Endometrial Carcinoma Tissues Research Articles

Long non-coding RNA JPX promotes endometrial carcinoma progression via janus kinase 2/signal transducer and activator of transcription 3

IntroductionAlthough LncRNA JPX has been linked to a number of malignancies, it is yet unknown how it relates to endometrial carcinoma (EC). Investigating the expression, functional activities, and underlying molecular processes of lncRNA JPX in EC was the goal of this work.MethodsRT-qPCR was used to examine the differences in lncRNA/microRNA (miRNA, miR)/mRNA expression between normal cervical and EC tissues or cells. Cell Counting Kit-8, flow cytometry, and transwell were used to evaluate the association between lncRNA JPX/miR-140-3p/phosphoinositide-3-kinase catalytic subunit α (PIK3CA) in Ishikawa and JEC cell lines. The impact of JPX on the downstream janus kinase (JAK)2/signal transducer and activator of transcription (STAT)3 signaling pathway was investigated using Western blot analysis.ResultsWhen comparing EC tissues to nearby normal tissues, JPX expression is markedly increased in EC tissues, with greater expression in advanced-stage EC. Furthermore, compared to normal epithelial cells, EC cell lines have higher levels of JPX expression. In Ishikawa and JEC endometrial cancer cell lines, we used siRNA-mediated suppression of JPX to find lower cell viability, increased apoptosis, cell cycle arrest, and reduced migration and invasion. We next verified that miR-140-3p binds to downstream target cells to impede the transcription and translation of PIK3CA, which in turn prevents the growth of Ishikawa and JEC cells. JPX functions as a ceRNA to adsorb miR-140-3p. This procedure required controlling JAK2/STAT3, a downstream signal.ConclusionJPX enhances the development of Ishikawa and JEC cells and activates downstream JAK2/STAT3 signal transduction via the miR-140-3p/PIK3CA axis, offering a possible therapeutic target for the treatment of EC.

Histone lactylation promotes malignant progression by facilitating USP39 expression to target PI3K/AKT/HIF-1α signal pathway in endometrial carcinoma

Histone lactylation has been reported to involve in tumorigenesis and development. However, its biological regulatory mechanism in endometrial carcinoma (EC) is yet to be reported in detail. In the present study, we evaluated the modification levels of global lactylation in EC tissues by immunohistochemistry and western blot, and it was elevated. The non-metabolizable glucose analog 2-deoxy-d-glucose (2-DG) and oxamate treatment could decrease the level of lactylation so as to inhibit the proliferation and migration ability, induce apoptosis significantly, and arrest the cell cycle of EC cells. Mechanically, histone lactylation stimulated USP39 expression to promote tumor progression. Moreover, USP39 activated PI3K/AKT/HIF-1α signaling pathway via interacting with and stabilizing PGK1 to stimulate glycolysis. The results of present study suggest that histone lactylation plays an important role in the progression of EC by promoting the malignant biological behavior of EC cells, thus providing insights into potential therapeutic strategies for endometrial cancer.

LncRNA linc01194 promotes the progress of endometrial carcinoma by up-regulating SOX2 through binding to IGF2BP1.

Endometrial carcinoma (EC) is one of the most common gynecological malignant tumors. Our study showed that long non-coding RNA (lncRNA) linc01194 plays an important role in EC. We explored the mechanism of lncRNA linc01194 in EC. The expression of lncRNA linc01194 was detected in The Cancer Genome Atlas database and starBase database. The potential targeted protein of linc01194 was predicted through the starBase database. To determine the role of linc01194 in EC, we downregulated or upregulated the level of linc01194 in EC cell lines and analyzed the cell behaviors and the changes of its potential target proteins. The expression of linc01194 in EC tissues is higher than that in normal endometrial tissues. The knockdown of linc01194 inhibited the cell proliferation, invasion and migration and promoted the apoptosis of EC cells, while overexpression of linc01194 promoted cell proliferation, invasion and migration and inhibited the apoptosis of EC cells. The starBase database revealed that linc01194 could bind to insulin-like growth factor 2 binding protein 1 (IGF2BP1). Previous results showed that in EC, IGF2BP1 could promote the expression of sex-determining region Y-box 2 (SOX2) by promoting the stability of SOX2 mRNA. Our results showed that linc01194 regulate the expression of IGF2BP1 and SOX2. Linc01194 can promote the expression of downstream protein SOX2 through binding to IGF2BP1, thus promoting the occurrence and development of EC.

CDK1 promotes the phosphorylation of KIFC1 to regulate the tumorgenicity of endometrial carcinoma.

