lncRNA DANCR suppresses odontoblast-like differentiation of human dental pulp cells by inhibiting wnt/β-catenin pathway

LncRNA-DANCR contributes to lung adenocarcinoma progression by sponging miR-496 to modulate mTOR expression

Long non‐coding RNAs (lncRNAs) have emerged as new and important regulators of pathological processes including tumour development. In this study, we demonstrated that differentiation antagonizing non‐protein coding RNA (DANCR) was up‐regulated in lung adenocarcinoma (ADC) and that the knockdown of DANCR inhibited tumour cell proliferation, migration and invasion and restored cell apoptosis rescued; cotransfection with a miR‐496 inhibitor reversed these effects. Luciferase reporter assays showed that miR‐496 directly modulated DANCR; additionally, we used RNA‐binding protein immunoprecipitation (RIP) and RNA pull‐down assays to further confirm that the suppression of DANCR by miR‐496 was RISC‐dependent. Our study also indicated that mTOR was a target of miR‐496 and that DANCR could modulate the expression levels of mTOR by working as a competing endogenous RNA (ceRNA). Furthermore, the knockdown of DANCR reduced tumour volumes in vivo compared with those of the control group. In conclusion, this study showed that DANCR might be an oncogenic lncRNA that regulates mTOR expression through directly binding to miR‐496. DANCR may be regarded as a biomarker or therapeutic target for ADC.

Long noncoding RNA DANCR is activated by SALL4 and promotes the proliferation and invasion of gastric cancer cells

Long noncoding RNAs (LncRNAs) play important roles in tumor development and progression. The expression of lncRNAs is frequently dysregulated in human cancer. DANCR (anti-differentiation noncoding RNA) is a newly identified lncRNA in human cancer, however, its functional roles and clinical value in gastric cancer (GC) remains unknown. In this study, we investigated the expression of DANCR in the tumor tissues and serum of GC patients and analyzed the correlation between DANCR expression levels and the clinicopathological characteristics. Our results showed that the expression of DANCR was higher in the tumor tissues than that in the adjacent non-cancerous tissues. The expression level of DANCR was also elevated in the serum of GC patients compared to that of healthy controls. The expression levels of DANCR were significantly associated with tumor size, TNM stage, lymphatic metastasis and invasion depth. DANCR knockdown inhibited the proliferation of GC cells by inducing cell cycle arrest and cell apoptosis. In addition, DANCR knockdown suppressed gastric cancer growth in vivo. Moreover, DANCR knockdown inhibited the migration and invasion of GC cells via the suppression of epithelial-mesenchymal transition (EMT). However, DANCR overexpression had the opposite effect. DANCR is activated by SALL4 in gastric cancer cells and exerted its oncogenic activities through the activation of β-catenin pathway. Taken together, our findings suggest that DANCR promotes the progression of gastric cancer and have the potential to serve as a novel diagnostic biomarker.

Differential Expression of Long Noncoding RNAs in Normal and Inflamed Human Dental Pulp

INTRODUCTION

Dental pulp inflammation is an excellent model for the interaction between tissue inflammation and regenerative processes. It is worthwhile to better understand molecular signaling of repair and regeneration in inflammatory processes. Emerging evidence suggests that long noncoding RNA (lncRNA) participates in immune system inflammatory processes. Here we investigate the expression of lncRNAs in pulpitis, the inflammation of dental pulp tissue, and identify lncRNAs that possibly participate in inflammation responses and odontogenesis.

METHODS

Integrated comparative lncRNA microarray was used to examine lncRNA and mRNA expression between inflamed and normal human pulp tissue. The differential expression of lncRNAs and mRNAs was then validated by quantitative real-time polymerase chain reaction. A bioinformatics analysis was performed to predict the function of differentially expressed lncRNAs and mRNAs.

RESULTS

Our data indicated 752 lncRNAs were significantly differentially expressed (fold change > 2.0; P < .05) in inflamed pulp tissues compared with normal pulp tissues, including 338 upregulated and 414 downregulated lncRNAs. Among the 646 differentially expressed mRNAs (fold change > 2.0; P < .05), 460 were upregulated, and 186 were downregulated. The differentially downregulated genes are enriched for gene ontology terms related to odontogenesis and cell development in biological processes, whereas the differentially upregulated genes are related to immune and inflammation processes.

CONCLUSIONS

LncRNAs are differentially expressed in inflamed human pulp tissue compared with normal pulp tissue, indicating that lncRNAs may play key roles in pulpitis pathogenesis and development.

