LncRNA NORAD, sponging miR-363-3p, promotes invasion and EMT by upregulating PEAK1 and activating the ERK signaling pathway in NSCLC cells

Role of microRNA-363 during tumor progression and invasion

Recent progresses in diagnostic and therapeutic methods have significantly improved prognosis in cancer patients. However, cancer is still considered as one of the main causes of human deaths in the world. Late diagnosis in advanced tumor stages can reduce the effectiveness of treatment methods and increase mortality rate of cancer patients. Therefore, investigating the molecular mechanisms of tumor progression can help to introduce the early diagnostic markers in these patients. MicroRNA (miRNAs) has an important role in regulation of pathophysiological cellular processes. Due to their high stability in body fluids, they are always used as the non-invasive markers in cancer patients. Since, miR-363 deregulation has been reported in a wide range of cancers, we discussed the role of miR-363 during tumor progression and metastasis. It has been reported that miR-363 has mainly a tumor suppressor function through the regulation of transcription factors, apoptosis, cell cycle, and structural proteins. MiR-363 also affected the tumor progression via regulation of various signaling pathways such as WNT, MAPK, TGF-β, NOTCH, and PI3K/AKT. Therefore, miR-363 can be introduced as a probable therapeutic target as well as a non-invasive diagnostic marker in cancer patients.

Absence of Scaffold Protein Tks4 Disrupts Several Signaling Pathways in Colon Cancer Cells

Tks4 is a large scaffold protein in the EGFR signal transduction pathway that is involved in several cellular processes, such as cellular motility, reactive oxygen species-dependent processes, and embryonic development. It is also implicated in a rare developmental disorder, Frank-ter Haar syndrome. Loss of Tks4 resulted in the induction of an EMT-like process, with increased motility and overexpression of EMT markers in colorectal carcinoma cells. In this work, we explored the broader effects of deletion of Tks4 on the gene expression pattern of HCT116 colorectal carcinoma cells by transcriptome sequencing of wild-type and Tks4 knockout (KO) cells. We identified several protein coding genes with altered mRNA levels in the Tks4 KO cell line, as well as a set of long non-coding RNAs, and confirmed these changes with quantitative PCR on a selected set of genes. Our results show a significant perturbation of gene expression upon the deletion of Tks4, suggesting the involvement of different signal transduction pathways over the well-known EGFR signaling.

Exosome-delivered circSATB2 targets the miR-330-5p/PEAK1 axis to regulate proliferation, migration and invasion of lung cancer cells

Exosomes can carry various kinds of RNAs to mediate intercellular communication. Circular RNA (circRNA) special AT-rich sequence-binding protein 2 (circSATB2) was identified as an oncogene in lung cancer. This study was performed to explore the association of circSATB2 with exosomes and the regulatory mechanism of circSATB2. Exosomes could transmit circSATB2 into lung cancer cells. Exosomes enhanced cell proliferation, invasion, and migration by carrying circSATB2. Exosomal circSATB2 abrogated the inhibitory effect of short hairpin (sh)-circSATB2 on lung cancer progression. Moreover, circSATB2 promoted tumor growth in vivo via exosomes. CircSATB2 interacted with microRNA-330-5p (miR-330-5p) and miR-330-5p targeted pseudopodium enriched atypical kinase 1 (PEAK1). In addition, circSATB2 affected the PEAK1 level via sponging miR-330-5p in lung cancer cells. All results suggested that exosomal transfer of circSATB2 contributed to the malignant development of lung cancer by acting as a sponge of miR-330-5p to upregulate PEAK1.

