Long noncoding RNA DLX6-AS1 promotes tumorigenesis by modulating miR-497-5p/FZD4/FZD6/Wnt/β-catenin pathway in pancreatic cancer

Schisandra chinensis Bee Pollen Extract Inhibits Proliferation and Migration of Hepatocellular Carcinoma HepG2 Cells via Ferroptosis-, Wnt-, and Focal Adhesion-Signaling Pathways

Purpose

Bee pollen possesses favorable anticancer activities. As a medicinal plant source, Schisandra chinensis bee pollen (SCBP) possesses potential pharmacological properties, such as reducing cisplatin-induced liver injury, but its anti-liver cancer effect is still rarely reported. This paper aims to investigate the effect and mechanism of SCBP extract (SCBPE) on hepatocellular carcinoma HepG2 cells.

Methods

The effect of SCBPE on cell proliferation and migration of HepG2 cells was evaluated based on MTT assay, morphology observation, or scratching assay. Furthermore, tandem mass tag-based quantitative proteomics was used to study the effect mechanisms. The mRNA expression levels of identified proteins were verified by RT-qPCR.

Results

Tandem mass tag-based quantitative proteomics showed that 61 differentially expressed proteins were obtained in the SCBPE group compared with the negative-control group: 18 significantly downregulated and 43 significantly upregulated proteins. Bioinformatic analysis showed the significantly enriched KEGG pathways were predominantly ferroptosis-, Wnt-, and hepatocellular carcinoma-signaling ones. Protein-protein interaction network analysis and RT-qPCR validation revealed SCBPE also downregulated the focal adhesion-signaling pathway, which is abrogated by PF-562271, a well-known inhibitor of FAK.

Conclusion

This study confirmed SCBPE suppressed the cell proliferation and migration of hepatocellular carcinoma HepG2 cells, mainly through modulation of ferroptosis-, Wnt-, hepatocellular carcinoma-, and focal adhesion-signaling pathways, providing scientific data supporting adjuvant treatment of hepatocellular carcinoma using SCBP.

LncRNAs as nodes for the cross-talk between autophagy and Wnt signaling in pancreatic cancer drug resistance

Pancreatic cancer is a malignancy with high mortality. In addition to the few symptoms until the disease reaches an advanced stage, the high fatality rate is attributed to its rapid development, drug resistance and lack of appropriate treatment. In the selection and research of therapeutic drugs, gemcitabine is the first-line drug for pancreatic cancer. Solving the problem of gemcitabine resistance in pancreatic cancer will contribute to the progress of pancreatic cancer treatment. Long non coding RNAs (lncRNAs), which are RNA transcripts longer than 200 nucleotides, play vital roles in cellular physiological metabolic activities. Currently, our group and others have found that some lncRNAs are aberrantly expressed in pancreatic cancer cells, which can regulate the process of cancer through autophagy and Wnt/β-catenin pathways simultaneously and affect the sensitivity of cancer cells to therapeutic drugs. This review presents an overview of the recent evidence concerning the node of lncRNA for the cross-talk between autophagy and Wnt/β-catenin signaling in pancreatic cancer, together with the practicability of lncRNAs and the core regulatory factors as targets in therapeutic resistance.

Molecular profile of metastasis, cell plasticity and EMT in pancreatic cancer: a pre-clinical connection to aggressiveness and drug resistance

The metastasis is a multistep process in which a small proportion of cancer cells are detached from the colony to enter into blood cells for obtaining a new place for metastasis and proliferation. The metastasis and cell plasticity are considered major causes of cancer-related deaths since they improve the malignancy of cancer cells and provide poor prognosis for patients. Furthermore, enhancement in the aggressiveness of cancer cells has been related to the development of drug resistance. Metastasis of pancreatic cancer (PC) cells has been considered one of the major causes of death in patients and their undesirable prognosis. PC is among the most malignant tumors of the gastrointestinal tract and in addition to lifestyle, smoking, and other factors, genomic changes play a key role in its progression. The stimulation of EMT in PC cells occurs as a result of changes in molecular interaction, and in addition to increasing metastasis, EMT participates in the development of chemoresistance. The epithelial, mesenchymal, and acinar cell plasticity can occur and determines the progression of PC. The major molecular pathways including STAT3, PTEN, PI3K/Akt, and Wnt participate in regulating the metastasis of PC cells. The communication in tumor microenvironment can provide by exosomes in determining PC metastasis. The components of tumor microenvironment including macrophages, neutrophils, and cancer-associated fibroblasts can modulate PC progression and the response of cancer cells to chemotherapy.

Investigating the regulatory role of miRNAs as silent conductors in the management of pathogenesis and therapeutic resistance of pancreatic cancer

Pancreatic cancer (PC) has the greatest mortality rate of all the main malignancies. Its advanced stage and poor prognosis place it at the bottom of all cancer sites. Hence, emerging biomarkers can enable precision medicine where PC therapy is tailored to each patient. This highlights the need for new, highly sensitive and specific biomarkers for early PC diagnosis. Prognostic indicators are also required to stratify PC patients. To avoid ineffective treatment, adverse events, and expenses, biomarkers are also required for patient monitoring and identifying responders to treatment. There is substantial evidence that microRNAs (miRs, miRNAs) play a critical role in regulating mRNA and, as a consequence, protein expression in normal and malignant tissues. Deregulated miRNA profiling in PC can help with diagnosis, treatment planning, and prognosis. Furthermore, knowledge of the primary effector genes and downstream pathways in PC can help pinpoint potential miRNAs for use in treatment. Different miRNA expression profiles may serve as diagnostic, prognostic markers, and therapeutic targets across the spectrum of malignant pancreatic illness. Dysregulation of miRNAs has been linked to the malignant pathophysiology of PC through affecting many cellular functions such as increasing invasive and proliferative prospect, supporting angiogenesis, cell cycle aberrance, apoptosis elusion, metastasis promotion, and low sensitivity to particular treatments. Accordingly, in the current review, we summarize the recent advances in the roles of oncogenic and tumor suppressor (TS) miRNAs in PC and discuss their potential as worthy diagnostic and prognostic biomarkers for PC, as well as their significance in PC pathogenesis and anticancer drug resistance.

Long noncoding RNA CASC9 promotes pancreatic cancer progression by acting as a ceRNA of miR-497-5p to upregulate expression of CCND1

BACKGROUND

Pancreatic cancer (PC) is an aggressive malignancy with poor prognosis. Accumulating studies have showed that long non-coding RNA (lncRNA) is a crucial regulator in various tumorigenesis and progression including PC. This research aims to explore the roles and molecular mechanism of lncRNA cancer susceptibility candidate 9 (CASC9) in PC.

METHODS

The expression levels of lncRNA CASC9 and miR-497-5p were evaluated in PC tissues and paired adjacent healthy tissues by quantitative real-time PCR. PC cell lines were transfected with lentivirus targeting lncRNA CASC9, and cells proliferation, migration and invasion tests were conducted. Dual luciferase reporter assays were also carried out to explore the relationship between lncRNA CASC9, miR-497-5p and Cyclin D1 (CCND1).

RESULTS

LncRNA CASC9 was significantly up-regulated in PC tissues, while miR-497-5p expression was down-regulated. Down-regulation of lncRNA CASC9 in PC cells can significantly suppress the cell aggressiveness both in vitro and in vivo; moreover, knock-down of miR-497-5p could neutralize this impact. Additionally, the luciferase activity assay has assured that CCND1 was a downstream target of miR-497-5p.

CONCLUSION

LncRNA CASC9 can promote the PC progression by modulating miR-497-5p/CCND1 axis, which is potential target for PC treatment.

Crosstalk between long noncoding RNA and microRNA in Cancer

miRNAs and lncRNAs play a central role in cancer-associated gene regulations. The dysregulated expression of lncRNAs has been reported as a hallmark of cancer progression, acting as an independent prediction marker for an individual cancer patient. The interplay of miRNA and lncRNA decides the variation of tumorigenesis that could be mediated by acting as sponges for endogenous RNAs, regulating miRNA decay, mediating intra-chromosomal interactions, and modulating epigenetic components. This paper focuses on the influence of crosstalk between lncRNA and miRNA on cancer hallmarks such as epithelial-mesenchymal transition, hijacking cell death, metastasis, and invasion. Other cellular roles of crosstalks, such as neovascularization, vascular mimicry, and angiogenesis were also discussed. Additionally, we reviewed crosstalk mechanism with specific host immune responses and targeting interplay (between lncRNA and miRNA) in cancer diagnosis and management.

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.

