Long noncoding RNA TUSC7 inhibits cell proliferation, migration and invasion by regulating SOCS4 (SOCS5) expression through targeting miR-616 in endometrial carcinoma

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.

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.

MicroRNAs, long non-coding RNAs, and circular RNAs and gynecological cancers: focus on metastasis

Gynecologic cancer is a significant cause of death in women worldwide, with cervical cancer, ovarian cancer, and endometrial cancer being among the most well-known types. The initiation and progression of gynecologic cancers involve a variety of biological functions, including angiogenesis and metastasis-given that death mostly occurs from metastatic tumors that have invaded the surrounding tissues. Therefore, understanding the molecular pathways underlying gynecologic cancer metastasis is critical for enhancing patient survival and outcomes. Recent research has revealed the contribution of numerous non-coding RNAs (ncRNAs) to metastasis and invasion of gynecologic cancer by affecting specific cellular pathways. This review focuses on three types of gynecologic cancer (ovarian, endometrial, and cervical) and three kinds of ncRNAs (long non-coding RNAs, microRNAs, and circular RNAs). We summarize the detailed role of non-coding RNAs in the different pathways and molecular interactions involved in the invasion and metastasis of these cancers.

Hsa_circ_0015382 is involved in the pathogenesis of preeclampsia by mediating THBS2 expression

BACKGROUND

Preeclampsia (PE) is a hypertensive disorder of pregnancy that causes significant maternal and perinatal morbidity and mortality. Circular RNA (circRNA) hsa_circ_0015382 is associated with the pathogenesis of PE, but its underlying regulatory mechanism remains to be explored.

METHODS

Relative RNA levels of hsa_circ_0015382, microRNA-616-3p and thrombospondin-2 (THBS2) were detected by quantitative reverse transcription-polymerase chain reaction. In vitro regulatory effects of hsa_circ_0015382 on the proliferation, migration, invasion and angiogenesis of trophoblasts were evaluated by CCK-8, flow cytometry for cell cycle, EdU, transwell, wound healing and HUVEC tube formation assays, respectively. Targeting interaction was verified by dual-luciferase reporter and RNA immunoprecipitation assays.

RESULTS

Hsa_circ_0015382 was highly expressed in placental tissues from PE patients. Upregulation of hsa_circ_0015382 repressed trophoblast proliferation, migration, invasion and lowered trophoblast-induced HUVEC tube formation. Hsa_circ_0015382 was validated as a miR-616-3p sponge and miR-616-3p targeted THBS2. Hsa_circ_0015382 could mediate trophoblast proliferation, migration, invasion and regulate trophoblast-induced HUVEC tube formation by sponging miR-616-3p and regulating THBS2 expression.

CONCLUSION

Hsa_circ_0015382 is associated with the pathogenesis of PPE by regulating the miR-616-3p/THBS2 axis.

HIGHLIGHTS

Hsa_circ_0015382 is overexpressed in preeclampsia patients. Hsa_circ_0015382 inhibits trophoblast proliferation, migration, invasion and decreases trophoblast-induced HUVEC tube formation. Hsa_circ_0015382 interacts with miR-616-3p to regulate THBS2 expression.

lncRNA TUSC7 sponges miR-10a-5p and inhibits BDNF/ERK pathway to suppress glioma cell proliferation and migration

OBJECTIVE

Gliomas as primary cerebral malignancies frequently occurring in adults have relatively high morbidity and mortality. The underlying role of long non-coding ribonucleic acids (lncRNAs) in malignancies has attracted much attention, among which tumor suppressor candidate 7 (TUSC7) is a novel tumor suppressor gene whose regulatory mechanism in human cerebral gliomas remains inconclusive.

METHODS AND RESULTS

In this study, bioinformatics analysis indicated that TUSC7 could specifically bind to microRNA (miR)-10a-5p, and according to quantitative polymerase chain reaction (q-PCR), miR-10a-5p was up-regulated in human glioma cells and negatively correlated with TUSC7 expression. Dual-luciferase reporter gene assay showed the ability of TUSC7 to bind to miR-10a-5p, and overexpression of TUSC7 notably inhibited miR-10a-5p expression, restrained human glioma cell proliferation and migration, and regulated cell cycle and cyclin expression via the brain-derived neurotrophic factor/extracellular signal-regulated kinase (BDNF/ERK) pathway. The inhibitory effect of TUSC7 on miR-10a-5p was also verified by designing miR-10a-5p overexpression and knockdown panels for wound healing, Transwell and Western blotting assays.