LncRNA-miRNA axis in tumor progression and therapy response: An emphasis on molecular interactions and therapeutic interventions

Epigenetic factors are critical regulators of biological and pathological mechanisms and they could interact with different molecular pathways. Targeting epigenetic factors has been an idea approach in disease therapy, especially cancer. Accumulating evidence has highlighted function of long non-coding RNAs (lncRNAs) as epigenetic factors in cancer initiation and development and has focused on their association with downstream targets. microRNAs (miRNAs) are the most well-known targets of lncRNAs and present review focuses on lncRNA-miRNA axis in malignancy and therapy resistance of tumors. LncRNA-miRNA regulates cell death mechanisms such as apoptosis and autophagy in cancers. This axis affects tumor metastasis via regulating EMT and MMPs. Besides, lncRNA-miRNA axis determines sensitivity of tumor cells to chemotherapy, radiotherapy and immunotherapy. Based on the studies, lncRNAs can be affected by drugs and genetic tools in cancer therapy and this may affect expression level of miRNAs as their downstream targets, leading to cancer suppression/progression. LncRNAs have both tumor-promoting and tumor-suppressor functions in cancer and this unique function of lncRNAs has complicated their implication in tumor therapy. LncRNA-miRNA axis can also affect other signaling networks in cancer such as PI3K/Akt, STAT3, Wnt/β-catenin and EZH2 among others. Notably, lncRNA/miRNA axis can be considered as a signature for diagnosis and prognosis in cancers.

Circ_0002111 modulates the growth process of papillary thyroid carcinoma cells by targeting the miR-363-3p/HMGB1 axis

Previous studies have suggested that circular RNAs (circRNAs) are engaged in the progression of papillary thyroid carcinoma (PTC). However, the mechanism of circ_0002111 in PTC is still unclear. In this study, quantitative real-time PCR was carried out to measure the expressions of circ_0002111, microRNAs (miRNAs) and high-mobility group box 1 (HMGB1). Immunohistochemistry assay and western blot were applied for the determination of protein levels. The assays of 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide and thymidine analog 5-ethynyl-2'-deoxyuridine were deployed to assess PTC cell viability and proliferation, respectively. Besides, the capacities of cell apoptosis, invasion and angiogenesis were determined by flow cytometry, transwell and tube formation assays, respectively. Moreover, the interaction between miR-363-3p and circ_0002111 or HMGB1 was confirmed using a dual-luciferase reporter assay. Lastly, we established a xenograft model for the examination of the function of circ_0002111 in vivo. It was found that the expression of circ_0002111 was enhanced in PTC tissues and cells. Silencing circ_0002111 apparently retarded the viability, proliferation, invasion and tube formation, as well as expedited the apoptosis of PTC cells. Besides, circ_0002111 knockdown impeded the growth of the tumor in vivo. For mechanism analysis, circ_0002111 adjusted the expression of HMGB1 by sponge adsorption of miR-363-3p. Moreover, miR-363-3p inhibitor regained the influence of cellular malignant phenotype caused by circ_0002111 knockdown. Additionally, miR-363-3p overexpression impacted the cell functions by targeting HMGB1 in PTC. Thus, silencing circ_0002111 constrained the progression of PTC by the miR-363-3p/HMGB1 axis, which perhaps provided a novel idea of the therapeutic in PTC.

lncRNA NORAD promotes lung cancer progression by competitively binding to miR-28-3p with E2F2

Lung cancer (LC) is a prevailing primary tumor in the lung. lncRNA non-coding RNA activated by DNA damage (NORAD) is a popular target in human cancers. This experiment is designed to probe the mechanism of lncRNA in LC progression. NORAD expression in normal lung epithelial cells and LC cells was examined and then silenced to assess its effect on LC cell proliferation, invasion, and migration. Subcellular localization of NORAD was analyzed through online databases and then corroborated by fractionation of nuclear and cytoplasmic RNA assay. The target binding relations between NORAD and miR-28-3p and between miR-28-3p and E2F2 were verified. Eventually, LC cells with NORAD silencing were transfected with miR-28-3p inhibitor or pcDNA3.1-E2F2 to measure LC cell proliferation, invasion, and migration. NORAD was overexpressed in LC cells and NORAD knockout led to suppressed LC cell proliferation, invasion, and migration. Besides, NORAD targeted miR-28-3p and miR-28-3p targeted E2F2 transcription. Inhibiting miR-28-3p or overexpressing E2F2 could both annul the inhibitory role of si-NORAD in LC cell proliferation, invasion, and migration. Generally, our findings demonstrated that NORAD competitively bound to miR-28-3p with E2F2, to promote LC cell progression.