A regulatory circuit of lncRNA NLGN1-AS1 and Wnt signalling controls clear cell renal cell carcinoma phenotypes through FZD4-modulated pathways

BACKGROUND

Recent evidence has indicated that long non-coding RNAs (lncRNAs) were emerged as key molecules in clear cell renal cell carcinoma (ccRCC). TCGA database showed that the expression level of lncRNA NLGN1-AS1 was up-regulated in ccRCC; However, whether NLGN1-AS1 implicated in the malignant progression of ccRCC remained unclear.

METHODS

Based on TCGA database, candidate lncRNAs were selected and quantitative real-time PCR (qRT-PCR) was utilized to verify the expression levels of candidate lncRNAs in human ccRCC tissues. Loss-of-function experiments were performed to examine the biological functions of NLGN1-AS1 both in vitro and in vivo. According to bioinformatics analysis, fluorescence reporter assays and rescue experiments, the underlying mechanisms of NLGN1-AS1 in ccRCC cell lines were so clearly understood.

RESULTS

As a novel lncRNA, NLGN1-AS1 was up-regulated in ccRCC cell lines and associated with poor prognosis of and ccRCC patients, which was correlated with the progression of ccRCC. Functionally, the down-regulation of NLGN1-AS1 significantly decreased the proliferation of ccRCC cells both in vitro and in vivo. Bioinformatics analysis and luciferase report assays identified that miR-136-5p was a direct target of NLGN1-AS1. We also determined that FZD4 were inhibitory targets of miR-136-5p, and that Wnt/β-catenin signaling was inhibited by both NLGN1-AS1 knockdown and miR-136-5p over-expression. In addition, we found that the suppression of proliferation and the inhibition of Wnt/β-catenin pathway induced by NLGN1-AS1 knockdown would require the over-expression of FZD4.

CONCLUSIONS

Our findings suggested that lncRNA NLGN1-AS1 could promote the progression of ccRCC by targeting miR-136-5p/FZD4 and Wnt/β-catenin pathway, and might serve as a novel potential therapeutic target to inhibit the progression of ccRCC.

LncRNAs as epigenetic regulators of epithelial to mesenchymal transition in pancreatic cancer

Pancreatic cancer is the leading cause of cancer-related mortality because of tumor metastasis. Activation of the epithelial-to-mesenchymal transition (EMT) pathway has been confirmed to be an important driver of pancreatic cancer progression from initiation to metastasis. Long noncoding RNAs (lncRNAs) have been reported to exert essential physiological functions in pancreatic cancer progression by regulating the EMT program. In this review, we have summarized the role of EMT-related lncRNAs in human pancreatic cancer and the potential molecular mechanisms by which lncRNAs can be vital epigenetic regulators of epithelial to mesenchymal transition. Specifically, EMT-activating transcription factors (EMT-TFs) regulate EMT via TGF-β/Smad, Wnt/β-catenin, and JAK/STAT pathways. In addition, the interaction between lncRNAs and HIF-1α and m6A RNA methylation also have an impact on tumor metastasis and EMT in pancreatic cancer. This review will provide insights into lncRNAs as promising biomarkers for tumor metastasis and potential therapeutic strategies for pancreatic cancer.

Strategies of LncRNA DLX6-AS1 on Study and Therapeutics

Accumulating evidence has revealed the vital regulatory roles of lncRNA DLX6-AS1 in various tumors at pre-transcriptional, transcriptional, and post-transcriptional levels, which makes it a potential prognosis factor and therapeutic target. In addition, the presence of lncRNA DLX6-AS1 in the exosomes of peripheral blood of patients with tumors may also contribute to it being a possible cancer-related biomarker. However, most literature studies are devoted to studying the effect of lncRNA DLX6-AS1 as a sponging molecule of miRNAs, the research of which is likely to get stuck into a dilemma. Literature studies published already have demonstrated an exciting cell malignant phenotype inhibition with the knockdown of lncRNA DLX6-AS1 in various tumor cell lines. With the comprehensive development of delivery systems, high-throughput sequencing, and aptamers, the problems of finding novel research methods and exploring the therapeutic options which are based on lncRNA DLX6-AS1 in vivo could come into a period to deal with. This review aims to summarize the research statuses of lncRNA DLX6-AS1, discuss other study methodologies and therapeutic strategies on it, which might be of help to the deep learning of lncRNA DLX6-AS1 and its application from basic to clinical research.

DLX6-AS1: A Long Non-coding RNA With Oncogenic Features

Long non-coding RNAs (lncRNAs) are a heterogeneous group of ncRNAs with characteristic size of more than 200 nucleotides. An increasing number of lncRNAs have been found to be dysregulated in many human diseases particularly cancer. However, their role in carcinogenesis is not precisely understood. DLX6-AS1 is an lncRNAs which has been unveiled to be up-regulated in various number of cancers. In different cell studies, DLX6-AS1 has shown oncogenic role via promoting oncogenic phenotype of cancer cell lines. Increase in tumor cell proliferation, migration, invasion, and EMT while suppressing apoptosis in cancer cells are the effects of DLX6-AS1 in development and progression of cancer. In the majority of cell experiment, mediator miRNAs have been identified which are sponged and negatively regulated by DLX6-AS1, and they in turn regulate expression of a number of transcription factors, eventually affecting signaling pathways involved in carcinogenesis. These pathways form axes through which DLX6-AS1 promotes carcinogenicity of cancer cells. Xenograft animal studies, also have confirmed enhancing effect of DLX6-AS1 on tumor growth and metastasis. Clinical evaluations in cancerous patients have also shown increased expression of DLX6-AS1 in tumor tissues compared to healthy tissues. High DLX6-AS1 expression has shown positive association with advanced clinicopathological features in cancerous patients. Survival analyses have demonstrated correlation between high DLX6-AS1 expression and shorter survival. In cox regression analysis, DLX6-AS1 has been found as an independent prognostic factor for patients with various types of cancer.

The Prognostic Value of the Developmental Gene FZD6 in Young Saudi Breast Cancer Patients: A Biomarkers Discovery and Cancer Inducers OncoScreen Approach

Wnt signalling receptors, Frizzleds (FZDs), play a pivotal role in many cellular events during embryonic development and cancer. Female breast cancer (BC) is currently the worldwide leading incident cancer type that cause 1 in 6 cancer-related death. FZD receptors expression in cancer was shown to be associated with tumour development and patient outcomes including recurrence and survival. FZD6 received little attention for its role in BC and hence we analysed its expression pattern in a Saudi BC cohort to assess its prognostic potential and unravel the impacted signalling pathway. Paraffin blocks from approximately 405 randomly selected BC patients aged between 25 and 70 years old were processed for tissue microarray using an automated tissue arrayer and then subjected to FZD6 immunohistochemistry staining using the Ventana platform. Besides, Ingenuity Pathway Analysis (IPA) knowledgebase was used to decipher the upstream and downstream regulators of FZD6 in BC. TargetScan and miRabel target-prediction databases were used to identify the potential microRNA to regulate FZD6 expression in BC. Results showed that 60% of the BC samples had a low expression pattern while 40% showed a higher expression level. FZD6 expression analysis showed a significant correlation with tumour invasion (p < 0.05), and borderline significance with tumour grade (p = 0.07). FZD6 expression showed a highly significant association with the BC patients’ survival outcomes. This was mainly due to the overall patients’ cohort where tumours with FZD6 elevated expression showed higher recurrence rates (DFS, p < 0.0001, log-rank) and shorter survival times (DSS, p < 0.02, log-rank). Interestingly, the FZD6 prognostic value was more potent in younger BC patients as compared to those with late onset of the disease. TargetScan microRNA target-prediction analysis and validated by miRabel showed that FZD6 is a potential target for a considerable number of microRNAs expressed in BC. The current study demonstrates a potential prognostic role of FZD6 expression in young BC female patients and provides a better understanding of the involved molecular silencing machinery of the Wnt/FZD6 signalling. Our results should provide a better understanding of FZD6 role in BC by adding more knowledge that should help in BC prevention and theranostics.

Pathway network of pyroptosis and its potential inhibitors in acute kidney injury

Acute kidney injury (AKI) is a worldwide problem, and there is no effective drug to eliminate AKI. The death of renal cells is an important pathological basis of intrinsic AKI. At present, targeted therapy for TEC death is a research hotspot in AKI therapy. There are many ways of cell death involved in the occurrence and development of AKI, such as apoptosis, necrosis, ferroptosis, and pyroptosis. This article mainly focuses on the role of pyroptosis in AKI. The assembly and activation of NLRP3 inflammasome is a key event in the occurrence of pyroptosis, which is affected by many factors, such as the activation of the NF-κB signaling pathway, mitochondrial instability and excessive endoplasmic reticulum (ER) stress. The activation of NLRP3 inflammasome can trigger its downstream inflammatory cytokines, which will lead to pyroptosis and eventually induce AKI. In this paper, we reviewed the possible mechanism of pyroptosis in AKI and the potential effective inhibitors of various key targets in this process. It may provide potential therapeutic targets for novel intrinsic AKI therapies based on pyroptosis, so as to develop better therapeutic strategies.

