Endometrial Cancer Progression Research Articles

NEDD4 Knockdown Suppresses Human Endometrial Stromal Cell Growth and Invasion by Regulating PTGS2-Mediated Ferroptosis in Endometriosis.

Endometriosis (EM) is a gynecological disease characterized by the benign growth of endometrial tissue outside the uterus. Upregulation of neuronally expressed developmentally downregulated 4 (NEDD4) has been reported to accelerate endometrial cancer progression. We explored whether abnormal expression of NEDD4 is correlated with EM. Endometrial tissue in patients without endometriosis was used to develop the original generation of endometrial stromal cells (ESCs). Different types of endometrial tissue of patients with endometriosis were used to measure the expression of NEDD4 by immunohistochemistry (IHC) and western blotting. Its biological functions in ESCs were investigated using a cell counting kit-8 assay, fluorescein diacetate (FDA) staining, and Transwell invasion assays. Additionally, its involvement in ferroptosis was assessed by measuring Fe2+, malondialdehyde (MDA), glutathione (GSH), and reactive oxygen species (ROS) levels and the expression of ferroptosis markers. Compared with normal controls, NEDD4 levels were significantly elevated in the endometrial tissue of patients with EM. Furthermore, NEDD4 expression was higher in the ectopic endometrium than in the eutopic endometrium. NEDD4 knockdown reduced the viability and invasive capacity of ESCs, increased Fe2+, MDA, and ROS levels, and decreased GSH content. Further analysis revealed that NEDD4 knockdown promoted ferroptosis in ESCs by increasing the expression of prostaglandin-endoperoxide synthase 2 (PTGS2). As an E3 ubiquitin ligase, NEDD4 reduced PTGS2 protein levels by accelerating its ubiquitination and subsequent proteasomal degradation. These findings suggest that inhibiting NEDD4 reduces ESC growth and invasion in EM by regulating PTGS2-dependent ferroptosis.

The causal relationship between anti-CD20 antibodies and endometrial cancer: a Mendelian randomization study

PurposeTo determine the effects of anti-B cell surface marker CD20 antibody on the occurrence and progression of endometrial cancer to provide insights into clinical treatment in the future.MethodsWe performed a two-sample Mendelian randomization analysis (MR) to analyze the causal relationship between EC and immune cell markers. The genome-wide association study (GWAS) data of MS4A1 single nucleotide polymorphism encoding gene of CD20 were collected, and a drug target MR analysis was performed to detect the causal relationship between anti-CD20 antibody and the risk of EC. The risk of follicular lymphoma was used as a positive control, and EC was used as the outcome.ResultsEC exerted an effect on 28 immunophenotypes, predominantly on CD20. CD20 in immunoglobulin D+ CD38− B cells, memory B cells, and unsw memory B cells increased after EC onset. In addition, we detected one immunophenotype that exerted a dangerous effect on EC, i.e., CD3/TD CD4+ (mature stage of the T cell group). Simultaneously, CD20 could be used as both a risk factor and a protective factor for EC (P > 0.05). Anti-CD20 antibodies significantly reduced the risk of follicular lymphoma, including two GWAS pooled datasets. In addition, anti-CD20 antibodies exerted a protective effect on EC in two GWAS pooled datasets (P > 0.05).ConclusionOur study confirms the close relationship between CD20 and EC. Anti-CD20 antibodies may exert a protective effect on EC and reduce the risk of EC morbidity, providing a reference for future clinical diagnosis and treatment. However, further clinical verification of our results is warranted.

The relationship between metabolic syndrome and survival of patients with endometrial cancer: a meta-analysis.

