Dysregulation of miR-181c expression influences recurrence of endometrial endometrioid adenocarcinoma by modulating NOTCH2 expression: An NRG Oncology/Gynecologic Oncology Group study

Integration of Genomic and Clinical Retrospective Data to Predict Endometrioid Endometrial Cancer Recurrence

Endometrial cancer (EC) incidence and mortality continues to rise. Molecular profiling of EC promises improvement of risk assessment and treatment selection. However, we still lack robust and accurate models to predict those at risk of failing treatment. The objective of this pilot study is to create models with clinical and genomic data that will discriminate patients with EC at risk of disease recurrence. We performed a pilot, retrospective, case−control study evaluating patients with EC, endometrioid type: 7 with recurrence of disease (cases), and 55 without (controls). RNA was extracted from frozen specimens and sequenced (RNAseq). Genomic features from RNAseq included transcriptome expression, genomic, and structural variation. Feature selection for variable reduction was performed with univariate ANOVA with cross-validation. Selected variables, informative for EC recurrence, were introduced in multivariate lasso regression models. Validation of models was performed in machine-learning platforms (ML) and independent datasets (TCGA). The best performing prediction models (out of >170) contained the same lncRNA features (AUC of 0.9, and 95% CI: 0.75, 1.0). Models were validated with excellent performance in ML platforms and good performance in an independent dataset. Prediction models of EC recurrence containing lncRNA features have better performance than models with clinical data alone.

Can miRNAs be useful biomarkers in improving prognostic stratification in endometrial cancer patients? An update review

Endometrial cancer (EC) is the most common gynecological cancer, with annual incidence rates in Western countries ranging between 15 and 25 per 100 000 women. About 15% to 20% of patients with EC have high-risk disease and follow an aggressive clinical course. Unfortunately, the assessment of histologic parameters is poorly reproducible and conventional clinicopathological and molecular features do not reliably predict either the patient's response to the available treatments or the definition of personalized therapeutic approaches. In this context, the identification of novel diagnostic and prognostic biomarkers, which can be integrated in the current classification schemes, represents an unmet clinical need and an important challenge. miRNAs are key players in cancer by regulating the expression of specific target genes. Their role in EC, in association with clinical and prognostic tumor biomarkers, has been investigated but, so far, with little consensus among the studies. The present review aims to describe the recent advances in miRNAs research in EC taking into consideration the current classification schemes and to highlight the most promising miRNAs. Finally, a perspective point of view sheds light on the challenges ahead in the landscape of EC.

Analysis of Prognostic Factors and Treatment Modes of Patients with Recurrent Endometrial Carcinoma

Objective

Recurrence of endometrial cancer after initial treatment can be complex and difficult to treat. The current main treatment modalities for patients with recurrent endometrial cancer (REC) include chemotherapy, radiotherapy, and surgery, which vary according to the individual patient. However, REC is often associated with a poor prognosis, and it is therefore important to investigate the risk factors affecting REC prognosis and to explore appropriate treatment modalities to improve the prognosis and treatment strategies for patients with REC.

Methods

Totally, 100 patients with REC admitted to our hospital from January 2013 to January 2018 were chosen to be research objects. Their pathological data were analyzed, including age, disease-free interval (DFI), recurrence site, and treatment plan after relapse (definitive local therapy (DLT) and palliative chemotherapy (PC)). According to these parameters, univariate and multivariate factors affecting the prognosis of REC patients and the curative effect of PC were analyzed, and the 3-year overall survival (OS) curve and progression-free survival (PFS) curve were drawn.

Results

After 3 years of follow-up, 30 patients had a poor prognosis and 70 had a good prognosis, according to which a single multifactorial analysis was performed for different prognoses, where the results of the single-factor analysis showed significant differences between patients with different prognoses in terms of pathomorphology, pathological grading, TFI, and treatment modality after relapse. Further multifactorial analysis showed that TFI and treatment modality after recurrence were independent factors affecting poor prognosis in REC patients. The 3-year OS and 3-year PFS of REC patients were 74.00% and 70.00%, respectively. Patients whose DFI was less than 12 months or treated with PC after relapse were notably associated with lower levels of 3-year OS and 3-year PFS. In addition, radiotherapy and chemotherapy, DFI, and chemotherapy plan after primary surgery were independent risk factors that affected the PC efficacy of REC patients.

