LncRNA XIST Promotes Pancreatic Cancer Proliferation Through miR-133a/EGFR

Exosomal lncRNA XIST promotes perineural invasion of pancreatic cancer cells via miR-211-5p/GDNF

Perineural invasion (PNI) is an essential form of tumor metastasis in multiple malignant cancers, such as pancreatic cancer, prostate cancer, and head and neck cancer. Growing evidence has revealed that pancreatic cancer recurrence and neuropathic pain positively correlate with PNI. Therefore, targeting PNI is a proper strategy for pancreatic cancer treatment. Exosomal lncRNA derived from pancreatic cancer cells is an essential component of the tumor microenvironment. However, whether exosomal lncXIST derived from pancreatic cancer cells can promote PNI and its exact mechanism remains to be elucidated. We show that lncXIST mediates nerve-tumor crosstalk via exosomal delivery. Our data reveal that exosomal lncXIST derived from pancreatic cancer cells is delivered to neural cells and promotes their release of glial-cell-line-derived neurotrophic factor (GDNF), essential in facilitating the PNI of pancreatic cancer. Mechanistically, microRNA-211-5p negatively regulates GDNF, and lncXIST serves as a miR-211-5p sponge. The function of exosomes in the dynamic interplay between nerves and cancer is confirmed in both in vivo and in vitro PNI models. Therefore, targeting pancreatic cancer cell-derived exosomal lncXIST may provide clues for a promising approach for developing a new strategy to combat PNI of pancreatic cancer.

LncRNA XIST Protects Against Polycystic Ovary Syndrome via the Regulation of miR-212-3p/RASA1 Axis

The polycystic ovary syndrome (PCOS), a common endocrine disorder, is mainly related to infertility. Moreover, it is characterized by promoted androgen, suppressed ovulation and insulin resistance. Long non-coding RNA X inactive specific transcript (lncRNA XIST), known as an oncogene or a cancer inhabited factor, is involved in several disease. However, the diagnostic mechanisms of lncRNA XIST in PCOS have not been clarified. Our study aimed to explain whether lncRNA XIST regulates KGN cells proliferation and apoptosis via microRNA (miR)-212-3p/RASA1 axis in PCOS. Levels of lncRNA XIST, miR-212-3p and RASA1 in KGN cells were detected through reverse transcription quantitative polymerase chain reaction (RT-qPCR) assay. Fluorescence in situ Hybridization (FISH) was performed to confirm the expression of lncRNA XIST and miR-212-3p in KGN cells. StarBase and dual-luciferase reporter assay were applied for exploring the interaction between miR-212-3p and RASA1. Cell viability, apoptosis, protein expression of Bcl-2 and Bax were assessed by MTT, flow cytometry analysis, RT-qPCR and western blot, respectively. We found that lncRNA XIST was low-expressed, miR-212-3p was over-expressed, and RASA1 was dramatically down-regulated in KGN cells. LncRNA XIST negatively regulated miR-212-3p expression in KGN cells. MiR-212-3p interacted with RASA1 and negatively regulated RASA1 levels in KGN cells. Up-regulation of lncRNA XIST signally decreased cells viability, stimulated more apoptotic cells, enhanced Bax expression, and depressed Bcl-2 level in KGN cells. However, these observations were abolished after miR-212-3p mimic treatment. Furthermore, miR-212-3p inhibitor significantly inhibited cell proliferation, enhanced more apoptotic cells, increased Bax expression, and decreased Bcl-2 level in KGN cells, and these effects were eliminated by RASA1-siRNA transfection. Our observations revealed that lncRNA XIST protects against PCOS through regulating miR-212-3p/RASA1 axis, suggesting that lncRNA XIST may be a promising therapeutic target for PCOS therapy.

The role of lncRNA HCG18 in human diseases

A substantial number of long noncoding RNAs (lncRNAs) have been identified as potent regulators of human disease. Human leukocyte antigen complex group 18 (HCG18) is a new type of lncRNA that has recently been proven to play an important role in the occurrence and development of various diseases. Studies have found that abnormal expression of HCG18 is closely related to the clinicopathological characteristics of many diseases. More importantly, HCG18 was also found to promote disease progression by affecting a series of cell biological processes. This article mainly discusses the expression characteristics, clinical characteristics, biological effects and related regulatory mechanisms of HCG18 in different human diseases, providing a scientific theoretical basis for its early clinical application.

Identification of functional genes in liver fibrosis based on bioinformatics analysis of a lncRNA-mediated ceRNA network

BACKGROUND

Liver fibrosis is a major global healths problem; nevertheless, its molecular mechanism are not completely clear. This study aimed to build a lncRNA-miRNA-mRNA network, identify potentially related lncRNAs, and explore the pathogenesis of liver fibrosis.

MATERIALS AND METHODS

We used the Gene Expression Omnibus databases and bioinformatics analysis to identify differentially expressed genes (DEGs) between liver fibrosis and normal tissues. The ceRNA network was constructed according to the interactions between DElncRNA, miRNA, and DEmRNA. Then, these DEGs were identified using functional enrichment analysis, and a protein-protein interaction (PPI) network was established. The critical lncRNAs were verified using the quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

The ceRNA network was composed of three lncRNAs, five miRNAs, and 93 mRNAs. Gene Ontology functional enrichment analysis revealed significant enhancement in cell components, molecular function, and biological process. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed pathways associated with transcriptional misregulation in cancer, including the Rap1 signaling pathway, proteoglycans in cancer, mineral absorption, HTLV-l infection, and central carbon metabolism in cancer. According to the PPI network and the GSE84044 database, seven hub genes associated with liver fibrosis were identified. In addition, qRT-PCR revealed that lncRNA AC100861 (lncRNA TNFRSF10A-DT) was explicitly decreased in liver fibrosis tissues and activated hepatic stellate cells.

CONCLUSIONS

In summary, this study preliminarily found that lncRNA TNFRSF10A-DT may be a biomarker for the diagnosis and outcome of liver fibrosis. We uncovered a novel lncRNA-mediated ceRNA regulatory mechanism in the pathogenesis of liver fibrosis.

Role of non-coding RNAs in neuroblastoma

Neuroblastoma is known as the most prevalent extracranial malignancy in childhood with a neural crest origin. It has been widely accepted that non-coding RNAs (ncRNAs) play important roles in many types of cancer, including glioma and gastrointestinal cancers. They may regulate the cancer gene network. According to recent sequencing and profiling studies, ncRNAs genes are deregulated in human cancers via deletion, amplification, abnormal epigenetic, or transcriptional regulation. Disturbances in the expression of ncRNAs may act either as oncogenes or as anti-tumor suppressor genes, and can lead to the induction of cancer hallmarks. ncRNAs can be secreted from tumor cells inside exosomes, where they can be transferred to other cells to affect their function. However, these topics still need more study to clarify their exact roles, so the present review addresses different roles and functions of ncRNAs in neuroblastoma.

Integrated analysis of lncRNA/circRNA-miRNA-mRNA in the proliferative phase of liver regeneration in mice with liver fibrosis

BACKGROUND

Non-coding RNAs play important roles in liver regeneration; however, their functions and mechanisms of action in the regeneration of fibrotic liver have not been elucidated. We aimed to clarify the expression patterns and regulatory functions of lncRNAs, circRNAs, miRNAs, and mRNAs in the proliferative phase of fibrotic liver regeneration.

METHODS

Based on a mouse model of liver fibrosis with 70% hepatectomy, whole-transcriptome profiling was performed using high-throughput sequencing on samples collected at 0, 12, 24, 48, and 72 h after hepatectomy. Hub genes were selected by weighted gene co-expression network analysis and subjected to enrichment analysis. Integrated analysis was performed to reveal the interactions of differentially expressed (DE) lncRNAs, circRNAs, miRNAs, and mRNAs, and to construct lncRNA-mRNA cis- and trans-regulatory networks and lncRNA/circRNA-miRNA-mRNA ceRNA regulatory networks. Real-Time quantitative PCR was used to validate part of the ceRNA network.

RESULTS

A total of 1,329 lncRNAs, 48 circRNAs, 167 miRNAs, and 6,458 mRNAs were differentially expressed, including 812 hub genes. Based on these DE RNAs, we examined several mechanisms of ncRNA regulatory networks, including lncRNA cis and trans interactions, circRNA parental genes, and ceRNA pathways. We constructed a cis-regulatory core network consisting of 64 lncRNA-mRNA pairs (53 DE lncRNAs and 58 hub genes), a trans-regulatory core network consisting of 103 lncRNA-mRNA pairs (18 DE lncRNAs and 85 hub genes), a lncRNA-miRNA-mRNA ceRNA core regulatory network (20 DE lncRNAs, 12 DE miRNAs, and 33 mRNAs), and a circRNA-miRNA-mRNA ceRNA core regulatory network (5 DE circRNAs, 5 DE miRNAs, and 39 mRNAs).