Metabolic syndrome (MetS) is associated with a high risk of endometrial cancer (EC). However, its impact on EC progression remains unclear. This meta-analysis examined the association between MetS and survival outcomes in EC patients. A comprehensive search of PubMed, EMBASE, and Web of Science databases up to May 22, 2024, was conducted. Two independent reviewers performed study selection, data extraction, and quality assessment. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using a random effects model. Nine studies comprising 13,579 endometrial cancer (EC) patients were included. Among these, 2,896 patients (21.3%) had MetS at the time of enrollment. The follow-up durations ranged from 3.4 to 14.2 years. The results showed that EC patients with MetS at baseline demonstrated significantly poorer overall survival (HR = 1.57, 95% CI = 1.19-2.07, p = 0.002; I2 = 25%) and progression-free survival (HR = 1.33, 95% CI = 1.08-1.63, p = 0.007; I2 = 16%). A similar association was observed for cancer-specific survival (HR = 1.26, 95% CI = 1.10-1.44, p = 0.001; I2 = 0%). Subgroup analyses based on study characteristics showed consistent results across studies conducted in countries with different follow-up durations. This meta-analysis suggests that MetS is associated with poor survival outcomes in EC patients. Further prospective studies are required to validate our findings. PROSPERO, identifier CRD42024561654.

E2F1-induced upregulation of TROAP contributes to endometrial cancer progression.

To investigate the role of Trophinin-associated protein (TROAP) in endometrial cancer (EC) progression and elucidate how the transcription factor E2F transcription factor 1 (E2F1) modulates EC by upregulating TROAP expression. TROAP expression in EC tissues and cell lines was analyzed using bioinformatics databases, quantitative real-time polymerase chain reaction (qRT-PCR), western blot, and immunohistochemistry. TROAP was knocked down in EC cells to assess its effects on proliferation, migration, invasion, and glycolysis. Potential transcription factors regulating TROAP were identified, and the relationship between E2F1 and TROAP gene regulation was examined using dual luciferase assay. In vivo tumor growth was evaluated using a mouse xenograft model. TROAP was overexpressed in EC tissues and cell lines compared with normal controls. High TROAP expression correlated with poor differentiation, advanced stage, lymph node metastasis, and worse overall survival in EC patients. Knockdown of TROAP inhibited the proliferation, migration, invasion, and glycolytic capacity of EC cells. E2F1 was identified as a transcriptional activator of TROAP. E2F1 overexpression enhanced TROAP expression and promoted EC cell proliferation, migration, and glycolysis in a TROAP-dependent manner. TROAP knockdown suppressed tumor growth in vivo. TROAP is transcriptionally activated by E2F1 and promotes EC progression by enhancing cell proliferation, metastasis, and glycolysis. The E2F1-TROAP axis may serve as a potential therapeutic target for EC treatment.

Deciphering the role of SAMHD1 in endometrial cancer progression

BackgroundEndometrial cancer (EC) presents significant clinical challenges due to its heterogeneity and complex pathophysiology. SAMHD1, known for its role as a deoxynucleotide triphosphate triphosphohydrolase, has been implicated in the progression of various cancers, including EC. This study focuses on elucidating the role of SAMHD1 in EC through its impact on TRIM27-mediated PTEN ubiquitination.ResultsUtilizing a combination of bioinformatics and cellular biology techniques, we investigated the interactions among SAMHD1, TRIM27, and PTEN. Our findings reveal that SAMHD1 modulates PTEN ubiquitination via TRIM27, impacting key pathways involved in EC pathogenesis. These interactions suggest a critical mechanism by which SAMHD1 could influence tumor behavior and progression in EC.ConclusionsThe results from this study underscore the potential of targeting the SAMHD1-TRIM27-PTEN axis as a therapeutic strategy in EC. By providing new insights into the molecular mechanisms underlying EC progression, our research supports the development of novel therapeutic approaches that could contribute to improve treatment strategies for patients with EC.

