), lncRNA profile of the CTNNB1-enriched EEC subgroup was highly similar to that of the CTNNB1-enriched liver cancer subgroup.

MATERIALS AND METHODS

We performed integrative analysis of lncRNAs in EEC using The Cancer Genome Atlas (TCGA) molecular RNAseq profiles of 191 primary tumors for which genomic data were also available. We established lncRNA subgroup classification, correlated it with chromatin modifying gene expression, and described correlations between our lncRNA classification and clinico-genomic tumor features.

CONCLUSIONS

Our results reveal the utility of systematic characterization of clinically annotated EEC in three clinically relevant subgroups. They also highlight the convergence of aberrations in polycomb- and trithorax-group genes in aggressive basal EEC subtypes, providing a rationale for further investigation of epigenetic therapy in this setting.

Combined large cell neuroendocrine carcinoma and endometrioid carcinoma of the endometrium: a shared gene mutation signature between the two histological components

A 61-year-old Japanese woman was diagnosed with FIGO Stage IB endometrioid cancer (EC) combined with large cell neuroendocrine carcinoma (LCNEC). Metastasis to the lymph nodes in the right bronchopulmonary area, mediastinum and brain were also identified. The patient eventually developed pleuritis and pericarditis carcinomatosa, and died of cancer at 51 months after surgery. Because gene aberrations in uterine neuroendocrine carcinoma are still not well understood, we examined alterations in the mutational hotspots of 50 selected cancer-associated genes. The EC and LCNEC components shared identical alterations in PTEN, PIK3CA and FGFR3. Both the EC and LCNEC components had heterozygous SBSs on CTNNB1 but at different codons (G34R in EC, and T41A in LCNEC). The altered gene signature raised a possibility that the EC and LCNEC components were derived from a common precursor lesion. The LCNEC independently obtained a significant CTNNB1 mutation and the lymph node metastasis originated from this component. Because the LCNEC component seemed to bring about the aggressive course of the disease and defined the patient outcome, further investigations are needed to elucidate the mechanism of NE carcinoma development in the endometrium.

Use of comprehensive genomic profiling to direct point-of-care management of patients with gynecologic cancers

OBJECTIVE

To determine the feasibility and clinical utility of using comprehensive genomic profiling (CGP) in the course of clinical care to identify clinically relevant tumor genomic alterations for patients with either rare or refractory gynecologic cancers to facilitate point-of-care management. Use of an expert, multidisciplinary, institutional molecular tumor board (MTB) assessment is discussed regarding input on putative targeted options for individualized therapy.

METHODS

A prospective clinical trial is ongoing. We report on the initial 69 patients with gynecologic cancers that were either rare or refractory to standard therapy. CGP was performed by Foundation Medicine, Inc. Genomic alterations were reviewed by members of an MTB. Consensus recommendations on genomically targeted, FDA-approved, on- and off-label therapies and clinical trials were sent to the treating physician, and decisions and outcomes were assessed.

RESULTS

Study outcomes were available for 64 patients. The mean number of genes altered per tumor was 4.97 (median=4; range, 1-26), and the average turnaround time from testing laboratory report to generation of formal recommendations was approximately three weeks. Evaluation of genomic and clinical data by the MTB led to generation of targeted treatment options in all 64 patients, and the percentage of patients for whom one or more of these recommendations were implemented by the treating physician was 39%. Sixty-four percent of the patients receiving targeted therapy based on a CGP result experienced radiologic response or showed evidence of clinical benefit or stable disease.

CONCLUSION

These data suggest that an institutional MTB is a feasible venue for reviewing tumor genomic profiling results and generating clinical recommendations. These data also support the need for further studies and guidelines on clinical decision making with greater availability of broad genomically based diagnostics.

The genomic landscape and evolution of endometrial carcinoma progression and abdominopelvic metastasis

Recent studies have detailed the genomic landscape of primary endometrial cancers, but the evolution of these cancers into metastases has not been characterized. We performed whole-exome sequencing of 98 tumor biopsies including complex atypical hyperplasias, primary tumors and paired abdominopelvic metastases to survey the evolutionary landscape of endometrial cancer. We expanded and reanalyzed The Cancer Genome Atlas (TCGA) data, identifying new recurrent alterations in primary tumors, including mutations in the estrogen receptor cofactor gene NRIP1 in 12% of patients. We found that likely driver events were present in both primary and metastatic tissue samples, with notable exceptions such as ARID1A mutations. Phylogenetic analyses indicated that the sampled metastases typically arose from a common ancestral subclone that was not detected in the primary tumor biopsy. These data demonstrate extensive genetic heterogeneity in endometrial cancers and relative homogeneity across metastatic sites.

An update of the classical Bokhman's dualistic model of endometrial cancer

According to the classical dualistic model introduced by Bokhman in 1983, endometrial cancer (EC) is divided into two basic types. The prototypical histological type for type I and type II of EC is endometrioid carcinoma and serous carcinoma, respectively. The traditional classification is based on clinical, endocrine and histopathological features, however, it sometimes does not reflect the full heterogeneity of EC. New molecular evidence, supported by clinical diversity of the cancer, indicates that the classical dualistic model is valid only to some extent. The review updates a mutational diversity of EC, introducing a new molecular classification of the tumour in regard to data presented by The Cancer Genome Atlas Research Network (TGCA).

Polycystic ovary syndrome: Endometrial markers

Women with polycystic ovarian syndrome (PCOS) present with several endometrial abnormalities possibly explaining some of the adverse endometrium-related outcomes in these women. PCOS and an increased miscarriage rate have been suggested to coincide, but the results are conflicting. Recent studies have also shown increased risks of pregnancy-induced hypertension, preeclampsia, and premature delivery that may be related to altered decidualization/placentation in affected women. In the long run, PCOS per se is associated with the occurrence of endometrial cancer (EC), with obesity aggravating the risk. Most investigated markers of the endometrial abnormalities in women with PCOS are related to steroid hormone action (ERs (estrogen receptors), PRs (progesterone receptors), ARs (androgen receptors), and steroid receptor coactivators), endometrial receptivity/decidualization (HOXA10, αvβ3 integrin, and IGFBP-1 (insulin-like growth factor-binding protein 1)), glucose metabolism (IRs (insulin receptors), glucose transporters, IGFs) and inflammation/immune cell migration ((IL-6 (interleukin 6), CCL2 (CC motif ligand), and uNK (uterine natural killer) cells). Despite several endometrial abnormalities in women with PCOS, the clinical relevance of these findings still awaits future clarification; to date, no common screening protocols/recommendations for women with PCOS have been established.

Regulation of epithelial-mesenchymal transition in endometrial cancer: connecting PI3K, estrogen signaling, and microRNAs

Endometrial cancer (EC) prognosis is dependent on many factors such as time of diagnosis, histological type, and degree of invasion. Type I EC has a more favorable prognosis as it is less prone to myometrial invasion, which is believed to be the first step in the metastatic cascade. Type II EC displays a more aggressive and motile phenotype, and therefore has a poorer prognosis. Recent work suggests that despite the epithelial nature of Type I and Type II endometrial tumors, both are capable of undergoing an epithelial-mesenchymal transition (EMT), which may facilitate myometrial invasion and metastasis. Activation of the PI3K/Akt pathway has been shown to contribute to EMT through the upregulation of EMT-associated factors. Recent research has also linked estrogen signaling and microRNAs to the regulatory mechanisms that drive EMT in EC. Understanding the intricate relationships between these pathways will provide a better understanding of metastatic progression in EC.