Long Non-coding RNAs and their Role in Metastasis

The effects of LncRNA PVT1 on clinical characteristics and survival in breast cancer patients: A protocol for systematic review and meta analysis

BACKGROUND

Currently, an increasing number of long noncoding RNAs (LncRNAs) have been reported to be abnormally expressed in human carcinomas and play a vital role in tumourigenesis. Some studies were carried out to investigate the influence of the expression of plasmacytoma variant translocation 1 (PVT1) on prognosis and its clinical significance in patients with breast cancer, while the results were contradictory and uncertain. A meta-analysis was conducted with controversial data to accurately assess the issue.

METHODS

A detailed search of relevant researches was performed in Wanfang, Chinese Biomedical Literature Database, Chinese National Knowledge Infrastructure, Chongqing VIP Chinese Science and Technology Periodical Database, PubMed, Embase, and Web of Science. Two reviewers independently conducted data extraction and literature quality evaluation. Odd ratio and its 95% confidence intervals were applied to evaluate the relationship between PVT1 and clinicopathological characteristics of breast cancer patients. Hazard ratios and its 95% confidence intervals were adopted to assess the prognostic effects of PVT1 on overall survival and disease-free survival. Meta-analysis was conducted with Stata 14.0 software.

RESULTS

This study will provide high-quality evidence-based medical evidence for the correlation between PVT1 expression and overall survival, and disease-free survival and clinicopathological features.

CONCLUSION

The study will provide updated evidence to evaluate whether the expression of PVT1 is in association with poor prognosis in patients with breast cancer.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/C2TYE.

FENDRR: A pivotal, cancer-related, long non-coding RNA

Long non-coding RNAs (lncRNAs) have more than 200 nucleotides and do not encode proteins. Based on numerous studies, lncRNAs have emerged as new and crucial regulators of biological function and have been implicated in the pathogenesis of a variety of diseases, especially cancers. Specific lncRNAs have been identified as novel molecular biomarkers for cancer diagnosis, prognosis, and treatment efficacy. Fetal-lethal non-coding developmental regulatory RNA (FENDRR, also known as FOXF1-AS1) is a novel lncRNA that is located at chr3q13.31 and has four exons and 3099 nucleotides, and its genomic site is located at chr3q13.31. FENDRR is abnormally expressed in a variety of cancers and is significantly associated with different clinical characteristics. In addition, FENDRR has shown potential as a biomarker for cancer diagnosis, prognosis, and treatment. In this review, we summarize the current understanding of FENDRR and its mechanistic role in cancer progression. We also discuss recent insights into the clinical significance of FENDRR for cancer diagnosis, prognosis, and treatment.

Increased level of long non coding RNA H19 is correlated with the downregulation of miR-326 and BCL-2 genes in pediatric acute lymphoblastic leukemia, a possible hallmark for leukemogenesis

Long non-coding RNAs (lncRNAs) and their role in competitive endogenous RNA (ceRNA) networks have emerged as fundamental debates in the biological processes of initiation and progression of cancer. This study aimed to identify and measure the expression levels of relevant ceRNA regulatory genes contributing to acute lymphoblastic leukemia (ALL). lncRNA H19 and BCL-2 mRNA were chosen based on in silico studies and their interactions with miR-326. Subsequently, the aforementioned coding/non-coding gene expression profiles were measured using qRT-PCR in 50 bone marrow samples, including 33 cases with pediatric ALL and 17 controls with no evidence of malignancy. lncRNA H19 was identified as an oncogenic factor which was noticeably increased in the newly diagnosed patients (P = 0.0019, AUC = 0.84) and negatively associated with miR-326 (r = -0.6, P = 0.02). Furthermore, a negative correlation was introduced between the transcriptional levels of miR-326 and the anti-apoptotic BCL-2 gene (r = -0.6, P = 0.028). The novel experimental and bioinformatic results achieved in this study may provide new insights into the molecular leukemogenesis of pediatric ALL.

Long Noncoding RNAs in Gastrointestinal Cancer: Tumor Suppression Versus Tumor Promotion

Approximately 80% of the human genome harbors biochemical marks of active transcription that its majority transcribes to noncoding RNAs, namely long noncoding RNAs (lncRNAs). LncRNAs are heterogeneous RNA transcripts that regulate critical biological processes such as cell survival and death. They involve in the progression of different cancers by affecting transcriptional and post-transcriptional modifications as well as epigenetic control of numerous tumor suppressors and oncogenes. Recent findings show that aberrant expression of lncRNAs is associated with tumor initiation, progression, invasion, and overall survival of patients with gastrointestinal (GI) cancers. Some lncRNAs play as tumor suppressors in all GI cancers, but others play as tumor promoters. However, some other lncRNAs might function as a tumor suppressor in one GI cancer, but as a tumor promoter in another GI cancer type. This fact highlights possible context dependency of the expression patterns and roles of at least some lncRNAs in GI cancer development and progression. Here, we review the functional relation of lncRNAs involved in the development and progression of GI cancer by focusing on their roles as tumor suppressor and tumor promoter genes.

ROR1-AS1 knockdown inhibits growth and invasion and promotes apoptosis in NSCLC cells by suppression of the PI3K/Akt/mTOR pathway

The role of ROR1-AS1 in non-small-cell lung cancer (NSCLC) remains unclear. Therefore, we aimed to investigate the functional role of ROR1-AS1 in NSCLC and to explore the underlying mechanisms. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay was performed to detect cell proliferation. Transwell assay was performed to evaluate cell invasive ability. Cell apoptotic rates and caspase-3/7 activity were determined to evaluate apoptosis. The expression levels of PI3K/Akt/mTOR pathway-related proteins were measured using Western blot analysis. Results showed that ROR1-AS1 expression was upregulated in NSCLC samples. Knockdown of ROR1-AS1 inhibited the viability and invasive ability of NSCLC cells. Knockdown of ROR1-AS1 induced apoptotic rate and caspase-3/7 activity and suppressed xenograft NSCLC tumor growth. In addition, ROR1-AS1 knockdown inhibited the activation of the PI3K/Akt/mTOR pathway in NSCLC cells. However, treatment with 740Y-P prevented the effects of si-ROR1-AS1 on viability, invasive ability, and apoptosis of NSCLC cells. These findings implied that ROR1-AS1 played an oncogenic role in NSCLC via regulating the PI3K/Akt/mTOR pathway.

LINC01152 upregulates MAML2 expression to modulate the progression of glioblastoma multiforme via Notch signaling pathway

Glioblastoma multiforme (GBM) brings serious physical and psychological pain to GBM patients, whose survival rate remains not optimistic. Long noncoding RNAs (lncRNAs) have been reported to participate in the progression of many cancers, including GBM. However, the mechanism and function of long intergenic non-protein coding RNA 1152 (LINC01152) in GBM are still unclear. In our study, we aimed to explore the function and mechanism of LINC01152 in GBM. Then qRT-PCR analysis was implemented to search the expression of RNAs in GBM tissues and cells. Functional assays such as EdU assay, colony formation assay, TUNEL assay and flow cytometry analysis were conducted to estimate GBM cell proliferation and apoptosis. RNA pull down assay, luciferase reporter assay, RIP and ChIP assays were implemented to search the binding between molecules. As a result, we discovered that LINC01152 was upregulated in GBM tissues and cells. LINC01152 and mastermind like transcriptional coactivator 2 (MAML2) could both play the oncogenic part in GBM. Moreover, LINC01152 positively regulated MAML2 in GBM by sponging miR-466 and recruiting SRSF1. In turn, RBPJ/MAML2 transcription complex was found to activate the transcription of LINC01152 in GBM cells. In conclusion, LINC01152 could upregulate the expression of MAML2 to promote tumorigenesis in GBM via Notch signaling pathway.

MicroRNA-505, Suppressed by Oncogenic Long Non-coding RNA LINC01448, Acts as a Novel Suppressor of Glycolysis and Tumor Progression Through Inhibiting HK2 Expression in Pancreatic Cancer

Background: MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs) play vital regulatory roles in pancreatic cancer (PC) initiation and progression. We aimed to explore the biological functions and underlying mechanisms of miR-505-3p (miR-505) in PC.

Methods: We first screened miRNA expression profiles using microarray in PC tissues and normal tissues, and then studied the function and underlying mechanism of miR-505. Moreover, we evaluated the regulatory effect of lncRNA LINC01448 on miR-505.