Clinical Value Evaluation of SKA3 in Endometrial Cancer and Its Promotion of Proliferation and Migration of Endometrial Cancer Cells

Background: Endometrial cancer is one of the common cancers in gynecology, which seriously endangers women’s reproductive health. Therefore, it is urgent to search for new diagnostic and prognostic monitoring markers for endometrial cancer. This study aimed to explore the clinical significance and biological role of spindle and kinetochore-associated complex subunit 3 (SKA3) in endometrial cancer. Methods: Weighted gene co-expression network analysis (WGCNA) and identification of differentially expressed genes (DEGs) were conducted to identify the key gene in endometrial cancer. The clinical significance of SKA3 within endometrial cancer was assessed through receiver operating characteristic (ROC) and Kaplan-Meier (KM) curves. Spearman correlation analysis, the STRING database, Cytoscape software, and the molecular complex detection (MCODE) algorithm were employed to investigate genes associated with SKA3. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were carried out for elucidating the functional role and pathways involving SKA3. The cBioPortal online platform was utilized to explore mutations in SKA3. The biological effects of SKA3 were further investigated through Cell Counting Kit-8 (CCK8) and cell scratch experiments. Results: SKA3 emerges as a pivotal gene in endometrial cancer, exhibiting a statistically significant high expression level. Its area under the curve (AUC) for diagnosing endometrial cancer stands at 0.943. Patients displaying elevated SKA3 expression demonstrated a notably poorer prognosis. In the context of endometrial cancer, 9 genes directly interact with SKA3. The functional pathway of SKA3 in endometrial cancer likely involves the mitotic pathway. The alterations observed in SKA3 in endometrial cancer primarily manifest as “mutations”. Specifically, SKA3 exhibits 26 mutation sites in endometrial cancer, distributed across 7 distinct regions and involving 4 mutation types. Furthermore, SKA3 is implicated in promoting the proliferation and migration of HEC-1A cells. Conclusion: SKA3, a key gene in endometrial cancer, holds significant diagnostic and prognostic value and may influence the progression in endometrial cancer.

KIFC1 depends on TRIM37-mediated ubiquitination of PLK4 to promote centrosome amplification in endometrial cancer

Endometrial cancer (EC), as one of the most common cancers, severely threatens female reproductive health. Our previous study has shown that Kinesin family member C1 (KIFC1) played crucial roles in the progression of EC. In addition, abnormal centrosome amplification, which was reported to be partially regulated by KIFC1, usually occurred in different cancers. However, whether KIFC1 promoted EC through centrosome amplification and the potential mechanism remain to be revealed. The present study demonstrated that overexpressed KIFC1, which exhibited a worse prognosis, had a positive correlation with an increased number of centrosomes in human EC samples. In addition, KIFC1 overexpression in EC cells prompted centrosome amplification, chromosomal instability, and cell cycle progression. Moreover, we demonstrated that KIFC1 inhibited E3 ubiquitin-protein ligase TRIM37 to maintain the stability of PLK4 by reducing its ubiquitination degradation, and finally promoting centrosome amplification and EC progression in vitro. Finally, the contributing role of KIFC1 and the inhibitory effect of TRIM37 on EC development and metastasis was verified in a nude mouse xenograft model. Our study elucidated that KIFC1 depends on TRIM37-mediated reduced ubiquitination degradation of PLK4 to promote centrosome amplification and EC progression, thus providing a potential prognostic marker and promising therapeutic target for EC in the future.

The mechanism of L1 cell adhesion molecule interacting with protein tyrosine kinase 2 to regulate the focal adhesion kinase–growth factor receptor-bound protein 2–son of sevenless–rat sarcoma pathway in the identification and treatment of type I high-risk endometrial cancer