This study aims to clarify the mechanical action of cyclin-dependent protein kinase 1 (CDK1) in the development of endometrial carcinoma (EMCA), which may be associated with the phosphorylation of kinesin family member C1 (KIFC1) and further activate the PI3K/AKT pathway. The protein and gene expression of CDK1 in EMCA tissues and tumor cell lines were evaluated by western blot, quantitative polymerase chain reaction, and immunohistochemistry staining. Next, Cell Counting Kit-8 and colony formation assay detected cell survival and proliferation. Cell migration and invasion were measured by Transwell assay. Cell apoptosis and cell cycle were tested by flow cytometry. Immunofluorescence staining of γH2AX was used to evaluate DNA damage, respectively. Subsequently, a co-immunoprecipitation assay was used to detect the interaction between CDK1 and KIFC1. The phosphorylated protein of KIFC1 and PI3K/AKT was detected by western blot. Finally, the effect of CDK1 on the tumor formation of EMCA was evaluated in a nude mouse xenograft model. CDK1 was highly expressed in EMCA tumor cell lines and tissues, which contributed to cell survival, proliferation, invasion, and migration, inhibited cell apoptosis, and induced DNA damage of EMCA cells dependent on the phosphorylation of KIFC1. Moreover, the CDK1-KIFC1 axis further activated PI3K/AKT pathway. Finally, CDK1 knockdown repressed tumor formation of EMCA in vivo. We report that increased CDK1 promotes tumor progression and identified it as a potential prognostic marker and therapeutic target of EMCA.

EXOSC5 maintains cancer stem cell activity in endometrial cancer by regulating the NTN4/integrin β1 signalling axis.

Endometrial carcinoma (EC) is a common type of uterine cancer in developed countries, originating from the uterine epithelium. The incidence rate of EC in Taiwan has doubled from 2005. Cancer stem cells (CSCs) are a subpopulation of cancer cells that have high tumorigenicity and play a crucial role in the malignant processes of cancer. Targeting molecules associated with CSCs is essential for effective cancer treatments. This study delves into the role of Exosome component 5 (EXOSC5) in EC. Data from The Cancer Genome Atlas suggests a correlation between high EXOSC5 mRNA expression and unfavorable EC prognosis. EXOSC5 knockdown diminished EC-CSC self-renewal and reduced expression of key cancer stemness proteins, including c-MYC and SOX2. Intriguingly, this knockdown significantly curtailed tumorigenicity and CSC frequency in EC tumor spheres. A mechanistic examination revealed a reduction in netrin4 (NTN4) levels in EXOSC5-depleted EC cells. Moreover, NTN4 treatment amplified EC cell CSC activity and, when secreted, NTN4 partnered with integrin β1, subsequently triggering the FAK/SRC axis to elevate c-MYC activity. A clear positive relation between EXOSC5 and NTN4 was evident in 93 EC tissues. In conclusion, EXOSC5 augments NTN4 expression, activating c-MYC via the integrin β1/FAK/SRC pathway, offering potential avenues for EC diagnosis and treatment.

Fer-mediated activation of the Ras-MAPK signaling pathway drives the proliferation, migration, and invasion of endometrial carcinoma cells.

The role of Feline sarcoma-related protein (Fer) in various cancers has been extensively studied, but its specific involvement and underlying mechanisms in the progression of endometrial carcinoma (EC) are yet to be fully understood. The expression levels of Fer were assessed in EC tissues and cell lines using real-time quantitative PCR and western blot analysis. CCK-8 assay, Edu staining, transwell assays, and flow cytometry, were conducted to evaluate the impact of Fer on EC cells. Furthermore, a mice xenograft model and immunohistochemistry (IHC) staining were utilized for in vivo analysis. The levels of Ras, pMek1/2, and pErk1/2 were determined by western blot assay. Ras-MAPK signaling pathway inhibitor was utilized to study the regulatory role of Fer on EC cells. Our findings revealed that Fer exhibited upregulation in both EC tissues and cell lines, concomitant with the activation of the Ras-MAPK signaling pathway. Silencing of Fer resulted in the suppression of cell proliferation, migration, invasion, and Ras-MAPK signaling pathway, while promoted hypoxia-induced apoptosis in RL95-2 and KLE cells. Fer overexpression stimulated cell proliferation, migration, invasion, and Ras-MAPK signaling pathway in Ishikawa and AN3-CA cells, which were reversed after treatment with either Ras or MAPK inhibitor. Moreover, silencing of Fer suppressed tumor growth and downregulated the expression of Ki-67, Ras, pMek1/2, and pErk1/2, but had no significant effect on Mek1/2 and Erk1/2, while upregulated caspase-3 expression in vivo. In summary, the upregulation of Fer in EC cells resulted in the enhancement of cell proliferation, migration, and invasion through the activation of the Ras-MAPK signaling pathway.

USP14 predicts poorer survival outcomes and promotes tumor progression in endometrial carcinoma by activating NF-κB signaling.

