lncRNA SNHG5 Modulates Endometrial Cancer Progression via the miR-25-3p/BTG2 Axis

The role of ncRNAs and exosomes in the development and progression of endometrial cancer

Endometrial cancer (EC) is one of the most common gynecologic cancers. In recent years, research has focused on the genetic characteristics of the tumors to detail their prognosis and tailor therapy. In the case of EC, genetic mutations have been shown to underlie their formation. It is very important to know the mechanisms of EC formation related to mutations induced by estrogen, among other things. Noncoding RNAs (ncRNAs), composed of nucleotide transcripts with very low protein-coding capacity, are proving to be important. Their expression patterns in many malignancies can inhibit tumor formation and progression. They also regulate protein coding at the epigenetic, transcriptional, and posttranscriptional levels. MicroRNAs (miRNAs), several varieties of which are associated with normal endometrium as well as its tumor, also play a particularly important role in gene expression. MiRNAs and long noncoding RNAs (lncRNAs) affect many pathways in EC tissues and play important roles in cancer development, invasion, and metastasis, as well as resistance to anticancer drugs through mechanisms such as suppression of apoptosis and progression of cancer stem cells. It is also worth noting that miRNAs are highly precise, sensitive, and robust, making them potential markers for diagnosing gynecologic cancers and their progression. Unfortunately, as the incidence of EC increases, treatment becomes challenging and is limited to invasive tools. The prospect of using microRNAs as potential candidates for diagnostic and therapeutic use in EC seems promising. Exosomes are extracellular vesicles that are released from many types of cells, including cancer cells. They contain proteins, DNA, and various types of RNA, such as miRNAs. The noncoding RNA components of exosomes vary widely, depending on the physiology of the tumor tissue and the cells from which they originate. Exosomes contain both DNA and RNA and have communication functions between cells. Exosomal miRNAs mediate communication between EC cells, tumor-associated fibroblasts (CAFs), and tumor-associated macrophages (TAMs) and play a key role in tumor cell proliferation and tumor microenvironment formation. Oncogenes carried by tumor exosomes induce malignant transformation of target cells. During the synthesis of exosomes, various factors, such as genetic and proteomic data are upregulated. Thus, they are considered an interesting therapeutic target for the diagnosis and prognosis of endometrial cancer by analyzing biomarkers contained in exosomes. Expression of miRNAs, particularly miR-15a-5p, was elevated in exosomes derived from the plasma of EC patients. This may suggest the important utility of this biomarker in the diagnosis of EC. In recent years, researchers have become interested in the topic of prognostic markers for EC, as there are still too few identified markers to support the limited treatment of endometrial cancer. Further research into the effects of ncRNAs and exosomes on EC may allow for cancer treatment breakthroughs.

Non-coding RNAs in gynecologic cancer

The term "gynecologic cancer" pertains to neoplasms impacting the reproductive tissues and organs of women encompassing the endometrium, vagina, cervix, uterus, vulva, and ovaries. The progression of gynecologic cancer is linked to various molecular mechanisms. Historically, cancer research primarily focused on protein-coding genes. However, recent years have unveiled the involvement of non-coding RNAs (ncRNAs), including microRNAs, long non-coding RNAs (LncRNAs), and circular RNAs, in modulating cellular functions within gynecological cancer. Substantial evidence suggests that ncRNAs may wield a dual role in gynecological cancer, acting as either oncogenic or tumor-suppressive agents. Numerous clinical trials are presently investigating the roles of ncRNAs as biomarkers and therapeutic agents. These endeavors may introduce a fresh perspective on the diagnosis and treatment of gynecological cancer. In this overview, we highlight some of the ncRNAs associated with gynecological cancers.

LncRNA THOR promotes endometrial cancer progression through the AKT and ERK signaling pathways

The long noncoding RNA (lncRNA) THOR is highly conserved and expressed in various human cancer tissues, although its potential role and underlying mechanism in endometrial cancer (EC) remain unknown. This study aims to explore THOR's biological function and molecular mechanism in EC progression. THOR expression in EC tissues and cell lines was detected by quantitative reverse transcription PCR (qRT-PCR) and in situ hybridization (ISH). THOR expression based on The Cancer Genome Atlas (TCGA) and clinical sample analyses was significantly higher in EC tissues than normal tissues, and higher THOR levels were closely associated with poor overall survival in EC. Additionally, a positive correlation between ISH-detected THOR expression and pathological grade was observed. CCK-8, colony formation, and transwell migration and invasion assays revealed that THOR significantly enhances the proliferation, migration, and invasion abilities of EC cells. Moreover, IGF2BP1 protein expression and ERK and AKT protein phosphorylation levels in EC cells increased significantly with THOR overexpression in EC cells. In conclusion, our findings suggest that THOR promotes EC cell growth and invasion, and IGF2BP1-mediated AKT and ERK signaling pathways activation might be involved. Clinically, THOR is significantly expressed in EC, and high THOR expression correlates with poor prognosis, making it a potential prognostic marker for EC.