Circ-ACAP2 facilitates the progression of colorectal cancer through mediating miR-143-3p/FZD4 axis

BACKGROUND

Circular RNAs (circRNAs) play crucial roles in multiple cancers, including colorectal cancer (CRC). Here, we explored the role of circRNA ArfGAP with coiled-coil, ankyrin repeat and PH domains 2 (circ-ACAP2) in the progression and radioresistance of CRC.

METHODS

Quantitative real-time polymerase chain reaction (qPCR) and Western blot assay were used to detect RNA and protein expression, respectively. The proliferation, apoptosis, migration, invasion and radioresistance of CRC cells were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, transwell migration assay, transwell invasion assay and colony formation assay. The target interaction between microRNA-143-3p (miR-143-3p) and circ-ACAP2 or frizzled class receptor 4 (FZD4) was verified by dual-luciferase reporter assay. Murine xenograft model was established to explore the role of circ-ACAP2 in vivo.

RESULTS

The expression of circ-ACAP2 was prominently enhanced in CRC tissues and cell lines. Circ-ACAP2 facilitated the proliferation, migration, invasion and radioresistance whereas inhibited the apoptosis of CRC cells. MiR-143-3p was a direct target of circ-ACAP2 in CRC cells. Circ-ACAP2 promoted the progression and radioresistance of CRC partly by sponging miR-143-3p. MiR-143-3p interacted with the 3' untranslated region (3'UTR) of FZD4 in CRC cells, and FZD4 overexpression partly reversed miR-143-3p-mediated effects in CRC cells. Wnt/β-catenin signalling was modulated by circ-ACAP2/miR-143-3p/FZD4 axis in CRC cells.

CONCLUSION

Circ-ACAP2 contributed to the development and radioresistance of CRC partly through targeting miR-143-3p/FZD4 axis, which provided novel potential diagnostic and therapeutic targets for CRC.

Autophagy and gastrointestinal cancers: the behind the scenes role of long non-coding RNAs in initiation, progression, and treatment resistance

Gastrointestinal (GI) cancers comprise a heterogeneous group of complex disorders that affect different organs, including esophagus, stomach, gallbladder, liver, biliary tract, pancreas, small intestine, colon, rectum, and anus. Recently, an explosion in nucleic acid-based technologies has led to the discovery of long non-coding RNAs (lncRNAs) that have been found to possess unique regulatory functions. This class of RNAs is >200 nucleotides in length, and is characterized by their lack of protein coding. LncRNAs exert regulatory effects in GI cancer development by affecting different functions such as the proliferation and metastasis of cancer cells, apoptosis, glycolysis and angiogenesis. Over the past few decades, considerable evidence has revealed the important role of autophagy in both GI cancer progression and suppression. In addition, recent studies have confirmed a significant correlation between lncRNAs and the regulation of autophagy. In this review, we summarize how lncRNAs play a behind the scenes role in the pathogenesis of GI cancers through regulation of autophagy.

DLX6-AS1: a putative lncRNA candidate in multiple human cancers

Long non-coding RNAs (lncRNAs) have important roles in regulating the expression of genes and act as biomarkers in the initial development of different cancers. Increasing research studies have verified that dysregulation of lncRNAs occurs in various pathological processes including tumorigenesis and cancer progression. Among the different lncRNAs, DLX6-AS1 has been reported to act as an oncogene in the development and prognoses of different cancers, by affecting many different signalling pathways. This review summarises and analyses the recent research studies describing the biological functions of DLX6-AS1, its overall effect on signalling pathways and the molecular mechanisms underlying its action on the expression of genes in multiple human cancers. Our critical analysis suggests that different signalling pathways associated to this lncRNA may be used as a biomarker for diagnosis, or targets of treatment in cancers.

miR‑497/MIR497HG inhibits glioma cell proliferation by targeting CCNE1 and the miR‑588/TUSC1 axis

Emerging evidence has shown that microRNA (miR)-497 serves pivotal roles in tumorigenesis, cancer progression, metastasis and chemotherapy resistance in several types of cancer. In the present study, the expression and biological functions of miR-497 host gene (MIR497HG) were investigated in glioma tissue. The expression levels of miR-497 and MIR497HG were measured in glioma, adjacent non-cancerous and normal brain tissue and their association with the prognosis of patients with glioma were analyzed. The biological roles of miR-497 and MIR497HG were investigated in glioma cell lines. In addition, bioinformatics analysis, luciferase reporter assay and functional experiments were performed to identify and validate the downstream targets of miR-497 or MIR497HG. The expression levels of miR-497 and MIR497HG were downregulated in glioma tissue and cell lines compared with those in adjacent non-cancerous and normal brain tissue and normal human cortical neuron cell line. Patients with low miR-497 or MIR497HG expression levels exhibited a poor prognostic outcome. In addition, forced overexpression of miR-497 or MIR497HG significantly inhibited the proliferation and cell cycle progression of glioma cell lines. Furthermore, the results indicated that miR-497 and MIR497HG exerted their biological functions by direct targeting of cyclin E1 and miR-588/tumor suppressor candidate 1. In summary, the data indicated that miR-497 and MIR497HG served as tumor suppressors and may be used as potential therapeutic targets and prognostic biomarkers in glioma.

Wnt Signaling Pathway Is among the Drivers of Liver Metastasis

Liver metastasis, originating either from a primary liver or other cancer types, represent a large cancer-related burden. Therefore, studies that add to better understanding of its molecular basis are needed. Herein, the role of the Wnt signaling pathway in liver metastasis is outlined. Its role in hepatocellular carcinoma (HCC) epithelial-mesenchymal transition (EMT), motility, migration, metastasis formation, and other steps of the metastatic cascade are presented. Additionally, the roles of the Wnt signaling pathway in the liver metastasis formation of colorectal, breast, gastric, lung, melanoma, pancreatic, and prostate cancer are explored. The special emphasis is given to the role of the Wnt signaling pathway in the communication between the many of the components of the primary and secondary cancer microenvironment that contribute to the metastatic outgrowth in the liver. The data presented herein are a review of the most recent publications and advances in the field that add to the idea that the Wnt pathway is among the drivers of liver metastasis and that its targeting could potentially relieve liver metastasis–related complications.

Non-Coding RNA and Frizzled Receptors in Cancer

Frizzled receptors have been long recognized for their role in Wnt/β-catenin signaling, a pathway known for its tumorigenic effects. More recent studies of frizzled receptors include efforts to understand non-coding RNA (ncRNA) regulation of these receptors in cancer. It has become increasingly clear that ncRNA molecules are important for regulating the expression of both oncogenic and tumor-suppressive proteins. The three most commonly described ncRNA molecules are microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs). Here, we review ncRNA molecules that directly or indirectly affect frizzled protein expression and downstream signaling. Exploring these interactions highlights the potential of incorporating ncRNA molecules into cancer prevention and therapy strategies that target frizzled receptors. Previous investigations of frizzled receptors and ncRNA have established strong promise for a role in cancer progression, but additional studies are needed to provide the substantial pre-clinical evidence required to translate findings to clinical applications.

CircRASSF2 facilitates the proliferation and metastasis of colorectal cancer by mediating the activity of Wnt/β-catenin signaling pathway by regulating the miR-195-5p/FZD4 axis

Circular RNAs (circRNA) are a key regulator of cancer progression, including colorectal cancer (CRC). Nevertheless, the role of circRASSF2 in CRC remains unclear. Quantitative real-time PCR was used to measure the expression of circRASSF2 and miR-195-5p. Cell counting kit 8 assay, colony formation assay, flow cytometry and transwell assay were used to determine the proliferation, apoptosis, migration and invasion of cells, respectively. The levels of proliferation, metastasis and Wnt/β-catenin signaling pathway-related proteins, as well as Frizzled 4 (FZD4) protein, were determined using western blot analysis. Furthermore, a dual-luciferase reporter assay, RNA immunoprecipitation assay and RNA pull-down assay were used to illumine the mechanism of circRASSF2. Animal experiments were used to determine the role of circRASSF2 in the tumor growth of CRC in vivo. Our study reported that circRASSF2 was upregulated in CRC tissues and cells, and its high expression was related to the poor prognosis of CRC patients. CircRASSF2 knockdown could inhibit proliferation, migration, invasion, and enhance apoptosis in CRC cells, and its overexpression had the opposite effect. Besides, our data revealed that circRASSF2 could sponge miR-195-5p, and miR-195-5p could target FZD4. The rescue experiments indicated that both miR-195-5p inhibitor and FZD4 overexpression could reverse the negative regulation of circRASSF2 silencing on CRC progression. Moreover, circRASSF2 could positively regulate the activity of Wnt/β-catenin signaling pathway by the miR-195-5p/FZD4 axis. In addition, circRASSF2 knockdown restrained the tumor growth of CRC in vivo. Our findings suggested that circRASSF2 might function as a tumor promoter to accelerate the progression of CRC via regulating the miR-195-5p/FZD4/Wnt/β-catenin pathway.