Ubiquitin-specific protease 14 (USP14), a member of the USP family, which catalyzes ubiquitin cleavage from a range of protein substrates, has been found dysregulated in several cancers. Our aim is to explore the functions and mechanism of USP14 in endometrial carcinoma (EC). Quantitative real-time PCR (qRT-PCR) and western blot (WB) were used to assess USP14 levels in EC tissues and adjacent nontumor tissues. USP14 overexpression or knockdown models were adopted to determine USP14-mediated effects on EC cell proliferation, migration, invasion, apoptosis, and epithelial-mesenchymal transition (EMT). The xenograft tumor experiment checked the effect of USP14 overexpression on tumor cell growth. Furthermore, the upstream signaling pathway of USP14 was predicted by bioinformatics. Consequently, EC tissues exhibited USP14 overexpression compared to normal paracancerous nontumor tissues. USP14 presence was linked to an adverse prognosis in EC cases. Functionally, USP14 overexpression reduced apoptosis and increased cell migration, invasion, and EMT in vivo and ex vivo. USP14 knockdown had the opposite effect. Mechanistically, NF-κB pathway activation occurred through the inhibitory effect of USP14 on I-κB expression. Conversely, NF-κB pathway inhibition attenuated USP14-mediated carcinogenic effects. Additionally, there existed a binding interaction between miR-124-3p and the 3'-UTR of USP14, resulting in USP14 activity inhibition. In summary, our research indicates that the involvement of miR-124-3p in USP14 regulation contributes to exacerbated EC progression through NF-κB pathway activation. The modulation of this pathway may be a new strategy for treating EC.

Tripartite motif containing 33 demonstrated anticancer effect by degrading c‑Myc: Limitation of glutamine metabolism and proliferation in endometrial carcinoma cells.

Tripartite motif containing 33 (TRIM33) has been reported to be involved in various tumor progression. However, its role in endometrial carcinoma (EC) remains to be elucidated. By mining the publicly available databases UALCAN and TIMER, low expression of TRIM33 was found in tumor tissues of EC patients. Clinically, downregulation of TRIM33 in EC tissues was positively correlated with the extensive muscle invasion and poor differentiation grade. Invitro, experiments performed on human HEC‑1‑A and AN3CA cells showed that overexpression of TRIM33 inhibited the proliferation, migration and invasion of EC cells, whereas TRIM33 knockdown resulted in the opposite results. Furthermore, upregulation of TRIM33 significantly inhibited the glutamine uptake and decreased the intracellular glutamate in EC cells, which is evidenced by the reduction of solute carrier family 1 member 5 and glutaminase. Invivo, TRIM33 also dramatically inhibited tumor growth and glutamine metabolism. Additionally, co‑immunoprecipitation assay confirmed the interaction between TRIM33 and c‑Myc. Overexpression of TRIM33 could reduce the protein stability of c‑Myc by promoting its degradation. In addition, upregulation of c‑Myc could reverse the effects of TRIM33 on EC cells. Together, the present study demonstrated that TRIM33 acted as a tumor suppressor in EC, which is manifested in its inhibition of glutamine metabolism and cell growth via promoting c‑Myc protein degradation.

LncRNA RBAT1 reduces chemosensitivity of cancer cells to carboplatin/paclitaxel by sponging miR‑27b in endometrial carcinoma

BackgroundA recent study reported the role of long non-coding RNA (lncRNA) RBAT1 in promoting the development of retinoblastoma and bladder cancer. However, its function in other cancers is unclear. We then studied the role of RBAT1 in endometrial carcinoma (EC).MethodsThe expression of RBAT1 and miR-27b in EC and paired non-tumor samples from advanced EC patients, as well as in plasma samples of EC patients and healthy controls were detected by RT-qPCR. The direct interaction between RBAT1 and miR-27b, and the subcellular location of RBAT1 were determined by RNA-RNA pulldown assay and subcellular fractionation assay, respectively.ResultsEC tissues showed increased expression levels of RBAT1 and decreased expression levels of miR-27b compared to that in non-tumor tissues. Moreover, EC patients showed higher plasma expression levels of RBAT1 and lower plasma expression levels of miR-27b compared to that in the controls. Drug-resistant (DR) patients showed higher expression levels of RBAT1 and lower expression levels of miR-27b in both EC tissues and plasma samples. RBAT1 was detected in both nuclear and cytoplasm and it directly interacted with miR-27b. RBAT1 and miR-27b did not affect the expression of each other. Upregulation of RBAT1 promoted the expression of multidrug-resistant-related protein (P-gp, MRP1, and BCRP). Overexpression of RBAT1 and inhibition of miR-27b promoted cell viability and impeded cell apoptosis and cell cycle arrest at G0-G1 phase, while knockdown of RBAT1 and overexpression of miR-27b inhibited cell viability and induced cell apoptosis and cell cycle arrest at G0-G1 phase. Moreover, miR-27b could abolish RBAT1-induced effects on cell viability, apoptosis and cell cycle.ConclusionRBAT1 may reduce the chemosensitivity of EC cells to carboplatin/paclitaxel by sponging miR-27b in EC.