Objective: The objective of this study was to investigate how L1 cell adhesion molecule (L1CAM) interacting with protein tyrosine kinase 2 (PTK2) affects endometrial cancer (EC) progression and determine its association with the focal adhesion kinase (FAK)–growth factor receptor-bound protein 2 (GRB2)–son of sevenless (SOS)–rat sarcoma (RAS) pathway. EC is a female cancer of major concern in the world, and its incidence has increased rapidly in recent years. L1CAM is considered a reliable marker of poor prognosis in patients with EC. Material and Methods: A single-center and prospective study was conducted using data from the Cancer Genome Atlas and samples from normal and EC tissues to explore the differential expression of L1CAM. Additional experimental models included human immortalized endometrial epithelium cells (hEECs) and EC cell lines such as KLE, RL95-2, and Ishikawa. L1CAM expression was regulated using lentiviruses designed for either overexpression or interference, and PTK2/focal adhesion kinase (FAK) signaling was inhibited with PF431396. Transfected KLE cells were injected into mice, and tumor growth was monitored over 14 days. Cellular proliferation and survival were assessed using cell counting kit, colony formation, and terminal deoxynucleotidyl transferase-mediated 2’-deoxyuridine 5’-triphosphate (dUTP) nick-end labeling assays. Metastatic behavior was evaluated through Transwell assays for cell migration and invasion. The expression levels of matrix metallopeptidase (MMP) 2 and MMP9 were determined by Western blot. In addition, the activation of the FAK–GRB2–SOS–RAS pathway was examined by assessing the protein levels of FAK, GRB2, SOS, and RAS. Results: There was a significant difference in L1CAM expression between EC tumor tissues and normal tissues, and L1CAM messenger RNA (1.85-fold) and L1CAM protein (2.59-fold) were significantly more expressed in EC tissues (P < 0.01) than in normal tissues. The tumor growth of L1CAM overexpressing EC cells was faster than that of negative control EC cells (6.43 fold; P < 0.001). L1CAM promoted the expression of FAK (1.43-2.72-fold; P < 0.001); enhanced EC cell proliferation (P < 0.01), survival and motility (P < 0.001), migration (P < 0.001), and invasion (P < 0.001); and activated the FAK–GRB2–SOS–RAS pathway, all of which were reversed when FAK expression was not upregulated (P < 0.001). Conclusion: By upregulating PTK2 and its encoded protein FAK, L1CAM was found to promote tumor progression and increase the activation of the FAK–GRB2–SOS–RAS pathway. These findings establish L1CAM and PTK2 as reference genes for poor prognostic prediction in EC and as targets for EC therapy, providing a valuable basis for distinguishing between benign and malignant endometrial conditions and justifying the necessity of targeted therapeutic approaches.

T-Box Transcription Factor 2 Mediates Chemoresistance of Endometrial Cancer via Regulating FSP1-involved Ferroptosis.

Chemotherapy is increasingly being used in the first-line treatment of endometrial cancer (EC) patients. However, chemoresistance seriously affects its efficacy. Understanding the underlying molecular mechanisms is critical for EC treatment. We explored the regulatory role of T-Box transcription factor 2 (TBX2)-ferroptosis suppressor protein 1 (FSP1) axis in ferroptosis and chemoresistance of EC. Cisplatin-resistant cell line Ishikawa/DDP cells were utilized to generate TBX2 and FSP1 overexpression and knockdown stable cell lines by using lentivirus infection and puromycin selection. Cell viability and ferroptosis status were evaluated in EC cells with or without Cisplatin and/or FSP1 inhibitor (iFSP1) using CKK-8, lipid peroxidation, malondialdehyde, and lactate dehydrogenase release assays. Endometrial carcinoma xenograft mouse model was established to further explore the function of TBX2-FSP1 axis on ferroptosis and tumor progression in EC. TBX2 suppressed Cisplatin-induced ferroptosis through up-regulating FSP1 expression level in EC cells. On the contrary, knockdown of TBX2 reduced FSP1 expression and significantly promoted Cisplatin-induced ferroptosis. TBX2 or FSP1 overexpression and knockdown promote and inhibit EC tumor growth under Cisplatin treatment, respectively. Interestingly, silence FSP1 could reverse TBX2-mediated ferroptosis inhibition and tumor-promoting effect. TBX2-FSP1 axis inhibits ferroptosis and enhances the Cisplatin resistance, which will provide an important theoretical basis and potential solution for the clinical treatment of EC.