CONCLUSIONS

These results reveal the expression patterns of lncRNAs, circRNAs, miRNAs, and mRNAs in the proliferative phase of fibrotic liver regeneration, as well as core regulatory networks of mRNAs and non-coding RNAs underlying liver regeneration. The findings provide insights into molecular mechanisms that may be useful in developing new therapeutic approaches to ameliorate diseases that are characterized by liver fibrosis, which would be beneficial for the prevention of liver failure and treatment of liver cancer.

Role of long non-coding RNAs in pancreatic cancer pathogenesis and treatment resistance- A review

Pancreatic cancer (PC) is one of the deadliest cancers associated with poor prognosis. The lack of reliable means of early cancer detection contributes to this disease's dismal prognosis. Long non-coding RNAs (LncRNAs) are protein-free RNAs produced by genome transcription; they play critical roles in gene expression regulation, epigenetic modification, cell proliferation, differentiation, and reproduction. Recent research has shown that lncRNAs play important regulatory roles in PC behaviors, in addition to their recently found functions. Several in-depth investigations have shown that lncRNAs are strongly linked to PC development and progression. Here, we discuss how lncRNAs, which are often overlooked, play many roles as regulators in the molecular mechanism underlying PC. This review also discusses the involved LncRNAs in PC pathogenesis and treatment resistance.

The role of long non-coding RNA HCG18 in cancer

The incidence of cancer is increasing worldwide and is becoming the most common cause of death. Identifying new biomarkers for cancer diagnosis and prognosis is important for developing cancer treatment strategies and reducing mortality. Long non-coding RNAs (lncRNAs) are non-coding, single-stranded RNAs that play an important role as oncogenes or tumor suppressors in the occurrence and development of human tumors. Abnormal expression of human leukocyte antigen complex group 18 (HCG18) is observed in many types of cancer, and its imbalance is closely related to cancer progression. HCG18 regulates cell proliferation, invasion, metastasis, and anti-apoptosis through a variety of mechanisms. Therefore, HCG18 is a potential tumor biomarker and therapeutic target. However, the therapeutic significance of HCG18 has not been well studied, and future research may develop new intervention strategies to combat cancer. In this study, we reviewed the biological function, mechanism, and potential clinical significance of HCG18 in various cancers to provide a reference for future research.

Potential roles of lncRNA-XIST/miRNAs/mRNAs in human cancer cells

Long non-coding RNAs (lncRNAs) are non-coding RNAs that contain more than 200 nucleotides but do not code for proteins. In tumorigenesis, lncRNAs can have both oncogenic and tumor-suppressive properties. X inactive-specific transcript (XIST) is a known lncRNA that has been implicated in X chromosome silencing in female cells. Dysregulation of XIST is associated with an increased risk of various cancers. Therefore, XIST can be a beneficial prognostic biomarker for human malignancies. In this review, we attempt to summarize the emerging roles of XIST in human cancers.

Long Noncoding RNA XIST Regulates Myocardial Infarction via miR-486-5p/SIRT1 Axis

Myocardial infarction (MI) is severe heart disease leading to the death worldwide. Long noncoding RNAs (lncRNAs) play a vital role in progression of numerous heart diseases. In the present study, we examined the effects of lncRNA XIST and underlying mechanism on hypoxia-induced apoptosis. In vitro model of MI was established by inducing hypoxia in H9c2 cells. CCK-8 assay was used to measure the cell viability in hypoxia-induced H9c2 cells. The rate of cell apoptosis was assessed by using caspase-3 assay. Transfection was carried out to upregulate the expressions of lncRNA XIST, and miR-486-5p. RT-qPCR was used to measure the levels of lncRNA XIST and miR-486-5p. Also, the relation between XIST and miR-486-5p was confirmed by using Luciferase reporter assay. Our findings revealed that hypoxia significantly downregulated the expressions of XIST. Also, the cell viability markedly increased due to the overexpression of XIST in hypoxia-induced H9c2 cells, while overexpression of XIST significantly reduced the cell apoptosis in hypoxia-induced H9c2 cells. On the other hand, opposite effects were observed due to the downregulation of XIST in hypoxia-induced H9c2 cells. Moreover, XIST negatively regulated the expression of miR-4486-5p and upregulation of XIST inhibited hypoxic injury by downregulating miR-486-5p. Furthermore, SIRT1 expression was negatively regulated by miR-486-5p. We concluded that lncRNA XIST might provide protection against injury induced by hypoxia via miR-486-5p/SIRT1 axis.

XIST silencing alleviated inflammation and mesangial cells proliferation in diabetic nephropathy by sponging miR-485

In this study, we investigated the role of XIST in the development of diabetic nephropathy (DN) and further explored its underlying mechanism. qRT-PCR was used to examine the level of XIST in serum of DN patients. ELISA, MTT, and flow cytometry were used to investigate the effect of XIST on biological functions of human mesangial cells (HMCs) treated with high glucose. The recovery experiments were used to explore the potential mechanism. The result showed XIST expression was elevated significantly in serums of DN patients. XIST silencing alleviated the induction of high glucose in biological behaviour of HMCs. Besides, miR-485 inhibitor revised the suppression by si-XIST in biological behaviour of high glucose induced HMCs. Furthermore, PSMB8 mimic relieved the inhibition of si-XIST in biological behaviour of high glucose induced HMCs. In short, XIST silencing could alleviate biological process and inflammation of HMCs treated with high glucose by sponging miR-485.

LncRNA RP11-59J16.2 aggravates apoptosis and increases tau phosphorylation by targeting MCM2 in AD

Alzheimer’s disease (AD) is a degenerative disease of central nervous system with unclear pathogenesis, accounting for 60%–70% of dementia cases. Long noncoding RNAs (LncRNAs) play an important function in the development of AD. This study aims to explore the role of differentially expressed lncRNAs in AD patients’ serum in the pathogenesis of AD. Microarray analysis was performed in the serum of AD patients and healthy controls to establish lncRNAs and mRNAs expression profiles. GO analysis and KEGG pathway analysis revealed that G₁/S transition of mitotic cell cycle might be involved in the development of AD. The result showed that RP11-59J16.2 was up-regulated and MCM2 was down-regulated in serum of AD patients. SH-SY5Y cells were treated with Aβ 1–42 to establish AD cell model. Dual luciferase reporter gene analysis verified that RP11-59J16.2 could directly interact with 3′UTR of MCM2 and further regulate the expression of MCM2. Inhibition of RP11-59J16.2 or overexpression of MCM2, CCK-8 assay and Annexin V FITC/PI apoptosis assay kit results showed that RP11-59J16.2 could reduce cell viability, aggravate apoptosis and increase Tau phosphorylation in AD cell model by inhibiting MCM2. In short, our study revealed a novel lncRNA RP11-59J16.2 that could promote neuronal apoptosis and increase Tau phosphorylation by regulating MCM2 in AD model, and indicated that lncRNA RP11-59J16.2 might be a potential target molecule for AD development.

Circ_0001955 promotes the progression of non-small cell lung cancer via miR-769-5p/EGFR axis

To elaborate on the role of circular RNA 0001955 (circ_0001955) on the proliferation and apoptosis of non-small cell lung cancer (NSCLC) cells and its underlying mechanism. Circ_0001955 expression in NSCLC was screened out through bioinformatics analysis based on GEO database. Circ_0001955, microRNA-769-5p (miR-769-5p), and epidermal growth factor receptor (EGFR) expression in NSCLC tissues and cell lines was examined using quantitative real-time PCR (qRT-PCR) and Western blot. Cell proliferation and apoptosis were examined using the CCK-8 method, BrdU experiment and flow cytometry analysis, respectively. Bioinformatics prediction, dual-luciferase reporter gene experiment and RNA immunoprecipitation (RIP) experiments were applied to validate the targeting relationship between miR-769-5p and circ_0001955 and the 3' UTR of EGFR. Pearson's correlation analysis was employed to validate the correlations among them. Circ_0001955 expression was up-regulated in NSCLC tissues and cell lines, and its overexpression was strongly associated with increased tumor TNM stage and lymph node metastasis. Circ_0001955 overexpression enhanced the proliferation and restrained the apoptosis in NSCLC cells, whereas knocking down circ_0001955 exerted the opposite effects. Circ_0001955 directly targeted miR-769-5p and negatively regulated its expression. EGFR, a target gene of miR-769-5p, could be indirectly and positively regulated by circ_0001955. Correlation analysis indicated that circ_0001955 was negatively correlated with miR-769-5p expression, while circ_0001955 was positively correlated with EGFR expression. Circ_0001955 facilitates the proliferation and represses the apoptosis of NSCLC cells by modulating miR-769-5p/EGFR axis.

Long noncoding RNAs (lncRNAs) in pancreatic cancer progression

Long noncoding RNAs (lncRNAs) are RNA molecules involved in gene regulation at transcriptional, post-transcriptional, and epigenetic levels. LncRNAs participate in regulating apoptosis and autophagy in pancreatic cancer (PCa) and can promote and/or decrease the proliferation rate of tumor cells. The metastasis of PCa cells is tightly regulated by lncRNAs and they can affect the mechanism of epithelial-mesenchymal transition (EMT) to modulate metastasis. The drug resistance of PCa cells, especially to gemcitabine, can be affected by lncRNAs. In addition, lncRNAs enriched in exosomes can be transferred among tumor cells to regulate their proliferation and metastasis. Antitumor compounds, such as curcumin and ginsenosides, can regulate lncRNA expression in PCa therapy. As we discuss here, the expression level of lncRNAs can be considered as both a diagnostic and prognostic tool in patients with PCa.