TMEM41A overexpression correlates with poor prognosis and immune alterations in patients with endometrial carcinoma.

Expression levels of transmembrane protein 41A (TMEM41A) are related to the progression of malignant tumors. However, the association between TMEM41A expression and endometrial carcinoma (EC) remains unclear. This study aims to identify the roles of TMEM41A expression in the prognosis of patients with EC and its correlation with EC progression. The TMEM41A expression and its correlation with the survival of patients with EC were assessed. Cox regression analysis was used to identify the prognostic factors, while nomograms were used to examine the association between the prognostic factors and the survival of patients with EC. Finally, the link between TMEM41A level and immune microenvironment and RNA modifications was investigated in EC. TMEM41A was overexpressed in EC. TMEM41A overexpression could diagnose the EC and evaluate the poor prognosis of patients. Overexpression of TMEM41A was associated with clinical stage, age, weight, histological subtype, tumor grade, and survival status of patients with EC. Clinical stage, age, tumor grade, radiotherapy, and TMEM41A overexpression were factors of poor prognosis in patients with EC. The nomograms revealed the correlation between the TMEM41A level and survival time of patients with EC at 1, 3, and 5 years. Furthermore, TMEM41A overexpression was significantly correlated with the level of the stromal score, immune score, estimate score, NK CD56 bright cells, iDC, NK cells, eosinophils, pDC, T cells, TReg, cytotoxic cells, mast cells, Th17 cells, neutrophils, aDC, NK CD56 dim cells, TFH, Th2 cells, CD8 T cells, macrophages, immune cell markers, and RNA modifications. TMEM41A is overexpressed in EC tissues and is associated with the prognosis, immune microenvironment, and RNA modification. Our preliminary studies indicate that overexpression of TMEM41A can potentially serve as a biomarker for EC treatment.

Circular RNA differential expression profiles and bioinformatics analysis of hsa_circRNA_079422 in human endometrial carcinoma

The aim of our study was to explore circular RNA (circRNA) expression profiles associated with human endometrial carcinoma (EC) and to analyse the molecular mechanisms involved in cancer development and their potential clinical importance. Differential expression profiles were revealed by Arraystar human circRNA microarray analysis. The results of the circRNA microarray were confirmed by quantitative real-time PCR. Interactions between circRNAs and microRNAs (miRNAs) were predicted using Arraystar’s miRNA target prediction software. The functions of the circRNA-miRNA coexpression network were identified by KEGG pathway analysis and GO analysis. Compared with para-tumorous tissues, 14 genes were significantly upregulated and 12 genes were significantly downregulated in EC tissues (P < 0.05). The quantitative real-time PCR data demonstrated consistency with the results of the microarray profile analysis. We generated a circRNA-miRNA coexpression network. Hsa_circRNA_079422 expression was significantly lower and miR-136-5p expression was higher in EC tissues than in normal endometrial tissues. KEGG pathway analysis and GO analysis indicated that hsa_circRNA_079422 might play roles in different signalling pathways and biological functions. We confirmed the presence of different circRNA expression profiles and predicted the circRNA-miRNA coexpression network in human EC tissues. Hsa_circRNA_079422 might be involved in the pathogenesis and biological process of EC via interactions with miRNAs. IMPACT STATEMENT What is already known on this subject? EC is a common malignancy of the female reproductive system. CircRNAs were demonstrated to exert critical roles in cancers, including EC. What do the results of this study add? The results of this study add circRNAs expression profiles, the circRNA-miRNA coexpression network and cancer-related circRNA-miRNA target genes in EC. It was first found that hsa_circRNA_079422 was downregulated, while miR-136-5p was upregulated in EC tissues. What are the implications of these findings for clinical practice and/or further research? In clinical practice, early EC diagnosis lacks specific biomarkers, so most EC patients are diagnosed at an advanced stage. In the management of EC patients, we also lack personalised adjuvant treatment that combines the clinical pathological characteristics. For the existing literature, we identified a new EC differential expression biomarker, hsa_circ_079422. It can be used to verify the correlation with EC clinical severity or poor prognosis. Its targeting can also be used to stratify EC patients with different molecular types, including to guide adjuvant therapy. In addition, we can verify and analyse regulatory pathways associated with it for the design of regulating engineering circRNA.

MiRNA-329-3p suppresses proliferation and metastasis of endometrial carcinoma through downregulating E2F1.

