Biomarkers in endometrial cancer: Possible clinical applications (Review)

Functional Analysis of RE1 Silencing Transcription Factor as a Putative Tumor Suppressor in Human Endometrial Cancer

Uterine cancer is the most common gynecologic malignancy in the United States, with endometrioid endometrial adenocarcinoma (EC) being the most common histologic sub-type. Considering the molecular classifications of EC, efforts have been made to identify additional biomarkers that can assist in diagnosis, prognosis, and individualized therapy. We sought to explore the relationship of Repressor Element 1 (RE1) silencing transcription factor (REST), which downregulates neuronal genes in non-neuronal tissue, along with matrix metalloproteinase-24 (MMP24) and EC. We analyzed the expression of REST and MMP24 in 31 cases of endometrial cancer and 16 controls. We then explored the baseline expression of REST and MMP24 in two EC cell lines (Ishikawa and HEC-1-A) compared to a benign cell line (t-HESC) and subsequently evaluated proliferation, migration, and invasion in the setting of loss of REST gene expression. REST and MMP24 expression were significantly lower in human EC samples compared to control samples. REST was highly expressed in EC cell lines, but decreasing REST gene expression increased proliferation (FC: 1.13X, p < 0.0001), migration (1.72X, p < 0.0001), and invasion (FC: 7.77X, p < 0.05) in Ishikawa cells, which are hallmarks of cancer progression and metastasis. These findings elicit a potential role for REST as a putative tumor suppressor in EC.

Integrating proteomics and explainable artificial intelligence: a comprehensive analysis of protein biomarkers for endometrial cancer diagnosis and prognosis

Endometrial cancer, which is the most common gynaecological cancer in women after breast, colorectal and lung cancer, can be diagnosed at an early stage. The first aim of this study is to classify age, tumor grade, myometrial invasion and tumor size, which play an important role in the diagnosis and prognosis of endometrial cancer, with machine learning methods combined with explainable artificial intelligence. 20 endometrial cancer patients proteomic data obtained from tumor biopsies taken from different regions of EC tissue were used. The data obtained were then classified according to age, tumor size, tumor grade and myometrial invasion. Then, by using three different machine learning methods, explainable artificial intelligence was applied to the model that best classifies these groups and possible protein biomarkers that can be used in endometrial prognosis were evaluated. The optimal model for age classification was XGBoost with AUC (98.8%), for tumor grade classification was XGBoost with AUC (98.6%), for myometrial invasion classification was LightGBM with AUC (95.1%), and finally for tumor size classification was XGBoost with AUC (94.8%). By combining the optimal models and the SHAP approach, possible protein biomarkers and their expressions were obtained for classification. Finally, EWRS1 protein was found to be common in three groups (age, myometrial invasion, tumor size). This article's findings indicate that models have been developed that can accurately classify factors including age, tumor grade, and myometrial invasion all of which are critical for determining the prognosis of endometrial cancer as well as potential protein biomarkers associated with these factors. Furthermore, we were able to provide an analysis of how the quantities of the proteins suggested as biomarkers varied throughout the classes by combining the SHAP values with these ideal models.

Identification of Endometrial Cancer-Specific microRNA Biomarkers in Endometrial Fluid

Abnormal uterine bleeding is a common benign gynecological complaint and is also the most common symptom of endometrial cancer (EC). Although many microRNAs have been reported in endometrial carcinoma, most of them were identified from tumor tissues obtained at surgery or from cell lines cultured in laboratories. The objective of this study was to develop a method to detect EC-specific microRNA biomarkers from liquid biopsy samples to improve the early diagnosis of EC in women. Endometrial fluid samples were collected during patient-scheduled in-office visits or in the operating room prior to surgery using the same technique performed for saline infusion sonohysterography (SIS). The total RNA was extracted from the endometrial fluid specimens, followed by quantification, reverse transcription, and real-time PCR arrays. The study was conducted in two phases: exploratory phase I and validation phase II. In total, endometrial fluid samples from 82 patients were collected and processed, with 60 matched non-cancer versus endometrial carcinoma patients used in phase I and 22 in phase II. The 14 microRNA biomarkers, out of 84 miRNA candidates, with the greatest variation in expression from phase I, were selected to enter phase II validation and statistical analysis. Among them, three microRNAs had a consistent and substantial fold-change in upregulation (miR-429, miR-183-5p, and miR-146a-5p). Furthermore, four miRNAs (miR-378c, miR-4705, miR-1321, and miR-362-3p) were uniquely detected. This research elucidated the feasibility of the collection, quantification, and detection of miRNA from endometrial fluid with a minimally invasive procedure performed during a patient in-office visit. The screening of a larger set of clinical samples was necessary to validate these early detection biomarkers for endometrial cancer.

lncRNA XIST/miR‑129‑2‑3p axis targets CCP110 to regulate the proliferation, invasion and migration of endometrial cancer cells