LncRNA BBOX1-AS1 promotes pituitary adenoma progression via sponging miR-361-3p/E2F1 axis

Pituitary adenoma is one of the most common intracranial tumors, more and more studies have shown that long non-coding RNA (lncRNA) plays a very important role in pituitary adenoma. However, there are few reports on the function of lncRNA BBOX1-AS1 in pituitary adenomas, and further exploration is needed. The objective of this research is to figure out what function BBOX1-AS1 plays in pituitary adenoma and how it regulates it. The expression of the E2F1, miR-361-3p and BOX1-AS1 genes was measured using a quantitative real-time PCR method. The functional involvement of BBOX1-AS1 in pituitary adenoma was examined utilizing the Transwell assay, western blot assays and the cell counting kit-8. RNA immunoprecipitation and luciferase reporter assays revealed that miR-361-3p binds to E2F1 or BBOX1-AS1. In addition, in-vivo assays were carried out. The expression of BBOX1-AS1 in pituitary adenoma tissues and cells has been increased, according to our findings. Furthermore, it is also noted that downregulation of BBOX1-AS1causes the inhibition of pituitary adenoma cells which result in invasion, apoptosis and proliferation, as well as boosting tumor development in vivo . In addition, BBOX1-AS1 knockdown inhibited tumor development in vivo . We identify BBOX1-AS1 bind to miR-361-3p and to suppress its expression in a negative way. Moreover, miR-361-3p has been shown to bind with E2F1 and inhibit its expression. E2F1 also corrected miR-361-3p-mediated cell invasion, proliferation and apoptosis in BBOX1-AS1-dysregulated pituitary adenoma cells in rescue tests. BBOX1-AS1 increases pituitary adenoma malignant activity by sponging miR-361-3p to upregulate E2F1 expression, which may lead to a new path in pituitary adenoma therapeutic attempts.

LncRNA XIST sponges microRNA-448 to promote malignant behaviors of colorectal cancer cells via regulating GRHL2

Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) are essential regulators in human cancers, while the role of lncRNA X-inactive-specific transcript (XIST) in colorectal cancer (CRC) via regulating miR-448 remains largely unknown. Herein, we aimed to elucidate the effect of the XIST/miR-448/grainyhead-like 2 (GRHL2) axis on CRC development. XIST, miR-448, and GRHL2 expression in CRC tissues from patients and in human CRC cell lines was assessed. Loss- and gain-function assays were implemented to unveil the roles of XIST, miR-448, and GRHL2 in screened CRC cells. The tumor growth in vivo was observed in nude mice. Binding relations among XIST, miR-448, and GRHL2 were evaluated. XIST and GRHL2 expressed highly whereas miR-448 expressed lowly in CRC tissues and cells. XIST or GRHL2 downregulation, or miR-448 elevation suppressed the malignant behaviors of CRC cells in vitro, and downregulated XIST or upregulated miR-448 also inhibited the tumor growth in vivo. miR-448 upregulation reversed the role of XIST elevation in CRC cells. XIST particularly bound to miR-448, and miR-448 targeted GRHL2. Knockdown of XIST upregulates miR-448 to impede malignant behaviors of CRC cells via inhibiting GRHL2. This study may provide novel biomarkers for CRC diagnosis and treatment.

Long non-coding RNA-X-inactive specific transcript inhibits cell viability, and induces apoptosis through the microRNA-30c-5p/Bcl2-like protein 11 signaling axis in human granulosa-like tumor cells

The role of long noncoding RNAs (lncRNAs) is being actively explored in polycystic ovary syndrome (PCOS). Recent research has shown that long non-coding RNA (lncRNA) X–inactive Specific Transcript (XIST) is overexpressed in patients with PCOS and is associated with poor pregnancy outcomes. However, the precise function and mechanism of action of lncRNA XIST in PCOS are unknown. We aimed to determine whether lncRNA XIST contributes to PCOS by modulating ovarian granulosa cell physiology. We also investigated any potential molecular regulatory mechanisms. In this study, we discovered that the lncRNA XIST was significantly downregulated in human ovarian granulosa-like tumor (KGN) cells. Notably, overexpression of lncRNA XIST decreased miR-30c-5p expression in KGN cells, inhibited proliferation, and induced apoptosis in KGN cells. However, cotransfection with amiR-30c-5p mimic significantly reduced these effects. Additionally, we discovered that the miR-30c-5p mimic effectively inhibited Bcl2-like protein 11 (BCL2L11) expression, a critical apoptotic promoter, whereas silencing of miR-30c-5p increased BCL2L11 expression, inhibited KGN cell proliferation, and induced apoptosis. In contrast, cotransfection of BCL2L11 with siRNA significantly reversed these effects. In conclusion, this study established that lncRNA XIST plays a critical role in PCOS by modulating the miR-30c-5p/BCL2L11 signaling axis and regulating ovarian granulosa cell physiology.

Long Non-Coding RNAs in Pancreatic Cancer: Biologic Functions, Mechanisms, and Clinical Significance

Despite tremendous efforts devoted to research in pancreatic cancer (PC), the mechanism underlying the tumorigenesis and progression of PC is still not completely clear. Additionally, ideal biomarkers and satisfactory therapeutic strategies for clinical application in PC are still lacking. Accumulating evidence suggests that long non-coding RNAs (lncRNAs) might participate in the pathogenesis of diverse cancers, including PC. The abnormal expression of lncRNAs in PC is considered a vital factor during tumorigenesis that affects tumor cell proliferation, migration, invasion, apoptosis, angiogenesis, and drug resistance. With this review of relevant articles published in recent years, we aimed to summarize the biogenesis mechanism, classifications, and modes of action of lncRNAs and to review the functions and mechanisms of lncRNAs in PC. Additionally, the clinical significance of lncRNAs in PC was discussed. Finally, we pointed out the questions remaining from recent studies and anticipated that further investigations would address these gaps in knowledge in this field.

Rutin Promotes Pancreatic Cancer Cell Apoptosis by Upregulating miRNA-877-3p Expression

(1) Background: pancreatic cancer is one of the most serious cancers due to its rapid and inevitable fatality, which has been proved very difficult to treat, compared with many other common cancers. Thus, developing an effective therapeutic strategy, especially searching for potential drugs, is the focus of current research. The exact mechanism of rutin in pancreatic cancer remains unknown. (2) Method: three pancreatic cancer cell lines were used to study the anti-pancreatic cancer effect of rutin. The potent anti-proliferative, anti-migration and pro-apoptotic properties of rutin were uncovered by cell viability, a wound-healing migration assay, and a cell apoptosis assay. High-throughput sequencing technology was used to detect the change of miRNAs expression. Immunoblotting analysis was used to detect the expression of apoptotic proteins. (3) Results: CCK-8 and EDU assays revealed that rutin significantly inhibited pancreatic cancer cells’ proliferation (p < 0.05). A wound-healing assay showed that rutin significantly suppressed pancreatic cancer cells’ migration (p < 0.05). A flow cytometric assay showed that rutin could promote pancreatic cancer cells’ apoptosis. Intriguingly, rutin significantly upregulated miR-877-3p expression to repress the transcription of Bcl-2 and to induce pancreatic cancer cell apoptosis. Accordingly, rutin and miR-877-3p mimics could promote apoptotic protein expression. (4) Conclusions: our findings indicate that rutin plays an important role in anti-pancreatic cancer effects through a rutin-miR-877-3p-Bcl-2 axis and suggests a potential therapeutic strategy for pancreatic cancer.

In Silico Analysis Identifies Upregulated lncRNA DLGAP1-AS1 Which Is Correlated to Poor Prognosis and Promotes Cell Proliferation in Glioblastoma

Long noncoding RNAs have been reported to regulate the tumorigenesis, growth, and metastasis of glioblastomas. In this study, we identified 1623 differently expressed mRNAs and 38 lncRNAs utilizing the CGGA and TCGA databases. Among these mRNAs and lncRNAs, we focused on DLGAP1-AS1 in this study. The results demonstrated that DLGAP1-AS1 was higher in WHO IV glioma than in WHO II and WHO III gliomas, higher in WHO III glioma than in WHO II glioma samples, higher in IDH1 wildtype glioma than in IDH1-mutant glioma samples, and higher in 1p/19q noncodeletion glioma than in 1p/19q codeletion glioma samples. Moreover, we observed that higher expression levels of DLGAP1-AS1 were correlated to shorter OS time in both low-grade and high-grade gliomas. Next, we evaluated the function of DLGAP1-AS1 in GBM using in vivo experiments. The data revealed that DLGAP1-AS1 knockdown greatly hindered U87 cell and U251 cell proliferation. Using coexpression network analysis, we identified that ATG4A was a potential downstream target of DLGAP1-AS1. The further analysis showed that ATG4B was significantly upregulated and correlated to shorter OS time in gliomas using both the CGGA and TCGA databases. Finally, we showed that ablated ATG4B greatly hindered GBM cell proliferation. Our conclusion suggested that DLGAP1-AS1 may be a potential prognosis biomarker and facilitated the occurrence and development of glioma via ATG4A in GBM.

