LncRNA PCAT1 promotes metastasis of endometrial carcinoma through epigenetical downregulation of E-cadherin associated with methyltransferase EZH2

The Promotive and Inhibitory Role of Long Non-Coding RNAs in Endometrial Cancer Course-A Review

Endometrial cancer is one of the most common malignant tumours in women. The development of this tumour is associated with several genetic disorders, many of which are still unknown. One type of RNA molecules currently being intensively studied in many types of cancer are long non-coding RNAs (lncRNAs). LncRNA-coding genes occupy a large fraction of the human genome. LncRNAs regulate many aspects of cell development, metabolism, and other physiological processes. Diverse types of lncRNA can function as a tumour suppressor or an oncogene that can alter migration, invasion, cell proliferation, apoptosis, and immune system response. Recent studies suggest that selected lncRNAs are important in an endometrial cancer course. Our article describes over 70 lncRNAs involved in the development of endometrial cancer, which were studied via in vivo and in vitro research. It was proved that lncRNAs could both promote and inhibit the development of endometrial cancer. In the future, lncRNAs may become an important therapeutic target. The aim of this study is to review the role of lncRNAs in the development of carcinoma of uterine body.

Analysis on EZH2: mechanism identification of related CeRNA and its immunoassay in hepatocellular carcinoma

OBJECTIVE

To screen the possible potential signaling pathways related to enhancer of zeste homolog 2 (EZH2) based on ceRNA mechanism, and to analyze the correlation between E2H2 and depths of various immune cell infiltration depths. The relationship between different immune checkpoints were also analyzed.

METHODS

First, the expression of EZH2 in pan-cancer (18 malignancies) was analyzed with the TCGA database. Hepatocellular carcinoma (HCC) tissues of 374 cases and normal tissues of 50 cases were analyzed in terms of the differential expression, overall survival (OS) and progression-free-survival (PFS). Then, we conducted GO and KEGG enrichment analysis on target gene. We also analyzed mRNA-miRNA and MicroRNA (miRNA)- long non-coding RNA (lncRNA) correlation with starbase databse, so as to determine the potential ceRNA mechanism associated with EZH2. Finally, immunoassay and drug-sensitivity analysis of EZH2 was performed.

RESULTS

Seven potential EZH2-related ceRNA pathways were screened out, namely lncRNA: Small Nucleolar RNA Host Gene 1 (SNHG1), SNHG 3, and SNHG 6-miR-101-3p-EZH2; and lncRNA: Long Intergenic Non-Protein Coding RNA 1978 (LINC01978), SNHG12, Ring Finger Protein 216 Pseudogene 1 (RNF216P1), and Coiled-coil Domain Containing 18 Antisense RNA 1 (CCDC18-AS1)-let-7c-5p-EZH2. Finally, 4 potential EZH2-related ceRNA pathways were identified through qPCR.According to immune correlation analysis, EZH2 may be positively correlated with T cells follicular helper, T cells Cluster of differentiation (CD)4 memory activated, Macrophages M0, and B cells memory (P < 0.05, cof > 0.2); while be negatively correlated with T cells CD4 + memory resting (P < 0.05, cof < -0.2). And EZH2 is positively correlated with Programmed Cell Death 1 (PDCD1) (R = 0.22), CD274 (R = 0.3) and Cytotoxic T-Lymphocyte Associated Protein 4 (CTLA4) (R = 0.23). According to drug sensitivity analysis, patients in the high expression group were more susceptible to the effects of various drugs including Sorafenib, 5-Fluorouracil, Doxorubicin, Etoposide, Paclitaxel, and Vinorelbine than those with low expression.

CONCLUSION

This study revealed seven potential pathways of Enhancer of Zeste Homolog 2 (EZH2)-related ceRNA mechanisms: lncRNA (SNHG3, 6) -Mir-101-3P-ezh2; lncRNA (SNHG12, RNF216P1)-let-7c-5p-EZH2. We also analyzed the immunity and drug sensitivity of EZH2. Our study proves that EZH2 still has great research prospects in HCC.