CONCLUSIONS

TUSC7 suppresses human glioma cell proliferation and migration by negatively modulating miR-10a-5p and inhibiting the BDNF/ERK pathway, thus acting as a tumor suppressor gene in human gliomas.

lncRNA-LET Regulates Glycolysis and Glutamine Decomposition of Esophageal Squamous Cell Carcinoma Through miR-93-5p/miR-106b-5p/SOCS4

Background

Dysregulated non-coding RNAs exhibit critical functions in various cancers. Nonetheless, the levels and corresponding functions of cirCSNX14 in esophageal squamous cell carcinoma (ESCC) yet remain to be elucidated.

Methods

Initially, the aberrant low levels of lncRNA-LET within ESCC tissues are validated via qRT-PCR observations. Moreover, the effects of lncRNA-LET upregulation on cell proliferation in vitro are determined. In addition, a series of assays determining the mechanistic views related to metabolism is conducted. Furthermore, the effects of lncRNA-LET in affecting tumor growth are investigated in vivo in a mouse model. Moreover, the interactions between lncRNA-LET and its networks are predicted and determined by RNA immunoprecipitation-assisted qRT-PCR as well as luciferase reporter assays.

Results

The downregulation of lncRNA-LET is correlated to the poor prognosis of ESCC patients. Moreover, the upregulated expression of lncRNA-LET could have reduced the cell viability. In vivo tumor inhibition efficacy assays showed that an increase of lncRNA-LET presented excellent inhibitory effects on cancer proliferation as reflected by tumor weight and volume in mice. Finally, the mechanistic views regarding the effects of miR-106b-5p or miR-93-5p and SOCS4 on ESCC are related to the feedback of lncRNA-LET.

Conclusion

Collectively, this study suggested that lncRNA-LET miR-93-5p or the miR-106b-5p-SOCS4 axis may provide great potential in establishing ESCC therapy.

lncRNA ZNF674-AS1 inhibits the migration, invasion and epithelial-mesenchymal transition of thyroid cancer cells by modulating the miR-181a/SOCS4 axis

Thyroid cancer (TC) is a very common endocrine cancer worldwide. Further understanding and revealing the molecular mechanism underlying thyroid cancer are indispensable for the development of effective diagnosis and treatments. Long non-coding RNAs (lncRNAs), a series of non-coding RNAs with a length of >200 nts, have been regarded as crucial regulators of many cancers playing a tumor suppressive or oncogenic role, depending on circumstances. lncRNA ZNF674-AS1 was reported to be abnormally expressed in TC, but the exact mechanism remains unclear. This study aims to probe the mechanism and roles of ZNF674-AS1 in TC. The expression patterns of RNAs and proteins were determined via qRT-PCR and western blotting, respectively. Cell proliferation, migration and invasion were detected using MTT and Transwell assays. ZNF674-AS1 and SOCS4 expression were remarkably reduced while miR-181a was upregulated in TC tissues and cells. Enforced expression of ZNF674-AS1 inhibited proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) in vitro and reduced tumour growth in vivo. Mechanistic assays verified that ZNF674-AS1 directly interacted with miR-181a to increase SOCS4 expression. In addition, miR-181a overexpression aggravated proliferation, metastasis and EMT by inhibiting SOCS4. Interestingly, inhibition of miR-181a diminished the promoting effects of ZNF674-AS1 silencing on the malignant behaviours of TC cells. These data illustrated that ZNF674-AS1 alleviated TC progression by modulating the miR-181a/SOCS4 axis (graphical abstract), further suggesting that ZNF674-AS1 might be used as a therapheutic target in TC treatment.