SOX4 inhibits ferroptosis and promotes proliferation of endometrial cancer cells via the p53/SLC7A11 signaling.

Sex-determining region Y-related high-mobility group box 4 (SOX4) has been reported to play a carcinogenic role in endometrial cancer (EC). However, the biological function and regulatory mechanisms of SOX4 in ferroptosis during the progression of EC are still unknown. The mRNA and protein levels were scrutinized by quantitative reverse-transcription polymerase chain reaction and western blot, respectively. The cell viability and proliferative capability were determined by cell counting kit-8 assay and 5-ethynyl-2'-deoxyuridine (EdU) assay. Transcriptional regulation of gene expression was investigated by dual-luciferase reporter assay and chromatin immunoprecipitation. Ferroptosis was evaluated by detection of reactive oxygen species, malondialdehyde, Fe2+, and ferroptosis-related proteins. The mice test was implemented to confirm the influence of SOX4 on EC tumor growth and ferroptosis in vivo. We here discovered the elevation of SOX4 in EC tissues and cells. Functionally, SOX4 knockdown hampered proliferation and promoted ferroptosis of EC cells. Mechanistically, SOX4 bound to p53 promoter and inhibited its transcriptional activity in EC cells. In addition, p53 transcriptionally suppressed SLC7A11 expression in EC cells. Downregulation of p53 reverses the effect of SOX4 knockdown on proliferation and ferroptosis of EC cells. Finally, in vivo experiments demonstrated that SOX4 depletion hindered tumor growth and triggered ferroptosis in EC. These findings collectively suggested that SOX4 inhibited ferroptosis and promoted proliferation of EC cells via the p53/SLC7A11 signaling. Our research unveiled a novel regulatory mechanism of ferroptosis in EC, offering promising perspectives for the development of EC therapies.

MYO3B promotes cancer progression in endometrial cancer by mediating the calcium ion-RhoA/ROCK1 signaling pathway

PurposeThis study aimed to investigate the effect of MYO3B on endometrial cancer (EC) proliferation and invasion.MethodsThe expression of MYO3B in EC tissues and cells was analyzed using TCGA database, immunohistochemical staining, real-time PCR, and western blot (WB). Cell proliferation was detected by CCK8, Annexin V-APC/PI flow cytometry was used to detect apoptosis, intracellular calcium ion (Ca2+) was detected by flow cytometry with Fluo-4 AM fluorescent probe, cell migration by scratch assay, and cell invasion by Transwell assay, and the expression of proteins related to Ca2+ homeostasis and RhoA/ROCK1 signaling pathway was detected by WB and immunofluorescence staining.ResultsThe expression of MYO3B was an influential factor in EC recurrence, and the expression of MYO3B was significantly up-regulated in EC tissues and cells, but down-regulated in KLE cells, and MYO3B knockdown inhibited the proliferation, migration, and invasion ability of EC cells and promoted apoptosis, suggesting that MYO3B plays a tumor-promoting role in EC. Furthermore, MYO3B knockdown decreased Ca2+ concentration in EC cells and the RhoA/ROCK1 signaling pathway was inhibited, and the effect of MYO3B knockdown on RhoA/ROCK1 signaling was reversed by treatment with the Calmodulin agonist CALP-2, and the effects of MYO3B knockdown on cell proliferation, migration, and invasion were reversed after treatment with the RhoA agonist U-46,619.ConclusionMYO3B promotes the proliferation and migration of endometrial cancer cells via Ca2+-RhoA/ROCK1 signaling pathway. High expression of MYO3B may be a biomarker for EC metastasis.

Role of Receptor for Advanced Glycation End-Products in Endometrial Cancer: A Review.