Existing evidences have revealed the crucial roles of E2 promoter binding factor-1 (E2F1) during the tumorigenesis and progression process of multiple human tumors. However, the expression patterns, biological functions, as well as the underlying molecular mechanism of E2F1 in endometrial carcinoma yet remain largely unclear. The expression patterns and clinical prognostic value of E2F1 in endometrial carcinoma were evaluated using bioinformatics methods. Protein and mRNA, miRNA expression levels in tissues and cells were measured using immunohistochemistry, western blotting, and qRT-PCR assays. Cell viability and cell cycle distribution were examined using CCK-8 assay and flow cytometry, respectively. Scratch healing assay and Transwell assay were applied to measure cell migration and invasion ability. Bioinformatic analysis and luciferase reporter assays were conducted to confirm the targeting relationship between E2F1 and miR-329-3p. Moreover, a series of in vitro and in vivo functional experiments were employed to evaluate the effect of the miR-329-3p/E2F1 axis on cell growth and metastasis. Clinically, E2F1 was aberrantly expressed in endometrial carcinoma tissues and was correlated with advanced FIGO stage, histological type, p53 mutation, poor survival, and degree of tumor cell differentiation. ROC curves analysis also reveals that E2F1 has a high AUC value (up to 0.952, 95% CI: 0.915-0.988), indicating the promising diagnostic value of E2F1 level in endometrial carcinoma. In addition, in vitro gain and loss-of-functional experiments verified that high E2F1 can promote cell proliferation, cell cycle, migration, invasion, and EMT process. In-depth mechanism studies revealed that E2F1 was a downstream target gene of miR-329-3p, and miR-329-3p overexpression could effectively abrogate its promotion of cell malignant biological behavior. Collectively, our findings suggested that the miR-329-3p/E2F1 axis plays a crucial role in the progression of endometrial carcinoma, indicating that E2F1 can be considered a promising diagnostic and prognostic biomarker for endometrial carcinoma patients.

Down-regulation of miR-424 inhibited the metastasis of endometrial carcinoma via targeting PTEN/PI3K/AKT signaling pathway.

Background: The incidence of endometrial carcinoma (EC) has been increasing annually, and treatment of advanced cases remains challenging. MicroRNA-424 (miR-424) was reported to affect several types of tumors, but its role in EC has not been studied. Methods: We generated transient knockdown models of miR-424 and PTEN in EC cells. We measured mRNA and protein expression using RT-PCR and western blotting. We evaluated cell proliferation, invasion, migration, and apoptosis using CCK8, Transwell, wound healing, and flow cytometry assays. We also investigated the effect of miR-424 and PTEN on tumor growth using a metastatic tumor model in nude mice. Results: The expression of miR-424 was significantly elevated in EC tissues and cell lines. MiR-424 inhibitor significantly restrained PTEN/PI3K/AKT signaling, while miR-424 mimic activated this pathway. Knockdown of PTEN significantly reversed the effects of miR-424 inhibitor on cell proliferation, invasion, migration, and apoptosis in EC cells. The significant inhibition of tumor growth and ki67 expression caused by miR-424 inhibitor were markedly promoted by sh-PTEN. Conclusions: Our findings suggest that miR-424 inhibitor could inhibit cell proliferation, invasion, migration, epithelial-mesenchymal transition (EMT) process, and tumor growth, while promoting apoptosis in EC. However, the effects of miR-424 inhibitor were markedly reversed by sh-PTEN. This study provides a potential novel therapeutic strategy for the prevention and treatment of EC by targeting miR-424.

Circ_0075960 targets the miR-202-5p/CTNND1 axis to promote the growth and migration of endometrial carcinoma cells via regulating Wnt/β-catenin signaling activity.

Endometrial carcinoma (EC) is one of the most common malignant tumors of the female reproductive tract, involving multiple molecular alterations. Circular RNA (circRNA) dysregulation is frequently observed in EC tissues, suggesting the involvement of circRNA in EC development. We aimed to investigate the role of circ_0075960 in EC. Real-time quantitative polymerase chain reaction (RT-qPCR) and western blot assays were applied for expression analysis. CCK-8, EdU, colony formation, flow cytometry and wound healing assays were employed for functional analysis. The predicted binding relationship between miR-202-5p and circ_0075960 or CTNND1 was validated by dual-luciferase reporter experiment. In vivo animal models were constructed in nude mice to verify the role of circ_0075960 in tumor growth. Circ_0075960 and CTNND1 were upregulated, while miR-202-5p was downregulated in EC. Knockdown of circ_0075960 induced EC cell apoptosis, suppressed cell proliferation and migration, and repressed tumor growth in animal models. MiR-202-5p was targeted by circ_0075960 and it directly bound to CTNND1 3'UTR. The inhibition of circ_0075960 knockdown or miR-202-5p enrichment on EC cell proliferation and migration was reversed by miR-202-5p depletion or CTNND1 overexpression, respectively. Circ_0075960 targeted miR-202-5p to positively regulate CTNND1 expression. Moreover, circ_0075960 knockdown weakened the activity of Wnt/β-catenin signaling via targeting the miR-202-5p/CTNND1 axis. Circ_0075960 targets the miR-202-5p/CTNND1 axis to modulate Wnt/β-catenin signaling activity, thus contributing to the malignant development of EC.