Research progress of DLX6-AS1 in human cancers

Long non-coding RNAs (lncRNAs) are a kind of translational-repressor RNAs composed of more than 200 nucleotides and formerly considered as "transcriptional noise". Recently studies have shown that lncRNAs could bind to multiple biomolecules such as DNA, transcription factors, RNA, chromatin complexes and proteins, and regulate target gene expression at multi-levels, thus playing an essential role in human tumors. DLX6-AS1, a recently discovered oncogenic lncRNA, is highly expressed in various human tumors, including lung cancer, liver cancer and pancreatic cancer. This paper mainly reviewed the regulatory mechanism of DLX6-AS1 as a competitive endogenous RNA (ceRNA) in tumor cell proliferation, cell apoptosis, angiogenesis, epithelial-mesenchymal transformation, chemotherapy resistance and metabolic changes. Furthermore, the translational value of DLX6-AS1 in cancer was also elucidated, which suggested its potential as a diagnostic or prognostic biomarker in cancer. In summary, this present article not only makes an in-depth analysis of the expression changes and carcinogenic mechanism of DLX6-AS1 in various human cancers, but also provides a new breakthrough for the diagnosis and treatment of cancers.

Circ_0003972 Promotes the Proliferation and Inflammation of Fibroblast-like Synovial Cells in Rheumatoid Arthritis through Regulation of the miR-654-5p/FZD4 Axis

BACKGROUND

Circular RNAs (circRNAs) have been shown to play an important role in rheumatoid arthritis (RA) progression. This study aims to explore the role and mechanism of circ_0003972 in RA progression.

METHODS

Quantitative real-time PCR was used to determine gene expression. The proliferation and apoptosis of human RA fibroblast-like synovial (HFLS-RA) cells were measured using cell counting kit 8 assay, EdU staining and flow cytometry. Western blot analysis was performed to measure protein expression, and ELISA assay was used to examine the concentrations of inflammation factors. The interaction between miR-654-5p and circ_0003972 or FZD4 was confirmed by dual-luciferase reporter assay and RIP assay.

RESULTS

Circ_0003972 was highly expressed in RA patients and HFLS-RA cells. Circ_0003972 knockdown inhibited the proliferation, inflammation, while promoted the apoptosis of TNFα-induced HFLS-RA cells. MiR-654-5p was downregulated in RA patients and HFLS-RA cells, and it could be sponged by circ_0003972. MiR-654-5p inhibitor reversed the effect of circ_0003972 silencing on the proliferation, inflammation, and apoptosis of TNFα-induced HFLS-RA cells. Frizzled-4 (FZD4) could be targeted by miR-654-5p, and its expression was positively regulated by circ_0003972. Furthermore, FZD4 overexpression also reversed the effects of miR-654-5p on proliferation, inflammation and apoptosis in TNFα-induced HFLS-RA cells.

CONCLUSION

Our data suggested that circ_0003972 might promote the proliferation and inflammation of HFLS-RA cells to accelerate RA progression via regulating miR-654-5p/FZD4.

DLX6-AS1: An Indispensable Cancer-related Long Non-coding RNA

BACKGROUND

There is increasing evidence that lncRNA, a type of transcript that is over 200 nucleotides in length and may serve as oncogenes or suppressor genes, is implicated in the pathophysiology of human diseases. In particular, tumorigenesis and progress are closely correlated with its abnormal expression. In addition, it may become a promising target for many oncology biotherapies. Abnormal DLX6-AS1 expression affects different cellular processes such as proliferation, aggression and metastasis. This review aims to probe into the pathophysiological functions and molecular mechanisms of DLX6-AS1 in various cancers.

METHODS

By retrieving the literature, this review summarizes the biological function and mechanism of LncRNA DLX6-AS1 in tumor occurrence.

RESULTS

The lncRNA DLX6-AS1 is a new tumor-related RNA that has recently been found to be aberrantly expressed in diverse cancers, such as pancreatic cancer, osteosarcoma, non-small cell lung cancer, gastric carcinoma, glioma, hepatocellular cancer, colorectal carcinoma, renal carcinoma, esophageal squamous cell cancer, ovarian cancer, Ewing sarcoma, cervical cancer, breast cancer, thyroid cancer, neuroblastoma, pulmonary adenocarcinoma, nasopharyngeal carcinoma, squamous laryngeal cancer and bladder cancer, etc. Meanwhile, it is identified that DLX6-AS1 regulates the aggression, translocation and proliferation of diverse cancers.

CONCLUSION

LncRNA DLX6-AS1 may be viable markers in tumors or a potential therapeutic target for multiple tumors.

Regulation of Hippo, TGFβ/SMAD, Wnt/β-Catenin, JAK/STAT, and NOTCH by Long Non-Coding RNAs in Pancreatic Cancer

Rapidly evolving and ever-increasing knowledge of the molecular pathophysiology of pancreatic cancer has leveraged our understanding altogether to a next level. Compared to the exciting ground-breaking discoveries related to underlying mechanisms of pancreatic cancer onset and progression, however, there had been relatively few advances in the therapeutic options available for the treatment. Since the discovery of the DNA structure as a helix which replicates semi-conservatively to pass the genetic material to the progeny, there has been conceptual refinement and continuous addition of missing pieces to complete the landscape of central dogma. Starting from transcription to translation, modern era has witnessed non-coding RNA discovery and central role of these versatile regulators in onset and progression of pancreatic cancer. Long non-coding RNAs (lncRNAs) have been shown to act as competitive endogenous RNAs through sequestration and competitive binding to myriad of microRNAs in different cancers. In this article, we set spotlight on emerging evidence of regulation of different signaling pathways (Hippo, TGFβ/SMAD, Wnt/β-Catenin, JAK/STAT and NOTCH) by lncRNAs. Conceptual refinements have enabled us to understand how lncRNAs play central role in post-translational modifications of various proteins and how lncRNAs work with epigenetic-associated machinery to transcriptionally regulate gene network in pancreatic cancer.

Long noncoding RNAs: role and contribution in pancreatic cancer

Noncoding RNAs are proclaimed to be expressed in various cancer types and one such type is found to be pancreatic ductal adenocarcinoma (PDAC). The long noncoding RNAs (LncRNAs) affect the migration, invasion, and growth of tumor cells by playing important roles in the process of epigenesis, post-transcription, and transcriptional regulation along with the maintenance of apoptosis and cell cycle. It is quite subtle whether the alterations in lncRNAs would impact PDAC progression and development. This review throws a spotlight on the lncRNAs associated with tumor functions: MALAT-1, HOTAIR, HOXA13, H19, LINC01559, LINC00460, SNHG14, SNHG16, DLX6-AS1, MSC-AS1, ABHD11-AS1, DUXAP8, DANCR, XIST, DLEU2, etc. are upregulated lncRNAs whereas GAS5, HMlincRNA717, MIAT, LINC01111, lncRNA KCNK15-AS1, etc. are downregulated lncRNAs inhibiting the invasion and progression of PDAC. These data provided helps in the assessment of lncRNAs in the development, metastasis, and occurrence of PDAC and also play a vital role in the evolution of biomarkers and therapeutic agents for the treatment of PDAC.

Knockdown of LncRNA PANDAR by CRISPR-dCas9 Decreases Proliferation and Increases Apoptosis in Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is the most common malignant epithelial tumor in the oral cavity. Emerging evidence has demonstrated the important function roles of long noncoding RNAs (lncRNAs) in human cancers. LncRNA promoter of CDKN1A antisense DNA damage activated RNA (PANDAR) functions as an oncogene in multiple carcinomas, whereas its function in OSCC has not been investigated yet. The aim of our study is to investigate the possible regulatory mechanism of PANDAR in OSCC. First of all, PANDAR was highly expressed in OSCC cells and loss-of-function assays mediated by CRISPR-dCas9 observed that PANDAR silencing restrained cell proliferation and promoted cell apoptosis. Then we found and confirmed the interaction between PANDAR and serine and arginine rich splicing factor 7 (SRSF7). Subsequently, serine/threonine-protein kinase pim-1 (PIM1) was proved to be regulated by PANDAR in SRSF7-dependant way. Rescue experiments validated that PANDAR modulated the proliferation and apoptosis in OSCC through PIM1. In conclusion, PANDAR bound with SRSF7 to increase PIM1 expression, hence promoting the development of OSCC. These data shed new lights into the seeking for effective diagnostic biomarkers and therapeutic targets for OSCC patients.