LncRNA small nucleolar RNA host gene 16 reduces sepsis-induced myocardial damage by regulating miR-421/suppressor of cytokine signaling 5 axis

Currently, sepsis-induced cardiomyopathy (SIC) remains as one of the most critical clinical syndromes in terminally ill patients. Noncoding RNAs (including microRNAs and long noncoding RNAs) are implicated in both the onset and development of SIC. We herein investigated the functional role and molecular target of long noncoding RNA small nucleolar RNA host gene 16 (SNHG16) in an in vitro SIC model of H9c2 myocardial cells. We used lipopolysaccharide (LPS) as endotoxin to treat H9c2 cells to mimic SIC damages. Cell Counting Kit 8 and apoptosis assay were performed to assess cell proliferation and cell death. Quantitative real-time-PCR and Western blot were employed to examine gene expression level at mRNA and protein level. Dual luciferase assay is used to validate the functional interactions between SNHG16/mi-R421 and miR-421/suppressor of cytokine signaling 5 (SOCS5). Inflammatory cytokines were measured by ELISA. Superoxide dismutase and malondialdehyde measurement was performed to assess oxidative stress, which was further confirmed by 2',7'-dichlorofluorescin diacetate staining. Our data demonstrated that in the LPS-induced sepsis model of myocardial cells, SNHG16 overexpression downregulated the expression level of miR-421, which sustained the expression of SOCS5 to alleviate the adverse effects of LPS, such as apoptosis, pro-inflammatory cytokines, and oxidative stress. Our data suggest that SNHG16 functions as a ceRNA to maintain SOCS5 level by targeting miR-421, thereby attenuating LPS-induced myocardial cell damages. Targeting miR-421 or modulating lncRNA SNHG16 level may be leveraged as a beneficial strategy against sepsis-induced cellular damage in cardiomyocytes.

Long noncoding RNA Gm44593 attenuates oxidative stress from age-related hearing loss by regulating miR-29b/WNK1

Long noncoding RNA has been reported to play important role in various disease. However, the function of lncRNA in age-related hearing loss still unclear. The aim of our study is to investigate the function and mechanism of lncRNA Gm44593 in AHL. ATP content, JC-1 assay, mitochondrial content, cell death rates and dual-luciferase reporter assay were performed to assess the function of lncRNA Gm44593 in HEI-OC1 cells. The expression of lncRNA Gm44593 was significantly upregulated upon H₂O₂ and starvation treatment. Overexpression of lncRNA Gm44593 manifestly reduced the cell death rates. The ATP content, mtDNA content and mitochondrial membrane potential were alleviated upon overexpression of lncRNA Gm44593. We also proved that miR-29b is the direct target of lncRNA Gm44593. Overexpression of miR-29b completely restored the effect induced by lncRNA Gm44593. In addition, we provided evidences that WNK1 is the direct target of miR-29b. Our research uncovers a potential role of lncRNA Gm44593 in age-related hearing loss. We provide new insights into potential therapeutic targets for the amelioration of age-related hearing loss.

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.

Long Non-Coding RNA Small Nucleolar RNA Host Gene 1 and MicroRNA-100-3p Expression in Endometrial Carcinoma and Its Effect on the Proliferation and Apoptosis of Ishikawa Cells

The aim of this study was to explore LncRNA SNHG1 and miRNA-100-3p expression in endometrial carcinoma and its effect on the proliferation and apoptosis of Ishikawa cells. A qRT-PCR assay was conducted to determine SNHG1 and miRNA-100-3p expression in endometrial cancer tissues and paracancerous tissues. Human endometrial cancer Ishikawa cells were cultured in vitro. Si-NC, si-SNHG1, si-SNHG1, anti-miRNA-NC, and si-SNHG1 were transfected into Ishikawa cells with anti-miRNA-519b-3p. A qRT-PCR assay was performed to determine SNHG1 and miRNA-100-3p expression, and the CCK-8 method was used to determine cell proliferation. Flow cytometry was conducted to determine cell cycle and apoptosis rate and a dualluciferase reporter experiment was carried out to test the targeting association between SNHG1 and miRNA-100-3p. Cleave Caspase-3, CHOP, and ATF4 expression were determined with the Western Blot method. SNHG1 expression level and miRNA-519b-3p expression level were much higher and much lower, respectively, in endometrial cancer tissues than in paracancerous tissues (P < 0.05). Transfection of si-SNHG1 can greatly attenuate cell viability and S cell ratio (P < 0.05), and increase G0/G1 cell ratio, apoptosis rate, Cleaved Caspase-3, CHOP, and ATF4 protein level (P < 0.05) compared to the si-NC group. Furthermore, the double luciferase reporter experiment confirmed that SNHG1 can competitively combine withmiRNA-100-3p. Also, co-transfection of si-SNHG1 and anti-miRNA-100-3p could significantly increase cell viability and S cell ratio (P < 0.05), and decrease G0/G1 cell ratio and apoptosis rate, and Cleaved Caspase-3, CHOP, and ATF4 protein levels compared to si-SNHG1+anti-miRNA-NC (P < 0.05). Interfering with SNHG1 could inhibit the proliferation of Ishikawa cells and promote apoptosis by upregulating miRNA-100-3p expression.