Centromere coiled-coil protein 110 (CCP110) plays a role in the development of several types of cancer; however, its regulatory mechanism and role in endometrial cancer is unclear. The present study revealed that CCP110 is regulated by a signaling pathway involving microRNA (miR/miRNA)-129-2-3p and the long non-coding RNA (lncRNA) X-inactive-specific transcript (XIST), and plays a role in controlling the proliferation, migration and invasion of endometrial cancer cells. CCP110 was upregulated in human endometrial cancer tissues, as revealed by immunohistochemistry, and high expression of the protein was related to reduced overall survival of the patients. Genetic knockdown of CCP110 by small interfering RNA promoted apoptosis and suppressed the proliferation, migration, invasion and colony formation of endometrial cancer cells significantly in the endometrial cancer Ishikawa and HEC-1B cell lines, as assessed by flow cytometry, and Cell Counting Kit-8, Transwell and colony formation assays. A bioinformatics analysis and luciferase reporter assay revealed that CCP110 is a target of miR-129-2-3p. Overexpression of miR-129-2-3p mimic fragments inhibited the proliferation, migration and invasion of endometrial cancer cells significantly, while co-overexpression of CCP110 counteracted these inhibitory effects. The expression level of the lncRNA XIST was upregulated significantly in endometrial cancer tissues, as assessed by reverse transcription-quantitative PCR assay, while that of miR-129-2-3p was downregulated significantly. A bioinformatics analysis and luciferase reporter assay showed that XIST could inhibit miR-129-2-3p via a miRNA sponge effect. Furthermore, co-overexpression of XIST antagonized the inhibitory effect of the miR-129-2-3p mimic on the luciferase reporter gene signal and protein expression of CCP110. Co-overexpression of XIST also abolished the inhibitory effect of the miR-129-2-3p mimic on the proliferation, migration and invasion of endometrial cancer cells. Overall, these data identified a novel regulatory mechanism of CCP110 involving XIST and miR-129-2-3p, which affected the development of endometrial carcinoma. CCP110, XIST and miR-129-2-3p could represent novel targets for the clinical treatment of endometrial cancer.

Gel-Based Proteomic Identification of Suprabasin as a Potential New Candidate Biomarker in Endometrial Cancer

Endometrial cancer (EC) is the most frequent gynaecologic cancer in postmenopausal women. We used 2D-DIGE and mass spectrometry to identify candidate biomarkers in endometrial cancer, analysing the serum protein contents of 10 patients versus 10 control subjects. Using gel-based proteomics, we identified 24 candidate biomarkers, considering only spots with a fold change in volume percentage ≥ 1.5 or intensity change ≤ 0.6, which were significantly different between cases and controls (p < 0.05). We used Western blotting analysis both in the serum and tissue of 43 patients for data validation. Among the identified proteins, we selected Suprabasin (SBSN), an oncogene previously associated with poor prognosis in different cancers. SBSN principal isoforms were subjected to Western blotting analysis in serum and surgery-excised tissue: both isoforms were downregulated in the tissue. However, in serum, isoform 1 was upregulated, while isoform 2 was downregulated. Data-mining on the TCGA and GTEx projects, using the GEPIA2.0 interface, indicated a diminished SBSN expression in the Uterine Corpus Endometrial Cancer (UCEC) database compared to normal tissue, confirming proteomic results. These results suggest that SBSN, specifically isoform 2, in tissue or serum, could be a potential novel biomarker in endometrial cancer.

Role of Precision Oncology in Type II Endometrial and Prostate Cancers in the African Population: Global Cancer Genomics Disparities

Precision oncology can be defined as molecular profiling of tumors to identify targetable alterations. Emerging research reports the high mortality rates associated with type II endometrial cancer in black women and with prostate cancer in men of African ancestry. The lack of adequate genetic reference information from the African genome is one of the major obstacles in exploring the benefits of precision oncology in the African context. Whilst external factors such as the geography, environment, health-care access and socio-economic status may contribute greatly towards the disparities observed in type II endometrial and prostate cancers in black populations compared to Caucasians, the contribution of African ancestry to the contribution of genetics to the etiology of these cancers cannot be ignored. Non-coding RNAs (ncRNAs) continue to emerge as important regulators of gene expression and the key molecular pathways involved in tumorigenesis. Particular attention is focused on activated/repressed genes and associated pathways, while the redundant pathways (pathways that have the same outcome or activate the same downstream effectors) are often ignored. However, comprehensive evidence to understand the relationship between type II endometrial cancer, prostate cancer and African ancestry remains poorly understood. The sub-Saharan African (SSA) region has both the highest incidence and mortality of both type II endometrial and prostate cancers. Understanding how the entire transcriptomic landscape of these two reproductive cancers is regulated by ncRNAs in an African cohort may help elucidate the relationship between race and pathological disparities of these two diseases. This review focuses on global disparities in medicine, PCa and ECa. The role of precision oncology in PCa and ECa in the African population will also be discussed.