RETRACTED: Exosomal miR-22-3p from human umbilical cord blood-derived mesenchymal stem cells protects against lipopolysaccharid-induced acute lung injury

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Concern was raised about the reliability of the Western blot results in Figs. 2D/H/L, and 7B/F, which appear to have the same eyebrow shaped phenotype as many other publications tabulated here (https://docs.google.com/spreadsheets/d/149EjFXVxpwkBXYJOnOHb6RhAqT4a2llhj9LM60MBffM/edit#gid=0). Concerns were also raised over the provenance of the flow cytometry plots in Fig. 1C. The journal requested the corresponding author comment on these concerns and provide the raw data. However the authors were not able to satisfactorily fulfil this request and therefore the Editor-in-Chief decided to retract the article.

MicroRNA-935 Directly Targets FZD6 to Inhibit the Proliferation of Human Glioblastoma and Correlate to Glioma Malignancy and Prognosis

MicroRNAs (miRNAs) are involved in human glioblastoma (GB). MiR-935 has been reported to have both tumor-inhibiting and tumorigenesis effects, but its role in GB remains unclear. Because of the high mortality and morbidity associated with the malignancy of GB, a deeper understanding of the molecular crosstalk that occurs in GB is needed to identify new potential targets for treatment. At present, the mechanism of GB at the molecular level is not fully understood. With the aid of bioinformatic analysis, miR-935 was significantly downregulated in GB, and it presented a poorer outcome. In the glioma cell line and in the nude mice model, the miR-935 inhibited cell proliferation by modulating cell circles in vitro and in vivo. Then, the target genes of miR-935 were analyzed by using the online database, and the direct binding was tested with a luciferase analysis. FZD6 was found to be the direct target of miR-935. The effect of miR-935 was recovered by the overexpression of FZD6 in vitro. In addition, the negative correlation of miR-935 and the expression of FZD6 were confirmed in our clinical samples, and the expression of FZD6 has a strong correlation with tumor malignancy and prognosis. This study showed that miR-935 directly inhibited the expression of FZD6 and inhibited the cell proliferation, thereby suppressing the development of GB, suggesting that miR-935 is a cancer suppressor miRNA and may become a prognostic biomarker or a promising potential therapeutic target for human GBs.

Involvement of Long Non-Coding RNAs in Glucose Metabolism in Cancer

The rapid and uncontrolled proliferation of cancer cells is supported by metabolic reprogramming. Altered glucose metabolism supports cancer growth and progression. Compared with normal cells, cancer cells show increased glucose uptake, aerobic glycolysis and lactate production. Byproducts of adjusted glucose metabolism provide additional benefits supporting hallmark capabilities of cancer cells. Long non-coding RNAs (lncRNAs) are a heterogeneous group of transcripts of more than 200 nucleotides in length. They regulate numerous cellular processes, primarily through physical interaction with other molecules. Dysregulated lncRNAs are involved in all hallmarks of cancer including metabolic alterations. They may upregulate metabolic enzymes, modulate the expression of oncogenic or tumor-suppressive genes and disturb metabolic signaling pathways favoring cancer progression. Thus, lncRNAs are not only potential clinical biomarkers for cancer diagnostics and prediction but also possible therapeutic targets. This review summarizes the lncRNAs involved in cancer glucose metabolism and highlights their underlying molecular mechanisms.

Expression and prognostic impact of FZDs in pancreatic adenocarcinoma

Background

Despite the high number of researches on pancreatic adenocarcinoma (PAAD) over past decades, little progress had been made due to lack of effective treatment regimens. We aimed to investigate the expression level, mutation, and clinical significance of the Frizzled (FZD) family in PAAD so as to establish a sufficient scientific evidence for clinical decisions and risk management.

Methods

PAAD samples were extracted from The Cancer Genome Atlas (TCGA). Oncomine, Gene expression profiling interactive analysis (GEPIA), human protein atlas (HPA), Kaplan–Meier Plotter, cBioPortal, LinkedOmics, DAVID database, and R software (× 64 3.6.2) were used to comprehensively analyze the roles of FZDs. p value below to 0.05 was considered as significant difference.

Results

In total, 179 PAAD tissues and 171 paracancerous tissues were included. The expression levels of FZD1, 2, 6, 7, and 8 were higher in PAAD tissues than those in normal pancreatic tissue. The higher the expression levels of FZD2 and FZD7, the higher the clinical stage. The overall survival (OS) time was significantly different between low FZD3, 4, 5, 6, and 9 expression group and high expression group. Multivariable analysis showed that FZD3 and FZD6 were independent prognostic factors. The recurrence free survival (RFS) time was significantly different between low FZD4 and FZD8 expression group and high expression group. The RFS difference between low FZD6 expression group and high expression group had not reached statistical significance (p = 0.067), which might be due to the small sample size. However, multivariable analysis showed that FZD6 was the only independent factor for RFS. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that FZDs played a critical role in the Wnt signaling pathway, which was further confirmation that FZDs were transmembrane receptors of Wnt signaling pathway.

Conclusions

Our results strongly indicated a crucial role of the FZD family in PAAD. FZD3 and FZD6 could be potential prognostic and predictive markers, and FZD6 might also function as a potential therapeutic target in PAAD by blocking Wnt/β-catenin pathway.

DLX6-AS1 is a potential biomarker and therapeutic target in cancer initiation and progression

Long noncoding RNAs (lncRNAs) are involved in multiple functions such as the regulation of cellular homeostasis. They play prominent roles in the pathogenesis of human cancer, and contribute to every hallmark of cancer. The novel cancer-related lncRNA DLX6 antisense RNA 1 (DLX6-AS1) plays an essential regulatory role in enhancing and initiating carcinogenesis and tumor progression. This progression is due to the aberrant regulation of downstream factors in vitro as well as in vivo. DLX6-AS1 is significantly dysregulated in various cancers. DLX6-AS1 functions in tumor initiation and progression are regulated at the epigenetic, transcription, and posttranscriptional regulation levels. DLX6-AS1 functions as an oncogene, binding to miRNA targeting sites competing endogenous RNAs and causing the upregulation of downstream tumor-related genes and carcinogenesis. The regulation and detailed molecular mechanisms of DLX6-AS1 and its potential role in malignancies are comprehensively described in this paper. DLX6-AS1 has the potential to become a novel biomarker and therapeutic target for cancer.

Serum Exosomal lncRNA DLX6-AS1 Is a Promising Biomarker for Prognosis Prediction of Cervical Cancer

Objective:

Deregulation of long noncoding RNAs (lncRNAs) is involved in the initiation and progression of cancer. LncRNA DLX6-AS1 is regarded as an oncogene in many cancer types. However, the clinical role of serum exosomal lncRNA DLX6-AS1 in cervical cancer (CC) is poorly known. This study aimed to analyze the diagnostic and prognostic value of serum exosomal lncRNA DLX6-AS1 in CC.

Methods:

A total of 114 patients with CC, 60 patients with CIN (cervical intraepithelial neoplasia), and 110 healthy women were enrolled in this study. Real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed to measure the serum exosomal lncRNA DLX6-AS1 levels in all participants.

Results:

Serum exosomal lncRNA DLX6-AS1 level was significantly elevated in CC patients compared with CIN patients and normal controls. In addition, high serum exosomal lncRNA DLX6-AS1 expression was positively associated with lymph node metastasis, differentiation, FIGO stage, and shortened survival. Patients with high serum exosomal lncRNA DLX6-AS1 expression were more prone to have a relapse. Furthermore, univariate and multivariate analyses suggested that serum exosomal lncRNA DLX6-AS1 was a potential prognostic indicator for overall survival of CC patients.

Conclusions:

These findings demonstrated that serum lncRNA DLX6-AS1 might serve as a promising marker for the diagnosis and prognosis prediction of CC.