Overexpression of long non-coding RNA differentiation antagonizing non-protein coding RNA inhibits the proliferation, migration and invasion and promotes apoptosis of renal cell carcinoma

Renal cell carcinoma (RCC) is the third most common cancer in the urological system; however, the pathogenesis remains unknown. Accumulating evidence has demonstrated that long non‑coding RNAs are dysregulated in various tumors and serves an important role in tumorigenesis and development. In the present study, expression of lncRNA differentiation antagonizing non‑protein coding RNA (DANCR) in 24 paired RCC and adjacent normal tissues was detected by reverse transcription‑quantitative polymerase chain reaction. The results revealed that DANCR is downregulated in RCC tissues compared with adjacent normal tissues. Subsequent study revealed that overexpression of lncRNA DANCR by transfection of pcDNA3.1‑DANCR could suppress 786‑O and ACHN (RCC cell) proliferation, migration and invasion, and induce apoptosis compared with cells transfected with the pcDNA3.1 vector. The results revealed that DANCR functions as a tumor suppressor in RCC. In conclusion, the present study, to the best of our knowledge, was the first to reveal DANCR as a tumor suppressor. The results implicate DANCR as a potential biomarker of RCC, and further study will be focused on the clinical significance and signaling pathways of DANCR.

Differential long noncoding RNA/mRNA expression profiling and functional network analysis during osteogenic differentiation of human bone marrow mesenchymal stem cells

BACKGROUND

Mesenchymal stem cells (MSCs) are the most promising cell types for bone regeneration and repair due to their osteogenic potential. MSC differentiation is precisely regulated and orchestrated by the mechanical and molecular signals from the extracellular environment, involving complex pathways regulated at both the transcriptional and post-transcriptional levels. However, the potential role of long noncoding RNA (lncRNA) in the osteogenic differentiation of human MSCs remains largely unclear.

METHODS

Here, we undertook the survey of differential coding and noncoding transcript expression profiling and functional network analysis during osteogenic differentiation of human bone marrow mesenchymal stem cells (BMSCs) using human whole transcriptome microarray. The key pathways, mRNAs, and lncRNAs controlling osteogenic differentiation of BMSCs were identified by further bioinformatic analysis. The role of lncRNA in the osteogenic differentiation of MSCs was verified by lncRNA overexpression or knockdown methods.

RESULTS

A total of 1269 coding transcripts with 648 genes significantly upregulated and 621 genes downregulated, and 1408 lncRNAs with 785 lncRNAs significantly upregulated and 623 lncRNAs downregulated were detected along with osteogenic differentiation. Bioinformatic analysis identified that several pathways may be associated with osteogenic differentiation potentials of BMSCs, such as the MAPK signaling pathway, the Jak-STAT signaling pathway, the Toll-like receptor signaling pathway, and the TGF-beta signaling pathway, etc. Bioinformatic analysis also revealed 13 core regulatory genes including seven mRNAs (GPX3, TLR2, BDKRB1, FBXO5, BRCA1, MAP3K8, and SCARB1), and six lncRNAs (XR_111050, NR_024031, FR374455, FR401275, FR406817, and FR148647). Based on the analysis, we identified one lncRNA, XR_111050, that could enhance the osteogenic differentiation potentials of MSCs.

CONCLUSIONS

The potential regulatory mechanisms were identified using bioinformatic analyses. We further predicted the interactions of differentially expressed coding and noncoding genes, and identified core regulatory factors by co-expression networks during osteogenic differentiation of BMSCs. Our results could lead to a better understanding of the molecular mechanisms of genes and lncRNAs, and their cooperation underlying MSC osteogenic differentiation and bone formation. We identified that one lncRNA, XR_111050, could be a potential target for bone tissue engineering.

LncRNA-ANCR down-regulation suppresses invasion and migration of colorectal cancer cells by regulating EZH2 expression

Our study aimed to explore the effects of long noncoding RNA (lncRNA)-ANCR on the invasion and migration of colorectal cancer (CRC) cells by regulating enhancer of zeste homolog 2 (EZH2) expression. CRC tissues and adjacent normal tissues were collected and CRC SW620 cells line and normal human intestinal epithelial cells (HIECs) were incubated. CRC SW620 cells line was transfected with ANCR-siRNA. The expressions of ANCR and EZH2 mRNA were measured by real-time quantitative polymerase chain reaction (RT-qPCR). EZH2 and trimethylation of H3K27 (H3K27me3) protein expressions were detected using Western blotting. The relationship between ANCR and EZH2 was determined through RNA pull-down and co-immunoprecipitation (co-IP) assays. Cell invasion and migration were determined by Trans-well and cell scratch assays. ANCR, EZH2 and H3K27me3 expressions were up-regulated in CRC tissues and SW620 cells (all P < 0.05). After transfected with ANCR-siRNA, SW620 cells showed decreased ANCR expression and EZH2 mRNA and protein expressions (all P < 0.05). According to the results of RNA pull-down and co-IP assays, ANCR could specifically bind to EZH2. The results of Trans-well and cell scratch tests showed that when ANCR expression was decreased, the invasion and migration abilities of SW620 cells significantly declined (both P < 0.05). In conclusion, these results suggest that lncRNA-ANCR could influence the invasion and migration of CRC cells by specifically binding to EZH2.

