lncRNA NEAT1 facilitates melanoma cell proliferation, migration, and invasion via regulating miR-495-3p and E2F3

Long non-coding intergenic RNA, LINC00273 induces cancer metastasis and stemness via miRNA sponging in triple negative breast cancer

LncRNAs and miRNAs, being the master regulators of gene expression, are crucial functional mediators in cancer. Our study unveils the critical regulatory role of the metastatic long non-coding RNA LINC00273 as the master regulator of oncogenes involved in cancer metastasis, stemness, and chemoresistance via its miRNA sponging mechanism. M2 (a salt of bis-Schiff base) mediated G quadruplex (G4) stabilization at the LINC00273 gene promoter remarkably inhibits LINC00273 transcription. Therefore, low-level LINC00273 transcripts are unable to efficiently sponge the miRNAs, which subsequently become available to bind and downregulate their target oncogenes. We have observed significantly different global transcriptomic scenarios in LINC00273 upregulated and downregulated circumstances in MDA-MB-231 triple-negative breast cancer model. Additionally, we have found the G4 sequence in the LINC00273 RNA to play a critical role in miRNA sequestration. miRNAs (miR-6789-5p, miR200b, miR-125b-5p, miR-4268, miR3978) have base pairing complementarity within the G4 region of LINC00273 RNA and the 3'-UTR (untranslated region) of MAPK12, TGF-β1, and SIX-1 transcripts. We have reported TGF-β1, SIX-1, and MAPK12 to be the direct downstream targets of LINC00273. The correlation between abnormal expression of lncRNA LINC00273 and TNBC aggressiveness strongly evidenced in our study shall accelerate the development of lncRNA-based anti-metastatic therapeutics.

Role of maternally expressed 8 small nucleolar RNA (MEG8) in osteogenic differentiation of periodontal ligament stem cells

OBJECTIVES

Periodontal ligament stem cells (PDLSCs) are essential for the treatment of bone diseases because of its great potential to differentiate into osteoblasts. Remarkably, increasing long-non-coding RNAs (lncRNAs) have been reported to be involved in the osteogenic differentiation of PDLSCs. Maternally expressed 8, small nucleolar RNA host gene (MEG8) is implicated in multiple diseases. This study intended to unearth the potential role of MEG8 and unveil the mechanism in PDLSCs undergoing osteoblastic differentiation.

MATERIALS AND METHODS

MEG8 expression was measured by quantitative real-time PCR (RT-qPCR) during osteogenic differentiation of PDLSCs into bone cells. Functional assays were used to uncover the biological function of MEG8. Besides, RNA pulldown, RNA-binding protein immunoprecipitation (RIP), and luciferase reporter assays were used to explore the molecular mechanism of MEG8.

RESULTS

MEG8 was apparently overexpressed in osteogenically differentiated PDLSCs. Moreover, MEG8 deficiency suppressed the osteoblastic differentiation of PDLSCs. Furthermore, MEG8 modulated the expression of transcription factor 4 (TCF4) by scavenging microRNA-495-3p (miR-495-3p) and microRNA-485-3p (miR-485-3p) through the competing endogenous RNA (ceRNA) mechanism, further stimulating the Wnt/β-catenin pathway.

CONCLUSION

MEG8 stimulates the capacity of PDLSCs for osteogenic differentiation through a ceRNA mode.

The crosstalk between non-coding RNAs and cell-cycle events: A new frontier in cancer therapy

The cell cycle comprises sequential events during which a cell duplicates its genome and divides it into two daughter cells. This process is tightly regulated to ensure that the daughter cell receives identical copied chromosomal DNA and that any errors in the DNA during replication are correctly repaired. Cyclins and their enzyme partners, cyclin-dependent kinases (CDKs), are critical regulators of G- to M-phase transitions during the cell cycle. Mitogenic signals induce the formation of the cyclin/CDK complexes, resulting in phosphorylation and activation of the CDKs. Once activated, cyclin/CDK complexes phosphorylate specific substrates that drive the cell cycle forward. The sequential activation and inactivation of cyclin-CDK complexes are tightly controlled by activating and inactivating phosphorylation events induced by cell-cycle proteins. The non-coding RNAs (ncRNAs), which do not code for proteins, regulate cell-cycle proteins at the transcriptional and translational levels, thereby controlling their expression at different cell-cycle phases. Deregulation of ncRNAs can cause abnormal expression patterns of cell-cycle-regulating proteins, resulting in abnormalities in cell-cycle regulation and cancer development. This review explores how ncRNA dysregulation can disrupt cell division balance and discusses potential therapeutic approaches targeting these ncRNAs to control cell-cycle events in cancer treatment.