MiR-302b Suppresses Tumor Metastasis by Targeting Frizzled 6 in OSCC

Oral squamous cell carcinoma (OSCC) accounts for approximately 90% of malignant epithelial tumors of the oral and maxillofacial region. OSCC has high rate of metastasis and poor prognosis. Tobacco and/or alcohol consumption and human papillomavirus infection are relatively exact susceptibility factors for OSCC, but the specific process of oral mucosal carcinogenesis and progression is very complicated. microRNA-302b (miR-302b) could regulate various characteristics of many tumor cells, such as proliferation and apoptosis, but its role and mechanism in OSCC have not been reported. This research aims to study the effect of miR-302b on the invasion and migration ability of OSCC and the mechanism by which it functions as well as to identify new prognostic indicators and therapeutic targets for OSCC patients. Functional studies showed that the miR-302b level was negatively correlated with the invasion and migration ability of OSCC. The studies also showed that the overexpression of miR-302b could attenuate the invasion and migration ability of OSCC cells and reduce lymphangiogenesis and the lung metastasis rate of OSCC cells in a mouse model. Mechanistic studies were performed by quantitative polymerase chain reactions, luciferase assays, and RNA pull-down experiments. The results verified that frizzled class receptor 6 (FZD6) is a target gene of miR-302b in OSCC that could promote cell invasion and migration. Clinical studies demonstrate that the protein expression level of FZD6 was higher in OSCC and metastatic lymph nodes than in normal oral mucosa epithelium. Taken together, these data showed that miR-302b could inhibit the invasion and migration ability of OSCC cells by targeting and downregulating FZD6, thereby inhibiting OSCC metastasis. As a new target gene of miR-302b, FZD6 has the potential to become a prognostic and therapeutic target for OSCC patients.

Regulation of Wnt Signaling Pathways at the Plasma Membrane and Their Misregulation in Cancer

Wnt signaling is one of the key signaling pathways that govern numerous physiological activities such as growth, differentiation and migration during development and homeostasis. As pathway misregulation has been extensively linked to pathological processes including malignant tumors, a thorough understanding of pathway regulation is essential for development of effective therapeutic approaches. A prominent feature of cancer cells is that they significantly differ from healthy cells with respect to their plasma membrane composition and lipid organization. Here, we review the key role of membrane composition and lipid order in activation of Wnt signaling pathway by tightly regulating formation and interactions of the Wnt-receptor complex. We also discuss in detail how plasma membrane components, in particular the ligands, (co)receptors and extracellular or membrane-bound modulators, of Wnt pathways are affected in lung, colorectal, liver and breast cancers that have been associated with abnormal activation of Wnt signaling. Wnt-receptor complex components and their modulators are frequently misexpressed in these cancers and this appears to correlate with metastasis and cancer progression. Thus, composition and organization of the plasma membrane can be exploited to develop new anticancer drugs that are targeted in a highly specific manner to the Wnt-receptor complex, rendering a more effective therapeutic outcome possible.

Promising long noncoding RNA DLX6-AS1 in malignant tumors

Although its diagnosis and treatment have greatly improved in recent decades, cancer remains the major cause of death worldwide. Thus, there is an urgent need to find novel biomarkers and therapeutic targets to improve efficiency of diagnosis and treatment of patients with cancer. Long noncoding RNAs (lncRNAs), a new class of noncoding RNAs (ncRNAs), have been found to play a salient role in human tumorigenesis and progression. Distal-less homeobox 6 antisense RNA 1 (DLX6-AS1) is a novel lncRNA with aberrant expression in various cancers tissues and cell lines compared with nontumor tissues and normal cell lines. Importantly, DLX6-AS1 is closely associated with tumor cell proliferation, apoptosis, invasion, and migration. Patients with high DLX6-AS1 expression often had poorer prognosis than those with low expression. The oncogenicity of DLX6-AS1 mainly (indirectly or indirectly) interacts with targeting genes, and then regulates downstream genes and signaling pathways. Together with the findings of animal model studies, these data suggest that DLX6-AS1 may serve as a feasible predictor or therapeutic target in different cancers. Herein, we summarize the main findings concerning the function and molecular mechanisms of DLX6-AS1 to identify a molecular basis for future clinical application.

Regulation of microRNA-497 expression in human cancer

MicroRNAs (miRNAs/miRs) are a type of non-coding single-stranded RNA, with a length of ~22 nt, which are encoded by endogenous genes and are involved in the post-transcriptional regulation of gene expression in animals and plants. Studies have demonstrated that miRNAs play an important role in the occurrence, development, metastasis, diagnosis and treatment of cancer. In recent years, miR-497 has been identified as one of the key miRNAs in a variety of cancer types and has been shown to be downregulated in a variety of solid tumors. However, the regulation of miR-497 expression involves a complex network, which is affected by several factors. The aim of the present review was to summarize the mechanism of regulation of miR-497 expression at the pre-transcriptional and transcriptional levels in cancer, as well as the role of miR-497 expression imbalance in cancer diagnosis, treatment and prognosis. The regulatory mechanisms of miR-497 expression may aid in our understanding of the causes of miR-497 expression imbalance and provide a reference value for further research on the diagnosis and treatment of cancer.

Crosstalk between long non-coding RNA DLX6-AS1, microRNAs and signaling pathways: A pivotal molecular mechanism in human cancers

Long non-coding RNAs (lncRNAs) are a type of non-protein coding RNA, which have been found to play multiple roles in various molecular and cellular processes by epigenetic regulation of gene expression at post transcriptional levels. LncRNAs may act either as an oncogene or as a tumor suppressor gene in different cancers. Aberrant expression and dysregulation of lncRNAs has been correlated with cancer development and tumor growth via several different signaling pathways. Therefore, lncRNAs could serve as diagnostic biomarkers and as therapeutic targetes in many human cancers. Previous studies have reported that dysregulated expression of the lncRNA called DLX6-AS1 in various cancer types, such as lung, colorectal, bladder, ovarian, hepatocellular, pancreatic and gastric. DLX6-AS1 plays an important role in tumorigenesis by affecting cell proliferation, migration, invasion, EMT, and apoptosis. DLX6-AS1 exerts these regulatory effects by interfering with various microRNA axes and signaling pathways including, Wnt/βcatenin, Notch, P13/AKT/mTOR, and STAT3. This review focuses on the possible mechanisms by which DLX6-AS1 regulates tumor initiation and progression. Accordingly, DLX6-AS1 may act as a novel potential biomarker for cancer diagnosis or therapy in future.

ceRNA network development and tumour-infiltrating immune cell analysis of metastatic breast cancer to bone

PURPOSE

Advanced breast cancer commonly metastasises to bone; however, the molecular mechanisms underlying the affinity for breast cancer cells to bone remains unclear. Thus, we developed nomograms based on a competing endogenous RNA (ceRNA) network and analysed tumour-infiltrating immune cells to elucidate the molecular pathways that may predict prognosis in patients with breast cancer.

METHODS

We obtained the RNA expression profile of 1091 primary breast cancer samples included in The Cancer Genome Atlas database, 58 of which were from patients with bone metastasis. We analysed the differential RNA expression patterns between breast cancer with and without bone metastasis and developed a ceRNA network. Cibersort was employed to differentiate between immune cell types based on tumour transcripts. Nomograms were then established based on the ceRNA network and immune cell analysis. The value of prognostic factors was evaluated by Kaplan-Meier survival analysis and a Cox proportional risk model.

RESULTS

We found significant differences in long non-coding RNAs (lncRNAs), 18 microRNAs (miRNAs), and 20 messenger RNAs (mRNAs) between breast cancer with and without bone metastasis, which were used to construct a ceRNA network. We found that the protein-coding genes GJB3, CAMMV, PTPRZ1, and FBN3 were significantly differentially expressed by Kaplan-Meier analysis. We also observed significant differences in the abundance of plasma cell and follicular helper T cell populations between the two groups. In addition, the proportion of mast cells, gamma delta T cells, and plasma cells differed depending on disease location and stage. Our analysis showed that a high proportion of follicular helper T cells and a low proportion of eosinophils promoted survival and that DLX6-AS1, Wnt6, and GABBR2 expression may be associated with bone metastasis in breast cancer.