Results: We demonstrated miR-505 that was significantly downregulated in PC tissues. We further revealed that miR-505 significantly inhibited cell proliferation, invasion, sphere formation, glucose consumption, and lactate production by targeting HK2. In addition, overexpression of miR-505 led to tumor growth inhibition in vivo, demonstrating that it acts as a tumor suppressor in PC. LINC01448 was identified as an oncogenic lncRNA that could reduce miR-505 expression. Subsequent studies confirmed that LINC01448 enhanced cell proliferation, invasion, sphere formation, glucose consumption, and lactate production by regulating the miR-505/HK2 pathway.

Conclusions: These findings demonstrated that miR-505, suppressed by LINC01448, could function as a key tumor suppressor by targeting HK2 in PC, elucidating an important role of the LINC01448/miR-505/HK2 pathway in regulating PC glycolysis and progression.

Atorvastatin Regulates MALAT1/miR-200c/NRF2 Activity to Protect Against Podocyte Pyroptosis Induced by High Glucose

BACKGROUND

Diabetic nephropathy (DN) is one of the main complications of diabetes mellitus (DM), which leads to the long-term loss of kidney functions. Long noncoding RNAs (LncRNAs) can alleviate DN by interacting with microRNAs (miRNAs). In this work, we aimed to explore the effects of the MALAT1/miR-200c/NRF2 regulatory axis on the pyroptosis and oxidative stress (Oxidative stress, OS) of renal podocytes in high glucose (HG) environment and whether the lipid-lowering drug atorvastatin (AT) can relieve renal OS through this approach.

METHODS

MPC-5, a mouse podocyte cell line, was induced by HG as a cell model. The protein expressions of caspase-1, GSDMD, NLRP3, NRF2, etc. were detected by Western blotting and immunofluorescence, and the mRNA level of caspase-1, GSDMD, NLRP3, NRF2, MALAT1, miR-200c was tested by qRT-PCR. The cell pyroptosis of podocytes treated with AT was verified by CCK-8 or flow cytometry. The levels of Malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) were measured by spectrophotometer, respectively.

RESULTS

The caspase-1 was upregulated in time-dependent manner and got the peak at 48 h and 30 mmol/L respectively in MPC-5 cells treated with HG. Further, the expression of GSDMD, MALAT1 and miR-200c were increased, while the level of NRF2, HO-1, OS-related indicators, were decreased simultaneously. Knockdown the MALAT1 protected MPC-5 cells from pyroptosis and OS induced by HG. However, overexpressing miR-200c in control-group cells increased pyroptosis and upregulated the OS level with HG culture medium. Further, atorvastatin protected MPC-5 cells from cell pyroptosis and downregulated the level of renal OS via attenuating the expression of MALAT1 and miR-200c.

CONCLUSION

Atorvastatin protects podocyte cells via MALAT1/miR-200c/NRF2 signal pathway from pyroptosis and OS induced by HG.

Long non-coding RNA GClnc1 knockdown suppresses progression of epithelial ovarian cancer by recruiting FOXC2 to disrupt the NOTCH1/NF-κB/Snail pathway

PURPOSE

Epithelial ovarian cancer (EOC) is a highly fatal gynecological cancer. A long noncoding RNA (lncRNA) gastric cancer-associated lncRNA1 (GClnc1) has been revealed to play critical roles in metastasis. Therefore, the present study aims to explore the correlation between GClnc1 and the metastasis and progression of EOC.

METHODS

First, 57 paired EOC and paracancerous tissues were collected to detect GClnc1 expression by RT-qPCR. Subsequently, OVC1 and SKOV3 cells with GClnc1 silencing/overexpression were developed to detect changes in cell activity, apoptosis, migration and invasion abilities. Then, the subcellular localization of GClnc1 was detected by nuclear/cytoplasmic fractionation, ISH and FISH assays. The binding relationships between GClnc1 and forkhead box protein C2 (FOXC2), and between FOXC2 and NOTCH1 were predicted and verified.

RESULTS

GClnc1 was significantly overexpressed in EOC tissues, and knockdown of GClnc1 inhibited cell viability and promoted apoptosis. Moreover, GClnc1 in the nucleus bound to the transcription factor FOXC2, thereby activating the transcription of NOTCH1. NOTCH1 overexpression enhanced the proliferation and epithelial-mesenchymal transition of SKOV3 and OVC1 cells. Moreover, NOTCH1 activated the NF-κB/Snail signaling. Finally, in vivo experiments demonstrated that GClnc1 knockdown suppressed the growth and metastasis of SKOV3 and OVC1 cells in vivo.

CONCLUSIONS

GClnc1 promoted NOTCH1 transcription by recruiting FOXC2, thereby activating the NF-κB/Snail signaling and promoting EOC cell growth and metastasis.

High-expression of LncRNA MAFG-AS1 is associated with the prognostic of patients with colorectal cancer

OBJECTIVE

Long noncoding RNAs (lncRNAs) have been proven to exhibit distinct functions on the convoluted processes of tumor developments. Some studies on the biological functions of lncRNA MAFG-AS1 (MAFG-AS1) in cancers revealed that they may serve as an oncogene in some kinds of tumors, including colorectal cancer (CRC). However, little is known about the role of MAFG-AS1 in the prognostic of CRC.

METHODS

A public dataset was mined for the screening of dysregulated lncRNAs in CRC. Quantitative real-time reverse transcription-polymerase chain reaction(qPCR) was used to compare the levels of MAFG-AS1 between paired MAFG-AS1 specimens and normal adjacent tissues. The correlations between MAFG-AS1 and clinic pathological features in CRC were analyzed using the chi-square test. The log-rank test and Kaplan-Meier test were carried out to compare the survival time of patients with high and low expressions of MAFG-AS1. Cox regression was applied for univariate and multivariate assays to validate whether MAFG-AS1 could be an independent factor in the prognosis of CRC.

RESULTS

We found that the distinct upregulation of MAFG-AS1 in various tumors was a common event. MAFG-AS1 was distinctly up-regulated in CRC specimens compared to matched non-tumor specimens (p < 0.01). High MAFG-AS1 expressions were closely associated with depth of invasion (p = 0.011) and TNM stage (p = 0.022). Survival assays revealed that patients with high expression of MAFG-AS1 have a shorter overall survival (p = 0.0030) and disease-free survival (p = 0.0002).

CONCLUSIONS

MAFG-AS1 can serve as a novel potential biomarker to predict CRC patients' survival time.

Emerging impact of the long noncoding RNA MIR22HG on proliferation and apoptosis in multiple human cancers

An increasing number of studies have shown that long noncoding RNAs (lncRNAs) play important roles in diverse cellular processes, including proliferation, apoptosis, migration, invasion, chromatin remodeling, metabolism and immune escape. Clinically, the expression of MIR22HG is increased in many human tumors (colorectal cancer, gastric cancer, hepatocellular carcinoma, lung cancer, and thyroid carcinoma), while in others (esophageal adenocarcinoma and glioblastoma), it is significantly decreased. Moreover, MIR22HG has been reported to function as a competitive endogenous RNA (ceRNA), be involved in signaling pathways, interact with proteins and interplay with miRNAs as a host gene to participate in tumorigenesis and tumor progression. In this review, we describe the biological functions of MIR22HG, reveal its underlying mechanisms for cancer regulation, and highlight the potential role of MIR22HG as a novel cancer prognostic biomarker and therapeutic target that can increase the efficacy of immunotherapy and targeted therapy for cancer treatment.

N6-methyladenine modification in noncoding RNAs and its function in cancer

Non-coding RNAs are the main component of the extensive transcription results of the mammalian genome. They are not transcribed into proteins but play critical roles in regulating multiple biological processes and affecting cancer progression. m6A modification is one of the most abundant internal RNA modification of mammalian cells, and it involves almost all aspects of RNA metabolism. Recent research revealed tight correlations between m6A modification and ncRNAs and indicated the interaction between m6A and ncRNAs act a pivotal part in the development of cancer. The correlation between m6A modification and ncRNAs provides a new perspective for exploring the potential regulatory mechanism of tumor gene expression, and suggest that m6A modification and ncRNAs may be important prognostic markers and therapeutic targets for multiple cancers. In this review, we summarize the potential regulatory mechanisms between m6A methylation and ncRNAs, highlighting how their relationship affects biological functions in cancer.