Mutual interaction of lncRNAs and epigenetics: focusing on cancer

Long noncoding RNAs are characterized as noncoding transcripts longer than 200 nucleotides in response to a variety of functions within the cells. They are involved in almost all cellular mechanisms so as epigenetics. Given that epigenetics is an important phenomenon, which participates in the biology of complex diseases, many valuable studies have been performed to demonstrate the control status of lncRNAs and epigenetics. DNA methylation and histone modifications as epigenetic mechanisms can regulate the expression of lncRNAs by affecting their coding genes. Reciprocally, the three-dimensional structure of lncRNAs could mechanistically control the activity of epigenetic-related enzymes. Dysregulation in the mutual interaction between epigenetics and lncRNAs is one of the hallmarks of cancer. These mechanisms are either directly or indirectly involved in various cancer properties such as proliferation, apoptosis, invasion, and metastasis. For instance, lncRNA HOTAIR plays a role in regulating the expression of many genes by interacting with epigenetic factors such as DNA methyltransferases and EZH2, and thus plays a role in the initiation and progression of various cancers. Conversely, the expression of this lncRNA is also controlled by epigenetic factors. Therefore, focusing on this reciprocated interaction can apply to cancer management and the identification of prognostic, diagnostic, and druggable targets. In the current review, we discuss the reciprocal relationship between lncRNAs and epigenetic mechanisms to promote or prevent cancer progression and find new potent biomarkers and targets for cancer diagnosis and therapy.

Application of Pelvic Magnetic Resonance Imaging Scan Combined with Serum Pyruvate Kinase Isozyme M2, Neutrophil Gelatinase-Associated Lipocalin, and Soluble Leptin Receptor Detection in Diagnosing Endometrial Carcinoma

Objective

To explore the application value of pelvic magnetic resonance imaging (MRI) scan combined with serum pyruvate kinase isozyme M2 (PKM2), neutrophil gelatinase-associated lipocalin (NGAL), and soluble leptin receptor (sOB-R) detection in diagnosing endometrial carcinoma (EC).

Methods

The clinical data of 45 patients with pathologically confirmed EC treated in our hospital from May 2019 to May 2020 were retrospectively analyzed. All patients received pelvic MRI scan, serum PKM2, NGAL and sOB-R detection was performed, and the combination of the two was performed so as to analyze the diagnostic application value of the three modalities.

Results

Compared with the joint detection, the number of true positive cases, sensitivity, specificity, and accuracy rate obtained by a single application of pelvic MRI or serum PKM2, NGAL, and sOB-R detection were obviously lower; the area under the ROC curve of the joint detection was obviously larger than that of single detection; the results of the joint detection were better than those of single detection (P < 0.05); the combined diagnosis obtained the highest sensitivity.

Conclusion

Combining pelvic MRI with serum PKM2, NGAL, and sOB-4 detection can effectively promote the diagnostic accuracy for EC, presenting significant clinical diagnostic value.

The biological function of the long non-coding RNA endogenous born avirus-like nucleoprotein in lung adenocarcinoma is mediated through the microRNA-655-3p/B-cell lymphoma-2 axis

Lung adenocarcinoma (LUAD) is a subtype of lung cancer, and therapy remains a great challenge. A growing body of evidence shows that long-chain non-coding RNAs (lncRNAs) play an important role in the occurrence and development of LUAD. This study investigated the roles and mechanisms of action of EBLN3P in LUAD. The bioinformatics software starBase and TargetScan were used to predict the binding sites of the lncRNA endogenous born avirus-like nucleoprotein (EBLN3P) and microRNA (miR)-655-3p in LUAD. The regulatory role of EBLN3P and miR-655-3p in cell proliferation was verified through the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2 H-tetrazolium bromide (MTT) assay. The binding sites between EBLN3P, miR-655-3p, and B-cell lymphoma-2 (Bcl-2) were assessed using dual-luciferase reporter assay, western blotting, and quantitative reverse transcription polymerase chain reaction (qRT-PCR). Flow cytometry (FCM) was performed to analyze the apoptotic rates of A549 cells after transfection. The results revealed that EBLN3P was upregulated, whereas miR-655-3p was downregulated in LUAD cell lines (A549 and NCI-H23). Bioinformatics analysis and dual-luciferase reporter assays indicated that EBLN3P interacted with miR-655-3p. Knockdown of EBLN3P notably inhibited the bioactivity and induced apoptosis in A549 cells by upregulating miR-655-3p. Mechanistically, miR-655-3p inhibits cell viability and induces apoptosis by inhibiting Bcl-2 expression. The high expression of Bcl-2 reversed the impact of miR-655-3p on the inhibition of cell bioactivity and induction of apoptosis in A549 cells. In conclusion, this study demonstrated that EBLN3P silencing inhibits bioactivity and induces apoptosis via the miR-655-3p/Bcl-2 axis, providing a potential therapeutic target for lung adenocarcinoma.