LncRNA-miRNA-mRNA regulatory axes in endometrial cancer: a comprehensive overview

INTRODUCTION

Recent research on tumorigenesis and progression has opened up an array of novel molecular mechanisms in the form of interactions between cellular non-coding RNAs (long non-coding RNA[lncRNA]/microRNA [miRNA]) and coding transcripts that regulate health and disease. Endometrial cancer (EC) is a prominent gynecological malignancy with a high incidence rate and poorly known etiology and prognostic factors that hinder the success of disease management. The emerging role of lncRNA-miRNA-mRNA interactions and their dysregulation in the pathophysiology of EC has been elucidated in many recent studies.

METHODS

A thorough literature review was conducted to explore information about lncRNA-miRNA-mRNA axes in EC.

RESULTS

Several lncRNAs act as molecular sponges that sequester various tumor suppressor miRNAs to inhibit their function, leading to the dysregulation of their target mRNA transcripts that contribute to the EC regulation.

CONCLUSIONS

This review summarizes these networks of molecular mechanisms and their contribution to different aspects of endometrial carcinogenesis, leading to a better conceptualization of the molecular pathways that underlie the disease and helping establish novel diagnostic biomarkers and therapeutic intervention points to aid the curative intent of EC.

Expression of Long Non-Coding RNA (lncRNA) SNHG5 in Patients with Refractory Diabetic Macular Edema and Its Regulatory Mechanism

BACKGROUND The aim of this study was to assess use of lncRNAs as biomarkers in serum and aqueous humor of patients with diabetic macular edema (DME). MATERIAL AND METHODS Optical coherence tomography and fundus photography were used to analyze the retinal features of the patients. RT-qPCR was used to analyze the differential expression of lncRNA snhg5 in patients who have idiopathic macular hole (MH), DME, or refractory DME. The relationship between SNHG5 and the clinical characteristics of the patients was analyzed. The effect of SNHG5 on the hyperplasia and apoptosis of human retino-microvascular endothelial cells (HRMECs) and its mechanism were analyzed in vitro. RESULTS Patients with idiopathic MH developed retinal nerve epithelium rupture and retinal fundus thickening, and patients with DME or refractory DME showed significant macular edema with hemorrhaging. The refractory DME patients improved after treatment but still showed significant macular edema and multiple laser scarring. SNHG5 expression was not only low in the atrial fluid and plasma in DME patients, but also lower in the refractory DME group compared to the idiopathic MH patients. SNHG5 expression in the aqueous humor and plasma was negatively correlated with disease duration, body mass index, and levels of fasting blood glucose, glycated hemoglobin, proteinuria, and glycosuria. In the in vitro experiments, SNHG5 expression was significantly downregulated in high glucose-induced HMECs. After SNHG5 overexpression, cell proliferation, angiogenesis, and VEGF-A protein levels were distinctly downregulated. CONCLUSIONS SNHG5 correlates with the development of DME and is a potential target for therapy.

LncRNA DCST1-AS1 Promotes Endometrial Cancer Progression by Modulating the MiR-665/HOXB5 and MiR-873-5p/CADM1 Pathways

Dysregulation of long noncoding RNA (lncRNA) is implicated in the initiation and progression of various tumors, including endometrial cancer (EC). However, the mechanism of lncRNAs in EC tumorigenesis and progression remains largely unexplored. In this work, we identified a novel lncRNA DC-STAMP domain-containing 1-antisense 1 (DCST1-AS1), which is highly upregulated and correlated with poor survival in EC patients. Overexpression of DCST1-AS1 significantly enhanced EC cell proliferation, colony formation, migration, and invasion in vitro and promoted tumor growth of EC in vivo. Mechanistically, DCST1-AS1 mediated EC progression by inducing the expression of homeobox B5 (HOXB5) and cell adhesion molecule 1 (CADM1), via acting as a competing endogenous RNA for microRNA-665 (miR-665) and microRNA-873-5p (miR-873-5p), respectively. In addition, we found that the expression of miR-665 and miR-873-5p was significantly downregulated, while HOXB5 and CADM1 expression levels were increased in EC tissues. Taken together, our findings support the important role of DCST1-AS1 in EC progression, and DCST1-AS1 may be used as a prognostic biomarker as well as a potential therapeutic target for EC.