The LINC01119-SOCS5 axis as a critical theranostic in triple-negative breast cancer

The development of triple-negative breast cancer (TNBC) is critically regulated by certain tumor-microenvironment-associated cells called mesenchymal stem/stromal cells (MSCs), which we and others have shown promote TNBC progression by activating pro-malignant signaling in neighboring cancer cells. Characterization of these cascades would better our understanding of TNBC biology and bring about therapeutics that eliminate the morbidity and mortality associated with advanced disease. Here, we focused on the emerging class of RNAs called long non-coding RNAs or lncRNAs and utilized a MSC-supported TNBC progression model to identify specific family members of functional relevance to TNBC pathogenesis. Indeed, although some have been described to play functional roles in TNBC, activities of lncRNAs as mediators of tumor-microenvironment-driven TNBC development remain to be fully explored. We report that MSCs stimulate robust expression of LINC01119 in TNBC cells, which in turn induces suppressor of cytokine signaling 5 (SOCS5), leading to accelerated cancer cell growth and tumorigenesis. We show that LINC01119 and SOCS5 exhibit tight correlation across multiple breast cancer gene sets and that they are highly enriched in TNBC patient cohorts. Importantly, we present evidence that the LINC01119-SOCS5 axis represents a powerful prognostic indicator of adverse outcomes in TNBC patients, and demonstrate that its repression severely impairs cancer cell growth. Altogether, our findings identify LINC01119 as a major driver of TNBC development and delineate critical non-coding RNA theranostics of potential translational utility in the management of advanced TNBC, a class of tumors in most need of effective and targeted therapy.

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.

MicroRNA as Epigenetic Modifiers in Endometrial Cancer: A Systematic Review

Simple Summary

Endometrial cancer (EC) is the 2nd most common gynecologic cancer worldwide. MicroRNAs (miRNAs) are small noncoding RNAs that contribute to epigenetic regulation. The objective of this systematic review is to summarize our current knowledge on the role of miRNAs in the epigenetic deregulation of tumor-related genes in EC. It includes all miRNAs reported to be involved in EC including their roles in DNA methylation and RNA-associated silencing. This systematic review should be useful for development of novel strategies to improve diagnosis and risk assessment as well as for new treatments aimed at miRNAs, their target genes or DNA methylation.

Abstract

The objective of this systematic review is to summarize our current knowledge on the influence of miRNAs in the epigenetic deregulation of tumor-related genes in endometrial cancer (EC). We conducted a literature search on the role of miRNAs in the epigenetic regulation of EC applying the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The following terms were used: microRNA, miRNA, miR, endometrial cancer, endometrium, epigenetic, epimutation, hypermethylation, lynch, deacetylase, DICER, novel biomarker, histone, chromatin. The miRNAs were classified and are presented according to their function (tumor suppressor or onco-miRNA), their targets (when known), their expression levels in EC tissue vs the normal surrounding tissue, and the degree of DNA methylation in miRNA loci and CpG sites. Data were collected from 201 articles, including 190 original articles, published between November 1, 2008 and September 30, 2020 identifying 313 different miRNAs implicated in epigenetic regulation of EC. Overall, we identified a total of 148 miRNAs with decreased expression in EC, 140 miRNAs with increased expression in EC, and 22 miRNAs with discordant expression levels. The literature implicated different epigenetic phenomena including altered miRNA expression levels (miR-182, -230), changes in the methylation of miRNA loci (miR-34b, -129-2, -130a/b, -152, -200b, -625) and increased/decreased methylation of target genes (miR-30d,-191). This work provides an overview of all miRNAs reported to be involved in epigenetic regulation in EC including DNA methylation and RNA-associated silencing. These findings may contribute to novel strategies in diagnosis, risk assessment, and treatments aimed at miRNAs, their target genes or DNA methylation.