Nine Pyroptosis-Related lncRNAs are Identified as Biomarkers for Predicting the Prognosis and Immunotherapy of Endometrial Carcinoma

Background

Endometrial carcinoma (EC) is one of the most common malignancies. Immunotherapy has shown promising effects in the treatment against specific subtypes of EC.

Methods

The RNA and clinical information of patients with EC were acquired from The Cancer Gene Atlas (TCGA) database. Firstly, the differentially expressed pyroptosis-related lncRNAs (PRLs) were screened between the tumor and normal control tissue. Secondly, the PRLs closely related to survival were identified by univariate and multivariate regression analysis, based on which, we evaluated the risk score for each EC patient to construct a risk signature. Moreover, we assessed the prognostic value, clinical relevance immunity, and immunotherapy based on this signature.

Results

We screened out 9 individual PRLs (AC087491.1, AL353622.1, AL035530.2, LINC02036, AL021578.1, AL390195.2, AC009097.2, AC004585.1, and AC244517.7) closely related to the prognosis of EC. Kaplan–Meier analyses showed a poorer prognosis for the patients in the high-risk FRLs signature (P < 0.001). The area under the curve (AUC) for 1 year, 2 years, 3 years was 0.693, 0.694, 0.750, respectively. Our risk model could be considered as an independent prognostic marker for EC (P < 0.001, HR:2.172, 95% CI:1.532–3.079). Moreover, immune functions and checkpoints were generally different in the 2 groups. Simulation analysis by termed immunophenoscores hinted that immunotherapy might bring optimal therapeutic effect in the low-risk group.

Conclusion

We successfully developed a novel signature with 9 lncRNAs related to pyroptosis, which may be used as biomarkers to evaluate the prognosis and immune treatment of EC.

A seven-m6A regulator-related CpG site-based prognostic signature for endometrial carcinoma

BACKGROUND

Endometrial carcinoma (EC) has become a common gynecologic malignancy with a high mortality. The m6A regulators have been identified to be closely associated with multiple human cancers including EC. However, the CpG methylation signature related to m6A regulators in EC remains unclear.

METHOD

The methylation profiles of EC patients including cancer samples and adjacent normal samples were obtained from The Cancer Genome Atlas (TCGA) database. The CpG sites in 20 m6A regulators were identified. Univariate Cox regression and LASSO Cox regression analysis were used to screen key CpG sites which were located at m6A regulators and significantly related to the prognosis of EC. The predictive model for EC prognosis was constructed, and multivariate Cox regression analysis was applied to explore whether the risk score derived from the model could function as an independent signature for EC prognosis. Meanwhile, a nomogram model was constructed by combing the independent prognostic signatures for prediction of the long-term survival in EC patients.

RESULTS

A total of 396 CpG sites located at 20 m6A regulators were identified. A specific predictive model for EC prognosis based on 7 optimal CpG sites was constructed, which presented good performance in prognosis prediction of EC patients. Moreover, risk score was determined to be an independent signature both in the training set and validation set. By bringing in three independent prognostic factors (age, risk score, and TNM stage), the nomogram was constructed and could effectively predict the 3- and 5-year survival rates of EC patients.

CONCLUSION

Our study suggested that the CpG sites located at m6A regulators might be considered as potential prognostic signatures for EC patients.

Knockdown of long non-coding RNA RP11-297P16.3 inhibits the migration and invasion of laryngeal squamous carcinoma cells

PURPOSE

Laryngeal cancer has a poor prognosis when progressing to an advanced stage with limited treatment options. Therefore, understanding the underlying mechanisms is important to identify novel treatment targets. Long non-coding RNAs (lncRNAs) have been shown to play oncogenic roles in cancer, including in laryngeal cancer. We previously discovered that the lncRNA RP11-297P16.3 is overexpressed in laryngeal squamous cell carcinoma (LSCC) based on RNA-sequencing data. Therefore, the aim of the present study was to investigate the effects of knockdown of RP11-297P16.3 on the migration and invasion of LSCC cells, and the significance of these effects.

METHODS

Six methods were employed to assess the function of RP11-297P16.3 including gene silencing, RT-PCR, the 5-Ethynyl-20-deoxyuridine (EdU) staining assay, Scratch wound-healing assay, transwell assay, and Western blot.