Comprehensive Library Generation for Identification and Quantification of Endometrial Cancer Protein Biomarkers in Cervico-Vaginal Fluid

Simple Summary

Endometrial cancer is the most common cancer of the female reproductive tract, and its incidence is rising. Early diagnosis has the potential to improve survival as women can receive care at the earliest possible stage when curative treatment is likely. Current tests for endometrial cancer diagnosis are sequentially invasive with low patient acceptability. A detection tool based on minimally invasive samples such as cervico-vaginal fluid would be a major advance in the field. This study focuses on the potential of detecting endometrial cancer based on the proteins and peptides expressed in cervico-vaginal fluid. Using Sequential window acquisition of all theoretical mass spectra (SWATH-MS), we present a spectral library of thousands of proteins in the cervico-vaginal fluid of women with or at risk of endometrial cancer. This important resource will enable the identification of endometrial cancer biomarkers in cervico-vaginal fluid and advances our knowledge of the role of proteomics in endometrial cancer detection.

Abstract

Endometrial cancer is the most common gynaecological malignancy in high-income countries and its incidence is rising. Early detection, aided by highly sensitive and specific biomarkers, has the potential to improve outcomes as treatment can be provided when it is most likely to effect a cure. Sequential window acquisition of all theoretical mass spectra (SWATH-MS), an accurate and reproducible platform for analysing biological samples, offers a technological advance for biomarker discovery due to its reproducibility, sensitivity and potential for data re-interrogation. SWATH-MS requires a spectral library in order to identify and quantify peptides from multiplexed mass spectrometry data. Here we present a bespoke spectral library of 154,206 transitions identifying 19,394 peptides and 2425 proteins in the cervico-vaginal fluid of postmenopausal women with, or at risk of, endometrial cancer. We have combined these data with a library of over 6000 proteins generated based on mass spectrometric analysis of two endometrial cancer cell lines. This unique resource enables the study of protein biomarkers for endometrial cancer detection in cervico-vaginal fluid. Data are available via ProteomeXchange with unique identifier PXD025925.

The Correlation of the IETA Ultrasound Score with the Histopathology Results for Women with Abnormal Bleeding in Western Romania

In the early differential diagnosis of endometrial cancer (EC), decisive and mandatory histological aspects are considered, in addition to obvious clinical manifestations. In addition, sonographic aspects are characteristic in relation to the stage, degree, and histological types of identified cancer. This bi-center retrospective observational study included 594 women with abnormal uterine bleeding outside pregnancy, for which a biopsy was performed in the Obstetrics and Gynecology Departments of the Emergency County Hospitals of Arad and Timis Counties, Romania, between 2015 and 2019. Most of the cases were represented by EC or endometrial hyperplasia (EH). Of the 594 cases, 25.5% (n = 153) were EC at women aged between 41 and 85 years. High International Endometrial Tumor Analysis (IETA) scores (3, 4) were associated with a relative risk of 2.9335 compared with other endometrial lesions (95% CI 2.3046 to 3.734, p < 0.0001, NNT 1.805). Histological aspects and pelvic ultrasound using IETA scores represent valuable noninvasive assets in diagnosing and differentiating endometrial cancer from benign uterine pathology.

A Narrative Review of the Role of Diet and Lifestyle Factors in the Development and Prevention of Endometrial Cancer

Simple Summary

The incidence and prevalence of endometrial cancer is increasing globally. The main factors involved in this increase have been the way women live today and what they eat and drink. In fact, the obesity pandemic that is sweeping across the planet is considered to be the main contributory feature. This review aims to introduce to a new audience, those that are not experts in the field, what is known about the different types of endometrial cancer and the mechanisms for their induction and protection. We also seek to summarise the existing knowledge on dietary and lifestyle factors that prevent endometrial development in susceptible populations and identify the main problem in this arena; the paucity of research studies and clinical trials that investigate the interaction(s) between diet, lifestyle and endometrial cancer risk whilst highlighting those areas of promise that should be further investigated.

Abstract

Endometrial cancer is the most common cancer affecting the reproductive organs of women living in higher-income countries. Apart from hormonal influences and genetic predisposition, obesity and metabolic syndrome are increasingly recognised as major factors in endometrial cancer risk, due to changes in lifestyle and diet, whereby high glycaemic index and lipid deposition are prevalent. This is especially true in countries where micronutrients, such as vitamins and minerals are exchanged for high calorific diets and a sedentary lifestyle. In this review, we will survey the currently known lifestyle factors, dietary requirements and hormonal changes that increase an individual’s risk for endometrial cancer and discuss their relevance for clinical management. We also examine the evidence that everyday factors and clinical interventions have on reducing that risk, such that informed healthy choices can be made. In this narrative review, we thus summarise the dietary and lifestyle factors that promote and prevent the incidence of endometrial cancer.