MicroRNA-495: a therapeutic and diagnostic tumor marker

Therapeutic and diagnostic progresses have significantly reduced the mortality rate among cancer patients during the last decade. However, there is still a high rate of mortality among cancer patients. One of the important reasons involved in the high mortality rate is the late diagnosis in advanced tumor stages that causes the failure of therapeutic strategies in these patients. Therefore, investigating the molecular mechanisms involved in tumor progression has an important role in introducing the efficient early detection markers. MicroRNAs (miRNAs) as stable factors in body fluids are always considered as non-invasive diagnostic and prognostic markers. In the present review, we investigated the role of miR-495 in tumor progression. It has been reported that miR-495 has mainly a tumor suppressor function through the regulation of transcription factors and tyrosine kinases as well as cellular processes such as multidrug resistance, chromatin remodeling, and signaling pathways. This review can be an effective step towards introducing the miR-495 as a non-invasive diagnostic/prognostic marker as well as a suitable target in tumor therapy.

LncRNA NEAT1 antagonizes the inhibition of melanoma proliferation, migration, invasion and EMT by Polyphyllin B

Polyphyllin B (PPB) is a compound with anti-tumor effects. Nuclear paraspeckle assembly transcript 1 (NEAT1) is a long-stranded noncoding RNA that induces epithelial-mesenchymal transition (EMT) of tumor cells and promotes tumor growth and metastasis. However, the role and mechanism of PPB on melanoma and the correlation between them remain unclear. In this study we screened NEAT1 by using LncRNA transcriptomic sequencing, and then transfected B16F10 cells using OVER-NEAT1 lentivirus. Next, we found that PPB had significant proliferation inhibition of melanoma and B16F10 cells through MTT assay and establishment of mouse subcutaneous transplantation tumor model; in addition, through wound healing assay, transwell assay and establishment of mouse melanoma lung metastasis model, we found that PPB significantly inhibited the invasion and migration of B16F10 cells in vitro, and inhibited the metastasis of melanoma to lung, bone and liver in vivo. Finally, changes in the expression levels of EMT-related proteins were assessed by western blot (WB) and immunohistochemistry, and PPB significantly downregulated the expression levels of MMP-9, N-cadherin, etc., and upregulated E-cadherin. While overexpressed NEAT1 showed the ability to promote melanoma proliferation, migration and invasion, in addition to partially reversed the inhibition of proliferation, migration and invasion of melanoma by PPB mentioned above.

LncRNA FENDRR Suppresses Melanoma Growth via Influencing c-Myc mRNA Level

Background

Long non-coding RNAs (lncRNAs) play an important role in the occurrence of melanoma. However, the specific molecular mechanisms that regulate its biological function are still poorly understood. Therefore, the main purpose of this study is to elucidate the internal mechanism of lncRNA-FENDRR as a biological marker for the occurrence of SKCM and its influence on its proliferation.

Results

FENDRR is low expressed in skin cutaneous melanoma (SKCM) tissues and appears to be at an even lower level as the tumor progresses. However, the high expression of FENDRR can affect the proliferation of SKCM cell line A375. The results of flow cytometry showed that after overexpression of FENDRR, the cell cycle was arrested in the G1/G0 phase. Bioinformatics analysis and RIP results showed that FENDRR could be combined with YTHDF1. Together, these complexes regulate c-Myc mRNA level and determine cell proliferation.

Conclusion

We found that overexpression of FENDRR can effectively inhibit SKCM, which provides a new theoretical basis for new therapeutic approaches and targeted RNA drugs.

miR-495-3p as a promising tumor suppressor in human cancers

Noncoding RNAs are a type of cellular RNA not having the ability to translate into proteins. As an important type of ncRNA with a length of about 22 nucleotides (nt), microRNAs were revealed to contribute to regulating the various cellular functions via regulating the protein translation of target genes. Among them, available studies proposed that miR-495-3p is a pivotal player in cancer pathogenesis. These studies showed that the expression level of miR-495-3p decreased in various cancer cells, suggesting its tumor suppressor role in cancer pathogenesis. Long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) are the important regulators of miR-495-3p via sponging it, leading to increased expression levels of its target genes. Moreover, miR-495-3p was shown to have a promising potential to be a prognostic and diagnostic biomarker in cancer. MiR-495-3p also could affect the resistance of cancer cells to chemotherapy agents. Here, we discussed the molecular mechanisms of miR-495-3p in various cancer including breast cancer. In addition, we discussed the miR-495-3p potential as a prognostic and diagnostic biomarker as well as its activity in cancer chemotherapy. Finally, we discussed the current limitations regarding the use of microRNAs in clinics and the future prospects of microRNAs.