Conclusion

DFI and treatment mode after relapse are independent factors affecting the prognosis of REC patients. DLT can obviously improve the prognosis of REC patients. For patients who can only choose PC, chemoradiotherapy and DFI after primary surgery are helpful to predict the chemotherapy effect, and the combination of paclitaxel and platinum drugs should be the first choice for chemotherapy.

Non-Coding RNAs as Prognostic Markers for Endometrial Cancer

Endometrial cancer (EC) has been classified over the years, for prognostic and therapeutic purposes. In recent years, classification systems have been emerging not only based on EC clinical and pathological characteristics but also on its genetic and epigenetic features. Noncoding RNAs (ncRNAs) are emerging as promising markers in several cancer types, including EC, for which their prognostic value is currently under investigation and will likely integrate the present prognostic tools based on protein coding genes. This review aims to underline the importance of the genetic and epigenetic events in the EC tumorigenesis, by expounding upon the prognostic role of ncRNAs.

Small Non-Coding-RNA in Gynecological Malignancies

Gynecologic malignancies, which include cancers of the cervix, ovary, uterus, vulva, vagina, and fallopian tube, are among the leading causes of female mortality worldwide, with the most prevalent being endometrial, ovarian, and cervical cancer. Gynecologic malignancies are complex, heterogeneous diseases, and despite extensive research efforts, the molecular mechanisms underlying their development and pathology remain largely unclear. Currently, mechanistic and therapeutic research in cancer is largely focused on protein targets that are encoded by about 1% of the human genome. Our current understanding of 99% of the genome, which includes noncoding RNA, is limited. The discovery of tens of thousands of noncoding RNAs (ncRNAs), possessing either structural or regulatory functions, has fundamentally altered our understanding of genetics, physiology, pathophysiology, and disease treatment as they relate to gynecologic malignancies. In recent years, it has become clear that ncRNAs are relatively stable, and can serve as biomarkers for cancer diagnosis and prognosis, as well as guide therapy choices. Here we discuss the role of small non-coding RNAs, i.e., microRNAs (miRs), P-Element induced wimpy testis interacting (PIWI) RNAs (piRNAs), and tRNA-derived small RNAs in gynecological malignancies, specifically focusing on ovarian, endometrial, and cervical cancer.

Notch and Endometrial Cancer

The human endometrium is a unique, highly dynamic tissue that undergoes cyclic changes of cell proliferation, differentiation, and death. Endometrial cancer is the most common malignancy among women in developed countries. Importantly, the incidence of endometrial cancer is rising in high-income countries. Currently histological classification is used for subtyping of endometrial cancer, while ongoing research is evaluating markers for more accurate molecular classification. Evolutionary conserved Notch signaling pathway regulates diverse cellular processes such as proliferation, differentiation, and cell invasion. Accumulating evidence links aberrant Notch signaling with diseases such as hyperplasia and endometrial cancer. This chapter summarizes the current state of Notch signaling investigations in the endometrium, endometriosis, and endometrial cancer.

Gynecologic cancers and non-coding RNAs: Epigenetic regulators with emerging roles

Gynecologic cancers involve the female genital organs, such as the vulva, vagina, cervix, endometrium, ovaries, and fallopian tubes. The occurrence and frequency of gynecologic cancer depends on personal lifestyle, history of exposure to viruses or carcinogens, genetics, body shape, and geographical habitat. For a long time, research into the molecular biology of cancer was broadly restricted to protein-coding genes. Recently it has been realized that non-coding RNAs (ncRNA), including long noncoding RNAs (LncRNAs), microRNAs, circular RNAs and piRNAs (PIWI-interacting RNAs), can all play a role in the regulation of cellular function within gynecological cancer. It is now known that ncRNAs are able to play dual roles, i.e. can exert both oncogenic or tumor suppressive functions in gynecological cancer. Moreover, several clinical trials are underway looking at the biomarker and therapeutic roles of ncRNAs. These efforts may provide a new horizon for the diagnosis and treatment of gynecological cancer. Herein, we summarize some of the ncRNAs that have been shown to be important in gynecological cancers.