Urinary Biomarkers and Their Potential for the Non-Invasive Detection of Endometrial Cancer

Endometrial cancer is the most common malignancy of the female genital tract and its incidence is rising in parallel with the mounting prevalence of obesity. Early diagnosis has great potential to improve outcomes as treatment can be curative, especially for early stage disease. Current tests and procedures for diagnosis are limited by insufficient accuracy in some and unacceptable levels of invasiveness and discomfort in others. There has, therefore, been a growing interest in the search for sensitive and specific biomarkers for endometrial cancer detection based on non-invasive sampling methodologies. Urine, the prototype non-invasive sample, is attractive for biomarker discovery as it is easily accessible and can be collected repeatedly and in quantity. Identification of urinary biomarkers for endometrial cancer detection relies on the excretion of systemic biomarkers by the kidneys or urinary contamination by biomarkers shed from the uterus. In this review, we present the current standing of the search for endometrial cancer urinary biomarkers based on cytology, genomic, transcriptomic, proteomic, and metabolomic platforms. We summarize the biomarker candidates and highlight the challenges inherent in urinary biomarker discovery. We review the various technologies with promise for biomarker detection and assess these novel approaches for endometrial cancer biomarker research.

Genomics and splicing events of type II endometrial cancers in the black population: racial disparity, socioeconomic and geographical differences

Endometrial cancer, also known as uterine cancer, is the most common gynaecological malignancy with burgeoning incidence and mortality rates globally. Racial disparity, socioeconomic and geographical differences are important determinants of endometrial cancer incidence and mortality. Endometrial cancer is mainly categorised as type I and type II. Although less prevalent, type II is the most aggressive form of the disease and typically diagnosed at a late stage, contributing to higher mortality. Black women are at higher risk of developing aggressive, type II disease. Type I tumours are related to higher levels of circulating estrogen with lower-grade tumours that have a good prognosis and frequently related to PTEN mutations. In comparison, type II tumours are estrogen-independent, typically have poor prognosis and associated with the p53, HER2, PPP2R1A, FBXW7 and PIK3R1 mutations. The risk of developing type II malignancy is higher in women with Lynch syndrome as a result of mutations in the MMR gene family. Genetic modifications contribute to aberrant alternative splicing events that are related to tumour development, progression and resistance to therapy. Alternative splicing events are rapidly emerging as potential biomarkers and therapeutic targets. Type II endometrial cancer lacks targeted therapy and biomarkers for novel therapeutic strategies. Recent advances have illustrated a number of molecular targets that are currently explored for the treatment of advanced, late-stage endometrial cancer. The aim of this review is to outline 1) the epidemiology of type II endometrial cancer in black women, 2) discuss the correlated risk factors that contribute to the development of type II endometrial cancer and 3) the associated molecular mechanisms and genetic factors underlying the disease, and 4) aberrant splicing events and biomarkers with therapeutic potential as novel drug targets.

ALKBH5 regulates IGF1R expression to promote the Proliferation and Tumorigenicity of Endometrial Cancer

N6-methyladenosine (m6A) messenger RNA methylation play important role in cell proliferation and tumorigenicity of endometrial cancer, but the key mechanism is not fully clear. Here, we found that RNA demethylase ALKBH5 expression was significantly upregulated in endometrial cancer, ALKBH5 was then identified to positively regulate proliferation and invasion of endometrial cancer. Mechanistically, the m6A eraser ALKBH5 demethylated target transcripts IGF1R and enhanced IGF1R mRNA stability, consequently promoting IGF1R translation and activating IGF1R signaling pathway. Thus, we demonstrated that ALKBH5 promoted proliferation and invasion of endometrial cancer via erasing IGF1R m6A-modifications, which suggests a potential therapeutic target for endometrial cancer.

Effects of Lactobacillus acidophilus and Bifidobacterium bifidum Probiotics on the Expression of MicroRNAs 135b, 26b, 18a and 155, and Their Involving Genes in Mice Colon Cancer

A wide range of sources supports that the link between diet and colorectal cancer may be due to an imbalance of the intestinal microflora. In this case, it seems that the probiotics may have a possible molecular mechanism via microRNAs (miRNAs). The present study is aimed to evaluate the effects of Lactobacillus acidophilus and Bifidobacterium bifidum probiotics on the expression of miRNAs 135b, 26b, 18a, and 155 and their target genes, including APC, PTEN, KRAS, and PU.1 in mouse azoxymethane (AOM)-induced colon cancer. Thirty-eight male BALB/c mice were randomly divided into four groups: the control, AOM, Lactobacillus acidophilus, and Bifidobacterium bifidum to deliberate the effects of the probiotics on the miRNAs and their target genes. Except for the control group, the rest groups were weekly given AOM (15 mg/kg, s.c) in three consecutive weeks to induce mouse colon cancer. The animals were given 1.5 g powders of L. acidophilus (1 × 10⁹ cfu/g) and B. bifidum (1 × 10⁹ cfu/g) in 30 cc drinking water in the related groups for 5 months. At the end of the study, the animals were sacrificed and their blood and colon samples were removed for the molecular analyses. The results showed that the expression of the miR-135b, miR-155, and KRAS was increased in the AOM group compared to the control group in both the plasma and the colon tissue samples, and the consumption of the probiotics decreased their expression. Moreover, the miR-26b, miR-18a, APC, PU.1, and PTEN expressions were decreased in the AOM group compared to the control group and the consumption of the probiotics increased their expressions. It seems that Lactobacillus acidophilus and Bifidobacterium bifidum though increasing the expression of the tumor suppressor miRNAs and their target genes and decreasing the oncogenes can improve colon cancer treatment.