Towards Personalized Medicine: Non-Coding RNAs and Endometrial Cancer

Endometrial cancer (EC) is the most frequent female cancer associated with excellent prognosis if diagnosed at an early stage. The risk factors on which clinical staging is based are constantly updated and genetic and epigenetic characteristics have recently been emerging as prognostic markers. The evidence shows that non-coding RNAs (ncRNAs) play a fundamental role in various biological processes associated with the pathogenesis of EC and many of them also have a prognosis prediction function, of remarkable importance in defining the therapeutic and surveillance path of EC patients. Personalized medicine focuses on the continuous updating of risk factors that are identifiable early during the EC staging to tailor treatments to patients. This review aims to show a summary of the current classification systems and to encourage the integration of various risk factors, introducing the prognostic role of non-coding RNAs, to avoid aggressive therapies where not necessary and to treat and strictly monitor subjects at greater risk of relapse.

Knockdown of long non-coding RNA small nucleolar RNA host gene 9 or hexokinase 2 both suppress endometrial cancer cell proliferation and glycolysis

AIM

Endometrial cancer (EC) is a common type of malignant gynecological cancer. Small nucleolar RNA host gene 9 (SNHG9) has been discovered to serve a role in several types of cancer; however, the role of SNHG9 in EC remains unclear. The present study aimed to investigate the effects of lncRNA SNHG9 on cell proliferation and glycolysis in EC cells.

METHODS

SNHG9 and hexokinase 2 (HK2) mRNA expression levels were measured by reverse transcription-quantitative PCR. Glucose consumption and lactate production were detected by the glycolysis cell-based assay kit. Cell Counting Kit-8 and colony formation assays were conducted to detect cell proliferation. The knockdown experiments of SNHG9 and HK2 were carried out by transfection of corresponding small interference RNAs (siRNA). The SNHG9-overexpressed plasmid was transfected into the cells to upregulate SNHG9. HK2 protein levels were analyzed by western blotting assay.

RESULTS

SNHG9 expression levels were significantly upregulated in EC tissues and cells. The knockdown of SNHG9 subsequently effectively attenuated cell proliferation and glycolysis in vitro, while SNHG9 overexpression reported the opposite effects. Notably, the transfection of 2-DG partially reversed the promoting effect of SNHG9 on glycolysis. Downregulation of HK2 markedly decreased cell proliferation and glycolysis in EC cells antagonized SNHG9.

CONCLUSION

Either downregulation of SNHG9 or HK2 inhibits EC cell proliferation and glycolysis via repressing EC cell proliferation and glycolysis.

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.

Knockdown of Long Noncoding RNA SNHG14 Protects H9c2 Cells Against Hypoxia-induced Injury by Modulating miR-25-3p/KLF4 Axis in Vitro

ABSTRACT

Cyanotic congenital heart disease (CCHD) is the main cause of death in infants worldwide. Long noncoding RNAs (lncRNAs) have been pointed to exert crucial roles in development of CHD. The current research is designed to illuminate the impact and potential mechanism of lncRNA SNHG14 in CCHD in vitro. The embryonic rat ventricular myocardial cells (H9c2 cells) were exposed to hypoxia to establish the model of CCHD in vitro. Quantitative real-time polymerase chain reaction was conducted to examine relative expressions of SNHG14, miR-25-3p, and KLF4. Cell viability was determined by the MTT assay. Lactate dehydrogenase (LDH) was measured by an LDH assay kit. Apoptosis-related proteins (Bax and Bcl-2) and KLF4 were detected by Western Blot. The targets of SNHG14 and miR-25-3p were verified by the dual-luciferase reporter assay. SNHG14 and KLF4 were upregulated, whereas miR-25-3p was downregulated in hypoxia-induced H9c2 cells and cardiac tissues of patients with CCHD compared with their controls. Knockdown of SNHG14 or overexpression of miR-25-3p facilitated cell viability, while depressing cell apoptosis and release of LDH in hypoxia-induced H9c2 cells. MiR-25-3p was a target of SNHG14 and inversely modulated by SNHG14. MiR-25-3p could directly target KLF4 and negatively regulate expression of KLF4. Repression of miR-25-3p or overexpression of KLF4 reversed the suppression impacts of sh-SNHG14 on cell apoptosis and release of LDH as well as the promotion impact of sh-SNHG14 on cell viability in hypoxia-induced H9c2 cells. Sh-SNHG14 protected H9c2 cells against hypoxia-induced injury by modulating miR-25-3p/KLF4 axis in vitro.