Establishment of a novel cell cycle-related prognostic signature predicting prognosis in patients with endometrial cancer

Background

Endometrial cancer (EnCa) ranks fourth in menace within women’s malignant tumors. Large numbers of studies have proven that functional genes can change the process of tumors by regulating the cell cycle, thereby achieving the goal of targeted therapy.

Methods

The transcriptional data of EnCa samples obtained from the TCGA database was analyzed. A battery of bioinformatics strategies, which included GSEA, Cox and LASSO regression analysis, establishment of a prognostic signature and a nomogram for overall survival (OS) assessment. The GEPIA and CPTAC analysis were applied to validate the dysregulation of hub genes. For mutation analysis, the “maftools” package was used.

Results

GSEA identified that cell cycle was the most associated pathway to EnCa. Five cell cycle-related genes including HMGB3, EZH2, NOTCH2, UCK2 and ODF2 were identified as prognosis-related genes to build a prognostic signature. Based on this model, the EnCa patients could be divided into low- and high-risk groups, and patients with high-risk score exhibited poorer OS. Time-dependent ROC and Cox regression analyses revealed that the 5-gene signature could predict EnCa prognosis exactly and independently. GEPIA and CPTAC validation exhibited that these genes were notably dysregulated between EnCa and normal tissues. Lower mutation rates of PTEN, TTN, ARID1A, and etc. were found in samples with high-risk score compared with that with low-risk score. GSEA analysis suggested that the samples of the low- and high-risk groups were concentrated on various pathways, which accounted for the different oncogenic mechanisms in patients in two groups.

Conclusion

The current research construct a 5-gene signature to evaluate prognosis of EnCa patients, which may innovative clinical application of prognostic assessment.

Progesterone receptor inhibits the proliferation and invasion of endometrial cancer cells by up regulating Krüppel-like factor 9

Background

Krüppel-like factor 9 (KLF9) is one of the most important members of the KLF family, and is abnormally expressed in many tumors. However, the detailed function of KLF9 in endometrial cancer (EC) was barely investigated.

Methods

In this study, a total of 52 paired EC tissues were recruited to detect the KLF9 expression. Then a serial of phenotypic experiments and mechanism researches were performed.

Results

The results showed that KLF9 expression was decreased in EC tissues, and the reduced expression of KLF9 is associated with highly metastatic capacity of EC cells. KLF9 could inhibit the proliferation and invasion of EC cells by inhibiting the Wnt/β-catenin signaling pathway. Progesterone receptor (PR) could bind to KLF9 promoter and a positive correlation between KLF9 and PR expression was witnessed.

Conclusions

Taken together, the reduction of KLF9 induced by PR might participate in the development of EC and targeting KLF9 may provide a novel strategy for EC management.

MiR-181c affects estrogen-dependent endometrial carcinoma cell growth by targeting PTEN