Machine Learning Supports Long Noncoding RNAs as Expression Markers for Endometrial Carcinoma

Uterine corpus endometrial carcinoma (UCEC) is the second most common type of gynecological tumor. Several research studies have recently shown the potential of different ncRNAs as biomarkers for prognostics and diagnosis in different types of cancers, including UCEC. Thus, we hypothesized that long noncoding RNAs (lncRNAs) could serve as efficient factors to discriminate solid primary (TP) and normal adjacent (NT) tissues in UCEC with high accuracy. We performed an in silico differential expression analysis comparing TP and NT from a set of samples downloaded from the Cancer Genome Atlas (TCGA) database, targeting highly differentially expressed lncRNAs that could potentially serve as gene expression markers. All analyses were performed in R software. The receiver operator characteristics (ROC) analyses and both supervised and unsupervised machine learning indicated a set of 14 lncRNAs that may serve as biomarkers for UCEC. Functions and putative pathways were assessed through a coexpression network and target enrichment analysis.

Pyruvate Kinase M2 Expression: A Potential Metabolic Biomarker to Differentiate Endometrial Precancer and Cancer That Is Associated with Poor Outcomes in Endometrial Carcinoma

Background: Pyruvate kinase M2 (PKM2) is a regulator of the processes of glycolysis and oxidative phosphorylation, but the roles that it plays in endometrial cancer remain largely unknown. This study evaluated the PKM2 expression in normal endometrium, endometrial hyperplasia, and endometrial carcinoma, and its prognostic value was investigated in endometrial carcinoma patients. Methods: A hospital-based retrospective review was conducted to examine the immunohistochemical PKM2 distribution in 206 endometrium samples from biopsies or hysterectomies. The immunoreactivity of PKM2 was divided into groups of low and high scores according to the extent and intensity of staining. Results: Intense cytoplasmic staining was observed for the PKM2 protein in malignant endometrial lesions. A high PKM2 score was observed in many endometrial carcinoma samples (50.0%), but there was a low percentage in endometrial atypical hyperplasia (12.5%). High PKM2 expression was not found in the normal endometrium (0.0%) nor endometrial hyperplasia without atypia (0.0%). The PKM2 protein score was significantly higher in endometrial carcinoma samples than premalignant endometrial lesions (p < 0.001). Notably, higher PKM2 scores in cases of endometrial carcinoma correlated with poor overall survival (p = 0.006), and the hazard ratio for death was 3.40 (95% confidence interval, 1.35–8.56). Conclusions: Our results indicate that the prevalence of PKM2^high tumor cells in endometrial carcinoma is significantly associated with worse prognostic factors and favors a poor prognosis. The expression of PKM2 is also a potential histopathological biomarker for use in the differential diagnosis of malignant and premalignant endometrial lesions.

Cervical, Ovarian and Endometrial Tumor Markers: Potential Clinical Value

Tumors markers can be described as molecular products expressed by neoplasia tissues (immunohistochemistry), or metabolized and secreted by tumor and characterized biochemically in body fluids such as blood and urine. They may have utility as indicators of tumor stage and grade as well useful for monitoring responses to treatment and predicting recurrence, progression, development of metastases, or even patient survival. Unfortunately, in some cases they may have no identified clinical potential. Several investigations have been carried out, especially in the last decade, using biotechnological methods, in order to identify new potential tumor markers. By translating these findings into clinical use one may facilitate accurate diagnosis and prognostic prediction, and contribute to individualized treatment. The objective of this review is to describe some biomarkers with potential use in clinical settings of uterine cervix, ovary, and endometrium carcinomas.

Potential new biomarkers for endometrial cancer

BACKGROUND

Incidence of endometrial cancer are rising both in the United States and worldwide. As endometrial cancer becomes more prominent, the need to develop and characterize biomarkers for early stage diagnosis and the treatment of endometrial cancer has become an important priority. Several biomarkers currently used to diagnose endometrial cancer are directly related to obesity. Although epigenetic and mutational biomarkers have been identified and have resulted in treatment options for patients with specific aberrations, many tumors do not harbor those specific aberrations. A promising alternative is to determine biomarkers based on differential gene expression, which can be used to estimate prognosis.