Expression and significance of immune checkpoint B7-homolog 4 in endometrial cancer

Objective: To investigate the expression of B7 homolog 4 (B7-H4) and its clinical significance in endometrial cancer. Methods: A total of 833 patients with endometrial cancer admitted to Peking Union Medical College Hospital, Chinese Academy of Medical Sciences from 2009 to 2019, were enrolled. The expression of B7-H4, mismatch repair (MMR), p53, programmed cell death ligand 1 (PD-L1) protein, and CD8+ T lymphocyte density in endometrial cancer tissues were detected by the EnVision two-step method of immunohistochemical staining. First-generation sequencing (Sanger method) was used to determine molecular subtyping of endometrial cancer. The χ2 test was used to compare the differences in positive expression rate of B7-H4 protein in endometrial cancer tissues with different clinicopathological features and molecular subtyping, PD-L1 protein expression, and CD8+ T lymphocyte density. Survival analyses [including recurrence-free survival (RFS) and disease-specific survival (DSS)] were performed for 664 patients with follow-up time≥3 months, with a median follow-up time of 31 months (range: 4-121 months), and the Cox proportional hazards regression model was used to analyze the relevant factors affecting the prognosis of patients with endometrial cancer. Results: (1) The median age of 833 patients was 58 years (range: 25-88 years); pathological type: 595 with endometrioid carcinoma, 238 with non-endometrioid carcinoma; surgical-pathological staging: 542 cases at stage Ⅰ, 38 cases at stage Ⅱ, 173 cases at stage Ⅲ, and 45 cases at stage Ⅳ. Molecular subtyping was performed in 590 patients, including 50 with POLE mutation, 163 with mismatch repair defect (MMR-d) type, 246 with nospecific molecular change (NSMP) type, and 131 with p53 mutation subtype. (2) B7-H4 protein was expressed with brownish-yellow stainind in the cell membrane and cytoplasm of endometrial carcinoma, and the positivity rate of B7-H4 protein was 71.5% (596/833). The positivity rates of B7-H4 protein among patients with different age, surgical-pathological stage, tumor grade, pathological type, depth of muscular invasion, presence or absence of lymphovascular space invasion, and molecular subtype were significantly different (all P<0.05). The positivity rates of B7-H4 protein among patients with different PD-L1 protein expression and CD8+ T lymphocyte density were not significantly different (P>0.05). The 5-year RFS (83.9%) and DSS (87.3%) of B7-H4 protein-positive patients had an increasing trend compared with the 5-year RFS (77.2%) and DSS (78.1%) of B7-H4 protein-negative patients, but there were not statistically significant differences (P=0.053, P=0.083). (3) Univariate analysis showed that the 5-year RFS and DSS of patients with different age, tumor grade, surgical-pathological stage, pathological type, depth of muscular invasion, lymphovascular space invasion, and molecular subtype were significantly different (all P<0.01). There were no significant differences in 5-year RFS (P=0.184, P=0.113) and DSS (P=0.549, P=0.247) among patients with different CD8+ T lymphocyte density and PD-L1 protein expression. Further analysis according to molecular subtype, the results of CD8+ T lymphocyte density and PD-L1 protein expression showed that the 5-year RFS and DSS of B7-H4 protein-positive patients were higher than those of B7-H4 protein-negative patients with NSMP subtype, low density of CD8+ T lymphocyte and PD-L1 protein-negative endometrial carcinoma (all P<0.05), however, there was no significant difference in 5-year DSS between B7-H4 protein-positive patients and B7-H4 protein-negative patients with PD-L1 protein-negative endometrial cancer (P=0.060). Multivariate analysis showed that positive expression of B7-H4 protein was an independent factor for 5-year RFS (HR=0.27, 95%CI: 0.09-0.78, P=0.016) and DSS (HR=0.16, 95%CI: 0.05-0.58, P=0.005) in patients with NSMP subtype endometrial carcinoma. In patients with low-density CD8+ T lymphocytes endometrial cancer, positive expression of B7-H4 protein was an independent factor for 5-year RFS (HR=0.45, 95%CI: 0.26-0.80, P=0.006), but it was not an independent factor for 5-year DSS. In patients with PD-L1 protein-negative endometrial cancer, B7-H4 protein was not an independent factor for 5-year RFS. Conclusion: B7-H4 protein expressed highly in endometrial carcinoma tissues, and its high expression is closely related to clinicopathological features, molecular subtype of p53 mutant and NSMP, and the favorable prognosis of patients with low density of CD8+ T lymphocyte immunophenotype endometrial carcinoma.