Emerging roles for long noncoding RNAs in skeletal biology and disease

Normal skeletal development requires tight coordination of transcriptional networks, signaling pathways, and biomechanical cues, and many of these pathways are dysregulated in pathological conditions affecting cartilage and bone. Recently, a significant role has been identified for long noncoding RNAs (lncRNAs) in developing and maintaining cellular phenotypes, and improvements in sequencing technologies have led to the identification of thousands of lncRNAs across diverse cell types, including the cells within cartilage and bone. It is clear that lncRNAs play critical roles in regulating gene expression. For example, they can function as epigenetic regulators in the nucleus via chromatin modulation to control gene transcription, or in the cytoplasm, where they can function as scaffolds for protein-binding partners or modulate the activity of other coding and noncoding RNAs. In this review, we discuss the growing list of lncRNAs involved in normal development and/or homeostasis of the skeletal system, the potential mechanisms by which these lncRNAs might function, and recent improvements in the methodologies available to study lncRNA functions in vitro and in vivo. Finally, we address the likely utility of lncRNAs as biomarkers and therapeutic targets for diseases of the skeletal system, including osteoarthritis, osteoporosis, and in cancers of the skeletal system.

The Role of Transient Receptor Potential Cation Channel, Subfamily C, Member 1 in the Odontoblast-like Differentiation of Human Dental Pulp Cells

INTRODUCTION

Calcium ions (Ca²⁺) actively participate in reparative dentin formation by promoting cellular proliferation and differentiation of human dental pulp cells (hDPCs). Transient receptor potential cation channel, subfamily C, member 1 (TRPC1) activates Ca²⁺ entry upon store depletion in a variety of cell types. However, the function of TRPC1 in hDPCs has not been reported. Therefore, we aimed to analyze the role of TRPC1 in hDPCs undergoing odontoblast-like differentiation.

METHODS

Immunohistochemical staining was used to determine the distribution of TRPC1 in pulp tissues. Western blot analysis was used to detect the protein level of TRPC1 in the odontoblast-like differentiation of hDPCs. Knockdown of TRPC1 was performed with an adenoviral vector to evaluate the role of TRPC1 in hDPCs during odontoblast-like differentiation.

RESULTS

The results showed that TRPC1 was highly expressed in the cytoplasm of dental pulp cells, especially in the odontoblast layer of the healthy pulp. Moreover, the protein level of TRPC1 increased in a time-dependent manner during the odontoblast-like differentiation of hDPCs. Importantly, knockdown of TRPC1 attenuated the process of odontoblast-like differentiation as indicated by the reduction in mineralized nodules and the down-regulation of dentin sialophosphoprotein and dentin matrix protein 1. Moreover, knockdown of TRPC1 decreased Ca²⁺ entry to the cytoplasm of hDPCs.

CONCLUSIONS

Our data indicated a pivotal role of TRPC1 in the odontoblastlike differentiation of hDPCs, which may be a therapeutic target to enhance reparative dentin formation.

The degradation of EZH2 mediated by lncRNA ANCR attenuated the invasion and metastasis of breast cancer

EZH2 (the Enhancer of Zeste Homolog 2), as a key epigenetic regulator and EMT inducer, participates in a variety of cancer metastasis. EZH2 stability is regulated by several types of post-translational modifications (PTMs).The long non-coding RNAs (lncRNA) have been implicated to have critical roles in multiple carcinogenesis through a wide range of mechanisms, including modulating the stability of proteins. To date, whether the stability of EZH2 protein is regulated by lncRNAs remains unexplored. Here we report the discovery of ANCR modulating the stability of EZH2, and hence in the invasion and metastasis of breast cancer cells. We determined that ANCR potentiated the CDK1-EZH2 interaction, which then increased the intensity of phosphorylation at Thr-345 and Thr-487 sites of EZH2, facilitating EZH2 ubiquitination and hence its degradation. Moreover, we also uncover ANCR is an important player in breast cancer progression and metastasis mainly through decreasing EZH2 stability. More specifically, we initially found that ANCR level was lower in breast cancer tissues and breast cancer cell lines, in contrast to their normal counterparts. We then demonstrated that knockdown of ANCR induced an EMT program and promoted cell migration and invasion in MCF10A (epithelial cells), whereas ectopic expression of ANCR repressed breast cancer cells migration and invasion. Furthermore, we validated in a nude mouse model that overexpression of ANCR in highly malignant and invasive MDA-MB-231 breast cancer cells significantly reduced the ability of the cells to form tumors and prevented the lung metastasis in vivo. Based on these data, our findings define a new mechanism underlying modulation of EZH2 stability by linking ANCR interaction with EZH2 to promote its phosphorylation that facilitates EZH2 degradation and suppresses breast cancer progression.