MicroRNAs (miRNAs), which is a type of non-coding and single-stranded small molecule RNA, bind either completely or incompletely to 3'-UTR of the target gene mRNA to inhibit mRNA translation or degradation. In our study, we aimed to explore the roles and mechanisms of miR-181c in the apoptosis of RL95-2 human endometrial carcinoma cells. Cell activity and apoptosis were detected by cell counting Kit-8 (CCK-8) assay and flow cytometry (FCM), respectively. Related mRNAs and proteins expression was determined by quantitative real-time reverse transcription PCR (qRT-PCR) and western blot assays, respectively. The binding capacity of PTEN-3'-UTR and miR-181c was assessed by luciferase reporter assay. The obtained results suggested that E2 evidently increased the cell activity of RL95-2 cells. In addition, miR-181c inhibitor suppressed the cell viability and enhanced the apoptosis capacity of E2-induced RL95-2 cells and distinctly reduced the miR-181c expression. We also found that miR-181c could bind to PTEN-3'-UTR and miR-181c inhibitor up-regulated the expression level of PTEN in E2-induced RL95-2 cells. Besides, overexpression of PTEN markedly promoted the apoptosis of E2-induced RL95-2 cells through regulating the Bax and Bcl-2 expression, and modulated the expression of AKT pathway, p53 and Cyclin D. In conclusion, our findings revealed that miR-181c affected the estrogen-dependent endometrial carcinoma cell growth by targeting PTEN. The potential effects of miR-181c on the apoptosis of E2-induced RL95-2 cells suggest that miR-181c could be an effective target for endometrial carcinoma therapies.

FAM98A promotes cancer progression in endometrial carcinoma

To investigate the expression status of FAM98A and its potential involvement in endometrial carcinoma, the relative expression of FAM98A in clinical endometrial carcinoma tissues was analyzed by immunohistochemistry and real-time polymerase chain reaction. Endogenous FAM98A protein was determined by Western blotting. The overall survival was calculated by the Kaplan-Meier's analysis. Cell growth/viability/proliferation was evaluated by cell counting, 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide assay, and clonogenic assay, respectively. Cell apoptosis was determined by the Annexin V/7-AAD double-staining methods followed by flow cytometry analysis. The regulatory effect of miR-142-3p on FAM98A was interrogated by luciferase reporter assay. Aberrant overexpression of FAM98A was found in endometrial carcinoma both in vitro and in vivo. Furthermore, high level of FMA98A was associated with poor prognosis. FAM98A deficiency in Ishikawa and RL95-2 cells significantly inhibited cell growth, cell viability, and cell proliferation. In addition, FAM98A-knockdown stimulated remarkable cell apoptosis, which might be mediated by down-regulation of BCL2 and up-regulation of BAX. Mechanistically, it was demonstrated that miR-142-3p directly targeted FAM98A, and modulated its expression. In conclusion, we unraveled the oncogenic properties of FAM98A in endometrial carcinoma and highlighted the miR-142-3p-FAM98A signaling in this disease.

The role of oncogenic Notch2 signaling in cancer: a novel therapeutic target

Deregulated Notch signaling is a key factor thought to facilitate the stem-like proliferation of cancer cells, thereby facilitating disease progression. Four subtypes of Notch receptor have been described to date, with each playing a distinct role in cancer development and progression, therefore warranting a careful and comprehensive examination of the targeting of each receptor subtype in the context of oncogenesis. Clinical efforts to translate the DAPT, which blocks Notch signaling, have been unsuccessful due to a combination of serious gastrointestinal side effects and a lack of complete blocking efficacy. There is therefore a clear need to identify better therapeutic strategies for targeting and manipulating Notch signaling. Notch2 is a Notch receptor that is commonly overexpressed in a range of cancers, and which is linked to a unique oncogenic mechanism. Successful efforts to block Notch2 signaling will depend upon doing so both efficiently and specifically in patients. As such, in the present review we will explore the role of Notch2 signaling in the development and progression of cancer, and we will assess agents and strategies with the potential to effectively disrupt Notch2 signaling and thereby yield novel cancer treatment regimens.

MicroRNA‑181c suppresses growth and metastasis of hepatocellular carcinoma by modulating NCAPG

Purpose: Numerous studies have shown that the expression of microRNA-181c (miR-181c) is inhibited in various cancers, which suggests that it has a cancer suppressive effect. In the current study, we evaluated the regulation and characteristics of miR-181c in human hepatocellular carcinoma (HCC).