RESULTS

The results show that the expression of RP11-297P16.3 in the si-lncRNA group was significantly decreased compared with those in the BC (blank control) and NC (negative control) groups. Moreover, knockdown of RP11-297P16.3 significantly inhibited the migration and invasion of LSCC cells but had no effect on cell proliferation. The protein expression of N-cadherin and vimentin was notably decreased after RP11-297P16.3 knockdown; whereas, the protein expression of cadherin was significantly increased CONCLUSION: These results suggested that RP11-297P16.3 may inhibit the migration and invasion of LSCC cells by regulating the epithelial-mesenchymal transition process, suggesting that RP11-297P16.3 is a potential new target for treating LSCC.

Long non-coding RNAs in endometrial physiology and pathophysiology

The endometrium is an essential component of the female uterus which provides the environment for pregnancy establishment and maintenance. Abnormalities of the endometrium not only lead to difficulties in establishing and maintaining pregnancy but also play a causative role in diseases of endometrial origin including endometriosis and endometrial cancer. Non-coding RNAs are proposed to play a role in regulating the genome in both normal endometrial physiology and pathophysiology. In this review, we first provide a general overview of non-coding RNAs and reproductive physiology of the endometrium. We then discuss the role on non-coding RNAs in normal endometrial physiology and pathophysiology of endometrial infertility. We then conclude with non-coding RNAs in the pathophysiology of endometriosis and endometrial cancer.

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.

Roles Played by YY1 in Embryonic, Adult and Cancer Stem Cells

Accumulating evidence strongly indicates that the presence of cancer stem cells (CSCs) leads to the emergence of worse clinical scenarios, such as chemo- and radiotherapy resistance, metastasis, and cancer recurrence. CSCs are a highly tumorigenic population characterized by self-renewal capacity and differentiation potential. Thus, CSCs establish a hierarchical intratumor organization that enables tumor adaptation to evade the immune response and resist anticancer therapy. YY1 functions as a transcription factor, RNA-binding protein, and 3D chromatin regulator. Thus, YY1 has multiple effects and regulates several molecular processes. Emerging evidence indicates that the development of lethal YY1-mediated cancer phenotypes is associated with the presence of or enrichment in cancer stem-like cells. Therefore, it is necessary to investigate whether and to what extent YY1 regulates the CSC phenotype. Since CSCs mirror the phenotypic behavior of stem cells, we initially describe the roles played by YY1 in embryonic and adult stem cells. Next, we scrutinize evidence supporting the contributions of YY1 in CSCs from a number of various cancer types. Finally, we identify new areas for further investigation into the YY1-CSCs axis, including the participation of YY1 in the CSC niche.

8q24.21 Locus: A Paradigm to Link Non-Coding RNAs, Genome Polymorphisms and Cancer

The majority of the human genome is comprised of non-protein-coding genes, but the relevance of non-coding RNAs in complex diseases has yet to be fully elucidated. One class of non-coding RNAs is long non-coding RNAs or lncRNAs, many of which have been identified to play a range of roles in transcription and translation. While the clinical importance of the majority of lncRNAs have yet to be identified, it is puzzling that a large number of disease-associated genetic variations are seen in lncRNA genes. The 8q24.21 locus is rich in lncRNAs and very few protein-coding genes are located in this region. Interestingly, the 8q24.21 region is also a hot spot for genetic variants associated with an increased risk of cancer. Research focusing on the lncRNAs in this area of the genome has indicated clinical relevance of lncRNAs in different cancers. In this review, we summarise the lncRNAs in the 8q24.21 region with respect to their role in cancer and discuss the potential impact of cancer-associated genetic polymorphisms on the function of lncRNAs in initiation and progression of cancer.

SP1-induced long non-coding RNA SNHG6 facilitates the carcinogenesis of chondrosarcoma through inhibiting KLF6 by recruiting EZH2

Small nucleolar RNA host gene 6 (SNHG6) is a newly discovered long non-coding RNA (lncRNA), while the regulatory mechanism of SNHG6 in chondrosarcoma is largely unknown. Here we found that SNHG6 expression was upregulated and showed positive correlation with the progression of chondrosarcoma. Functional assays demonstrated that SNHG6 was required for the proliferation, migration, and invasion of chondrosarcoma cells. Mechanistic study revealed that SNHG6 could recruit EZH2 and maintain high level of H3K27me3 to repress the transcription of tumor-suppressor genes, including KLF6. KLF6 was found to bind to the promoter region of SP1 and restrained its transcription, while SP1 could be recruited to the promoter region of SNHG6 and promoted its transcription to form a positive loop. In summary, this study reveals that SP1-induced SNHG6 forms a positive loop to facilitate the carcinogenesis of chondrosarcoma through the suppression of KLF6 by recruiting EZH2, which manifests the oncogenic function of SNHG6 in chondrosarcoma.