Endometrial cancer (EC) is the most common gynecological malignancy. EC is associated with metabolic disorders that may promote non-enzymatic glycation and activate the receptor for advanced glycation end-products (RAGE) signaling pathways. Thus, we assumed that RAGE and its ligands may contribute to EC. Of particular interest is the interaction between diaphanous-related formin 1 (Diaph1) and RAGE during the progression of human cancers. Diaph1 is engaged in the proper organization of actin cytoskeletal dynamics, which is crucial in cancer invasion, metastasis, angiogenesis, and axonogenesis. However, the detailed molecular role of RAGE in EC remains uncertain. In this review, we discuss epigenetic factors that may play a key role in the RAGE-dependent endometrial pathology. We propose that DNA methylation may regulate the activity of the RAGE pathway in the uterus. The accumulation of negative external factors, such as hyperglycemia, inflammation, and oxidative stress, may interfere with the DNA methylation process. Therefore, further research should take into account the role of epigenetic mechanisms in EC progression.

Developing patient-derived organoids to demonstrate JX24120 inhibits SAMe synthesis in endometrial cancer by targeting MAT2B

Endometrial cancer (EC) is one of the most common gynecologic malignancies, which lacking effective drugs for intractable conditions or patients unsuitable for surgeries. Recently, the patient-derived organoids (PDOs) are found feasible for cancer research and drug discoveries. Here, we have successfully established a panel of PDOs from EC and conducted drug repurposing screening and mechanism analysis for cancer treatment. We confirmed that the regulatory β subunit of methionine adenosyltransferase (MAT2B) is highly correlated with malignant progression in endometrial cancer. Through drug screening on PDOs, we identify JX24120, chlorpromazine derivative, as a specific inhibitor for MAT2B, which directly binds to MAT2B (Kd = 4.724 μM) and inhibits the viability of EC PDOs and canonical cell lines. Correspondingly, gene editing assessment demonstrates that JX24120 suppresses tumor growth depending on the presence of MAT2B in vivo and in vitro. Mechanistically, JX24120 induces inhibition of S-adenosylmethionine (SAMe) synthesis, leading to suppressed mTORC1 signaling, abnormal energy metabolism and protein synthesis, and eventually apoptosis. Taken together, our study offers a novel approach for drug discovery and efficacy assessment by using the PDOs models. These findings suggest that JX24120 may be a potent MAT2B inhibitor and will hopefully serve as a prospective compound for endometrial cancer therapy.

Analysis of the correlation between gut microbiome imbalance and the development of endometrial cancer based on metagenomics.

Endometrial cancer (EC) is the most prevalent gynecologic malignancy, with a higher risk in obese women, suggesting the potential involvement of gut microbiota in the progression of EC. However, there is no direct evidence of a connection between EC and the human gut microbiota. Using metagenomic sequencing, we investigated the relationship between gut microbiome imbalance and cancer development in patients with EC. In this prospective case-control study, we included 15 patients with EC based on endometrial biopsy in the case group and 15 women admitted to the hospital for female pelvic floor issues during the same time who did not have endometrial lesions from January 2023 to June 2023 in control group. The microbiota structure of EC cases and controls without benign or malignant endometrial lesions during the same time period was analyzed using metagenomic sequencing technology. We employed Alpha diversity analysis to reflect the richness and diversity of microbial communities. Statistical algorithm Bray-Curtis was utilized to calculate pairwise distances between samples, obtaining a beta diversity distance matrix. Subsequently, hierarchical clustering analysis was conducted based on the distance matrix. The results showed that the composition of bacterial colonies in both groups was dominated by Firmicutes, which had a higher proportion in the control group, followed by Bacteroidetes in the control group and Proteobacteria and Bacteroidetes in the case group. The abundance of Klebsiella (P = .02) was significantly higher, and the abundance of Alistipes (P = .04), Anearobutyricum (P = .01), and bacteria in Firmicutes such as Oscillospira and Catenibacterium was markedly lower in the case group than in the control group. These results demonstrated conclusively that a gut microbiome imbalance was associated with the development of EC.