Identification and Validation of lncRNA-AC087588.2 in Lung Adenocarcinoma: A Novel Prognostic and Diagnostic Indicator

Lung adenocarcinoma (LUAD) is the most common histological lung cancer, and it is the leading cause of cancer-related deaths worldwide. Long non-coding RNAs (lncRNAs) have been implicated in the initiation and progression of various cancers. LncRNA-AC087588.2 (ENSG00000274976) is a novel lncRNA that is abnormally expressed in diverse cancer types, including LUAD. However, the clinical significance, prognostic value, diagnostic value, immune role, and the potential biological function of AC087588.2 LUAD remain elusive. In this study, we found that AC087588.2 was upregulated and associated with a poor prognosis in LUAD. In addition, univariate and multivariate Cox regression analysis indicated that AC087588.2 could be an independent prognostic factor for LUAD. Functionally, the knockdown of AC087588.2 restrained LUAD cell proliferation and migration in vitro. Finally, we constructed a ceRNA network that included hsa-miR-30a-5p and four mRNAs (ANLN, POLR3G, EHBP1, and ERO1A) specific to AC087588.2 in LUAD. The Kaplan–Meier survival analysis showed that lower expression of hsa-miR-30a-5p and higher expression of ANLN, POLR3G, EHBP1, and ERO1A were associated with adverse clinical outcomes in patients with LUAD. This finding provided a comprehensive view of the AC087588.2-mediated ceRNA network in LUAD, thereby highlighting its potential role in the diagnosis and prognosis of LUAD.

Over-Expression of Long Non-Coding RNA-AC099850.3 Correlates With Tumor Progression and Poor Prognosis in Lung Adenocarcinoma

Lung adenocarcinoma (LUAD) is the most common histological lung cancer, and it is the leading cause of cancer-related deaths worldwide. Long noncoding RNAs (lncRNAs) have been implicated in the initiation and progression of various cancers. LncRNA-AC099850.3 is a novel lncRNA that is abnormally expressed in diverse cancer types including LUAD. However, the clinical significance, prognostic value, diagnostic value, immune role, and potential biological function of AC099850.3 LUAD remain elusive. In this study, we found that AC099850.3 was highly expressed in LUAD and associated with an advanced tumor stage, poor prognosis, and immune infiltration. Receiver operating curve analysis revealed the significant diagnostic ability of AC099850.3 (AUC=0.888). Functionally, the knockdown of AC099850.3 restrained LUAD cell proliferation and migration in vitro. Finally, we constructed a competitive endogenous RNAs (ceRNA) network that included hsa-miR-101-3p and 4 mRNAs (ESPL1, AURKB, BUB3, and FAM83D) specific to AC099850.3 in LUAD. Kaplan-Meier survival analysis showed that a lower expression of miR-101-3p and a higher expression of ESPL1, AURKB, BUB3, and FAM83D, were associated with adverse clinical outcomes in patients with LUAD. This finding provided a comprehensive view of the AC099850.3-mediated ceRNA network in LUAD, thereby highlighting its potential role in the diagnosis and prognosis of LUAD.

Long non-coding RNAs and exosomal lncRNAs: Potential functions in lung cancer progression, drug resistance and tumor microenvironment remodeling