Long noncoding RNA ZFPM2-AS1 regulates renal cell carcinoma progression via miR-130a-3p/ESCO2

Previous studies reported that long noncoding RNA (lncRNA) ZFPM2-AS1 is upregulated in renal cell carcinoma (RCC). However, the biological role of lncRNA ZFPM2-AS1 in RCC has not been explored. In this study, we investigated the role of lncRNA ZFPM2-AS1 in the progression of RCC. Quantitative real-time polymerase chain reaction was used for gene expression analysis, and functional assays including Cell Counting Kit-8 assay, flow cytometry-based apoptosis assay and transwell migration assays were performed to examine the malignant phenotypes. The functional interaction between ZFPM2-AS1 or miR-130A-3P and their targets was detected by dual-luciferase reporter assay. We found that the expressions of ZFPM2-AS1 and ESCO2 were upregulated in RCC tissues and cells, whereas miR-130a-3p was downregulated. The expression level of ZFPM2-AS1 is significantly associated with advanced TNM, distant metastasis, lymphatic metastasis, and a poor overall survival in RCC patients. Silencing ZFPM2-AS1 in RCC cells suppressed cell proliferation, invasion, and migration, and induced cell apoptosis. ZFPM2-AS1 interacted with miR-130A-3P and negatively regulated its expression in RCC cells. We further showed that ESCO2 was a downstream target of miR-130a-3p. Both miR-130a-3p inhibitor and ESCO2 overexpression could rescue the inhibitory effects of ZFPM2-AS1 knockdown in RCC cells. Together, our study demonstrates that ZFPM2-AS1 plays an oncogenic role in RCC progression via the miR-130a-3p/ESCO2 axis.

LncRNA PTPRG-AS1 facilitates glycolysis and stemness properties of esophageal squamous cell carcinoma cells through miR-599/PDK1 axis

BACKGROUND AND AIM

Esophageal squamous cell carcinoma (ESCC) is the most significant subtype of esophageal cancer featured with high occurrence. Long noncoding RNAs (lncRNAs) have been proved to modulate the biological properties of cancer cells, including cell proliferation, invasion, migration, and apoptosis. LncRNA protein tyrosine phosphatase receptor type G-antisense RNA 1 (PTPRG-AS1) has been reported to play as an oncogene in diverse cancers. However, the detailed function PTPRG-AS1 may exert in ESCC is unclear.

METHODS

PTPRG-AS1 expression in ESCC cells was investigated via quantitative reverse transcription real-time polymerase chain reaction (RT-qPCR). The effects of PTPRG-AS1 on ESCC cell proliferation, migration, glycolysis, and stemness were verified through functional assays. Mechanism assays including RIP assay, RNA pull down assay, and luciferase reporter assays were performed to verify the molecular mechanism of PTPRG-AS1.

RESULTS

PTPRG-AS1 silencing hindered the proliferation, migration, glycolysis and stemness of ESCC cells. PTPRG-AS1 regulated pyruvate dehydrogenase kinase 1 (PDK1) expression via sponging miR-599. The PTPRG-AS1/miR-599/PDK1 axis was further verified to aggravate the progression of ESCC cells.

CONCLUSION

PTPRG-AS1 sponged miR-599 to up-regulate PDK1 expression, thereby promoting the proliferation and migration as well as glycolysis and stemness properties of ESCC cells.

Association between Arsenic Level, Gene Expression in Asian Population, and In Vitro Carcinogenic Bladder Tumor

The IARC classified arsenic (As) as "carcinogenic to humans." Despite the health consequences of arsenic exposure, there is no molecular signature available yet that can predict when exposure may lead to the development of disease. To understand the molecular processes underlying arsenic exposure and the risk of disease development, this study investigated the functional relationship between high arsenic exposure and disease risk using gene expression derived from human exposure. In this study, a three step analysis was employed: (1) the gene expression profiles obtained from two diverse arsenic-exposed Asian populations were utilized to identify differentially expressed genes associated with arsenic exposure in human subjects, (2) the gene expression profiles induced by arsenic exposure in four different myeloma cancer cell lines were used to define common genes and pathways altered by arsenic exposure, and (3) the genetic profiles of two publicly available human bladder cancer studies were used to test the significance of the common association of genes, identified in step 1 and step 2, to develop and validate a predictive model of primary bladder cancer risk associated with arsenic exposure. Our analysis shows that arsenic exposure to humans is mainly associated with organismal injury and abnormalities, immunological disease, inflammatory disease, gastrointestinal disease, and increased rates of a wide variety of cancers. In addition, arsenic exerts its toxicity by generating reactive oxygen species (ROS) and increasing ROS production causing the imbalance that leads to cell and tissue damage (oxidative stress). Oxidative stress activates inflammatory pathways leading to transformation of a normal cell to tumor cell specifically; there is significant evidence of the advancing changes in oxidative/nitrative stress during the progression of bladder cancer. Therefore, we examined the relation of differentially expressed genes due to exposure of arsenic in human and bladder cancer and developed a bladder cancer risk prediction model. In this study, integrin-linked kinase (ILK) was one of the most significant pathways identified between both arsenic exposed population which plays a key role in eliciting a protective response to oxidative damage in epidermal cells. On the other hand, several studies showed that arsenic trioxide (ATO) is useful for anticancer therapy although the mechanisms underlying its paradoxical effects are still not well understood. ATO has shown remarkable efficacy for the treatment of multiple myeloma; therefore, it will be helpful to understand the underlying cancer biology by which ATO exerts its inhibitory effect on the myeloma cells. Our study found that MAPK is one of the most active network between arsenic gene and ATO cell line which is involved in indicative of oxidative/nitrosative damage and well associated with the development of bladder cancer. The study identified a unique set of 147 genes associated with arsenic exposure and linked to molecular mechanisms of cancer. The risk prediction model shows the highest prediction ability for recurrent bladder tumors based on a very small subset (NKIRAS2, AKTIP, and HLA-DQA1) of the 147 genes resulting in AUC of 0.94 (95% CI: 0.744-0.995) and 0.75 (95% CI: 0.343-0.933) on training and validation data, respectively.

Effects of lncRNA LINC01320 on Proliferation and Migration of Pancreatic Cancer Cells through Targeted Regulation of miR-324-3p

Objective

LINC01320 is a new oncogenic gene. Nevertheless, the effect of LINC01320 on pancreatic cancer (PC) is still unclear. This research aimed to seek the influence of LINC01320 on PC and its possible mechanism.

Methods

RT-qPCR is used to test the LINC01320 in tissues and cells. Cell viability, apoptosis, migration, and invasiveness are detected to explore the role of LINC01320 in PC, and target genes are predicted by bioinformatics methods. The mechanism of action was further explored by transfection of specific siRNA, miRNA mimetics, or miRNA inhibitors. In order to verify the effect of LINC01320 in vivo, we carried out tumor xenotransplantation.

Results

We conclude that LINC01320 is highly expressed in PC tissues and cell strains. LINC01320 high expression was bound up with a poor prognosis. LINC01320 gene knockout inhibited the growth, migration, and invasiveness of PC cells. In addition, LINC01320 is expressed by miR-324-3p, which is also supported by in vivo experiments.

Conclusion

LINC01320 is highly expressed in PC, and it can suppress the growth and migration of PC cells through targeted regulation of miR-324-3p, which is expected to become a latent target for clinical treatment.

Long non-coding RNA XIST: a novel oncogene in multiple cancers

Long non-coding RNA (lncRNA) X-inactive specific transcript (XIST) is an important lncRNA derived from the XIST gene in mammals. XIST is abnormally expressed in numerous tumors, in most of which XIST functions as an oncogene. XIST is involved in multiple aspects of carcinogenesis, including tumor onset, progression, and prognosis. In our review, we collected and analyzed the recent studies on the impact of XIST in human tumor development. The multilevel molecular functions of XIST in human tumors are comprehensively reviewed to clarify the pathologic mechanisms and to offer a novel direction for further study.

Long Noncoding Competing Endogenous RNA Networks in Pancreatic Cancer

Pancreatic cancer (PC) is a highly malignant disease characterized by insidious onset, rapid progress, and poor therapeutic effects. The molecular mechanisms associated with PC initiation and progression are largely insufficient, hampering the exploitation of novel diagnostic biomarkers and development of efficient therapeutic strategies. Emerging evidence recently reveals that noncoding RNAs (ncRNAs), including long ncRNAs (lncRNAs) and microRNAs (miRNAs), extensively participate in PC pathogenesis. Specifically, lncRNAs can function as competing endogenous RNAs (ceRNAs), competitively sequestering miRNAs, therefore modulating the expression levels of their downstream target genes. Such complex lncRNA/miRNA/mRNA networks, namely, ceRNA networks, play crucial roles in the biological processes of PC by regulating cell growth and survival, epithelial-mesenchymal transition and metastasis, cancer stem cell maintenance, metabolism, autophagy, chemoresistance, and angiogenesis. In this review, the emerging knowledge on the lncRNA-associated ceRNA networks involved in PC initiation and progression will be summarized, and the potentials of the competitive crosstalk as diagnostic, prognostic, and therapeutic targets will be comprehensively discussed.