The landscape of long non-coding RNAs in tumor stroma

AIMS

Long non-coding RNAs (lncRNAs) are associated with cancer development, while their relationship with the cancer-associated stromal components remains poorly understood. In this review, we performed a broad description of the functional landscape of stroma-associated lncRNAs in various cancers and their roles in regulating the tumor-stroma crosstalk.

MATERIALS AND METHODS

We carried out a systematic literature review of PubMed, Scopus, Medline, Bentham, and EMBASE (Elsevier) databases by using the keywords "LncRNAs in cancer," "LncRNAs in tumor stroma," "stroma," "cancer-associated stroma," "stroma in the tumor microenvironment," "tumor-stroma crosstalk," "drug resistance of stroma," and "stroma in immunosuppression" till July 2020. We collected the latest articles addressing the biological functions of stroma-associated lncRNAs in cancer.

KEY FINDINGS

These articles reported that dysregulated stroma-associated lncRNAs play significant roles in modulating the tumor microenvironment (TME) by the regulation of tumor-stroma crosstalk, epithelial to mesenchymal transition (EMT), endothelial to mesenchymal transition (EndMT), extracellular matrix (ECM) turnover, and tumor immunity.

SIGNIFICANCE

The tumor stroma is a substantial portion of the TME, and the dysregulation of tumor stroma-associated lncRNAs significantly contributes to cancer initiation, progression, angiogenesis, immune evasion, metastasis, and drug resistance. Thus, stroma-associated lncRNAs could be potentially useful targets for cancer therapy.

LncRNAs in Cancer: From garbage to Junk

Sequencing-based transcriptomics has significantly redefined the concept of genome complexity, leading to the identification of thousands of lncRNA genes identification of thousands of lncRNA genes whose products possess transcriptional and/or post-transcriptional regulatory functions that help to shape cell functionality and fate. Indeed, it is well-established now that lncRNAs play a key role in the regulation of gene expression through epigenetic and posttranscriptional mechanims. The rapid increase of studies reporting lncRNAs alteration in cancers has also highlighted their relevance for tumorigenesis. Herein we describe the most prominent examples of well-established lncRNAs having oncogenic and/or tumor suppressive activity. We also discuss how technical advances have provided new therapeutic strategies based on their targeting, and also report the challenges towards their use in the clinical settings.

Role of HAND2-AS1 in human tumors

Long noncoding RNAs (lncRNAs) are molecules more than 200 nucleotides in length. They play roles in various cells, mainly regulating cell growth, differentiation, and apoptosis. They also participate in the pathogenesis of many diseases. In fact, several studies have shown that lncRNAs function as cancer or tumor suppressor genes and play important roles in the occurrence and development of cancer in humans. New evidence has shown that lncRNA heart and neural crest derivatives expressed 2-antisense RNA 1 (lncRNA HAND2-AS1) hinders the occurrence and development of various tumors. Overexpression of HAND2-AS1 was found to be significantly related to the clinical and pathological characteristics of cancer patients, as well as the regulation of cell proliferation, apoptosis, invasion, metastasis, and energy metabolism through several possible mechanisms. Therefore, HAND2-AS1 may be a promising tumor biomarker and therapeutic target. Here, we review the biological functions, mechanisms, and potential clinical significance of HAND2-AS1 in numerous human tumors.

Epigenetic Mechanisms of LncRNAs Binding to Protein in Carcinogenesis

Epigenetic dysregulation is an important feature for cancer initiation and progression. Long non-coding RNAs (lncRNAs) are transcripts that stably present as RNA forms with no translated protein and have lengths larger than 200 nucleotides. LncRNA can epigenetically regulate either oncogenes or tumor suppressor genes. Nowadays, the combined research of lncRNA plus protein analysis is gaining more attention. LncRNA controls gene expression directly by binding to transcription factors of target genes and indirectly by complexing with other proteins to bind to target proteins and cause protein degradation, reduced protein stability, or interference with the binding of other proteins. Various studies have indicated that lncRNA contributes to cancer development by modulating genes epigenetically and studies have been done to determine which proteins are combined with lncRNA and contribute to cancer development. In this review, we look in depth at the epigenetic regulatory function of lncRNAs that are capable of complexing with other proteins in cancer development.

The Long Noncoding RNA NEAT1 Promotes Sarcoma Metastasis by Regulating RNA Splicing Pathways

Soft-tissue sarcomas (STS) are rare malignancies showing lineage differentiation toward diverse mesenchymal tissues. Half of all high-grade STSs develop lung metastasis with a median survival of 15 months. Here, we used a genetically engineered mouse model that mimics undifferentiated pleomorphic sarcoma (UPS) to study the molecular mechanisms driving metastasis. High-grade sarcomas were generated with Cre recombinase technology using mice with conditional mutations in Kras and Trp53 (KP) genes. After amputation of the limb bearing the primary tumor, mice were followed for the development of lung metastasis. Using RNA-sequencing of matched primary KP tumors and lung metastases, we found that the long noncoding RNA (lncRNA) Nuclear Enriched Abundant Transcript 1 (Neat1) is significantly upregulated in lung metastases. Furthermore, NEAT1 RNA ISH of human UPS showed that NEAT1 is upregulated within a subset of lung metastases compared with paired primary UPS. Remarkably, CRISPR/Cas9-mediated knockout of Neat1 suppressed the ability of KP tumor cells to colonize the lungs. To gain insight into the underlying mechanisms by which the lncRNA Neat1 promotes sarcoma metastasis, we pulled down Neat1 RNA and used mass spectrometry to identify interacting proteins. Interestingly, most Neat1 interacting proteins are involved in RNA splicing regulation. In particular, KH-Type Splicing Regulatory Protein (KHSRP) interacts with Neat1 and is associated with poor prognosis of human STS. Moreover, depletion of KHSRP suppressed the ability of KP tumor cells to colonize the lungs. Collectively, these results suggest that Neat1 and its interacting proteins, which regulate RNA splicing, are involved in mediating sarcoma metastasis. IMPLICATIONS: Understanding that lncRNA NEAT1 promotes sarcoma metastasis, at least in part, through interacting with the RNA splicing regulator KHSRP may translate into new therapeutic approaches for sarcoma.

Long non-coding RNA PSMA3-AS1 enhances cell proliferation, migration and invasion by regulating miR-302a-3p/RAB22A in glioma

Glioma is the most prevalent solid tumor in the central nervous system (CNS). Recently, it has been indicated that long non-coding RNAs (lncRNAs) substantially adjust the development of a variety of human cancers. In the present study, it was found and verified via microarray analysis that lncRNA PSMA3-AS1 exhibited a high expression in glioma tissues and cell lines. Then CCK-8, 5-Ethynyl-2'-deoxyuridine (EdU) staining, plate clone assay, Transwell assay, Western blotting and nude mouse model were adopted to verify PSMA3-AS1's effects on glioma. Knockdown of PSMA3-AS1 inhibited the migration, proliferation and invasion of glioma cells in vivo and in vitro. Besides, PSMA3-AS1 bound to miR-302a-3p directly reduced the expression of miR-302a-3p, thus functioning as an endogenous sponge confirmed by luciferase reporter assay and bioinformatics analysis. PSMA3-AS1 knockdown remarkably enhanced the role of miR-302a-3p overexpression in cell behaviors in glioma. Moreover, these assays also confirmed that RAB22A was a target of miR-302a-3p. In this research, therefore, the PSMA3-AS1/miR-302a-3p/RAB22A pathway regulatory axis may be revealed in the pathogenesis of glioma, and PSMA3-AS1 can be used as an underlying target for the treatment and prognosis of glioma.

Circulating Non-coding RNAs in Renal Cell Carcinoma-Pathogenesis and Potential Implications as Clinical Biomarkers

Liquid biopsy-the determination of circulating cells, proteins, DNA or RNA from biofluids through a "less invasive" approach-has emerged as a novel approach in all cancer entities. Circulating non-(protein) coding RNAs including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and YRNAs can be passively released by tissue or cell damage or actively secreted as cell-free circulating RNAs, bound to lipoproteins or carried by exosomes. In renal cell carcinoma (RCC), a growing body of evidence suggests circulating non-coding RNAs (ncRNAs) such as miRNAs, lncRNAs, and YRNAs as promising and easily accessible blood-based biomarkers for the early diagnosis of RCC as well as for the prediction of prognosis and treatment response. In addition, circulating ncRNAs could also play a role in RCC pathogenesis and progression. This review gives an overview over the current study landscape of circulating ncRNAs and their involvement in RCC pathogenesis as well as their potential utility as future biomarkers in RCC diagnosis and treatment.