METHODS

We evaluated 589 patients to determine differential expression between normal and malignant patient samples. We then supplemented these evaluations with immunohistochemistry staining of endometrial tumors and normal tissues. Additionally, we used the Library of Integrated Network-based Cellular Signatures to evaluate the effects of 1826 chemotherapy drugs on 26 cell lines to determine the effects of each drug on HPRT1 and AURKA expression.

RESULTS

Expression of HPRT1, Jag2, AURKA, and PGK1 were elevated when compared to normal samples, and HPRT1 and PGK1 showed a stepwise elevation in expression that was significantly related to cancer grade. To determine the prognostic potential of these genes, we evaluated patient outcome and found that levels of both HPRT1 and AURKA were significantly correlated with overall patient survival. When evaluating drugs that had the most significant effect on lowering the expression of HPRT1 and AURKA, we found that Topo I and MEK inhibitors were most effective at reducing HPRT1 expression. Meanwhile, drugs that were effective at reducing AURKA expression were more diverse (MEK, Topo I, MELK, HDAC, etc.). The effects of these drugs on the expression of HPRT1 and AURKA provides insight into their role within cellular maintenance.

CONCLUSIONS

Collectively, these data show that JAG2, AURKA, PGK1, and HRPT1 have the potential to be used independently as diagnostic, prognostic, or treatment biomarkers in endometrial cancer. Expression levels of these genes may provide physicians with insight into tumor aggressiveness and chemotherapy drugs that are well suited to individual patients.

High throughput silencing identifies novel genes in endometrioid endometrial cancer

OBJECTIVE

To validate the gene expression profile obtained from the previous microarray analysis and to further study the biological functions of these genes in endometrial cancer. From our previous study, we identified 621 differentially expressed genes in laser-captured microdissected endometrioid endometrial cancer as compared to normal endometrial cells. Among these genes, 146 were significantly up-regulated in endometrial cancer.

MATERIALS AND METHODS

A total of 20 genes were selected from the list of up-regulated genes for the validation assay. The qPCR confirmed that 19 out of the 20 genes were up-regulated in endometrial cancer compared with normal endometrium. RNA interference (RNAi) was used to knockdown the expression of the upregulated genes in ECC-1 and HEC-1A endometrial cancer cell lines and its effect on proliferation, migration and invasion were examined.

RESULTS

Knockdown of MIF, SOD2, HIF1A and SLC7A5 by RNAi significantly decreased the proliferation of ECC-1 cells (p < 0.05). Our results also showed that the knockdown of MIF, SOD2 and SLC7A5 by RNAi significantly decreased the proliferation and migration abilities of HEC-1A cells (p < 0.05). Moreover, the knockdown of SLC38A1 and HIF1A by RNAi resulted in a significant decrease in the proliferation of HEC1A cells (p < 0.05).

CONCLUSION

We have identified the biological roles of SLC38A1, MIF, SOD2, HIF1A and SLC7A5 in endometrial cancer, which opens up the possibility of using the RNAi silencing approach to design therapeutic strategies for treatment of endometrial cancer.

Pir2/Rnf144b is a potential endometrial cancer biomarker that promotes cell proliferation

Endometrial cancer is one of the most common gynaecological cancers in developed countries. Its incidence has increased 20% over the last decade and the death rate has increased >100% over the past two decades. Current models for prediction of prognosis and treatment response are suboptimal, and as such biomarkers to support clinical decision-making and contribute to individualised treatment are needed. In this study, we show that the E3-ubiquitin ligase PIR2/RNF144B is a potential targetable biomarker in endometrial cancer. At transcript level, it is expressed both in normal endometrium and tumour samples, but at protein level, it is expressed in tumours only. By using endometrial cancer cell lines, we demonstrated that PIR2/RNF144B is stabilised via phosphorylation downstream of GSK3β and this is necessary for the proliferation of endometrial cancer cells, in the absence of oestrogenic growth stimuli. Here, inactivation of GSK3β activity is associated with loss of PIR2/RNF144B protein and consequent inhibition of cell proliferation. Our results, therefore, substantiate PIR2/RNF144B as a novel candidate for targeted therapy in endometrial cancer.

A novel lncRNA-focus expression signature for survival prediction in endometrial carcinoma

Background

Endometrial cancer (UCEC) is a complex malignant tumor characterized by both genetic level and clinical trial. Patients with UCEC exhibit the similar clinical features, however, they have distinct outcomes due to molecular heterogeneity. The aim of this study was to access the prognostic value of long non-coding RNAs (lncRNAs) in UCEC patients and to identify potential lncRNA signature for predicting patients’ survival and improving patient-tailored treatment.

Methods

We performed a comprehensive genome-wide analysis of lncRNA expression profiles and clinical data in a large cohort of 301 UCEC patients. UCEC patients were randomly divided into the discovery cohort (n = 150) and validation cohort (n = 151). A novel lncRNA-focus expression signature was identified in the discovery cohort, and independently accessed in the validation cohort. Additionally, the lncRNA signature was evaluated by multivariable Cox regression and stratification analysis as well as functional enrichment analysis.