Long non-coding RNA LINC00525 interacts with miR-31-5p and miR-125a-5p to act as an oncogenic molecule in spinal chordoma

LINC00525 is a new-researched long non-coding RNA (lncRNA) in a few cancers. This study aims at researching the function of LINC00525 in spinal chordoma and the underlying mechanism of action. LINC00525, microRNA-31-5p (miR-31-5p) and microRNA-125a-5p (miR-125a-5p) detection was performed by quantitative real-time polymerase chain reaction (qRT-PCR). We found the high expression of LINC00525 but the low levels of miR-31-5p and miR-125a-5p in spinal chordoma tissues. After LINC00525 was downregulated in spinal chordoma cells, there were inhibitory effects on cell proliferation, migration, invasion and EMT but a promoting effect on cell apoptosis. MiR-31-5p and miR-125a-5p were the downstream targets of LINC00525. The function of LINC00525 knockdown in spinal chordoma cells were achieved by upregulating miR-31-5p and miR-125a-5p. Tumorigenesis of spinal chordoma in vivo was also inhibited by knockdown of LINC00525 via the promotion of miR-31-5p and miR-125a-5p. All these results suggested that LINC00525 targeted miR-31-5p and miR-125a-5p to promote the tumorigenesis and progression of spinal chordoma. LINC00525 can be a novel molecular target in spinal chordoma.

Suppression of bromodomain-containing protein 4 protects trophoblast cells from oxidative stress injury by enhancing Nrf2 activation

Oxidative stress is considered a key hallmark of preeclampsia, which causes the dysregulation of trophoblast cells, and it contributes to the pathogenesis of preeclampsia. Emerging evidence has suggested bromodomain-containing protein 4 (BRD4) as a key regulator of oxidative stress in multiple cell types. However, whether BRD4 participates in regulating oxidative stress in trophoblast cells remains undetermined. The current study was designed to explore the potential function of BRD4 in the regulation of oxidative stress in trophoblast cells. Our data revealed that BRD4 expression was elevated in trophoblast cells stimulated with hydrogen peroxide. Exposure to hydrogen peroxide caused marked decreases in the levels of proliferation and invasion but promoted apoptosis and the production of ROS in trophoblast cells. Knockdown of BRD4, or treatment with a BRD4 inhibitor, markedly increased the levels of cell proliferation and invasion and decreased apoptosis and ROS production following the hydrogen peroxide challenge. Further data indicated that suppression of BRD4 markedly decreased the expression levels of Keap1, but increased the nuclear expression of Nrf2 and enhanced Nrf2-mediated transcriptional activity. BRD4 inhibition-mediated protective effects were markedly reversed by Keap1 overexpression or Nrf2 inhibition. Overall, these results demonstrated that BRD4 inhibition attenuated hydrogen peroxide-induced oxidative stress injury in trophoblast cells by enhancing Nrf2 activation via the downregulation of Keap1. Our study highlights the potential importance of the BRD4/Keap1/Nrf2 axis in the modulation of the oxidative stress response in trophoblast cells. Targeted inhibition of BRD4 may offer new opportunities for the development of innovative therapeutic approaches to treat preeclampsia.