Circular RNA circ_0005667 promotes cisplatin resistance of endometrial carcinoma cells by regulating IGF2BP1 through miR-145-5p.

Circular RNA (circRNA) plays a significant role in cisplatin (DDP) resistance. The purpose of this study was to explore the role of circ_0005667 in DDP resistance of endometrial carcinoma (EC) cells. The expression of circular RNA circ_0005667, microRNA-145-5p (miR-145-5p) and insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) in DDP-sensitive and DDP-resistant EC tissues and EC cells was determined by quantitative real-time PCR (qRT-PCR). The expression of apoptosis-related proteins, drug resistance-related proteins and IGF2BP1 proteins were detected by western blot. The half-maximal inhibitory concentration (IC 50 ) of DDP was determined using a cell counting kit-8 (CCK-8) assay. For functional assays, cell proliferation, migration, invasion and cell apoptosis were determined using 5-ethynyl-2'-deoxyuridine (EdU) assay, wound healing assay, transwell assay and flow cytometry assay, respectively. The binding relationship between miR-145-5p and circ_0005667 or IGF2BP1 was verified by dual-luciferase reporter assay. A xenograft experiment was applied to clarify the functional role of circ_0005667 in vivo . Levels of circ_0005667 and IGF2BP1 were markedly increased, whereas miR-145-5p was downregulated in DDP-resistant EC tissues and cells. The circ_0005667 deficiency could enhance DDP sensitivity, inhibit cell proliferation, migration and invasion and promote cell apoptosis in DDP-resistant EC cells in vitro . Mechanistically, circ_0005667 modulated IGF2BP1 expression through sponging miR-145-5p. In addition, miR-145-5p depletion attenuated circ_0005667 silencing-induced effects in EC cells. The regulation of miR-145-5p in DDP resistance involved low IGF2BP1 expression. In vivo experiments revealed that circ_0005667 silencing could improve the sensitivity of the tumor to DDP. Circ_0005667 enhanced DDP resistance in EC by elevating IGF2BP1 through sponging miR-145-5p.

M6A‐related long noncoding RNAs predict prognosis and indicate therapeutic response in endometrial carcinoma

N6-methyladenosine (m6A) has been identified as the most common, abundant, and conserved internal transcriptional modification. Long noncoding RNAs (lncRNAs) are noncoding RNAs consisting of more than 200 nucleotides, and the expression of various lncRNAs may affect cancer prognosis. The impact of m6A-associated lncRNAs on uterine corpus endometrial carcinoma (UCEC) prognosis is unknown. In this study, UCEC prognosis-related m6A lncRNAs were screened, bioinformatics analysis was performed, and experimental validation was conducted. Endometrial carcinoma (EC) and normal tissue samples were obtained from The Cancer Genome Atlas. The prognosis-related m6A lncRNAs screened by the least absolute shrinkage and selection operator method were used for multivariate Cox proportional risk regression modeling. Principal component analysis and Gene Ontology, immune function difference, and drug sensitivity analyses of the prognostic models were performed. Prognostic analysis was conducted for m6A-associated lncRNAs. The immune infiltration relationship of m6A-associated lncRNAs in EC was identified using the ssGSEA immune infiltration algorithm. A competing endogenouse RNA network was constructed using the LncACTdb database. Finally, quantitative real-time polymerase chain reaction (qRT-PCR) assays were used to validate the differences in m6A-related lncRNA expression in normal and EC cells. CDKN2B-AS1 and MIR924HG were found to be risk factors for EC. RAB11B-AS1 was a protective factor in EC patients. MIR924HG expression was upregulated in KLE and RL95-2 endometrial cancer cell lines. Prognostic models involved RAB11B-AS1, LINC01812, HM13-IT1, TPM1-AS, SLC16A1-AS1, LINC01936, and CDKN2B-AS1. The high-risk group was more sensitive to five compounds (ABT.263, ABT.888, AP.24534, ATRA, and AZD.0530) than the low-risk group. These findings contribute to understanding of the function of m6A-related lncRNAs in UCEC and provide promising therapeutic strategies for UCEC.

TRF-20-S998LO9D inhibits endometrial carcinoma by upregulating SESN2.