Results

We detected a novel lncRNA-focus expression signature (LFES) consisting of 11 lncRNAs that were associated with survival based on risk scoring strategy in UCEC. The risk score based on the LFES was able to separate patients of discovery cohort into high-risk and low-risk groups with significantly different overall survival and progression-free survival, and has been successfully confirmed in the validation cohort. Furthermore, the LFES is an independent prognostic predictor of survival and demonstrates superior prognostic performance compared with the clinical covariates for predicting 5-year survival (AUC = 0.887). Functional analysis has linked the expression of prognostic lncRNAs to well-known tumor suppressor or ontogenetic pathways in endometrial carcinogenesis.

Conclusions

Our study revealed a novel 11-lncRNA signature to predict survival of UCEC patient. This lncRNA signature may be a valuable and alternative marker for risk evaluation to aid patient-tailored treatment and improve the outcome of patients with UCEC.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3983-0) contains supplementary material, which is available to authorized users.

FoxM1: Repurposing an oncogene as a biomarker

The past few decades have witnessed a tremendous progress in understanding the biology of cancer, which has led to more comprehensive approaches for global gene expression profiling and genome-wide analysis. This has helped to determine more sophisticated prognostic and predictive signature markers for the prompt diagnosis and precise screening of cancer patients. In the search for novel biomarkers, there has been increased interest in FoxM1, an extensively studied transcription factor that encompasses most of the hallmarks of malignancy. Considering the attractive potential of this multifarious oncogene, FoxM1 has emerged as an important molecule implicated in initiation, development and progression of cancer. Bolstered with the skill to maneuver the proliferation signals, FoxM1 bestows resistance to contemporary anti-cancer therapy as well. This review sheds light on the large body of literature that has accumulated in recent years that implies that FoxM1 neoplastic functions can be used as a novel predictive, prognostic and therapeutic marker for different cancers. This assessment also highlights the key features of FoxM1 that can be effectively harnessed to establish FoxM1 as a strong biomarker in diagnosis and treatment of cancer.

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.

Uterine Carcinosarcoma and High-Risk Endometrial Carcinomas: A Clinicopathological Comparison

Objective

This retrospective study aimed to evaluate the clinicopathological characteristics of carcinosarcoma, grade 3 endometrial endometrioid carcinoma (G3EEC), uterine serous carcinoma (USC), and uterine clear cell adenocarcinoma (CC) to determine whether carcinosarcoma exhibited the same characteristics and outcomes as the other 3 high-risk endometrial cancers.

Methods

A total of 358 patients recruited from the Obstetrics and Gynecology Hospital of Fudan University were included in this study; the cases included 44 carcinosarcomas, 118 G3EECs, 118 USCs, and 78 CCs. Kaplan-Meier and Cox proportional hazards models were used to analyze outcomes and prognostic factors.

Results

Uterine carcinosarcomas had significantly worse outcomes (overall survival, disease-specific survival, and recurrence-free survival) compared with G3EEC, USC, and CC (P< 0.001), whereas the other 3 shared similar outcomes. Carcinosarcoma type was an independent factor, even stratified by stage. Eighty-three percent of recurred carcinosarcoma patients occurred within 1 year. Compared with USC and CC, patients with carcinosarcoma had a greater incidence of deep myometrial invasion (55.8%,P <0.05) and cervical stromal involvement (P= 0.046). The carcinomatous regions of carcinosarcomas demonstrated a similar ER/P53 expression pattern as did USC and CC. However, all features were similar in carcinosarcoma and G3EEC patients, although the P53-positive rate was higher in carcinosarcoma patients compared with G3EEC patients (59.0% vs 38.5%,P= 0.037). For carcinosarcomas, a multivariate analysis showed that advanced stage (P= 0.006) was an independent prognostic factor for disease-specific survival. With regard to endometrioid-or-not epithelial and heterologous-or-homologous sarcomatous components, none of these components demonstrated apparent relationship with prognosis.

Conclusions

Carcinosarcomas exhibited significantly poorer outcomes than did G3EECs, USCs, and CCs. Therefore, it seems reasonable to regard carcinosarcomas as a particular type among high-risk epithelial endometrial carcinomas.

MicroRNA expression in human endometrial adenocarcinoma

Background

MicroRNAs are small non-coding RNAs that play crucial roles in the pathogenesis of different cancer types. The aim of this study was to identify miRNAs that are differentially expressed in endometrial adenocarcinoma compared to healthy endometrium. These miRNAs can potentially be used to develop a panel for classification and prognosis in order to better predict the progression of the disease and facilitate the choice of treatment strategy.