LncRNAs: Novel Biomarkers for Pancreatic Cancer

Pancreatic cancer is one of the most deadly neoplasms and the seventh major cause of cancer-related deaths among both males and females. This cancer has a poor prognosis due to the lack of appropriate methods for early detection of cancer. Long non-coding RNAs (lncRNAs) have been recently found to influence the progression and initiation of pancreatic cancer. MACC1-AS1, LINC00976, LINC00462, LINC01559, HOXA-AS2, LINC00152, TP73-AS1, XIST, SNHG12, LUCAT1, and UCA1 are among the oncogenic lncRNAs in pancreatic cancer. On the other hand, LINC01111, LINC01963, DGCR5, MEG3, GAS5, and LINC00261 are among tumor suppressor lncRNAs in this tissue. In the current review, we summarize the roles of these two classes of lncRNAs in pancreatic cancer and discuss their potential as attractive diagnostic and prognostic biomarkers for pancreatic cancer. We also identified that the low expression of MEG3, LINC01963, and LINC00261 and the high expression of MACC1-AS1, LINC00462, LINC01559, and UCA1 were significantly correlated with worse survival in pancreatic cancer patients. Further research on these lncRNAs will provide new clues that could potentially improve the early diagnosis, prognostic prediction, and personalized treatments of patients with pancreatic cancer.

LncRNA RGMB-AS1 facilitates pancreatic cancer cell proliferation and migration but inhibits cell apoptosis via miR-574-3p/PIM3 axis

Pancreatic cancer (PC) is among the most notorious malignancies worldwide. Long noncoding RNA (lncRNA) repulsive guidance molecule bone morphogenetic protein (BMP) coreceptor b antisense RNA 1 (RGMB-AS1) was an oncogene in glioma. However, the RGMB-AS1 function in PC remains largely unknown. Herein, quantitative real-time polymerase chain reaction was performed to analyze the expression of RGMB-AS1. We determined RGMB-AS1 influence on PC cell malignant behaviors via functional assays. Besides, we applied subcellular fractionation and fluorescence in situ hybridization (FISH) assays to confirm the cellular distribution of RGMB-AS1 in PC cells. We used mechanism assays to detect the regulatory axis of RGMB-AS1 in PC cells. Briefly, the level of RGMB-AS1 expression in PC cells was abnormally high. RGMB-AS1 knockdown impeded PC cell proliferation and migration, but induced cell apoptosis, and RGMB-AS1 overexpression led the opposite consequences. RGMB-AS1 acted as a competing endogenous RNA (ceRNA) to sequester miR-574-3p and thereby regulated Pim-3 proto-oncogene, serine/threonine kinase (PIM3) expression. Conclusively, our work revealed the cancer-promoting function of RGMB-AS1 in PC and that the regulatory mechanism of the RGMB-AS1/miR-574-3p/PIM3 axis might contribute to novel biomarker development in PC treatment.NEW & NOTEWORTHY RGMB-AS1 promotes PC cell proliferation, elevates PC cell migration capacity, inhibits PC cell apoptosis, and promotes PC cell proliferation and migration but inhibits cell apoptosis via targeting miR-574-3p. PIM3 is directly targeted by miR-574-3p.

LncRNA SNHG7 Regulates Mesenchymal Stem Cell Through the Notch1/Jagged1/Hes-1 Signaling Pathway and Influences Folfirinox Resistance in Pancreatic Cancer

Pancreatic cancer (PC) is one of the deadliest gastrointestinal cancers, accounting for the fourth highest number of cancer-related fatalities. Increasing data suggests that mesenchymal stem cells (MSCs) might influence the drug resistance of GC cells in the tumor microenvironment and play essential roles in drug resistance development. However, the precise underlying process remains a mystery. The purpose of this study was to look at the control of MSC-induced SNHG7 in pancreatic cancer. In vitro and in vivo sphere formation, colony formation, and flow cytometry investigations revealed the stemness and Folfirinox resistance in pancreatic cancer cells. To confirm the direct connections between SNHG7 and other related targets, RNA pulldown and immunoprecipitation tests were performed. MSC co-culture enhanced the stemness and Folfirinox resistance in pancreatic cancer cells according to the findings. MSC co-culture increased SNHG7 expression in pancreatic cancer cells, contributing to the stemness and Folfirinox resistance. We demonstrated that Notch1 interacted with SNHG7 and could reverse the facilitative effect of SNHG7 on the stemness and Folfirinox resistance in pancreatic cancer cells. Finally, our findings showed that MSCs increased SNHG7 expression in pancreatic cancer cells, promoting the stemness and Folfirinox resistance via the Notch1/Jagged1/Hes-1 signaling pathway. These findings could provide a novel approach and therapeutic target for pancreatic cancer patients.

Long non-coding RNA HLA complex group 18 promotes gastric cancer progression by targeting microRNA-370-3p expression

OBJECTIVES

Our research was aimed at investigating the biological character of human leukocyte antigen complex group 18 (HCG18) on gastric cancer (GC) progression and its potential mechanisms.

METHODS

The expression characteristics and prognostic values of HCG18 in GC were evaluated through the GEPIA database and Kaplan-Meier plotter database. Quantitative real-time PCR and Western blot were used for quantification of messenger RNA expression, microRNA (miRNA) expression and protein expression. Cell proliferation, migration and invasion were detected by cell counting kit-8 assay, 5'-bromo-2'-deoxyuridine assay and Transwell assay, respectively. Dual-luciferase reporter gene assay and RNA immunoprecipitation assay were used for examination of the interactions among HCG18, miR-370-3p and epidermal growth factor receptor (EGFR) 3'UTR.

KEY FINDINGS

HCG18 expression was up-regulated in GC tissues, and its high expression was closely associated with increased tumour size, advanced TNM stage, poor differentiation of tumour tissues and unfavourable prognosis of patients with GC. Additionally, HCG18 overexpression promoted the proliferation, migration and invasion of GC cells, and its knockdown suppressed the malignant phenotypes of GC cells. Furthermore, HCG18 served as a miRNA sponge to repress miR-370-3p and indirectly up-regulated EGFR expression in GC cells.

CONCLUSIONS

HCG18 served as a tumour-promoting factor in GC progression by modulating the miR-370-3p/EGFR axis.

Silencing of long non-coding RNA SNHG15 suppresses proliferation, migration and invasion of pancreatic cancer cells by regulating the microRNA-345-5p/RAB27B axis

Pancreatic cancer (PC) is the seventh most common cause of cancer-associated mortality worldwide. The current study aimed to investigate the function and molecular mechanism underlying long non-coding (lnc)RNA SNHG15 in PC tissues and cells. Relative expression levels of lncRNA SNHG15, miR-345-5p and RAB27B in PC cells and tissues were examined by performing reverse transcription-quantitative PCR. The association between SNHG15, miR-345-5p and RAB27B was validated using a Dual-luciferase reporter assay. Proliferation, invasion and migration of PC cells were analysed by conducting MTT, wound healing and Transwell assays. Western blotting was performed to detect the relative expression of the RAB27B protein. The relative expression level of lncRNA SNHG15 and RAB27B was elevated, but that of miR-345-5p was decreased in PC. Silencing of SNHG15 suppressed the proliferation, invasion and migration of PC cells in vitro and suppressed tumour growth in xenograft mice in vivo. miR-345-5p was the target gene of SNHG15 and suppressed cell proliferation, migration and invasion in PC. Furthermore, miR-345-5p targeted RAB27B. The use of miR-345-5p inhibitor or overexpression of RAB27B reversed the suppressive effect of the small interfering RNA si-SNHG15-1 exerted on the proliferation, invasion and migration of PC cells. Silencing of SNHG15 inhibited the proliferation, invasion and migration of PC cells by mediating the miR-345-5p/RAB27B axis, thereby implying its potential as a prognostic marker and target for PC therapy.