The roles of long noncoding RNAs in breast cancer metastasis

Breast cancer is the most significant threat to female health. Breast cancer metastasis is the major cause of mortality in breast cancer patients. To fully unravel the molecular mechanisms that underlie the breast cancer cell metastasis is critical for developing strategies to improve survival and prognosis in breast cancer patients. Recent studies have revealed that the long noncoding RNAs (lncRNAs) are involved in breast cancer metastasis through a variety of molecule mechanisms, though the precise functional details of these lncRNAs are yet to be clarified. In the present review, we focus on the functions of lncRNAs in breast cancer invasion and metastasis, with particular emphasis on the functional properties, the regulatory factors, the therapeutic promise, as well as the future challenges in studying these lncRNA.

Dual Effects of Non-Coding RNAs (ncRNAs) in Cancer Stem Cell Biology

The identification of cancer stem cells (CSCs) as initiators of carcinogenesis has revolutionized the era of cancer research and our perception for the disease treatment options. Additional CSC features, including self-renewal and migratory and invasive capabilities, have further justified these cells as putative diagnostic, prognostic, and therapeutic targets. Given the CSC plasticity, the identification of CSC-related biomarkers has been a serious burden in CSC characterization and therapeutic targeting. Over the past decades, a compelling amount of evidence has demonstrated critical regulatory functions of non-coding RNAs (ncRNAs) on the exclusive features of CSCs. We now know that ncRNAs may interfere with signaling pathways, vital for CSC phenotype maintenance, such as Notch, Wnt, and Hedgehog. Here, we discuss the multifaceted contribution of microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), as representative ncRNA classes, in sustaining the CSC-like traits, as well as the underlying molecular mechanisms of their action in various CSC types. We further discuss the use of CSC-related ncRNAs as putative biomarkers of high diagnostic, prognostic, and therapeutic value.

Expression and Clinicopathological Significances of lncRNAs: Could ARA and ZEB2NAT be the Potential Breast Cancer-Related Biomarkers?

INTRODUCTION

Pieces of evidence have shown that a significant proportion of cancer-prone factors are not attributed to alterations in protein-coding sequences. Adriamycin resistance-related (ARA) and natural antisense of ZEB2 (ZEB2NAT) long non-coding RNAs (lncRNAs) have been indicated with oncogenic properties by regulating various signaling pathways and epithelial-to-mesenchymal transition (EMT), which may have diagnostic and prognostic potential as a novel group of biomarkers.

AIM

The current study aimed to evaluate the expression status of ARA and ZEB2NAT lncRNAs and their clinicopathological significance in a population with breast cancer (BC).

METHODS

Total RNA was extracted from 60 tumor samples and their normal adjacent tissues (NATs). The lncRNA expressions were measured using quantitative reverse transcription PCR (RT-qPCR) and statistical analyses were performed by SPSS version 25.

RESULTS

Our data showed a significant upregulation of ARA and ZEB2NAT lncRNAs in tumor tissues compared to NATs (p <0.001; p = 0.021, respectively). ARA and ZEB2NAT expression were observed to be significantly associated with tumor grade, nuclear grade, tumor stages, and lymph node metastasis (p <0.05). Additionally, ARA expression was significantly correlated with breastfeeding status (p = 0.027).

CONCLUSION

our data revealed that ARA and ZEB2NAT lncRNAs were overexpressed in BC. Furthermore, the selected lncRNAs were found to might be the potential biomarkers for BC diagnosis and prognosis. However, the findings of the current research are required to be replicated in other studies with larger sample sizes.

Overexpression of long noncoding RNA PTPRG-AS1 is associated with poor prognosis in epithelial ovarian cancer

OBJECTIVE Long noncoding RNAs (lncRNAs) have been shown to play a critical role in tumor progression. Abnormal expression of LncRNA PTPRG antisense RNA 1 (PTPRG-AS1) has been reported in several tumors. Hence, we aimed to determine the expression and clinical significance of PTPRG-AS1 in epithelial ovarian cancer (EOC) patients. METHODS The expressions of PTPRG-AS1 were assessed in 184 pairs of EOC tumor specimens and adjacent normal tissues. The levels of target lncRNAs and GAPDH were examined using standard SYBR-Green methods. The relationships between the expressions of PTPRG-AS1 and the clinicopathological features were analyzed using the chi-square test. Multivariate analysis using the Cox proportional hazards model was performed to assess the prognostic value of PTPRG-AS1 in EOC patients. RESULTS We confirmed that the expressions of PTPRG-AS1 were distinctly higher in the EOC tissue compared with the adjacent non-tumor specimens (p < 0.01). Higher levels of PTPRG-AS1 in EOC patients were associated with advanced FIGO stage (p = 0.005), grade (p = 0.006), and distant metastasis (p = 0.005). Survival analyses revealed that patients with high expressions of PTPRG-AS1 had a distinctly decreased overall survival (p = 0.0029) and disease-free survival (p = 0.0009) compared with those with low expressions of PTPRG-AS1. Multivariate assays indicated that PTPRG-AS1 expression was an independent prognostic factor for both overall survival and disease-free survival in EOC (Both p < 0.05). CONCLUSIONS Our study suggests that PTPRG-AS1 may serve as a novel prognostic biomarker for EOC patients.

NF-κB-Interacting Long Noncoding RNA Regulates HIV-1 Replication and Latency by Repressing NF-κB Signaling

NF-κB-interacting long noncoding RNA (NKILA) was recently identified as a negative regulator of NF-κB signaling and plays an important role in the development of various cancers. It is well known that NF-κB-mediated activation of human immunodeficiency virus type 1 (HIV-1) long terminal repeat (LTR)-driven gene expression is required for HIV-1 transcription and reactivation of latency. However, whether NKILA plays essential roles in HIV-1 replication and latency is unclear. Here, by ectopic expression and silencing experiments, we demonstrate that NKILA potently inhibits HIV-1 replication in an NF-κB-dependent manner by suppressing HIV-1 LTR promoter activity. Moreover, NKILA showed broad-spectrum inhibition on the replication of HIV-1 clones with different coreceptor tropisms as well as on LTR activity of various HIV-1 clinical subtypes. Chromatin immunoprecipitation (ChIP) assays revealed that NKILA expression abolishes the recruitment of p65 to the duplicated κB binding sites in the HIV-1 LTR. NKILA mutants disrupting NF-κB inhibition also lost the ability to inhibit HIV-1 replication. Notably, HIV-1 infection or reactivation significantly downregulated NKILA expression in T cells in order to facilitate viral replication. Downregulated NKILA was mainly due to reduced acetylation of histone K27 on the promoter of NKILA by HIV-1 infection, which blocks NKILA expression. Knockdown of NKILA promoted the reactivation of latent HIV-1 upon phorbol myristate acetate (PMA) stimulation, while ectopic NKILA suppressed the reactivation in a well-established clinical model of withdrawal of azidothymidine (AZT) in vitro These findings improve our understanding of the functional suppression of HIV-1 replication and latency by NKILA through NF-κB signaling.IMPORTANCE The NF-κB pathway plays key roles in HIV-1 replication and reactivation of HIV-1 latency. A regulator inhibiting NF-κB activation may be a promising therapeutic strategy against HIV-1. Recently, NF-κB-interacting long noncoding RNA (NKILA) was identified to suppress the development of different human cancers by inhibiting IκB kinase (IKK)-induced IκB phosphorylation and NF-κB pathway activation, whereas the relationship between NKILA and HIV-1 replication is still unknown. Here, our results show that NKILA inhibits HIV-1 replication and reactivation by suppressing HIV-1 long terminal repeat (LTR)-driven transcription initiation. Moreover, NKILA inhibited the replication of HIV-1 clones with different coreceptor tropisms. This project may reveal a target for the development of novel anti-HIV drugs.