RNA sequencing-based long non-coding RNA analysis and immunoassay in ovarian endometriosis

PROBLEM

The mechanism underlying endometriosis is currently unknown. However, studies have indicated that immunity plays an important role in endometriosis occurrence and development. Long non-coding RNAs (lncRNAs) do not encode proteins but participate in a variety of biological processes via different mechanisms. This study investigated differences in immune cells and immune-related lncRNAs via high-throughput RNA sequencing (RNA-seq) analysis of ectopic and eutopic endometria with endometriosis.

METHOD OF STUDY

RNA-seq was performed in six pairs of ectopic and eutopic endometria samples, and real-time quantitative polymerase chain reaction was used to verify the results of RNA-seq for 30 pairs of samples. Different immune cell types were identified based on the RNA-seq results, using ImmuCellAI. Immune-related lncRNAs were obtained by analyzing immune-related genes from the ImmPort Database and RNA-seq results.

RESULTS

A total of 952 differentially expressed lncRNAs were identified, of which 446 were immune-related. The ectopic and eutopic endometrium could easily be distinguished in the principal component analysis of immune-related lncRNAs. Analysis of 24 immune cell types revealed the differential abundance of 13 types. Sixty immune-related mRNAs were associated with the top 20 dysregulated immune-related lncRNAs, 11 of which were transcripts of immune cell marker genes.

CONCLUSIONS

Our data indicated that a variety of dysregulated lncRNAs were associated with immunity, and these may provide a basis for future immune-related endometriosis research.

Circ_0109046 promotes the malignancy of endometrial carcinoma cells through the microRNA-105/SOX9/Wnt/β-catenin axis

Emerging evidence suggests the important involvements of circular RNAs (circRNAs) in cancer progression. This study focuses on the function of Circ_0109046 on the malignancy of endometrial carcinoma (EC) cells and the molecules involved. First, high expression of Circ_0109046 was found in EC tissues compared to the adjacent tissues, and it predicted unfavorable prognosis in patients. Similarly, high expression of Circ_0109046 was confirmed in EC cells relative to that in normal endometrial epithelial cells. Silencing of Circ_0109046 in AN3-CA cells inhibited proliferation and aggressiveness but increased apoptosis of cells. Circ_0109046 was mainly sub-localized in cytoplasm, and it mediated SOX9 expression through sponging microRNA (miR)-105. The proliferation and aggressiveness of EC cells suppressed by Circ_0109046 downregulation was recovered upon SOX9 overexpression. SOX9 activated the Wnt/β-catenin pathway. Furthermore, downregulation of Circ_0109046 reduced the growth of xenograft tumors in nude mice. This study evidenced that Circ_0109046 upregulates SOX9 expression through sponging miR105, leading to activation of Wnt/β-catenin signaling and the malignant growth of EC. This study may offer novel understanding in EC treatment.

PCAT1 induced by transcription factor YY1 promotes cholangiocarcinoma proliferation, migration and invasion by sponging miR-216a-3p to up-regulate oncogene BCL3

This study was designed to illustrate the function and role of PCAT1 in CCA. The relative expression was confirmed by RT-qPCR and western blot. The biological function of PCAT1 was evaluated by CCK8, EdU, colony formation, wound healing, transwell, and subcutaneous tumor formation assays. Protein levels of EMT markers were measured by western blot. The binding relationship was predicted by JASPAR and starBase. The binding of YY1 to PCAT1 promoter was assessed by ChIP and luciferase reporter. The binding capacity between miR-216a-3p and PCAT1 as well as BCL3 was assessed by luciferase reporter and AGO2-RIP assays. In this study, we found that PCAT1 was up-regulated in CCA tissues and cells, and the PCAT1 overexpression was associated with poor prognosis. Moreover, PCAT1 was assessed as an independent risk factor of prognosis for CCA patients. Amplified PCAT1 was found to promote tumor proliferation, migration, invasion and EMT process, whereas PCAT1 knockdown inhibited these malignant phenotypes. Mechanistically, PCAT1 was predominantly localized in the cytoplasm and competitively bound miR-216a-3p to increase BCL3 expression. In addition, PCAT1 was activated by transcription factor YY1. This study revealed that PCAT1 acted as an oncogene in CCA, and the YY1/PCAT1/miR-216a-3p/BCL3 axis exhibited critical functions in CCA progression.