LncRNA PTTG3P induced aberrant glycosylated IgA1 production and B cell growth in IgA nephropathy

Growing evidences suggested that lncRNAs played functional role in several cell functions such as cell growth, invasion, migration, metabolize, apoptosis, and differentiation. However, roles of lncRNA in the development and progression of IgAN remain unknown. In this reference, we indicated that PTTG3P level was overexpressed in IgAN samples compared to healthy subject. PTTG3P expression was also higher in urinary of IgAN cases than in urinary of healthy control. Furthermore, the urinary expression of PTTG3P was correlated with PTTG3P expression in intra-renal of IgAN cases. PTTG3P overexpression induced B cell growth and enhanced cyclin D1 and ki-67 expression. Overexpression of PTTG3P induced IL-1β and IL-8 production. miR-383 level was decreased in IgAN samples compared to healthy subject. In addition, miR-383 expression was also lower in urinary of IgAN cases than in urinary of healthy control. Elevated miR-383 expression decreased luciferase intensity regulated with PTTG3P, while overexpression of miR-383 had no effect on luciferase intensity of the mutant PTTG3P. PTTG3P overexpression suppressed miR-383 expression in B cells. Ectopic miR-383 expression suppressed B cell growth and IL-1β and IL-8 production. Finally, we showed that overexpression of PTTG3P promoted B cell growth and IL-1β and IL-8 production via regulating miR-383. There results proved that PTTG3P played crucial role in progression of IgAN.

XIST Inhibition Attenuates Calcium Oxalate Nephrocalcinosis-Induced Renal Inflammation and Oxidative Injury via the miR-223/NLRP3 Pathway

The roles of the lncRNA X inactive specific transcript (XIST) in many diseases, including cancers and inflammatory sickness, have been previously elucidated. However, renal calculus remained poorly understood. In this study, we revealed the potential effects of XIST on kidney stones that were exerted via inflammatory response and oxidative stress mechanisms. We established a glyoxylate-induced calcium oxalate (CaOx) stone mouse model and exposed HK-2 cells to calcium oxalate monohydrate (COM). The interactions among XIST, miR-223-3p, and NOD-like receptor protein 3 (NLRP3) and their respective effects were determined by RNAs and protein expression, luciferase activity, and immunohistochemistry (IHC) assays. Cell necrosis, reactive oxygen species (ROS) generation, and inflammatory responses were detected after silencing XIST, activating and inhibiting miR-223-3p, and both knocking down XIST and activating miR-223-3p in vitro and in vivo. The XIST, NLRP3, caspase-1, and IL-1β levels were notably increased in kidney samples from glyoxylate-induced CaOx stone model mice. XIST knockdown significantly suppressed the inflammatory damage and ROS production and further attenuated oxalate crystal deposition. miRNA-223-3p mimics also exerted the same effects. Moreover, we verified the interactions among XIST, miRNA-223-3p and NLRP3, and the subsequent effects. Our results suggest that the lncRNA XIST participates in the formation and progression of renal calculus by interacting with miR-223-3p and the NLRP3/Caspase-1/IL-1β pathway to mediate the inflammatory response and ROS production.

Knockdown of LINC00657 inhibits the viability, migration and invasion of pancreatic cancer cells by regulating the miR-520h/CKS1B axis

Long non-coding RNA LINC00657 has a critical role in multiple cancers. The aim of the present study was to investigate the regulatory effect of LINC00657 in pancreatic cancer (PC) and reveal its molecular mechanism of function. The expression levels of LINC00657 and microRNA (miR)-520h were detected by reverse transcription-quantitative PCR in PC tissues and cell lines. MTT, wound healing and Transwell assays were used to detect cell viability, migration and invasion, respectively. Dual-luciferase reporter assay was utilized to examine the relationship between LINC00657 and miR-520h and that between miR-520h and cyclin-dependent kinases regulatory subunit 1 (CKS1B). Western blotting was performed to detect CKS1B expression. The expression levels of LINC00657 and CKS1B were enhanced and miR-520h expression level was reduced in PC tissues and cell lines compared with adjacent normal tissues or HPDE6 cells. LINC00657 knockdown decreased the viability, migration and invasion of PC cells. Additionally, LINC00657 targeted miR-520h and negatively modulated miR-520h expression. Furthermore, miR-520h overexpression inhibited the viability, migration and invasion of PC cells. In addition, miR-520h targeted CKS1B and reversely regulated CKS1B expression. miR-520h inhibition and CKS1B overexpression alleviated the inhibition effect of LINC00657 knockdown on the viability, migration and invasion of PACA-2 PC cells. In conclusion, the results of the present study demonstrated that LINC00657 knockdown repressed the viability, migration and invasion of PC cells via targeting the miR-520h/CKS1B axis, which may offer a future target for PC therapy.

Research updates on the clinical implication of long noncoding RNA in digestive system cancers and chemoresistance

Long noncoding RNAs (lncRNAs) are implicated in various biological processes, such as cell proliferation, differentiation, apoptosis, migration, and invasion. They are also key players in various biological pathways. LncRNA was considered as 'translational noise' before 1980s. It has been reported that lncRNAs are aberrantly expressed in different cancers, either as oncogene or tumor suppressor gene. Therefore, more and more lncRNAs are recognized as potential diagnostic biomarkers and/or therapeutic targets. As competitive endogenous RNA, lncRNAs can interact with microRNA to alter the expression of target genes, which may have extensive clinical implications in cancers, including diagnosis, treatment, prognosis, and chemoresistance. This review comprehensively summarizes the functions and clinical relevance of lncRNAs in digestive system cancers, especially as a potential tool to overcome chemoresistance.

The impact of LncRNA dysregulation on clinicopathology and survival of pancreatic cancer: a systematic review and meta-analysis (PRISMA compliant)

Purpose

An increasing number of studies have reported a significant association between long non-coding RNAs (lncRNAs) dysregulation and pancreatic cancers. In the present study, we aimed to gather articles to evaluate the prognostic value of long non coding RNA in pancreatic cancer.

Experimental design

We systematically searched all eligible articles from databases of PubMed, Web of Science, and Scopus to meta-analysis of published articles and screen association of multiple lncRNAs expression with clinicopathology and/or survival of pancreatic cancer. The pooled hazard ratios (HRs) and their 95% confidence intervals (95% CIs) were used to analysis of overall survival, disease-free survival and progression-free survival were measured with a fixed or random effects model.

Results

A total of 39 articles were included in the present meta-analysis. Our results showed that dysregulation of lncRNAs were linked to overall survival (39 studies, 4736 patients HR = 0.41, 95% CI 0.25 ± 0.58, random-effects in pancreatic cancer. Moreover, altered lncRNAs were also contributed to progression-free survival (8 studies, 1180 patients HR: 1.88, 95% CI (1.35–2.62) and disease-free survival (2 studies, 285 patients, HR: 6.07, 95% CI 1.28–28.78). In addition, our findings revealed the association between dysregulated RNAs and clinicopathological features in this type of cancer.

Conclusions

In conclusion, dysregulated lncRNAs could be served as promising biomarkers for diagnosis and prognosis of pancreatic cancer.

LncRNA GACAT1 induces tongue squamous cell carcinoma migration and proliferation via miR-149

Recent studies have observed that lncRNAs (long non‐coding RNAs) are involved in the progression of various tumours including tongue squamous cell carcinoma (TSCC). Recently, a new lnRNA, GACAT1, has been firstly identified in gastric cancer. However, its potential role in TSCC remains unknown. In this reference, we observed that GACAT1 was overexpressed in TSCC samples and cell lines. Of 25 TSCC specimens, GACAT1 expression was overexpressed in 18 patients (18/25, 72%) compared to non‐tumour specimens. Ectopic expression of GACAT1 induced cell growth and migration and promoted epithelial to mesenchymal transition in TSCC. In addition, ectopic expression of GACAT1 decreased miR‐149 expression in SCC1 cell. We observed that miR‐149 expression was down‐regulated in TSCC cell lines. Moreover, we observed that GACAT1 expression was negatively correlated with miR‐149 expression. GACAT1 overexpression induced TSCC cell growth and migration via regulating miR‐149 expression. These data provided that GACAT1 played an oncogenic role in the progression of TSCC partly through modulating miR‐149 expression.

Downregulation of lncRNA XIST promotes proliferation and differentiation, limits apoptosis of osteoblasts through regulating miR-203-3p/ZFPM2 axis

Background: Bone fracture is a common medical condition. Evidence suggested that long noncoding RNAs (lncRNAs) could regulate the bio-function in osteoblast. In this study, we explored the role and mechanism of lncRNA X-inactive specific transcript (XIST) on the proliferation, apoptosis, and differentiation of osteoblasts using MC3T3-E1 cells. Methods: Expression of XIST, microRNA-203-3p (miR-203-3p), and zinc finger protein multitype 2 (ZFPM2) was measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability and apoptosis of MC3T3-E1 cells were measured using the Cell Counting Kit-8 (CCK-8) and the flow cytometry. Western blot was used to measure the expression of cell cycle-related proteins, apoptosis-related proteins, and ZFPM2. Levels of differentiation-related factors were measured by qRT-PCR, western blot, and alkaline phosphatase (ALP) kit. Target interaction between miR-203-3p and XIST or ZFPM2 was predicted through bioinformatics analysis and verified by dual-luciferase reporter, RNA immunoprecipitation (RIP) assay, or RNA pull-down assay. Results: The expression of XIST and ZFPM2 was increased while miR-203-3p was decreased in plasmas and MC3T3-E1 cells. Knockdown of XIST promoted the proliferation, differentiation, but limited apoptosis in MC3T3-E1 cells. . Mechanically, overexpression of XIST could reverse the bio-function of miR-203-3p transfection. Additionally, miR-203-3p inverted a series of bio-functional effects of ZFPM2. Furthermore, anti-miR-203-3p rescued si-XIST-induced downregulation of ZFPM2. Conclusion: Downregulation of lncRNA XIST promoted osteoblast proliferation and differentiation, but limited apoptosis by miR-203-3p/ZFPM2 axis.