Long non-coding RNA LINC01116 is overexpressed in lung adenocarcinoma and promotes tumor proliferation and metastasis

Long non-coding RNA LINC01116 is involved in the occurrence and progression of a variety of cancers. However, the specific role of LINC01116 in lung adenocarcinoma (LUAD) remains unclear. In this work, we found that LINC01116 was overexpressed in LUAD tissues and cell lines and that increased expression was significantly associated with worse prognoses in patients with LUAD. Univariate and multivariate Cox regression analyses indicated that LINC01116 was an independent risk factor for the prognosis of patients with LUAD. Downregulation of LINC01116 significantly inhibited cell proliferation and migration, promoted cell apoptosis, and prevented cell progression from G1 to S phase. In addition, downregulation of LINC01116 significantly inhibited the epithelial-mesenchymal transition, leading to an increased expression of the epithelial marker E-cadherin and decreased expression of the mesenchymal markers N-cadherin and vimentin. In summary, our results suggest that LINC01116 may act as an oncogene in LUAD and may be a valuable prognostic biomarker for patients with LUAD.

The role of long non-coding RNAs in drug resistance of cancer

Long non-coding RNAs (lncRNAs), a class of long RNAs, are longer than 200 nucleotides in length but lack protein-coding capacity. LncRNAs, as critical genomic regulators, are involved in genomic imprinting regulation, histone modification and gene expression regulation as well as tumor initiation and progression. However, it is also found that lncRNAs are associated with drug resistance in several types of cancer. Drug resistance is an important reason for clinical chemotherapy failure, and the molecular mechanism of tumor resistance is complex, which is a process of multi-cause, multi-gene and multi-signal transduction pathway interaction. Then comprehending the mechanisms of chemoresistance will help find ways to control the tumor progression effectively. Therefore, in this review, we will construct lncRNAs /drug resistance interaction network and shed light on the role of lncRNAs in drug resistance.

Long-Noncoding RNA (lncRNA) in the Regulation of Hypoxia-Inducible Factor (HIF) in Cancer

Hypoxia is dangerous for oxygen-dependent cells, therefore, physiological adaption to cellular hypoxic conditions is essential. The transcription factor hypoxia-inducible factor (HIF) is the main regulator of hypoxic metabolic adaption reducing oxygen consumption and is regulated by gradual von Hippel-Lindau (VHL)-dependent proteasomal degradation. Beyond physiology, hypoxia is frequently encountered within solid tumors and first drugs are in clinical trials to tackle this pathway in cancer. Besides hypoxia, cancer cells may promote HIF expression under normoxic conditions by altering various upstream regulators, cumulating in HIF upregulation and enhanced glycolysis and angiogenesis, altogether promoting tumor proliferation and progression. Therefore, understanding the underlying molecular mechanisms is crucial to discover potential future therapeutic targets to evolve cancer therapy. Long non-coding RNAs (lncRNA) are a class of non-protein coding RNA molecules with a length of over 200 nucleotides. They participate in cancer development and progression and might act as either oncogenic or tumor suppressive factors. Additionally, a growing body of evidence supports the role of lncRNAs in the hypoxic and normoxic regulation of HIF and its subunits HIF-1α and HIF-2α in cancer. This review provides a comprehensive update and overview of lncRNAs as regulators of HIFs expression and activation and discusses and highlights potential involved pathways.

The Role of Long Non-Coding RNAs in Thyroid Cancer

Thyroid cancer, the most common endocrine malignancy, has become the most commonly diagnosed malignant solid tumor. Moreover, some cases have poor prognosis, and the survival period is only 3-5 months. Long noncoding RNAs (lncRNAs) are a group of functional RNA molecules more than 200 nucleotides in length that lack the ability to encode protein but participate in all aspects of gene regulation. Functionally, many lncRNAs play essential roles in epigenetic regulation at transcriptional and post-transcriptional levels via various molecular mechanisms. Recent studies have discovered important roles for lncRNAs during the complex process of carcinogenesis in thyroid cancer. In this review, we focus on lncRNAs dysregulated in thyroid cancer and summarize recently reported associations between lncRNAs and thyroid cancer in order to demonstrate the significant value of lncRNAs in diagnosis and treatment.

Long Non-coding RNA TDRKH-AS1 Promotes Colorectal Cancer Cell Proliferation and Invasion Through the β-Catenin Activated Wnt Signaling Pathway

Colorectal cancer (CRC) is a common cancer worldwide, with a lower 5-years survival rate. Recently, long non-coding RNAs (lncRNAs) have been well-studied as the oncogenes or the tumor suppressors in multiple malignancies, including CRC. However, their biological functions and potential mechanisms in human cancer remain unclear. Here, we evaluated the expression of TDRKH-AS1 in CRC tissues and identified its potential targets. We found that TDRKH-AS1 is upregulated in majority of CRC patients, which is also significantly correlated with their malignant characteristics and their dismal prognoses. The high expression of TDRKH-AS1 can promote cancer cell proliferation substantially and invasion based on in vitro experiments. We also recognized that the TDRKH-AS1 targets the β-catenin in the Wnt signaling pathway to exert its carcinogenic activity. TDRKH-AS1 could serve as a promising prognostic predictor and a potential therapeutic target for further early diagnoses and treatments via a non-invasive method.

Long non-coding RNA RAMS11 promotes metastatic colorectal cancer progression

Colorectal cancer (CRC) is the most common gastrointestinal malignancy in the U.S.A. and approximately 50% of patients develop metastatic disease (mCRC). Despite our understanding of long non-coding RNAs (lncRNAs) in primary colon cancer, their role in mCRC and treatment resistance remains poorly characterized. Therefore, through transcriptome sequencing of normal, primary, and distant mCRC tissues we find 148 differentially expressed RNAs Associated with Metastasis (RAMS). We prioritize RAMS11 due to its association with poor disease-free survival and promotion of aggressive phenotypes in vitro and in vivo. A FDA-approved drug high-throughput viability assay shows that elevated RAMS11 expression increases resistance to topoisomerase inhibitors. Subsequent experiments demonstrate RAMS11-dependent recruitment of Chromobox protein 4 (CBX4) transcriptionally activates Topoisomerase II alpha (TOP2α). Overall, recent clinical trials using topoisomerase inhibitors coupled with our findings of RAMS11-dependent regulation of TOP2α supports the potential use of RAMS11 as a biomarker and therapeutic target for mCRC.

Clinicopathological and prognostic value of SNHG6 in cancers: a systematic review and a meta-analysis

BACKGROUND

Dysregulation of the long non-coding RNA small nucleolar RNA host gene 16 (lncRNA SNHG6) has been found in multiple cancers. However, a definite conclusion on the clinical value of lncRNA SNHG6 expression in human cancers has not been determined. The purpose of the present meta-analysis was to comprehensively elucidate the association between SNHG6 expression and clinical outcomes in cancers.

METHODS

A systematic search was performed through the PubMed, Web of Science, Chinese National Knowledge Infrastructure (CNKI), and Wangfang databases for relevant studies. The pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were collected to estimate the prognostic value, and the odds ratios (ORs) with 95% CIs were used to evaluate the relationship between lncRNA SNHG6 expression and clinicopathological features, including tumor invasion depth, lymph node metastasis (LNM), distance metastasis (DM), and TNM stage.

RESULTS

In total, 914 patients from 13 studies were included in this meta-analysis. The pooled results suggested that evaluated SNHG6 expression could predict an unfavorable overall survival (OS) (HR = 2.04, 95% CI:1.56-2.52) with no heterogeneity (I² = 0.0%, p = 0.996). Subgroup analysis indicated a significant association between high SNHG6 expression and shorter OS in those studies with digestive system cancers (HR = 2.05, 95% CI: 1.47-2.62), or with sample size < 70 (HR = 2.70, 95% CI: 1.29-4.11), or with multivariate analysis (HR = 2.04, 95% CI: 1.44-2.64). Moreover, elevated SNHG6 expression was positively associated with tumor invasion depth (OR = 1.76, 95% CI: 1.18-2.63), LNM (OR = 1.60, 95% CI: 1.18-2.17), DM (OR = 1.90, 95% CI: 1.37-2.64) and advanced TNM stage (OR = 1.88, 95% CI: 1.36-2.60) in patients with cancers.

CONCLUSIONS

High lncRNA SNHG6 expression was correlated with tumor invasion depth, LNM, DM, and advanced TNM stage, suggesting that SNHG6 may serve as a promising prognostic biomarker of human cancers.