Pyroptosis-associated genes and tumor immune response in endometrial cancer

The occurrence and progression of tumors are linked to the process of pyroptosis. However, the precise involvement of pyroptosis-associated genes (PRGs) in endometrial cancer (EC) remains uncertain. 29 PRGs were identified as being either up-regulated or down-regulated in EC. PRGs subgroup analysis demonstrated distinct survival outcomes and diverse responses to chemotherapy and immune checkpoint blockade therapy. A higher expression of GPX4 and NOD2, coupled with lower levels of CASP6, PRKACA, and NLRP2, were found to be significantly associated with higher overall survival (OS) rates (p < 0.05). Conversely, lower expression of NOD2 was linked to lower progression-free survival (p = 0.021) and advanced tumor stage(p = 0.0024). NOD2, NLRP2, and TNM stages were identified as independent prognostic factors (p < 0.001). The LASSO prognostic model exhibited a notable decrease in OS among EC patients in the high-risk score group (ROC-AUC10-years: 0.799, p = 0.00644). Furthermore, NOD2 displayed a positive correlation with the infiltration of immune cells and the expression of immune checkpoints (p < 0.001). GPX4 and CASP6 are significantly associated with TMB and MSI (RTMB = 0.39; RMSI = 0.23). Additionally, a substantial upregulation of NOD2 was confirmed in both EC cells and tissue, indicating a positive relationship between advanced TNM stage (p < 0.0001) and infiltration of M1 phenotype macrophages. Nonetheless, its impact on patient OS did not reach statistical significance (p = 0.141). Our findings have contributed to the advancement of a prognostic model for EC patients. NOD2 receptor-mediated pyroptosis mechanism potentially regulates tumor immunity and promotes the transformation of macrophages from the M2 phenotype to the M1 phenotype, which significantly impacts the progression of EC.

Adipocytes Promote Endometrial Cancer Progression Through Activation of the SIRT1-HMMR Signaling Axis.

Adipocyte is a predominant component of the omental adipose tissue that influences the tumor microenvironment and increases the risk of endometrial cancer progression (EC), however, little is known about the underlying mechanism. In this study, using a co-culture model, we found that the adipocyte-EC cell interaction promoted SIRT1 signaling in vitro and in vivo xenograft mice models. Furthermore, immunostaining of SIRT1 protein showed significantly higher expression of SIRT1 in endometrial cancer patients than in normal endometria. RNA sequencing analysis revealed HMMR (hyaluronan-mediated motility receptor), an oncogene, as a downstream effector of SIRT1 in adipocyte-associated EC. Transient knockdown and chromatin immunoprecipitation assays showed that SIRT1 inhibition impedes transcription of the HMMR gene via FOXM1, and reduced expression of HMMR in co-cultured EC cells blocks AURKA activation via TPX2, leading to cell cycle arrest. This is the first study to report the positive correlation between SIRT1 and HMMR in EC patient tumors and might be used as a potential biomarker in EC. Notably, SIRT1 regulates HMMR expression in a FOXM1-dependent manner, and interfering with SIRT1 may provide a promising strategy for the management of endometrial cancer.

RAB17 promotes endometrial cancer progression by inhibiting TFRC-dependent ferroptosis

Studies have indicated that RAB17 expression levels are associated with tumor malignancy, and RAB17 is more highly expressed in endometrial cancer (EC) tissues than in peritumoral tissues. However, the roles and potential mechanisms of RAB17 in EC remain undefined. The present study confirmed that the expression of RAB17 facilitates EC progression by suppressing cellular ferroptosis-like alterations. Mechanistically, RAB17 attenuated ferroptosis in EC cells by inhibiting transferrin receptor (TFRC) protein expression in a ubiquitin proteasome-dependent manner. Because EC is a blood-deprived tumor with a poor energy supply, the relationship between RAB17 and hypoglycemia was investigated. RAB17 expression was increased in EC cells incubated in low-glucose medium. Moreover, low-glucose medium limited EC cell ferroptosis and promoted EC progression through the RAB17-TFRC axis. The in vitro results were corroborated by in vivo studies and clinical data. Overall, the present study revealed that increased RAB17 promotes the survival of EC cells during glucose deprivation by inhibiting the onset of TFRC-dependent ferroptosis.