Methods

Formalin fixed paraffin embedded endometrial tissue samples were collected from the Örebro university hospital. QPCR was used to quantify the expression levels of 742 miRNAs in 30 malignant and 20 normal endometrium samples. After normalization of the qPCR data, miRNAs differing significantly in expression between normal and cancer samples were identified, and hierarchical clustering analysis was used to identify groups of miRNAs with coordinated expression profiles.

Results

In comparisons between endometrial adenocarcinoma and normal endometrium samples 138 miRNAs were found to be significantly differentially expressed (p < 0.001) among which 112 miRNAs have not been previous reported for endometrial adenocarcinoma.

Conclusion

Our study shows that several miRNAs are differentially expressed in endometrial adenocarcinoma. These identified miRNA hold great potential as target for classification and prognosis of this disease. Further analysis of the differentially expressed miRNA and their target genes will help to derive new biomarkers that can be used for classification and prognosis of endometrial adenocarcinoma.

Electronic supplementary material

The online version of this article (doi:10.1186/s12935-014-0088-6) contains supplementary material, which is available to authorized users.

Lack of association between deficient mismatch repair expression and outcome in endometrial carcinomas of the endometrioid type

OBJECTIVE

Endometrial carcinomas of the endometrioid type (EEC) are associated with a good prognosis. However, about 20% of them recur and new prognostic markers are needed. Microsatellite instability (MSI), associated with mismatch repair (MMR) deficiency, is a frequent alteration in EECs that has been associated with prognosis. However, its prognostic impact on EECs remains unclear. The aim of the present study was to clarify the relationship between MMR deficiency and outcome in a large cohort of well classified EECs.

METHODS

A total of 212 EEC samples were analyzed by immunohistochemistry for the MMR genes MLH-1, MSH-2, MSH-6 and PMS-2. Kaplan-Meier survival analysis and log-rank tests were performed to study the prognostic significance of dMMR taking into account clinical and pathological parameters.

RESULTS

We observed no association between MMR deficiency and OS or PFS in our 212 EEC patients (p-value=0.6565 and 0.4380, respectively). When we performed the analysis in different FIGO-stage groups, we did not find association between MMR and OS or PFS in stages I, I/II or III/IV. When we analyzed the specific group of patients with lymphatic invasion separately, MMR expression was not associated with OS or PFS either.

CONCLUSIONS

MMR deficiency does not seem to be a good prognostic marker in endometrioid type endometrial carcinomas.

The IGF Hormonal Network in Endometrial Cancer: Functions, Regulation, and Targeting Approaches

Epidemiological as well as clinical and experimental data identified the insulin-like growth factors (IGF1, IGF2) as important players in gynecological cancers in general, and endometrial tumors in particular. The IGF1 receptor (IGF1R), which mediates the proliferative and anti-apoptotic activities of both ligands, emerged in recent years as a promising therapeutic target in oncology. However, most clinical trials conducted so far led to mixed results, emphasizing the need to identify biomarkers that can predict responsiveness to anti-IGF1R-targeted therapies. This article will review recent data regarding the role and expression of IGF system components in endometrial cancer. In addition, we will review data on the interplay between the IGF signaling pathway and tumor suppressors p53 and breast cancer susceptibility gene-1 (BRCA1). Anti-oncogenes p53 and BRCA1 play a key role in the etiology of gynecological cancers and, therefore, their interaction with IGF1R is of high relevance in translational terms. A better understanding of the complex mechanisms underlying the regulation of the IGF system will improve our ability to develop effective treatment modalities for endometrial tumors.

Candidate biomarkers for genetic and clinicopathological diagnosis of endometrial cancer

The recent increase in the frequency of endometrial cancer has emphasized the need for accurate diagnosis and improved treatment. The current diagnosis is still based on conventional pathological indicators, such as clinical stage, tumor differentiation, invasion depth and vascular invasion. However, the genetic mechanisms underlying endometrial cancer have gradually been determined, due to developments in molecular biology, leading to the possibility of new methods of diagnosis and treatment planning. New candidate biomarkers for endometrial cancer include those for molecular epigenetic mutations, such as microRNAs. These biomarkers may permit earlier detection of endometrial cancer and prediction of outcomes and are likely to contribute to future personalized therapy for endometrial cancer.

IGF1R-directed targeted therapy enhances the cytotoxic effect of chemotherapy in endometrial cancer

This study evaluated the potential ability of MK-0646 to inhibit IGF1-mediated biological actions and cell signaling events in Type 1 and Type 2 endometrial cancer. We found that MK-0646 treatment significantly decreased IGF1R expression. In addition, pretreatment with MK-0646 decreased the IGF1-induced phosphorylation of IGF1R, AKT and ERK. Apoptosis analyses showed that MK-0646 abolished the anti-apoptotic effect of IGF1. Furthermore, MK-0646 treatment abolished the IGF1-stimulatory effect on proliferation and enhanced the cytotoxic effect of cisplatin. These findings indicate that specific inhibition of IGF1R could be a useful therapeutic approach for Type 1 and Type 2 endometrial cancer.