Expression level of long noncoding RNA NKILAmiR103-miR107 inflammatory axis and its clinical significance as potential biomarker in patients with colorectal cancer

Background:

Inflammatory cytokines have been observed in colorectal cancer (CRC) tissues and can promote the susceptibility to metastasis of CRC cells. Diverse regulatory mechanisms of long ncRNAs (lncRNAs) and microRNAs (miRNAs) involved in the inflammatory responses are associated with tumor progression. The aim of this research was to investigate the expression level of the nuclear factor-kappa B interacting lncRNA (NKILA)‐miR103-miR107 regulatory axis and its clinical significance as a potential biomarker in patients with CRC.

Materials and Methods:

In the present study, we investigated the expression levels of miR103, miR107, and NKILA in 21 paired CRC tissues and corresponding adjacent tissues, using real‐time polymerase chain reaction technique. Receiver operating characteristic (ROC) curve was used to analyze the prognostic value of biomarkers and to compare their predictive value.

Results:

It was found that the expression level of miR103 was significantly increased with the development of CRC (cancerous vs. corresponding normal tissues; 2.29 ± 1.65 vs. 1.16 ± 0.64, P = 0.003). Moreover, miR107 was upregulated in CRC tissues compared with paired normal tissues (2.1 ± 1.4 vs. 1.25 ± 0.83, P = 0.005), while NKILA displayed an opposite expression pattern versus miR103/107, but it was not statistically significant (3.69 ± 5.2 vs. 4.35 ± 5.99, P > 0.05). The ROC analysis demonstrated that miR103 had the best diagnostic ability performance with area under curve of 0.723 (0.545–0.901).

Conclusion:

We identified miR103/107 as tumor-promoting miRNAs with diagnostic value in cancer patients and presumptive negative regulators of NKILA, a potential cancer metastatic suppressor. Strategies that disrupt this regulatory axis might block CRC progression.

Non-coding RNAs in GI cancers: from cancer hallmarks to clinical utility

One of the most unexpected discoveries in molecular oncology, in the last decades, was the identification of a new layer of protein coding gene regulation by transcripts that do not codify for proteins, the non-coding RNAs. These represent a heterogeneous category of transcripts that interact with many types of genetic elements, including regulatory DNAs, coding and other non-coding transcripts and directly to proteins. The final outcome, in the malignant context, is the regulation of any of the cancer hallmarks. Non-coding RNAs represent the most abundant type of hormones that contribute significantly to cell-to cell communication, revealing a complex interplay between tumour cells, tumour microenvironment cells and immune cells. Consequently, profiling their abundance in bodily fluids became a mainstream of biomarker identification. Therapeutic targeting of non-coding RNAs represents a new option for clinicians that is currently under development. This review will present the biology and translational value of three of the most studied categories on non-coding RNAs, the microRNAs, the long non-coding RNAs and the circular RNAs. We will also focus on some aspirational concepts that can help in the development of clinical applications related to non-coding RNAs, including using pyknons to discover new non-coding RNAs, targeting human-specific transcripts which are expressed specifically in the tumour cell and using non-coding RNAs to increase the efficiency of immunotherapy.

Investigating the role of BCAR4 in ovarian physiology and female fertility by genome editing in rabbit

Breast Cancer Anti-estrogen Resistance 4 (BCAR4) was previously characterised in bovine species as a gene preferentially expressed in oocytes, whose inhibition is detrimental to in vitro embryo development. But its role in oogenesis, folliculogenesis and globally fertility in vivo remains unknown. Because the gene is not conserved in mice, rabbits were chosen for investigation of BCAR4 expression and function in vivo. BCAR4 displayed preferential expression in the ovary compared to somatic organs, and within the ovarian follicle in the oocyte compared to somatic cells. The transcript was detected in follicles as early as the preantral stage. Abundance decreased throughout embryo development until the blastocyst stage. A lineage of genome-edited rabbits was produced; BCAR4 expression was abolished in follicles from homozygous animals. Females of wild-type, heterozygous and homozygous genotypes were examined for ovarian physiology and reproductive parameters. Follicle growth and the number of ovulations in response to hormonal stimulation were not significantly different between genotypes. Following insemination, homozygous females displayed a significantly lower delivery rate than their heterozygous counterparts (22 ± 7% vs 71 ± 11% (mean ± SEM)), while prolificacy was 1.8 ± 0.7 vs 6.0 ± 1.4 kittens per insemination. In conclusion, BCAR4 is not essential for follicular growth and ovulation but it contributes to optimal fertility in rabbits.

Long non-coding RNA polymorphisms on 8q24 are associated with the prognosis of gastric cancer in a Chinese population

Background

Gastric cancer (GC) remains the third leading cause of cancer death in China. Although genome-wide association studies have identified the association between several single nucleotide polymorphisms (SNPs) on 8q24 and the risk of GC, the role of these SNPs in the prognosis of GC in Chinese populations has not yet been fully evaluated. Therefore, this study was conducted to explore the association between long non-coding RNA (lncRNA) polymorphisms on 8q24 and the prognosis of GC.

Methods

We genotyped 726 surgically resected GC patients to explore the association between eight SNPs in the lncRNAs CCAT1 (rs10087719, rs7816475), PCAT1 (rs1026411), PRNCR1 (rs12682421, rs13252298), and CASC8 (rs1562430, rs4871789, rs6983267) transcribed from the 8q24 locus and the prognosis of GC in a Chinese population.

Results

We found that the patients carrying rs12682421 AA genotypes survived for a shorter time than those with the GG/GA genotype (HR = 1.39, 95% confidence interval (CI) [1.09-1.78]). Compared with the CC/CT genotype, the TT genotype of rs1562430 was associated with an increased risk of death (HR = 1.38, 95% CI [1.06-1.80]). Furthermore, the results also identified the rs1026411 SNP as an independent prognostic factor for poor survival in GC patients. Patients carrying AA/AG variant genotypes had a 36% increased risk of death compared to those carrying the GG genotype (HR = 1.36, 95% CI [1.06-1.74]). These findings suggested that the rs12682421, rs1026411 and rs1562430 SNPs may contribute to the survival of GC and be prognostic markers for GC.

Long Non-coding RNA MIR4435-2HG Promotes Colorectal Cancer Proliferation and Metastasis Through miR-206/YAP1 Axis

Objective: Long non-coding RNAs (lncRNAs) are critical to colorectal cancer (CRC) progression. In the current study, the objective was the exploration of the role played by lncRNA MIR4435-2HG in CRC proliferation and metastasis.

Methods: lncRNA MIR4435-2HG expression and its association with CRC were analyzed using database and clinical specimens. The influences exerted by MIR4435-2HG on cell proliferating process, invading process, and migrating process of CRC were identified after MIR4435-2HG knockdown. The influences exerted by MIR4435-2HG on tumor growth and metastasis were assessed in vivo. The underlying mechanistic associations between MIR4435-2HG, microRNA miR-206, and the transcription factor Yes-associated protein 1 (YAP1) were assessed using bioinformatics and a luciferase reporter gene assay.

Results: MIR4435-2HG was highly expressed in CRC tissue in contrast with that in regular tissues and displayed relations to poor prognosis. MIR4435-2HG knockdown could suppress CRC cell proliferation, invasion, and migration. Moreover, MIR4435-2HG knockdown inhibited CRC growth and liver metastasis in vitro. We found MIR4435-2HG knockdown reduced YAP1, CTGF, AREG, vimentin, Snail, Slug, and Twist expression but enhanced E-cadherin expression. Functionally, MIR4435-2HG acted as a competing endogenous RNA (ceRNA) to upregulate YAP1 by sponging miR-206.

Conclusions: MIR4435-2HG promoted CRC growth and metastasis through miR-206/YAP1 axis and is likely to play prognostic marker roles and be therapeutically targeted in CRC.

Expression of long non-coding RNA H19 predicts distant metastasis in minimally invasive follicular thyroid carcinoma

Downregulation of lncRNA H19 (H19) expression is associated with an unfavorable prognosis in some cancers. However, little was known as to whether there was an association between H19 and minimally invasive follicular thyroid carcinoma (MI-FTC). In our study, we used quantitative real-time polymerase chain reaction (qRT-PCR) to determine H19 expression in 186 patients with MI-FTC who underwent initial surgery. Of the 186 patients with MI-FTC, 21 patients show distant metastasis （M+）at the initial operation established the diagnosis of MI-FTC. Of the 165 patients who did not show distant metastasis at diagnosis during the follow-up period (≥10 years), 28 patients undergone M+ and 137 patients has no distant metastasis（M-）after the initial operation. Low H19 expression was associated with large tumor size, vascular invasion, and distant metastasis. Univariate analysis showed that gender (male), age (45 years or older), primary tumor size (4 cm or more), vascular invasion and H19 level (<1.12) were significant prognostic factors related to postoperative distant metastases. Multivariate analysis showed that age, primary tumor size (4 cm or more) and vascular invasion was a significant prognostic factor for survival. Patients with low H19 expression showed a poorer outcome in MI-FTC patients. Receiver-operating characteristic (ROC) curve analysis demonstrated H19 could distinguish M+ from M- patientswith a value of area under the curve (AUC). Our findings suggest that H19 is a potential prognostic factor for evaluating prognosis and the metastatic potential of MI-FTC at an initial operation stage.