CONCLUSIONS

We developed a bioinformatic tool for exploring the molecular mechanisms of bone metastasis in patients with breast cancer and identified factors that may predict the occurrence of bone metastasis.

lncRNA SNHG5 promotes cell proliferation, migration and invasion in oral squamous cell carcinoma by sponging miR-655-3p/FZD4 axis

Recently, previous studies have shown that long non-coding RNA (lncRNA) can act as a tumor promoter or inhibitor in the pathogenesis of oral squamous cell carcinoma (OSCC). However, the regulatory mechanism of lncRNA SNHG5 is unknown in OSCC. Therefore, the functional mechanism of lncRNA SNHG5 in OSCC was initially revealed in this study. Here, RT-qPCR and western blot analysis were used to assess mRNA and protein expression. The functional mechanism of SNHG5 was investigated by MTT, Transwell and luciferase reporter assays. The results showed that SNHG5 expression was upregulated in OSCC and promoted the viability, migration and invasion of OSCC cells. In addition, SNHG5 is the sponge of miR-655-3p in OSCC. And miR-655-3p was found to play an inhibitory effect in OSCC by interacting with SNHG5. Moreover, miR-655-3p directly targets FZD4 and negatively regulates its expression in OSCC. Functionally, FZD4 promoted the progression of OSCC by interacting with the SNHG5/miR-655-3p axis. In conclusion, lncRNA SNHG5 promotes cell proliferation, migration and invasion in OSCC by regulating miR-655-3p/FZD4 axis.

The Search for Molecular Markers in a Gene-Orphan Case Study of a Pediatric Spinal Cord Pilocytic Astrocytoma

BACKGROUND/AIM

We herein presented a case of pediatric spinal cord pilocytic astrocytoma diagnosed on the basis of histopathological and clinical findings.

MATERIALS AND METHODS

Given the paucity of data on genetic features for this tumor, we performed exome, array CGH and RNA sequencing analysis from nucleic acids isolated from a unique and not repeatable very small amount of a formalin-fixed, paraffin-embedded (FFPE) specimen.

RESULTS

DNA mutation analysis, comparing tumor and normal lymphocyte peripheral DNA, evidenced few tumor-specific single nucleotide variants in DEFB119, MUC5B, NUDT1, LTBP3 and CPSF3L genes. Differently, tumor DNA was not characterized by for the main pilocytic astrocytoma gene variations, including BRAFV600E. An inframe trinucleotides insertion involving DLX6 or lnc DLX6-AS1 genes was scored in 44.9% of sequenced reads; the temporal profile of this variation on the expression of DLX-AS1 was investigated in patient's urine-derived exosomes, reporting no significant variation in the one-year molecular follow-up. Array CGH identified a tumor microdeletion at the 6q25.3 chromosomal region, spanning 1,01 Mb and comprising ZDHHC14, SNX9, TULP4 and SYTL3 genes. The expression of these genes did not change in urine-derived exosomes during the one-year investigation period. Finally, RNAseq did not reveal any of the common pilocytic BRAF-KIAA1549 genes fusion events.

CONCLUSION

To our knowledge, the present report is one of the first described gene-orphan case studies of a pediatric spinal cord pilocytic astrocytoma.

LncRNA DLX6-AS1 as a potential molecular biomarker in the clinicopathology and prognosis of various cancers: a meta-analysis

Objective: Recent studies have shown that distal-less homeobox 6 antisense 1 (DLX6-AS1) is aberrantly expressed in various cancers and is associated with poor prognosis. This meta-analysis is designed to investigate the effects of DLX6-AS1 expression on clinicopathological features and survival outcomes. Methods: All eligible studies were searched from Pubmed, Web of Science, Embase, the Cochrane Library, and Wanfang database, up to August 2019. The literature was selected according to the inclusion and exclusion criteria listed in this work, and the quality of each eligible study was assessed. Each patient’s clinicopathological features and survival data were analyzed using Stata12.0 software. Begg’s test and sensitivity analysis were also conducted. Results: A total of 12 articles were included, covering 841 patients. Results showed that high expression of DLX6-AS1 was significantly closely associated with poor overall survival in tumor patients (hazard ratio (HR) = 2.30, confidence interval (95% CI): 1.70–3.09, P<0.01). This meta-analysis also showed that overexpression of DLX6-AS1 was significantly associated with tumor stage (P<0.01), tumor size (P<0.01), lymph node metastasis (P<0.01), and distant metastasis (P<0.01). Begg’s test suggested no publication bias. Conclusion: This meta-analysis revealed that high expression of DLX6-AS1 was related to the advanced clinicopathological characteristics of human digestive system cancers (gastric cancer, esophageal cancer, colon cancer, pancreatic cancer, and hepatocellular carcinoma) and other cancers such as ovarian cancer, osteosarcoma and non-small cell lung cancer, and DLX6-AS1 has important predictive value for poor prognosis. However, more studies are needed to further corroborate these findings.

Knockdown of LncRNA DLX6-AS1 inhibits HK-2 cell pyroptosis via regulating miR-223-3p/NLRP3 pathway in lipopolysaccharide-induced acute kidney injury

Sepsis-induced acute kidney injury (AKI) represents a severe medical complication. Recently, there is growing evidence indicating the regulatory role of long non-coding RNAs (lncRNAs) in AKI pathophysiology. The present study investigated lncRNA DLX6 antisense RNA 1 (DLX6-AS1) expression in septic AKI patients and to decipher the relevant mechanisms underlying DLX6-AS1-mediated HK-2 cell pyroptosis in lipopolysaccharide (LPS)-induced AKI. The results revealed that DLX6-AS1 was up-regulated in the serum from septic AKI patients. DLX6-AS1 expression were positively associated with the creatinine levels in the serum from the septic AKI patients. In vitro studies showed that LPS induced cytotoxicity and enhanced DLX6-AS1 expression of HK-2 cells; increased NLR family pyrin domain containing 3 (NLRP3), interleukin (IL)-1β and IL-18 expression. DLX6-AS1 overexpression promoted cytotoxicity and pyroptosis of HK-2 cells; while DLX6-AS1 knockdown counteracted the LPS-induced cytotoxicity and pyroptosis of HK-2 cells. More importantly, DLX6-AS1 sponged miR-223-3p resulting in repression of miR-223-3p expression in HK-2 cells. MiR-223-3p could bind to the 3' untranslated region of NLRP3, which results in the suppressed NLRP3 expression of HK-2 cells. Further rescue experiments showed that enhanced miR-223-3p expression partially reversed the cytotoxicity and pyroptosis of HK-2 cells upon LPS stimulation or with DLX6-AS1 overexpression. Conclusively, this study identified enhanced DLX6-AS1 expression in the serum from AKI patients. Further mechanistic findings deciphered that DLX6-AS1 mediated LPS-mediated cytotoxicity and pyroptosis in HK-2 via miR-223-3p/NLRP3 axis.

LINC00473 contributes to the radioresistance of esophageal squamous cell carcinoma by regulating microRNA‑497‑5p and cell division cycle 25A

Long non-coding RNA (lncRNA) LINC00473 plays a carcinogenic role in a variety of different tumor types. Nevertheless, the mechanisms through which LINC00473 regulates the radiosensitivity of esophageal squamous cell carcinoma (ESCC) cells remains elusive. In the present study, reverse transcription-quantitative PCR was used to quantify the expression of LINC00473, microRNA (miRNA/miR)-497-5p and cell division cycle 25A (CDC25A) in ESCC tissues. The association between LINC00473 expression and the clinicopathological characteristics of patients with ESCC was also assessed. Furthermore, Cell Counting kit-8 and colony formation assays were carried out to monitor the proliferation of ESCC cells exposed to X-ray radiation. A dual-luciferase reporter assay was also conducted to analyze the interaction between LINC00473 and miR-497-5p, as well as the interaction between CDC25A and miR-497-5p. The findings of the present study demonstrated that in ESCC tissues and cells, the expression levels of LINC00473 and CDC25A were significantly upregulated, while the expression of miR-497-5p was downregulated. The high expression level of LINC00473 was associated with a higher T stage, lymph node metastasis stage and a lower tumor differentiation grade in patients with ESCC. Following irradiation, transfection with miR-497-5p mimics reduced the promoting effect of LINC00473 overexpression on ESCC cell proliferation, and partially impeded the resistance of ESCC cells to X-ray radiation induced by LINC00473 overexpression. Moreover, transfection with miR-497-5p inhibitors partially alleviated the inhibitory effects of LINC00473 knockdown on cellular proliferation, and partly reversed the sensitivity of cells to X-ray irradiation induced by LINC00473 knockdown. Furthermore, it was confirmed that miR-497-5p was able to bind LINC00473 and the 3′-untranslated region of CDC25A. On the whole, the findings of the present study demonstrate that LINC00473 reduces the radiosensitivity of ESCC cells by modulating the miR-497-5p/CDC25A axis.