Among the different kinds of tumors threatening human life, lung cancer is one that is commonly observed in both males and females. The aggressive behavior of lung cancer and interactions occurring in tumor microenvironment enhances the malignancy of this tumor. The lung tumor cells have demonstrated capacity in developing chemo- and radio-resistance. LncRNAs are a category of non-coding RNAs that do not encode proteins, but their aberrant expression is responsible for tumor development, especially lung cancer. In the present review, we focus on both lncRNAs and exosomal lncRNAs in lung cancer, and their ability in regulating proliferation and metastasis. Cell cycle progression and molecular mechanisms related to lung cancer metastasis such as EMT and MMPs are regulated by lncRNAs. LncRNAs interact with miRNAs, STAT, Wnt, EZH2, PTEN and PI3K/Akt signaling pathways to affect progression of lung cancer cells. LncRNAs demonstrate both tumor-suppressor and tumor-promoting functions in lung cancer. They can be considered as biomarkers in lung cancer and especially exosomal lncRNAs present in body fluids are potential tools for minimally invasive diagnosis. Furthermore, we discuss regulation of lncRNAs by anti-cancer drugs and genetic tools as well as the role of these factors in therapy response of lung cancer cells.

Perioperative Suppression of Schwann Cell Dedifferentiation Reduces the Risk of Adenomyosis Resulting from Endometrial–Myometrial Interface Disruption in Mice

We have recently demonstrated that endometrial–myometrial interface (EMI) disruption (EMID) can cause adenomyosis in mice, providing experimental evidence for the well-documented epidemiological finding that iatrogenic uterine procedures increase the risk of adenomyosis. To further elucidate its underlying mechanisms, we designed this study to test the hypothesis that Schwann cells (SCs) dedifferentiating after EMID facilitate the genesis of adenomyosis, but the suppression of SC dedifferentiation perioperatively reduces the risk. We treated mice perioperatively with either mitogen-activated protein kinase kinase (MEK)/extracellular-signal regulated protein kinase (ERK) or c-Jun N-terminal kinase (JNK) inhibitors or a vehicle 4 h before and 24 h, 48 h and 72 h after the EMID procedure. We found that EMID resulted in progressive SCs dedifferentiation, concomitant with an increased abundance of epithelial cells in the myometrium and a subsequent epithelial–mesenchymal transition (EMT). This EMID-induced change was abrogated significantly with perioperative administration of JNK or MEK/ERK inhibitors. Consistently, perioperative administration of a JNK or a MEK/ERK inhibitor reduced the incidence by nearly 33.5% and 14.3%, respectively, in conjunction with reduced myometrial infiltration of adenomyosis and alleviation of adenomyosis-associated hyperalgesia. Both treatments significantly decelerated the establishment of adenomyosis and progression of EMT, fibroblast-to-myofibroblast trans-differentiation and fibrogenesis in adenomyotic lesions. Thus, we provide the first piece of evidence strongly implicating the involvement of SCs in the pathogenesis of adenomyosis induced by EMID.

Detection and analysis of long noncoding RNA expression profiles related to epithelial-mesenchymal transition in keloids

BACKGROUND

The role of epithelial-mesenchymal transition (EMT) in the pathogenesis of keloids is currently raising increasing attention. Long noncoding RNAs (lncRNAs) govern a variety of biological processes, such as EMT, and their dysregulation is involved in many diseases including keloid disease. The aim of this study was to identify differentially expressed EMT-related lncRNAs in keloid tissues versus normal tissues and to interpret their functions.

RESULTS

Eleven lncRNAs and 16 mRNAs associated with EMT were identified to have differential expression between keloid and normal skin tissues (fold change > 1.5, P < 0.05). Gene Ontology (GO) analysis showed that these differentially expressed mRNAs functioned in the extracellular matrix, protein binding, the positive regulation of cellular processes, the Set1C/COMPASS complex and histone acetyltransferase activity. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis demonstrated that these mRNAs are involved in pathways in cancer. The lncRNA, XLOC_000587 may promote cell proliferation and migration by enhancing the expression of ENAH, while AF268386 may facilitate the invasive growth of keloids by upregulating DDR2.

CONCLUSIONS

We characterized the differential expression profiles of EMT-related lncRNAs and mRNAs in keloids, which may contribute to preventing the occurrence and development of keloids by targeting the corresponding signaling pathways. These lncRNAs and mRNAs may provide biomarkers for keloid diagnosis and serve as potential targets for the treatment of this disease.