LncRNA XIST modulates HIF-1A/AXL signaling pathway by inhibiting miR-93-5p in colorectal cancer

Background

Long noncoding RNA (LncRNA) XIST is one of the genes that exists in different types of cancers. Earlier researches showed that XIST can advance the progression of colorectal cancer. Nevertheless, the potential molecular mechanism of XIST in combination with miR‐93‐5p has not been explored in colorectal cancer.

Methods

We performed qRT‐PCR to explore the level of XIST. And a serious experiments in vitro and in vivo were performed to explore the function of XIST. The relationship between XIST/HIF‐1A and miR‐93‐5p was confirmed by RIP and dual‐luciferase assays.

Results

In the present research, our team demonstrated the upregulation of XIST expression, which was related to tumor progression, and the downregulation of miR‐93‐5p in cells and tissues of colorectal cancer. XIST is the competitive endogenous RNA of miR‐93‐5p to promote HIF‐1A, and then the upregulated AXL level facilitates the EMT process, migration, and proliferation of colorectal cancer. At last, we proved that XIST enhanced the in vivo and in vitro activities of colorectal cancer by regulating AXL signaling.

Conclusion

In summary, the above results indicate that XIST promotes colorectal cancer tumorigenesis by regulating miR‐93‐5p/HIF‐1A/AXL signaling pathway, which will supply a novel perspective to diagnose and treat colorectal cancer disease.

The genetic script of metastasis

Metastasis is a pivotal event that changes the course of cancers from benign and treatable to malignant and difficult to treat, resulting in the demise of patients. Understanding the genetic control of metastasis is thus crucial to develop efficient and sustainable targeted therapies. Here we discuss the alterations in epigenetic mechanisms, transcription, chromosomal instability, chromosome imprinting, non-coding RNAs, coding RNAs, mutant RNAs, enhancers, G-quadruplexes, and copy number variation to dissect the genetic control of metastasis. We conclude that the genetic control of metastasis is predominantly executed through epithelial to mesenchymal transition and evasion of cell death. We discuss how genetic regulatory mechanisms can be harnessed for therapeutic purposes to achieve sustainable control over cancer metastasis.

Prognostic and clinicopathological significance of SNHG6 in human cancers: a meta-analysis

Background

Recently, accumulating evidence has suggested that the aberrant expression of SNHG6 exists in a variety of tumors and has a correlation with poor clinical outcomes across cancer patients. Considering the inconsistent data among published studies, we aim to assess the prognostic effect of SNHG6 on malignancies.

Methods

We retrieved relevant publications in Web of Science, Embase, MEDLINE, PubMed and Cochrane Library based on predefined selection criteria, up to October 1, 2019. Pooled hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs) were utilized to evaluate the correlation between SNHG6 and overall survival (OS), recurrence-free survival (RFS) and progression-free survival (PFS) as well as clinicopathology.

Results

In total, 999 patients from 14 articles were enrolled in our meta-analysis. The results revealed that augmented SNHG6 expression was significantly correlated with poor OS (HR = 2.20, 95% CI = 1.76–2.75, P < 0.001) and RFS (HR = 3.10, 95% CI = 1.90–5.07, P < 0.001), but not with PFS (HR = 2.11, 95% CI = 0.82–5.39, P = 0.120). In addition to lung cancer and ovarian cancer, subgroup analysis showed that the prognostic value of SNHG6 across multiple tumors was constant as the tumor type, sample size, and methods of data extraction changed. Moreover, cancer patients with enhanced SNHG6 expression were prone to advanced TNM stage (OR = 3.31, 95% CI = 2.46–4.45, P < 0.001), distant metastasis (OR = 4.67, 95% CI = 2.98–7.31, P < 0.001), lymph node metastasis (OR = 2.59, 95% CI = 1.41–4.77, P = 0.002) and deep tumor invasion (OR = 3.75, 95% CI = 2.10–6.69, P < 0.001), but not associated with gender, histological grade and tumor size.

Conclusions

SNHG6 may serve as a promising indicator in the prediction of prognosis and clinicopathological features in patients with different kinds of tumors.

Identify potential clinical significance of long noncoding RNA forkhead box P4 antisense RNA 1 in patients with early stage pancreatic ductal adenocarcinoma

Previous studies have shown that forkhead box P4 antisense RNA 1 (FOXP4‐AS1) is dysregulated in tumor tissues and can serve as a prognostic indicator for multiple cancers. However, the clinical significance of FOXP4‐AS1 in pancreatic ductal adenocarcinoma (PDAC) remains unclear. The goal of this study is to recognize the possible clinical significance of long noncoding RNA FOXP4‐AS1 in patients with early stage PDAC. A total of 112 patients from The Cancer Genome Atlas (TCGA) PDAC cohort, receiving RNA sequencing, were involved in the study. Survival analysis, functional mechanism, and potential small molecule drugs of target therapy of FOXP4‐AS1 were performed in this study. Survival analysis in TCGA PDAC cohort suggested that patients with high FOXP4‐AS1 expression had significantly augmented possibility of death than in PDAC patients with lower FOXP4‐AS1 expression (adjusted P = .008; adjusted HR = 2.143, 95% CI = 1.221‐3.760). In this study, a genome‐wide RNA sequencing dataset was used to identify 927 genes co‐expressing with FOXP4‐AS1 in PDAC tumor tissues. A total of 676 differentially expressed genes were identified between different FOXP4‐AS1 expression groups. Functional enrichment analysis of these genes and gene set enrichment analysis for PDAC genome‐wide RNA sequencing dataset was done. We have found that FOXP4‐AS1 may function in PDAC by participating in biological processes and pathways including oxidative phosphorylation, tricarboxylic acid cycle, classical tumor‐related pathways such as NF‐kappaB as well as Janus kinase/signal transducers in addition to activators of transcription, cell proliferation, and adhesion. In addition, we also screened two potential targeted therapeutic small molecule drugs (dimenhydrinate and metanephrine) for FOXP4‐AS1 in PDAC. In conclusion, our present study demonstrated that higher expression of FOXP4‐AS1 in PDAC tumor tissues were related with an inferior medical outcome. Through multiple genome‐wide approaches, we identified the potential molecular mechanisms of FOXP4‐AS1 in PDAC and two targeted therapeutic drugs for it.

Resveratrol improves high-fat diet-induced insulin resistance in mice by downregulating the lncRNA NONMMUT008655.2

As essential players in the field of diabetes treatment, resveratrol (RSV) has received much attention in recent years. However, it is unclear whether it can improve insulin resistance by regulating the long-chain non-coding RNA (lncRNA). The objective of this study was to investigate whether RSV improves high-fat diet-induced insulin resistance in mice by regulating thelncRNANONMMUT008655.2 in vivo and in vitro. To this end, animal and cell insulin resistance models were developed. Specifically, C57BL/6J mice were fed a high-fat diet (HFD) and administered RSV for eight weeks. Additionally, mouse Hepa cells were treated with palmitic acid, transfected with siRNA NONMMUT008655.2, and treated with RSV. Treated mice and cells were then compared to normal controls that were not exposed to RSV. In the animal model, RSV was found to decrease the levels of fasting blood glucose, triglycerides, and low-density lipoprotein cholesterol, as well as the insulin index and area under the curve; while increasing the insulin sensitivity index. Besides, RSV decreased the expression levels of SOCS3, G6PC, and FOXO1 yet increased that of p-Akt and p-FOXO1 in mice. The same results were observed following knockdown of NONMMUT008655.2 in cells. Overall, our results suggest that RSV may improve hepatic insulin resistance and control blood glucose levels by downregulating lncRNA NONMMUT008655.2.