Decreased miR-132 plays a crucial role in diabetic encephalopathy by regulating the GSK-3β/Tau pathway

Diabetic encephalopathy (DE) is a global concern and Gordian knot worldwide. miRNA-132 (miR-132) is a class of negative gene regulators that promote diabetic pathologic mechanisms and its complications. However, the molecular mechanisms of miR-132 in DE are elusive, thus an alternative therapeutic strategy is urgently in demand. The present study explored the protective effect and the underlying mechanism of miR-132 on DE via the GSK-β/Tau signaling pathway. Experimentally, a type 2 DM rat model was developed by incorporating a high-fat diet and streptozotocin injection. Further, the DE model was screened via the Morris Water Maze test. Primary hippocampal neurons and HT-22 cells were used for in vitro analysis. We found that hyperglycemia exacerbates cognitive impairment in T2DM rats. When we isolated the primary hippocampus neurons, the expression of miR-132 RNA was low in both the DE hippocampus and primary neurons. GSK-3β and Tau 404 were highly expressed in injured HT-22 cells and diabetic hippocampal tissues. miR-132 downregulated the expression of GSK-3β. Besides, a binding and colocalized relationship between GSK3β and Tau was also reported. These findings suggest that miR-132 exerts protective effects from DE injury by repressing GSK-3β expression and alleviating Tau hyperphosphorylation in HT-22 cells and hippocampus tissues.

Latest Advances of Long Non-Coding RNA SNHG5 in Human Cancers

Long non-coding RNAs (lncRNAs) have been potent regulators in the initiation and development of human cancers regarding their biological roles in the modulation of dosage compensation effect, epigenetics and cell differentiation. Recently, aberrant expression of lncRNA small nucleolar RNA host gene 5 (SNHG5) has been observed in various solid tumors, which was intently correlated with tumor range, metastasis, pathological stage and prognosis. Additional mechanical investigation disclosed that SNHG5 was involved in multiple cellular activities, including proliferation, migration, invasion, cell-cycle, apoptosis and autophagy, via targeting miRNAs, signaling pathways and other biological molecules or proteins. In this review, we summarized the latest advances made towards understanding the roles of SNHG5 in human cancers and further discussed potential methods that could be adopted for clinical interventions.

Long non-coding RNA PVT1-mediated miR-543/SERPINI1 axis plays a key role in the regulatory mechanism of ovarian cancer

PURPOSE

To investigate the regulation mechanism of long non-coding RNA (lncRNA) plasmocytoma variant translocation 1 (PVT1) in ovarian cancer (OC).

METHODS

The levels of PVT1, microRNA (miR)-543, serpin peptidase inhibitor-clade I (neuroserpin)-member 1 (SERPINI1) in OC tissues and OVCAR-3, A2780, TOV-112D of OC cell lines were detected by quantitative real-time PCR (qRT-PCR) and Western Blot (WB). Cell proliferation, migration, invasion, apoptosis and the regulatory relationship between genes and target genes were analyzed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), Transwell, flow cytometry and dual luciferase reporter (DLR). The OC patients were followed up for 5 years to analyze the relationship between PVT1 and 5-year overall survival (OS).

RESULTS

In contrast with miR-543, PVT1 and SERPINI1 were highly expressed in OC tissues and cell lines, and high levels of PVT1 were significantly associated with lower 5-year OS of patients. Down-regulating PVT1 not only inhibited the malignant proliferation, migration and invasion of OC cells, but promoted cell apoptosis. PVT1 regulated miR-543 in a targeted manner, and its overexpression could attenuate the anticancer effect of miR-543 on OC cells. In addition, miR-543 also directly targeted SERPINI1, and miR-543 knockdown weakened the inhibitory effect of down-regulated SERPINI1 on OC progression. Furthermore, we found that PVT1 acted as a competitive endogenous RNA to sponge miR-543, thereby regulating the expression of SERPINI1.

CONCLUSION

PVT1 can mediate the molecular mechanism of OC by miR-543/SERPINI1 axis regulatory network, which is a new therapeutic direction for OC.

LncRNA SNHG5: A new budding star in human cancers

Long non-coding RNA (LncRNA) belongs to non-coding RNAs longer than 200 nucleic acids. More and more studies have revealed that lncRNA can participate in the occurrence and pathophysiology of diseases, especially in cancers. Although research on lncRNAs has doubled year by year, little is known about the specific regulatory mechanisms of lncRNAs in diseases. The main purpose of this review is to explore the molecular mechanism and clinical significance of SNHG5 in cancers. We systematically search Pubmed to obtain relevant literature on SNHG5. In this review, the functional role, molecular mechanism, and clinical significance of SNHG5 in human cancers are described in detail. Small nucleolar RNA host gene 5 (SNHG5) has been shown to be involved in the development and tumorigenesis of a variety of cancers (colorectal, bladder, gastric, endometrial, acute lymphocytic leukemia, osteosarcoma, etc.). Its disorder is closely related to metastasis, pathological staging, and prognosis. LncRNA SNHG5 might be a potential and novel diagnostic marker for cancer patients, a target for molecular targeted therapy, and a prognostic diagnostic marker.