Materials and methods: Samples of tumor tissues and adjacent non-tumor tissues were collected from 52 patients with HCC, and expression levels of miR-181c in these samples were investigated via quantitative real-time polymerase chain reaction. HCC cell migration and invasion were investigated via wound healing assays and transwell assays. HCC cell apoptosis rates were assessed via flow cytometry, and HCC proliferation was assessed via 5-ethynyl-20-deoxyuridine assays. In vivo tumors were initiated by subcutaneously inoculating HCC cells into nude mice. And various biomarkers were investigated via western blotting.

Results: In microarray datasets and tumor tissues, significant downregulation of miR-181c was apparent compared with non-tumorous adjacent tissues. Expression of miR-181c in HCC cells was also significantly lower than it was in normal human liver cells. miR-181c regulated the migration, invasion, apoptosis, and proliferation of HCC cell lines in vitro, and tumor development in vivo. Observations also suggest that miR-181c regulates NCAPG in HCC cells, and its expression affects cellular invasion, migration, proliferation, and apoptosis. There was a negative correlation between miR-181c expression and NCAPG in HCC tissue samples.

Conclusion: miR-181c exhibits tumor-suppression via the regulation of NCAPG levels.

A Prediction Model for Preoperative Risk Assessment in Endometrial Cancer Utilizing Clinical and Molecular Variables

The utility of comprehensive surgical staging in patients with low risk disease has been questioned. Thus, a reliable means of determining risk would be quite useful. The aim of our study was to create the best performing prediction model to classify endometrioid endometrial cancer (EEC) patients into low or high risk using a combination of molecular and clinical-pathological variables. We then validated these models with publicly available datasets. Analyses between low and high risk EEC were performed using clinical and pathological data, gene and miRNA expression data, gene copy number variation and somatic mutation data. Variables were selected to be included in the prediction model of risk using cross-validation analysis; prediction models were then constructed using these variables. Model performance was assessed by area under the curve (AUC). Prediction models were validated using appropriate datasets in The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. A prediction model with only clinical variables performed at 88%. Integrating clinical and molecular data improved prediction performance up to 97%. The best prediction models included clinical, miRNA expression and/or somatic mutation data, and stratified pre-operative risk in EEC patients. Integrating molecular and clinical data improved the performance of prediction models to over 95%, resulting in potentially useful clinical tests.

Low-volume disease in endometrial cancer: The role of micrometastasis and isolated tumor cells

Nodal assessment represents an integral part of staging procedure for endometrial cancer. The widespread diffusion of sentinel node mapping determinates a phenomenon of migration from stage I to stage III disease, especially for low-risk endometrial cancer patients. The adoption of sentinel node mapping and pathological ultrastaging increase the detection of low volume disease (i.e., micrometastasis and isolated tumor cells), being low volume disease detected in >30% of patients with positive nodes. The prognostic role of low volume disease is discussed as well as the possible adjuvant strategies for patients diagnosed with micrometastasis and isolated tumor cells. The role of further prospective treatments in endometrial cancer, including molecular and genetic profiling, is critically reviewed.

MicroRNA-449a Inhibits Tumor Metastasis through AKT/ERK1/2 Inactivation by Targeting Steroid Receptor Coactivator (SRC) in Endometrial Cancer

Endometrial cancer represents the leading frequency in gynecological malignancy in developed countries. Even with early detection, metastasis and recurrence remain the main reasons for a high death rate. MicroRNA-449a (miR-449a) has been reported to function as a tumor suppressor, yet the role of miR-449a in endometrial cancer metastasis has not been investigated. The present study identified that miR-449a was downregulated in advanced endometrial cancer. Overexpression of miR-449a decreased the migration and invasion of KLE and AN3CA endometrial cancer cells. Using luciferase reporter assays, we identified that miR-449a directly targeted the steroid receptor coactivator (SRC) by binding to sites in the 3' untranslated regions. Elevated expressions of SRC have been witnessed in advanced endometrial cancer tissues and have promoted tumor metastasis. We also identified that the suppressive effect of miR-449a on metastasis could be mediated by downregulating SRC and that miR-449a could suppress AKT and ERK1/2 pathway activation in endometrial cancer cells. These findings contribute to the current understanding of the function of miR-449a in endometrial cancer.