Non-coding RNAs in pancreatic ductal adenocarcinoma: New approaches for better diagnosis and therapy

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignancies with a 5-year survival rate less than 8%, which has remained unchanged over the last 50 years. Early detection is particularly difficult due to the lack of disease-specific symptoms and a reliable biomarker. Multimodality treatment including chemotherapy, radiotherapy (used sparingly) and surgery has become the standard of care for patients with PDAC. Carbohydrate antigen 19-9 (CA 19-9) is the most common diagnostic biomarker; however, it is not specific enough especially for asymptomatic patients. Non-coding RNAs are often deregulated in human malignancies and shown to be involved in cancer-related mechanisms such as cell growth, differentiation, and cell death. Several micro, long non-coding and circular RNAs have been reported to date which are involved in PDAC. Aim of this review is to discuss the roles and functions of non-coding RNAs in diagnosis and treatments of PDAC.

MicroRNAs: emerging driver of cancer perineural invasion

The perineural invasion (PNI), which refers to tumor cells encroaching on nerve, is a clinical feature frequently occurred in various malignant tumors, and responsible for postoperative recurrence, metastasis and decreased survival. The pathogenesis of PNI switches from 'low-resistance channel' hypothesis to 'mutual attraction' theory between peripheral nerves and tumor cells in perineural niche. Among various molecules in perineural niche, microRNA (miRNA) as an emerging modulator of PNI through generating RNA-induced silencing complex (RISC) to orchestrate oncogene and anti-oncogene has aroused a wide attention. This article systematically reviewed the role of microRNA in PNI, promising to identify new biomarkers and offer cancer therapeutic targets.

X-Inactive-Specific Transcript: Review of Its Functions in the Carcinogenesis

X-inactive-specific transcript (XIST) is one of the firstly discovered long non-coding RNAs with prominent roles in the process of X inactivation. Moreover, this transcript contributes in the carcinogenic process in different tissues. In addition to interacting with chromatin modifying molecules, XIST can be served as a molecular sponge for miRNAs to modulate expression of miRNA targets. Most of the studies have indicated an oncogenic role for XIST. However, in prostate cancer, a single study has indicated a tumor suppressor role for this lncRNA. Similar result has been reported for XIST in oral squamous cell carcinoma. In hepatocellular carcinoma, breast cancer, ovarian cancer, osteosarcoma, and renal cell carcinoma, different studies have reported inconsistent results. In the present manuscript, we review function of XIST in the carcinogenesis.

Biological Function of Long Non-coding RNA (LncRNA) Xist

Long non-coding RNAs (lncRNAs) regulate gene expression in a variety of ways at epigenetic, chromatin remodeling, transcriptional, and translational levels. Accumulating evidence suggests that lncRNA X-inactive specific transcript (lncRNA Xist) serves as an important regulator of cell growth and development. Despites its original roles in X-chromosome dosage compensation, lncRNA Xist also participates in the development of tumor and other human diseases by functioning as a competing endogenous RNA (ceRNA). In this review, we comprehensively summarized recent progress in understanding the cellular functions of lncRNA Xist in mammalian cells and discussed current knowledge regarding the ceRNA network of lncRNA Xist in various diseases. Long non-coding RNAs (lncRNAs) are transcripts that are more than 200 nt in length and without an apparent protein-coding capacity (Furlan and Rougeulle, 2016; Maduro et al., 2016). These RNAs are believed to be transcribed by the approximately 98-99% non-coding regions of the human genome (Derrien et al., 2012; Fu, 2014; Montalbano et al., 2017; Slack and Chinnaiyan, 2019), as well as a large variety of genomic regions, such as exonic, tronic, and intergenic regions. Hence, lncRNAs are also divided into eight categories: Intergenic lncRNAs, Intronic lncRNAs, Enhancer lncRNAs, Promoter lncRNAs, Natural antisense/sense lncRNAs, Small nucleolar RNA-ended lncRNAs (sno-lncRNAs), Bidirectional lncRNAs, and non-poly(A) lncRNAs (Ma et al., 2013; Devaux et al., 2015; St Laurent et al., 2015; Chen, 2016; Quinn and Chang, 2016; Richard and Eichhorn, 2018; Connerty et al., 2020). A range of evidence has suggested that lncRNAs function as key regulators in crucial cellular functions, including proliferation, differentiation, apoptosis, migration, and invasion, by regulating the expression level of target genes via epigenomic, transcriptional, or post-transcriptional approaches (Cao et al., 2018). Moreover, lncRNAs detected in body fluids were also believed to serve as potential biomarkers for the diagnosis, prognosis, and monitoring of disease progression, and act as novel and potential drug targets for therapeutic exploitation in human disease (Jiang W. et al., 2018; Zhou et al., 2019a). Long non-coding RNA X-inactive specific transcript (lncRNA Xist) are a set of 15,000-20,000 nt sequences localized in the X chromosome inactivation center (XIC) of chromosome Xq13.2 (Brown et al., 1992; Debrand et al., 1998; Kay, 1998; Lee et al., 2013; da Rocha and Heard, 2017; Yang Z. et al., 2018; Brockdorff, 2019). Previous studies have indicated that lncRNA Xist regulate X chromosome inactivation (XCI), resulting in the inheritable silencing of one of the X-chromosomes during female cell development. Also, it serves a vital regulatory function in the whole spectrum of human disease (notably cancer) and can be used as a novel diagnostic and prognostic biomarker and as a potential therapeutic target for human disease in the clinic (Liu et al., 2018b; Deng et al., 2019; Dinescu et al., 2019; Mutzel and Schulz, 2020; Patrat et al., 2020; Wang et al., 2020a). In particular, lncRNA Xist have been demonstrated to be involved in the development of multiple types of tumors including brain tumor, Leukemia, lung cancer, breast cancer, and liver cancer, with the prominent examples outlined in Table 1. It was also believed that lncRNA Xist (Chaligne and Heard, 2014; Yang Z. et al., 2018) contributed to other diseases, such as pulmonary fibrosis, inflammation, neuropathic pain, cardiomyocyte hypertrophy, and osteoarthritis chondrocytes, and more specific details can be found in Table 2. This review summarizes the current knowledge on the regulatory mechanisms of lncRNA Xist on both chromosome dosage compensation and pathogenesis (especially cancer) processes, with a focus on the regulatory network of lncRNA Xist in human disease.

LncRNA XIST promotes liver cancer progression by acting as a molecular sponge of miR-200b-3p to regulate ZEB1/2 expression

Objective

To evaluate the predictive value of long non-coding RNA (lncRNA) X-inactive specific transcript (XIST) for survival, and determine the involvement of miRNA(miR)-200b-3p and zinc finger E-box-binding homeobox (ZEB) 1/2 in the pro-tumor effect of lncRNA XIST in liver cancer.

Methods

We evaluated lncRNA XIST expression in liver cancer tissues and cell lines by quantitative reverse transcription polymerase chain reaction (RT-qPCR) and analyzed the correlation between its expression and overall survival of liver cancer patients by Kaplan–Meier analysis. Its effects on cell proliferation, migration, and invasion were analyzed by Cell-Counting Kit-8 and Transwell assays. The association between lncRNA XIST and miR-200b-3p, and the effects of lncRNA XIST on ZEB1/2 expression were explored using luciferase reporter assays, real-time PCR, and western blotting.

Results

The lncRNA XIST was significantly upregulated in liver cancer, and increased lncRNA XIST expression was associated with a poor prognosis. The lncRNA XIST promoted liver cancer cell proliferation, migration, and invasion in vitro, and acted as a molecular sponge for miR-200b-3p, and also regulated the expression of ZEB1/2 via miR-200b-3p.

Conclusion

The lncRNA XIST is an oncogenic lncRNA that promotes liver cancer metastasis, and its pro-metastatic phenotype can be partially attributed to the lncRNA XIST/miR-200b-3p/ZEB1/2 signaling axis.

LncRNA testis-specific transcript, Y-linked 15 (TTTY15) promotes proliferation, migration and invasion of colorectal cancer cells via regulating miR-29a-3p/DVL3 axis

BACKGROUND

Long non-coding RNA testis-specific transcript, Y-linked 15 (TTTY15) is oncogenic in prostate cancer, however its expression and function in colorectal cancer remain largely unknown.

METHODS

Paired colorectal cancer samples/normal tissues were collected, and the expression levels of TTTY15, miR-29a-3p and disheveled segment polarity protein 3 (DVL3) were examined by quantitative real-time polymerase chain reaction (qRT-PCR); TTTY15 shRNA and overexpression plasmids were transfected into HT29 and HCT-116 cell lines using lipofectamine reagent, respectively; the proliferation and colony formation were detected by CCK-8 assay and plate colony formation assay; qRT-PCR and Western blot were used to analyze the changes of miR-29a-3p and DVL3; dual-luciferase reporter gene assay was used to determine the regulatory relationships between miR-29a-3p and TTTY15, miR-29a-3p and DVL3.