Long Noncoding RNA DLX6-AS1 Regulates the Growth and Aggressiveness of Colorectal Cancer Cells Via Mediating miR-26a/EZH2 Axis

Objective: To understand the regulation of long noncoding RNA DLX6-AS1-mediated miR-26a/EZH2 axis in the growth of colorectal cancer (CRC) cells. Methods: The expression of DLX6-AS1, miR-26a, and EZH2 was detected in CRC tissues by quantitative reverse transcription-polymerase chain reaction. The CRC HT-29 cell line was selected for transfection and subjected to observe the growth by MTT and colony formation assays, cell cycle by flow cytometry, and migration and invasion by wound healing and Transwell assays, respectively. Finally, the expression of cycle- and metastasis-related proteins was detected by western blotting. Results: DLX6-AS1 and EZH2 were increased, with a decreased miR-26a in CRC tissues, showing significant negative correlations between DLX6-AS1 and miR-26a, and between miR-26a and EZH2. CRC patients at advanced stage or with lymphatic metastasis had higher DLX6-AS1 expression. Dual-luciferase reporter gene assay uncovered the targeting correlations between DLX6-AS1 and miR-26a, or miR-26a and EZH2. After transfection of DLX6-AS1 siRNA or EZH2 siRNA, the growth and metastasis of CRC cells were suppressed, arresting the cells in G0/G1 phase, with a magnificent reduction in the ratio of cells in S phase or G2/M phase; meanwhile, Cyclin D1, Vimentin, and MMP9 expressions decreased evidently, whereas E-cadherin expression was upregulated. Changes above were fully reversed after transfection of miR-26a inhibitor, whereas si-EZH2 transfection abolished the positive role of miR-26a inhibitor on growth of CRC cells. Conclusion: Silencing DLX6-AS1 may block the malignant features of CRC cells by inhibiting the expression of EZH2 through upregulation of miR-26a. Thus, it is critical to the development and progression of CRC.

DNAH17-AS1 promotes pancreatic carcinoma by increasing PPME1 expression via inhibition of miR-432-5p

BACKGROUND

The incidence and mortality rates of pancreatic carcinoma (PC) are rapidly increasing worldwide. Long noncoding RNAs (lncRNAs) play critical roles during PC initiation and progression. Since the lncRNA DNAH17-AS1 is highly expressed in PC, the regulation of DNAH17-AS1 in PC was investigated in this study.

AIM

To investigate the expression and molecular action of lncRNA DNAH17-AS1 in PC cells.

METHODS

The PC expression data for the lncRNA DNAH17-AS1 was downloaded from The Cancer Genome Atlas database and used to examine its profile. Western blot and reverse transcription-quantitative PCR were employed to assess protein and mRNA expression. A subcellular fractionation assay was used to determine the location of DNAH17-AS1 in cells. In addition, the regulatory effects of DNAH17-AS1 on miR-432-5p, PPME1, and tumor activity were investigated using luciferase reporter assay, MTT viability analysis, flow cytometry, and transwell migration analysis.

RESULTS

DNAH17-AS1 was upregulated in PC cells and was associated with aggressive tumor behavior and poor prognosis for patients. Silencing DNAH17-AS1 promoted the apoptosis and reduced the viability, invasion, and migration of PC cells. In addition, DNAH17-AS1 served as a PC oncogene by downregulating miR-432-5p which normally directly targeted PPME1 to downregulate its expression.

CONLUSION

DNAH17-AS1 functions in PC as a tumor promoter by regulating the miR-432-5p/PPME1 axis. This finding may provide new insights for PC prognosis and therapy.

lncRNA DLX6-AS1 Promotes Proliferation of Laryngeal Cancer Cells by Targeting the miR-26a/TRPC3 Pathway

Purpose

Laryngeal cancer is the most prevalent tumor type in head and neck cancers. Early diagnosis is considered as an important strategy for improving prognosis. The lncRNA DLX6-AS1 has been shown to modulate tumor phenotypes in several types of cancer, but the role of DLX6-AS1 in laryngeal cancer and its concrete mechanisms are not clear.

Methods

Tissue samples from laryngeal cancer patients and corresponding clinical data were used for detailed analysis. The laryngeal cancer cell lines HEp-2 and Tu-177 were studied. Cell proliferation, ROS production, mitochondrial respiratory function, intracellular and mitochondrial calcium influx were assessed. Western blotting, quantitative RT-PCR and luciferase assays were used to analyze the interactions. A xenografted tumor model was established to analyze the effects of DLX6-AS1 on tumor growth in vivo.

Results

lncRNA DLX6-AS1 had increased expression in tumor tissues compared with adjacent normal tissues and in higher clinical stages compared with lower stages, which was associated with poor prognosis. In detail, DLX6-AS1 knockdown decreased cell proliferation and affected key mitochondrial metabolic parameters in both HEp-2 and Tu-177 cells. Moreover, DLX6-AS1 knockdown suppressed TRPC3-mediated mitochondrial calcium uptake and ROS production. Furthermore, miR-26a functioned as a link between these two molecules, as it could be absorbed by DLX6-AS1 and thus regulated the levels of TRPC3. Finally, the DLX6-AS1/miR-26a/TRPC3 axis modulated laryngeal cancer proliferation both in vitro and in vivo.

Conclusion

This study provides new evidence that a novel lncRNA, DLX6-AS1, regulates mitochondrial calcium homeostasis, respiration and tumor proliferation via modulating the miR-26a/TRPC3 axis in laryngeal cancer.

Long non-coding RNA DLX6-AS1 regulates neuroblastoma progression by targeting YAP1 via miR-497-5p

AIMS

The lncRNA distal-less homeobox 6 antisense 1 (DLX6-AS1) has been reported to be an oncogenic lncRNA in diverse malignant cancers; however, whether it has oncogenic role in neuroblastoma(NB) remain largely unknown. This study explored the expression status, function and potential mechanism of DLX6-AS1 in NB.

MAIN METHOD

In the current study, a total of 70 human NB tissues and matched adjacent non-tumor tissues were collected. Quantitative PCR (qPCR) was performed to study the expression differences of DLX6-AS1 in tissues and NB cell lines. Proliferation, migration, invasion and EMT status of transfected NB cells were evaluated by WST-1 assay, colony formation unit assay, Transwell assay and qPCR, respectively. The interaction between DLX6-AS1 and its potential targets was confirmed by luciferase reporter assay. Xenograft models were established to evaluate tumor proliferation in vivo.

KEY FINDING

We found that the expression of DLX6-AS1 was significantly increased in both NB tissues and cell lines, and elevated DLX6AS1 expression was positively correlated with advanced stage and poor survival. Proliferation rate, migration and invasion ability, as well as EMT process of NB cells was inhibited after DLX6-AS1 knockdown, meanwhile, the tumor growth in vivo was impaired after DLX6-AS1 inhibition. Further analysis showed that DLX6-AS1 regulates the expression of YAP1 by sponging miR-497-5p. DLX6-AS1 directly interacts with miR-497-5p and reduces the binding of miR-497-5p to YAP1 3'UTR, thus inhibiting the degradation of YAP1 by miR-497-5p.

SIGNIFICANCE

This work demonstrates that DLX6-AS1 partially enhances the proliferation, migration and invasion abilities of NB cells through the miR-497-5p/YAP1 pathway, DLX6-AS1 might act as a promising therapeutic target for NB.

lncRNA NEAT1 Facilitates Cell Proliferation, Invasion and Migration by Regulating CBX7 and RTCB in Breast Cancer

Purpose

To investigate the association between the lncRNA NEAT1 and breast cancer, and to determine the influence of NEAT1 on regulation of other signaling molecules in breast cancer.

Methods

In the present study, we measured levels of the lncRNA NEAT1 in 106 breast cancer patients and in a human breast cancer cell line by qRT-PCR. The correlation between NEAT1 expression and patients’ clinical characteristics was analyzed with in-house and TCGA data. We used cellular functioning assays and cell immunofluorescence assay to evaluate the role of NEAT1 and its target molecules in proliferation, invasion and migration in breast cancer. We used Western blotting to explore possible targets of NEAT1 and a subcellular fractionation assay to locate NEAT1 expression.

Results

NEAT1 was overexpressed in breast cancer tissue and also closely related to advanced clinical stages and positive lymph node metastases. NEAT1 levels were also tightly correlated to prognosis for breast cancer patients in survival analyses. Cellular function assays revealed that downregulation of NEAT1 could inhibit breast cancer cell viability, invasion and migration. Western blotting revealed down-regulation of CBX7 and up-regulation of RTCB following NEAT1 inhibition. Based on the cytoplasmic and nuclear expression of NEAT1, we investigated the possible regulation of CBX7 and RTCB by NEAT1. Results showed that NEAT1 regulated the expression of CBX7 and RTCB, possibly by binding of NEAT1 to DNA in the nucleus, which facilitates cell proliferation, invasion and migration.

Conclusion

The current results suggest that the lncRNA NEAT1 is upregulated in breast cancer and facilitates tumor cell viability, invasion and migration via CBX7 and RTCB.