Mismatch repair deficiency and aberrations in the Notch and Hedgehog pathways are of prognostic value in patients with endometrial cancer

The aim of this study was to investigate the prognostic value of the Hedgehog (Gli, Patched-1, Shh, Smo) and Notch (Jag1, Notch2, Notch3) pathway members, in comparison to a panel of proteins (ER, PgR, HER2/neu, Ki67, p53, p16, PTEN and MMR) previously suggested to be involved in the pathogenesis of endometrial cancer, in association with clinical outcome and standard clinicopathological characteristics. A total of 204 patients with histological diagnosis of endometrial cancer treated from 2004 to 2013 were included. The evaluation of protein expression was assessed by immunohistochemistry. Univariate analysis showed that higher Ki67 labeling, expression of PTEN, p16, Notch2 and Notch3 proteins, as well as MMR proficiency were associated with increased relapse and mortality rate. Additionally, Patched-1 protein expression was associated with worse DFS, while p53 overexpression was associated with worse OS. In multivariate analyses, patients with MMR proficient tumors had more than double risk for death than patients with MMR deficient (MMRd) tumors (adjusted HR = 2.19, 95% CI 1.05–4.58, p = 0.036). Jag1 positivity conferred reduced mortality risk (HR = 0.48, 95% CI 0.23–0.97, p = 0.042). However, as shown by hierarchical clustering, patients fared better when their tumors expressed high Jag1 protein in the absence of Notch2 and Notch3, while they fared worse when all three proteins were highly expressed. Patched-1 positivity conferred higher risk for relapse (HR = 2.04, 95% CI 1.05–3.96, p = 0.036).

Aberrant expression of key components of the Notch and Hedgehog signaling pathways, as well as MMRd may serve as independent prognostic factors for recurrence and survival in patients with endometrial cancer.

Identification of key pathways and genes in endometrial cancer using bioinformatics analyses

Endometrial cancer (EC) is one of the most common gynecological cancer types worldwide. However, to the best of our knowledge, its underlying mechanisms remain unknown. The current study downloaded three mRNA and microRNA (miRNA) datasets of EC and normal tissue samples, GSE17025, GSE63678 and GSE35794, from the Gene Expression Omnibus to identify differentially expressed genes (DEGs) and miRNAs (DEMs) in EC tumor tissues. The DEGs and DEMs were then validated using data from The Cancer Genome Atlas and subjected to gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis. STRING and Cytoscape were used to construct a protein-protein interaction network and the prognostic effects of the hub genes were analyzed. Finally, miRecords was used to predict DEM targets and an miRNA-gene network was constructed. A total of 160 DEGs were identified, of which 51 genes were highly expressed and 100 DEGs were discovered from the PPI network. Three overlapping genes between the DEGs and the DEM targets, BIRC5, CENPF and HJURP, were associated with significantly worse overall survival of patients with EC. A number of DEGs were enriched in cell cycle, human T-lymphotropic virus infection and cancer-associated pathways. A total of 20 DEMs and 29 miRNA gene pairs were identified. In conclusion, the identified DEGs, DEMs and pathways in EC may provide new insights into understanding the underlying molecular mechanisms that facilitate EC tumorigenesis and progression.

Non-Coding RNAs in Endometrial Physiopathology

The Human Genome Project led to the discovery that about 80% of our DNA is transcribed in RNA molecules. Only 2% of the human genome is translated into proteins, the rest mostly produces molecules called non-coding RNAs, which are a heterogeneous class of RNAs involved in different steps of gene regulation. They have been classified, according to their length, into small non-coding RNAs and long non-coding RNAs, or to their function, into housekeeping non-coding RNAs and regulatory non-coding RNAs. Their involvement has been widely demonstrated in all cellular processes, as well as their dysregulation in human pathologies. In this review, we discuss the function of non-coding RNAs in endometrial physiology, analysing their involvement in embryo implantation. Moreover, we explore their role in endometrial pathologies such as endometrial cancer, endometriosis and chronic endometritis.