RESULTS

TTTY15 was significantly up-regulated in cancerous tissues of colorectal cancer samples, positively correlated with the expression of DVL3, while negatively correlated with the expression of miR-29a-3p. After TTTY15 shRNAs were transfected into colorectal cancer cells, the proliferation and metastasis of cancer cells were significantly inhibited, while TTTY15 overexpression had opposite biological effects. TTTY15 shRNA could reduce the expression of DVL3 on both mRNA and protein levels, and the luciferase activity of TTTY15 sequence was also inhibited by miR-29a-3p. DVL3 was also validated as a target gene of miR-29a-3p, and it could be repressed by miR-29a-3p mimics or TTTY15 shRNA.

CONCLUSION

TTTY15 is abnormally upregulated in colorectal cancer tissues, and it can modulate the proliferation and metastasis of colorectal cancer cells. It functions as the ceRNA to regulate the expression of DVL3 by sponging miR-29a-3p.

Long non-coding RNA XIST promotes retinoblastoma cell proliferation, migration, and invasion by modulating microRNA-191-5p/brain derived neurotrophic factor

Long non-coding RNA (lncRNA) X–inactive specific transcript (XIST) is oncogenic in multiple cancers. Herein, the present study is aimed at delving into how XIST functions in retinoblastoma (RB) and investigating its underlying mechanism. In this study, XIST, miR-191-5p, BDNF mRNA, and BDNF expression levels in RB tissues or cell lines were examined by quantitative real-time polymerase chain reaction (qRT-PCR) or Western blot. The models of gain-of-function and loss-of-function were established by the transfection of pcDNA3.1-XIST, XIST siRNA, and miR-191-5p mimics and inhibitors into SO-Rb50 and Y79 cells, respectively. RB cell proliferation, migration, invasion, and apoptosis were detected employing cell counting kit-8 (CCK-8), Transwell, and terminal deoxynucleotidyl transferased UTP nick end labeling (TUNEL) assays. The regulatory relationships among XIST, miR-191-5p, and BDNF were affirmed utilizing bioinformatics analysis, luciferase reporter assay, qRT-PCR, as well as Western blot. We reported that, XIST expression was markedly elevated in RB tissue and RB cells. XIST overexpression accelerated RB cell proliferation, migration, and invasion, and attenuated RB cell apoptosis but miR-191-5p exerted the opposite effects. Besides, BDNF expression was inhibited by miR-191-5p in both mRNA and protein levels. XIST indirectly improved BDNF expression by repressing miR-191-5p expression as a competitive endogenous RNA. In conclusion, XIST expression is abnormally elevated in RB tissues and XIST can modulate proliferation, migration, invasion, and apoptosis of RB cells by regulating miR-191-5p/BDNF axis.

Long non-coding RNA X-inactive specific transcript promotes osteosarcoma metastasis via modulating microRNA-758/Rab16

Background

As a common malignant bone sarcoma, osteosarcoma (OS) affects the health and lives of many people. Here, we probed the effects of long non-coding RNA (lncRNA) X-inactive specific transcript (XIST) and microRNA-758 (miR-758) on OS metastasis, and examined possible downstream effector.

Methods

Quantitative reverse transcription PCR (qRT-PCR) was performed to detect the expressions of XIST and miR-758 in OS tissues and cells. Cell transfection was carried out to alter the levels of XIST and miR-758 in OS cells, and cell viability, migration, and invasion were assessed. Subsequently, qRT-PCR and a dual-luciferase reporter assay were conducted to analyze the regulatory effects of XIST on miR-758 and miR-758 on Rab16. Finally, we investigated whether Rab16 was the downstream effector of XIST/miR-758 axis.

Results

XIST was highly expressed in OS tissues and cells, but the opposite was seen for miR-758. In OS cells, migration, invasion, and epithelial-mesenchymal transformation (EMT) was promoted by overexpression of XIST and miR-758 inhibitor, but were inhibited by XIST knockdown and miR-758 mimics. XIST regulated miR-758 expression, and miR-758 regulated Rab16 expression in OS cells. Overexpression of Rab16 reversed the effects of miR-758 mimics on OS cell migration and invasion.

Conclusions

XIST contributed to OS cell migration, invasion, and EMT via regulation of miR-758/Rab16.

LncRNA XIST upregulates TRIM25 via negatively regulating miR-192 in hepatitis B virus-related hepatocellular carcinoma

BACKGROUND

Long non-coding RNA (lncRNA) XIST has been implicated in the progression of a variety of tumor diseases. The purpose of this study was to explore the molecular role of lncRNA XIST in human hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC).

METHODS

The expression levels of lncRNA XIST, miR-192 and TRIM25 in HBV-related HCC tissues and HepG2.2.15 cells were detected by qRT-PCR. Biological information and luciferin gene reporter assay were performed to detect the interaction among lncRNA XIST, miR-192 and TRIM25. CCk-8 assay, wound healing assay and colony formation assay were conducted to detect the proliferation and migration ability of HepG2.2.15 cells.

RESULTS

qRT-PCR results showed that the expression levels of lncRNA XIST were remarkably increased in HBV-related HCC tissues and HepG2.2.15 cells. In addition, miR-192 was a direct target gene of lncRNA XIST, and the expression of miR-192 and lncRNA XIST were negatively correlated. Moreover, overexpression of miR-192 observably inhibited the proliferation and migration of HCC cells, while overexpression of lncRNA XIST showed an opposite effect. Furthermore, TRIM25 was a direct target of miR-192, and lncRNA XIST could up-regulate the expression of TRIM25 by targeting miR-192.

CONCLUSION

LncRNA XIST could up-regulate the expression of TRIM25 by targeting and binding to miR-192, thus accelerating the occurrence and development of HCC.

LncRNA SNHG8 Serves as an Oncogene in Breast Cancer Through miR-634/ZBTB20 Axis

Background

Small nucleolus RNA Host Gene 8 (SNHG8) belongs to a subgroup with long non-coding RNAs. LncRNA SNHG8 presents up-regulated in miscellaneous cancers, like gastric cancer, liver cancer, and esophageal squamous cell cancer. Nevertheless, the expression pattern and the pathological function of lncRNA SNHG8 in breast cancer remain obscure.

Methods

We examined the expression levels of lncRNA SNHG8 in the tissue samples and cell lines from breast cancer via RT-qPCR in the present study. The functions of lncRNA SNHG8 on the progression of breast cancer cell were examined by CCK-8, EdU, Transwell chamber assays, and flow cytometry analyses. The expression of proteins was assessed using Western blot assay.

Results

We found that proliferation, migration, and invasion of breast cancer cells were significantly inhibited due to knockdown of lncRNA SNHG8, while inducing apoptosis of these cells. Mechanistically, SNHG8 functioned as an inhibitor of miR-634 in tumor tissues.

Conclusion

LncRNA SNHG8 sponged the miR-634 to increase the expression level of ZBTB20, thus further aggravating the malignancy of breast cancer. Hence, the lncRNA SNHG8-miR-634-ZBTB20 axis may be a promising therapeutic target to treat breast cancers.

Long Noncoding RNA CERS6-AS1 Accelerates the Proliferation and Migration of Pancreatic Cancer Cells by Sequestering MicroRNA-15a-5p and MicroRNA-6838-5p and Modulating HMGA1

OBJECTIVES

As one of the most aggressive human tumors, pancreatic cancer (PC) is accompanied by poor treatment and prognosis. Although emerging evidence has highlighted the importance of long noncoding RNAs in multiple cancers, the specific regulatory roles mostly remain obscure. Our aim was to disclose the role of CERS6 antisense RNA 1 (CERS6-AS1) in PC.

METHODS

Quantitative real-time polymerase chain reaction analysis was used to examine the expression of CERS6-AS1 in PC cell lines. Western blot analysis was used to assess the protein levels of high-mobility group AT-hook 1 (HMGA1). Colony formation, 5-ethynyl-20-deoxyuridine, transwell, and wound healing assays were performed to detect the functions of CERS6-AS1 on PC development. In addition, RNA pull-down, RNA immunoprecipitation, and luciferase reporter assays were implemented to delve into the regulatory mechanism of CERS6-AS1 in PC.

RESULTS

CERS6-AS1 was significantly upregulated in PC. CERS6-AS1 silence obviously inhibited cell proliferation and migration in PC. Furthermore, CERS6-AS1 sponged microRNA-15a-5p (miR-15a-5p) and microRNA-6838-5p (miR-6838-5p) to regulate HMGA1. Moreover, rescue assays verified that CERS6-AS1 was involved in cell proliferation and migration in PC via targeting miR-15a-5p/miR-6838-5p/HMGA1 axis.

CONCLUSIONS

CERS6-AS1 enhanced HMGA1 expression to contribute to the progression of PC by sequestering miR-15a-5p and miR-6838-5p.