Effects of lncRNA TUSC7 on the malignant biological behavior of osteosarcoma cells via regulation of miR-375

The present study aimed at investigating how long-chain non-coding RNA (lncRNA) tumor suppressor candidate 7 (TUSC7) regulates the malignant biological behavior of osteosarcoma cells. Tumor tissues and adjacent tissues of 30 patients with osteosarcoma were collected, and the expression levels of lncRNA TUSC7 and miR-375 were detected by RT-qPCR. lncRNA TUSC7 mimic and miR-375 mimic transfection models were established in MG63 osteosarcoma cells, and Transwell assays were used to detect the migration ability of MG63 cells. An MTT assay was used to assess the proliferation ability of MG63 cells. lncRNA TUSC7 in osteosarcoma tissue was significantly lower than that of adjacent tissues, while miR-375 levels were significantly higher than that of adjacent tissues; the two levels have a negative correlation. lncRNA TUSC7 mimic inhibited MG63 proliferation and migration abilities. miR-375 mimic promoted MG63 proliferation and migration abilities. The lncRNA TUSC7 mimic and miR-375 mimic co-transfection system could partially rescue the inhibition of lncRNA TUSC7 mimic on MG63 cells. In conclusion, lncRNA TUSC7 inhibited the proliferation and migration of MG63 osteosarcoma cells by regulating miR-375.

Identification of long noncoding RNA RP11-89K21.1 and RP11-357H14.17 as prognostic signature of endometrial carcinoma via integrated bioinformatics analysis

Background

Endometrial carcinoma (EC) is one of the most common malignant tumors in gynecology. The potential functions and mechanisms of long noncoding RNAs (lncRNAs) in the occurrence and progression of EC remains unclear. It’s meaningful to explore lncRNAs signature for providing prognostic value of EC.

Methods

The differentially expressed lncRNAs and their prognostic values in EC were investigated based on The Cancer Genome Atlas (TCGA) database; the transcriptional factors (TFs), the competing endogenous RNA (ceRNA) mechanism, functional regulatory network and immune infiltration of RP11-89K21.1 and RP11-357H14.17 were further explored by various bioinformatics tools and databases.

Results

We firstly identified high expression of RP11-89K21.1 and RP11-357H14.17 were closely associated with shorten overall survival (OS) and poor prognosis in patients with EC. We also elucidated the networks of transcription factor and co-expression genes associated with RP11-89K21.1 and RP11-357H14.17. Furthermore, the ceRNA network mechanism was successfully constructed through 2 lncRNAs (RP11-89K21.1 and RP11-357H14.17), 11 miRNAs and 183 mRNAs. Functional enrichment analysis revealed that the targeting genes of RP11-89K21.1 and RP11-357H14.17 were strongly associated with microRNAs in cancer, vessel development, growth regulation, growth factor and cell differentiation, and involved in pathways including pathways in cancer, microRNAs in cancer and apoptotic signaling pathway.

Conclusions

We demonstrated for the first time that RP11-89K21.1 and RP11-357H14.17 may play crucial roles in the occurrence, development and malignant biological behavior of EC, and can be regarded as potential prognostic biomarkers for EC.

LINC00668 Modulates SOCS5 Expression Through Competitively Sponging miR-518c-3p to Facilitate Glioma Cell Proliferation

Glioma is a common invasive cancer with unfavorable prognosis in patients. Long non-coding RNAs (lncRNAs) exert significant functions in carcinogenesis of various cancers including glioma. Among them, long intergenic non-coding RNA 668 (LINC00668) was reported to function as oncogene in various cancers, but its molecular mechanism in glioma has not been thoroughly researched. Our current study aimed to investigate the role and molecular mechanism of LINC00668 in glioma cells. We initially found out that LINC00668 was up-regulated in glioma cells. Through a series of function assays, LINC00668 was verified to facilitate cell proliferation and inhibit apoptosis in glioma. Then, by means of online databases, RNA pull down assay and RIP assay, we verified the binding relation between LINC00668 and miR-518c-3p. Also, the next function assays exposed that miR-518c-3p was the tumor suppressor in glioma cells. Similarly, SOCS5 (suppressor of cytokine signaling 5) was found to bind with miR-518c-3p, which repressed glioma tumorigenesis by targeting SOCS5. Moreover, rescue assays manifested that LINC00668 modulated expression of SOCS5 in a miR-518c-3p-dependent way and further regulated glioma tumorigenesis. Overall, LINC00668 modulates SOCS5 expression through competitively sponging miR-518c-3p to facilitate glioma cell proliferation.