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

More than 140 thousands of women suffer from endometrial carcinoma in the worldwide, and over 40 thousand of the patients die before and after in surgery and chemoradiotherapy because of its metastasis. However, its molecular mechanism is much less known compared to other cancers. In this study, we demonstrated that long non-coding RNA PCAT1 is dramatically increased in the tissues and plasma from endometrial carcinoma (EC) (n = 100, all p < 0.001) controlled by its paracancerous tissue, and cell lines including RL-952, HEC-1-B, KLE, Ishikawa, and AN3CA compared to the cells from normal endometrium (all p < 0.001). When lncRNA PCAT1 was knocked-down, the KLE and AN3CA cells exhibited slow capability on proliferation and colony formation in vitro. With the silence of lncRNA PCAT1, the cells were markedly inhibited on migration and invasion in vitro (all p < 0.001), which were confirmed on the EC patient subjects. When expressions of lncRNA PCAT1 were interfered in the cells, expressions of E-cadherin but not N-cadherin and Vimentin were significantly promoted with a strong up-regulation accompanied by nearly completed recoveries on migration and invasion (all p < 0.001). In order to analyze the association of lncRNA PCAT1 and E-cadherin, we silenced the expressions of both genes and unveiled that EC migration and invasion were significantly congested (all p < 0.001). Importantly, we found that the E-cadherin down-regulation caused by lncRNA PCAT1 associates with histone methyltransferase EZH2. When over-expression of EZH2 was applied in the PCAT1 silenced cells, the expression of E-cadherin experienced significant decrease in the cell lines. Reversely, when expression of EZH2 was annulled in the PCAT1 silenced cells, the expression of E-cadherin was significantly boosted in the cells (all p < 0.001). Furthermore, the interaction of lncRNA PCAT1 and EZH2 were approved with immunoprecipitation. Our data demonstrated that the methyltransferase EZH2 related up-regulation of lncRNA PCAT1 along with down-regulation of E-cadherin could be essential in oncogenesis of endometrial carcinoma in both EC cells and patient subjects. These compact data suggest that combination of lncRNA PCAT1, EZH2 and E-cadherin could provide valued information for efficient EC diagnostics, which would propose a potential target for EC treatment with EZH2i on methyltransferation.

Enhancing the Bystander and Abscopal Effects to Improve Radiotherapy Outcomes

In this paper, we summarize published articles and experiences related to the attempt to improve radiotherapy outcomes and, thus, to personalize the radiation treatment according to the individual characteristics of each patient. The evolution of ideas and the study of successively published data have led us to envisage new biophysical models for the interpretation of tumor and healthy normal tissue response to radiation. In the development of the model, we have shown that when mesenchymal stem cells (MSCs) and radiotherapy are administered simultaneously in experimental radiotherapy on xenotumors implanted in a murine model, the results of the treatment show the existence of a synergic mechanism that is able to enhance the local and systemic actions of the radiation both on the treated tumor and on its possible metastasis. We are convinced that, due to the physical hallmarks that characterize the neoplastic tissues, the physical-chemical tropism of MSCs, and the widespread functions of macromolecules, proteins, and exosomes released from activated MSCs, the combination of radiotherapy plus MSCs used intratumorally has the effect of counteracting the pro-tumorigenic and pro-metastatic signals that contribute to the growth, spread, and resistance of the tumor cells. Therefore, we have concluded that MSCs are appropriate for therapeutic use in a clinical trial for rectal cancer combined with radiotherapy, which we are going to start in the near future.

SNHG16: A Novel Long-Non Coding RNA in Human Cancers

Long noncoding RNAs (lncRNAs) have recently been considered as central regulators in diverse biological processes controlling tumorigenesis. Small nucleolar RNA host gene 16 (SNHG16) is an important tumor-associated lncRNA mainly involved in tumorigenesis and progression by competing with endogenous RNA (ceRNA) which sponges tumor-suppressive microRNA (miRNA), and by its recruitment mechanism. SNHG16 is overexpressed in tumor tissues and cell lines of different kinds of cancers, and its presence is associated with a poor clinical prognosis. Reviewing all publications about SNHG16 revealed that it plays a key role in the different hallmarks that define human cancer, including promoting proliferation, activating migration and invasion, inhibiting apoptosis, affecting lipid metabolism and chemoresistance. This review highlights the role that the aberrant expression of SNHG16 plays in the development and progression of cancer, and suggests that SNHG16 may function as a potential biomarker and therapeutic target for human cancers.

The Emerging Role of Long Non-Coding RNAs in the Metastasis of Hepatocellular Carcinoma

Long non-coding RNAs (lncRNAs) play multifaceted roles in modulating gene expression under both physiological and pathological processes. The dysregulation of lncRNAs has been increasingly linked with many human diseases, including a plethora of cancers. Mounting evidence indicates that lncRNAs are aberrantly expressed in hepatocellular carcinoma (HCC) and can regulate HCC progression, as well as metastasis. In this review, we summarize the recent findings on the expanding roles of lncRNAs in modulating various functions of HCC, and elaborate on how can lncRNAs impact HCC metastasis and progression via interacting with chromatin, RNA, and proteins at the epigenetic, transcriptional, and post-transcriptional levels. This mini-review also highlights the current advances regarding the signaling pathways of lncRNAs in HCC metastasis and sheds light on the possible application of lncRNAs for the prevention and treatment of HCC.

Clinicopathological and prognostic value of LINC01296 in cancers: a meta-analysis

Objective: The long intergenic non-coding RNA 01296 (LINC01296) has been reported to be overexpressed in multiple tumours. However, the role of LINC01296 in clinicopathologic and prognostic value in cancers remains completely unknown. The aim of the present meta-analysis was to comprehensively elucidate the correlation between LINC01296 with clinicopathological features and survival outcomes in tumours. Methods: Electronic databases of PubMed, Web of Science, Chinese National Knowledge Infrastructure (CNKI), and Wanfang Database were used to search relevant studies. The role of LINC01296 in cancers was evaluated by pooled hazard ratios (HRs), odds ratios (ORs) and 95% confidence intervals (CIs). Results: In total, nine studies compromising 720 participants were enrolled in this analysis. The pooled results showed increased LINC01296 expression could predict unfavourable overall survival (OS) (HR = 1.89, 95%CI = 1.47-2.43, p < .001). Additionally, elevated LINC01296 expression was correlated with clinical stage (OR = 2.95, 95%CI = 2.13-4.08, p < .001), lymph node metastasis (OR = 2.76, 95%CI = 2.00-3.81, p < .001), tumour size (OR = 2.80, 95%CI = 1.77-4.41, p < .001), and tumour differentiation (OR = 2.11, 95%CI = 1.36-3.27, p < .001) in patients with cancers. Conclusion: The results of this meta-analysis indicated LINC01296 was a novel biomarker for prognosis and clinicopathological parameters in cancers.

Long Noncoding RNA LINC01125 Enhances Cisplatin Sensitivity of Ovarian Cancer via miR-1972

Background

Ovarian cancer (OC) is the most frequent aggressive cancer among women worldwide, and chemoresistance is the major challenge in the clinical treatment of OC. Recently, there is evidence that long noncoding RNAs (lncRNAs) are closely related to the regulation of cisplatin (CDDP) resistance in OC cells. However, whether LINC01125, a novel lncRNA, can improve the sensitivity of OC to cisplatin remains unknown.

Material/Methods

In this study, we analyzed aberrantly expressed lncRNAs in miR-200a-overexpressing OC samples by using GSE122123. LINC01125 and miR-1972 expressions were measured by qRT-PCR. The effect of LINC01125 overexpression on cell proliferation was determined by CCK-8 and colony formation assays. The sensitivity of OC cells to cisplatin was determined by CCK-8 assays. The interaction between LINC01125 and miR-1972 was verified through dual-luciferase reporter and RNA immunoprecipitation (RIP) assays, and bioinformatics analysis was performed to predict the target genes of miR-1972.

Results

Our results indicated that LINC01125 expression was significantly downregulated in CDDP-resistant OC tissues and cell lines. Overexpression of LINC01125 inhibited OC cell proliferation and enhanced the cytotoxicity of CDDP in OC cells. Additionally, LINC01125 participated in the apoptosis pathway by directly binding to miR-1972 in OC cells.

Conclusions

Therefore, we suggest that LINC01125 might act as a tumor suppressor in OC and enhances the cisplatin sensitivity of OC cells by binding to miR-1972.