Role of INPP4B in the proliferation, migration, invasion, and survival of human endometrial cancer cells.

Inositol polyphosphate 4-phosphatase type II (INPP4B) has been identified as a tumor repressor in several human cancers while its role in endometrial cancer has not been investigated yet. Therefore, the current study was designed to determine whether INPP4B participates in the progression of endometrial cancer by utilizing clinical data and experimental determination. We first include six chemotherapy-treated patients with recurrent and metastatic endometrioid carcinoma to determine the relationship between INPP4B mutation and relative tumor burden. By using siRNA-mediated gene silencing and vector-mediated gene overexpression, we further determined the effect of manipulating INPP4B expression on the proliferation, invasion, and survival of endometrial cancer cells. Furthermore, the repressing effect of INPP4B together with its role in chemotherapy was further validated by xenograft tumor-bearing mice models. Western blot analysis was used to explore further downstream signaling modulated by INPP4B expression manipulation. Two of the patients were found to have INPP4B mutations and the mutation frequency of INPP4B increased during the progression of chemotherapy resistance. Endometrial cancer cells with silenced INPP4B expression were found to have promoted tumor cell proliferation, invasion, and survival. Endometrial cancer cells overexpressing INPP4B were found to have decreased tumor cell proliferation, invasion, and survival. An in vivo study using six xenograft tumor-bearing mice in each group revealed that INPP4B overexpression could suppress tumor progression and enhance chemosensitivity. Furthermore, INPP4B overexpression was found to modulate the activation of Wnt3a signaling. The current study suggested that INPP4B could be a suppressor in endometrial cancer progression and might be a target for endometrial cancer treatment. Also, INPP4B might serve as a predictor of chemosensitivity determination.

206P Unveiling the link: How metabolic syndrome drives endometrial cancer progression

206P Unveiling the link: How metabolic syndrome drives endometrial cancer progression

LncRNA LINC00173 inhibits the development of endometrial cancer by interacting with HNRNPC

BackgroundPrevious research has elaborated on the role of long non-coding RNA LINC00173 in the pathogenesis of various cancers; however, our knowledge of its clinical consequences and mechanisms in endometrial cancer (EC) is limited. Our current work is aimed at investigating the effect of LINC00173 in combination with its upstream gene HNRNPC on EC progression. MethodsLINC00173 and HNRNPC levels were investigated by qRT-PCR or western blotting in EC tissues. The functional roles of HNRNPC and LINC00173 were assessed using transwell, colony formation and CCK-8 assays. A xenograft was used to verify the phenotype of LINC00173 after its overexpression. The regulatory role between HNRNPC and LINC00173 was investigated using RIP and RNA pull-down analysis. ResultsIn EC tissues, LINC00173 expression was down-regulated. We observed that increased LINC00173 inhibited EC cell growth and migration. LINC00173 was a downstream target of HNRNPC, and its expression level was elevated by HNRNPC silencing. LINC00173 overexpression shifted part of HNRNPC into the cytoplasm from the nucleus of EC cells. Furthermore, HNRNPC expression was upregulated in EC and its silencing inhibited EC cell malignancy in vitro. ConclusionLINC00173 can impair the malignancy of EC cell by interacting with HNRNPC. This finding may contribute to the understanding of the tumorigenic effects of HNRNPC and LINC00173 on EC.