Long noncoding RNA NR2F1-AS1 stimulates the tumorigenic behavior of non-small cell lung cancer cells by sponging miR-363-3p to increase SOX4

Long noncoding RNA (lncRNA), specifically the upregulation of lncRNA NR2F1 antisense RNA 1 (NR2F1-AS1), has been involved in the progression of non-small cell lung cancer (NSCLC), but the mechanisms that underlie this remain unclear. In this study, the expression of NR2F1-AS1, miR-363-3p, and SOX4 was assessed in NSCLC cells. A loss-of-function assay was used to measure the tumorigenicity of NSCLC cells. The glycolysis and glutamine metabolism of NSCLC cells was also measured via extracellular acidification rate, consumption of glucose and glutamine, and production of lactate and ATP. The relationships among NR2F1-AS1, miR-363-3p, and SOX4 were detected via dual-luciferase reporter assay. HK-2, GLS1, and SOX4 levels were also analyzed. We found that both NSCLC tissues and cells had higher levels of NR2F1-AS1. Silencing of NR2F1-AS1 inhibited the tumorigenicity of cells in vitro and reduced the glycolysis and glutamine metabolism of NSCLC cells. Regarding its mechanism, NR2F1-AS1 positively regulated the SOX4 level by sponging miR-363-3p. Furthermore, miR-363-3p inhibition or SOX4 overexpression reversed the repressing role of sh-NR2F1-AS1 in the tumorigenicity of NSCLC cells. In summary, NR2F1-AS1 promotes the tumorigenicity of NSCLC cells by regulating miR-363-3p/SOX4.

RHO GTPase-Related Long Noncoding RNAs in Human Cancers

RHO GTPases are critical signal transducers that regulate cell adhesion, polarity, and migration through multiple signaling pathways. While all these cellular processes are crucial for the maintenance of normal cell homeostasis, disturbances in RHO GTPase-associated signaling pathways contribute to different human diseases, including many malignancies. Several members of the RHO GTPase family are frequently upregulated in human tumors. Abnormal gene regulation confirms the pivotal role of lncRNAs as critical gene regulators, and thus, they could potentially act as oncogenes or tumor suppressors. lncRNAs most likely act as sponges for miRNAs, which are known to be dysregulated in various cancers. In this regard, the significant role of miRNAs targeting RHO GTPases supports the view that the aberrant expression of lncRNAs may reciprocally change the intensity of RHO GTPase-associated signaling pathways. In this review article, we summarize recent advances in lncRNA research, with a specific focus on their sponge effects on RHO GTPase-targeting miRNAs to crucially mediate gene expression in different cancer cell types and tissues. We will focus in particular on five members of the RHO GTPase family, including RHOA, RHOB, RHOC, RAC1, and CDC42, to illustrate the role of lncRNAs in cancer progression. A deeper understanding of the widespread dysregulation of lncRNAs is of fundamental importance for confirmation of their contribution to RHO GTPase-dependent carcinogenesis.

Non-coding RNA Activated by DNA Damage: Review of Its Roles in the Carcinogenesis

Long intergenic non-coding RNA 00657 (LINC00657) or "non-coding RNA activated by DNA damage" (NORAD) is an extremely conserved and copious long non-coding RNA (lncRNA). This transcript has pivotal role in the preservation of genome integrity. Several researches have appraised the role of NORAD in the evolution of human cancers with most of them indicating an oncogenic role for this lncRNA. Several miRNAs such as miR-199a-3p, miR-608, miR-155-5p, miR-590-3p, miR-495-3p, miR-608, miR-202-5p, miR-125a-3p, miR-144-3p, miR-202-5p, and miR-30a-5p have been recognized as targets of NORAD in different cancer cell lines. In addition, NORAD has interactions with cancer-related pathways, particularly STAT, TGF-β, Akt/mTOR, and PI3K/AKT pathway. Over-expression of NORAD has been related with poor clinical outcome of patients with diverse types of neoplasms. Collectively, NORAD is a prospective marker and target for combating cancer.