Aim: To explore the roles of transfer RNA-derived small RNAs (tsRNAs) in endometrial carcinoma (EC). Materials & methods: tsRNA profiles for EC from TCGAwere analyzed. The functions and mechanisms of tsRNA were explored using in vitro experiments. Results: 173 dysregulated tsRNAswere identified. After validating in EC tissues and serumal exosomesamples from EC patients, a downregulated tsRNA in both EC tissues and serumal exosomes (i.e., tRF-20-S998LO9D) was observed. Exosomal tRF-20-S998LO9D had an area under the curve of 0.768. tRF-20-S998LO9D overexpression inhibited proliferation, migration and invasionand promoted apoptosis of EC cells andtRF-20-S998LO9D knockdown further confirmed its effects. Further analyses showed that tRF-20-S998LO9D upregulated SESN2 in protein levels. Conclusion: tRF-20-S998LO9D inhibits EC cells by upregulating SESN2.

OTUB2 promotes the progression of endometrial cancer by regulating the PKM2-mediated PI3K/AKT signaling pathway.

Endometrial carcinoma (EC) morbidity and mortality have been increasing in recent years. Otubain 2 (OTUB2) was shown to be upregulated in EC patients, so the aim of this study was to explore the role of OTUB2 in EC. Cell Counting Kit-8 (CCK-8), colony formation, enzyme-linked immunosorbent assay, the wound healing assay, and Transwell invasion assays were used to investigate the specific role of OTUB2 in EC tumorigenesis.Real-timepolymerase chain reaction andwestern blot analysis were used to detect the expression of OTUB2 in EC tissues and cells. OTUB2 is upregulated in EC patients and cell lines and is associated with a poor prognosis. The overexpression of OTUB2 promoted glycolysis and induced the proliferation, migration, and invasion of endometrial cancer cells. The silencing of OTUB2 had the opposite effect. In addition, the silencing of OTUB2 significantly suppressed the expression levels of PKM2. Importantly, inhibition of the PKM2/PI3K/AKT signaling pathway significantly reversed the promoting effect of OTUB2 overexpression on EC. OTUB2 regulated the proliferation and invasion of EC cells by regulating the PKM2/PI3K/AKT signaling pathway. OTUB2 may serve as a potential prognostic and therapeutic target in EC.

Histone Deacetylase 3 Governs β-Estradiol-ERα-Involved Endometrial Tumorigenesis via Inhibition of STING Transcription.

Simple SummaryEndometrial carcinoma is one of the most threatening gynecological malignancies to women’s health, with mortality linked to it increasing, and finding novel and effective methods to combat endometrial carcinoma is becoming a clinical challenge. The stimulator of interferon genes (STING) pathway plays a crucial role in antitumor immunity, and it is strictly regulated by many types of post-translational modifications. The aim of our study was to uncover the expression and the contribution of acetylation involved in the regulation of STING to endometrial cancer. We confirmed that STING expression was deregulated by both β-estradiol and HDAC3, and worked as an important regulator of proliferation and apoptosis. Inhibition of HDAC3 increased STING expression, thereby inhibiting tumorigenesis. Therefore, this study uncovers a novel molecular mechanism by which HDAC3 inhibits STING transcription via β-estradiol-ERα, and provides a promising therapy with a combination of HDAC and STING for combating endometrial cancer.Purpose: The stimulator of interferon genes (STING) pathway plays a crucial role in antitumor immunity, and it is strictly regulated by many types of post-translational modifications. However, the contribution of acetylation involved in the regulation of STING to endometrial tumorigenesis remains unclear. Methods: We attempted to identify the key role of STING in endometrial carcinoma (EC) tissue and cell lines and explore its epigenetic regulation mechanism by HDACs that are critically involved in EC. We used IHC and qRT-PCR to detect the protein level and mRNA level of STING expression in endometrial carcinoma tissues, then explored the potential role of STING in tumor proliferation and apoptosis by CCK8 and flow cytometry, and identified the STING effect in the tumorigenicity by a mouse xenograft assay. We explored the possible relationship of acetylation alteration in STING regulation by ChIP analysis and Co-IP, and we knocked out STING in ECC1 and Ishikawa cells using CRISPR-Cas9 to further confirm the critical role of STING restoration induced by HDAC3 inhibitor RGFP-966 in the proliferation and apoptosis. Results: We found that STING expression was largely decreased and worked as an important regulator of cell proliferation and apoptosis; either activated or overexpressed STING, with both pharmacological and genetic approaches, largely blocked cell proliferation and induced apoptosis in EC. Moreover, STING expression was deregulated by both β-estradiol and HDAC3. Mechanically, we determined that HDAC3 can interact with β-estradiol-ERα and induce deacetylation of histone 3 lysine 4 at the STING promoter, thereby decreasing STING expression. Inhibition of HDAC3 increased STING expression, thereby inhibiting tumorigenesis. Conclusion: This study reveals a novel molecular mechanism by which HDAC3 inhibits STING transcription via β-estradiol-ERα and provides a promising therapy (a combination of HDAC and STING) for combating endometrial cancer.