An integrated in silico-in vitro investigation to assess the skin sensitization potential of 4-Octylphenol

One of the major challenges in chemical toxicity testing is the possibility to protect human health against adverse effects with non-animal methods. In this paper, 4-Octylphenol (OP) was tested for skin sensitization and immunomodulatory effects using an integrated in silico-in vitro test approach. In silico tools (QSAR TOOLBOX 4.5, ToxTree and VEGA) were used together with several in vitro tests including HaCaT cells (quantification of IL-6; IL-8; IL-1α and IL-18 by ELISA and expression of genes TNF, IL1A, IL6 and IL8 by RT- qPCR), RHE model (quantification of IL-6; IL-8; IL-1α and IL-18 by ELISA) and THP-1 activation assay (CD86/CD54 expression and IL-8 release). Additionally, the immunomodulatory effect of OP was investigated using lncRNAs MALAT1 and NEAT1 expression and LPS-induced THP-1 activation (CD86/CD54 expression and IL-8 release). The in silico tools predicted OP as a sensitizer. In vitro tests are also concordant with the in silico prediction. OP increased IL-6 expression (HaCaT cells); IL-18 and IL-8 expressions (RHE model). An irritant potential was also shown by a great expression of IL-1α (RHE model); and increased expression of CD54 marker and IL-8 in THP-1 cells. Immunomodulatory effects of OP were demonstrated by the downregulation of NEAT1, MALAT1 (epigenetic markers), IL6 and IL8; and an increase in LPS-induced CD54 and IL-8 expressions. Overall, results indicate that OP is a skin sensitizer, being positive in three key events of the AOP for skin sensitization, also showing immunomodulatory effects.

Modeling CRISPR-Cas13d on-target and off-target effects using machine learning approaches

A major challenge in the application of the CRISPR-Cas13d system is to accurately predict its guide-dependent on-target and off-target effect. Here, we perform CRISPR-Cas13d proliferation screens and design a deep learning model, named DeepCas13, to predict the on-target activity from guide sequences and secondary structures. DeepCas13 outperforms existing methods to predict the efficiency of guides targeting both protein-coding and non-coding RNAs. Guides targeting non-essential genes display off-target viability effects, which are closely related to their on-target efficiencies. Choosing proper negative control guides during normalization mitigates the associated false positives in proliferation screens. We apply DeepCas13 to the guides targeting lncRNAs, and identify lncRNAs that affect cell viability and proliferation in multiple cell lines. The higher prediction accuracy of DeepCas13 over existing methods is extensively confirmed via a secondary CRISPR-Cas13d screen and quantitative RT-PCR experiments. DeepCas13 is freely accessible via http://deepcas13.weililab.org .

Identification of potential immune-related ceRNA Regulatory Network in UVB-irradiated human skin

For a better understanding the molecular biomarkers in UVB-induced skin damage, and its potential mechanism, we downloaded two microarray data sets on skin UVB damage from the Gene Expression Omnibus (GEO): GSE21429, GSE56754. By using the Limma package to analyze differential gene expression and co-expression network analysis to screen module genes, 16 common genes were identified (16 up-regulated). Gene Ontology analysis to explore the functional roles of these genes indicated that the common genes were associated mainly with melanin biosynthetic process and metabolic process. Gene Set Enrichment Analysis provided evidence that the most gene sets enriched in immune and inflammation-related signaling pathways in the UVB-treated subjects, as compared with the untreated subjects. The PPI network genes were ranked according to the degree of connectivity, the top three ranked genes: "MLANA", "GPR143" and "SFTPC" were identified as potential biomarkers using the area under the receiver operating characteristic curve. The relative proportion of 22 immune cell types was then calculated by using the CIBERSORT algorithm. A higher follicular helper T cell ratio in UVB-treated samples compared to untreated samples was observed. Moreover, three hub genes have also been shown to be associated with immune cells. Finally, through multiple online miRNA databases, we propose MLANA-miR-573-MALAT1/NEAT1, GPR143-miR-138-5p-MALAT1/ KCNQ1OT1 might be potential RNA regulatory pathways that control disease progression in UVB-induced skin damage. In summary, the present results provide novel insights into the UVB-radiation related biological process changes, and further offer a new clinical application for prognosis and diagnostic prediction of UVB radiation-mediated skin damage.

An Updated Review of Contribution of Long Noncoding RNA-NEAT1 to the Progression of Human Cancers

Long non-coding RNAs (lncRNAs) present pivotal roles in cancer tumorigenesis and progression. Recently, nuclear paraspeckle assembly transcript 1 (NEAT1) as a lncRNA has been shown to mediate cell proliferation, migration, and EMT in tumor cells. NEAT1 by targeting several miRNAs/mRNA axes could regulate cancer cell behavior. Therefore, NEAT1 may function as a potent biomarker for the prediction and treatment of some human cancers. In this review, we summarized various NEAT1-related signaling pathways that are critical in cancer initiation and progression.

Identification of the ageing-related prognostic gene signature, and the associated regulation axis in skin cutaneous melanoma

Skin cutaneous melanoma (SKCM) has substantial malignancy and a poor prognosis. The function of ageing-related genes (ARGs) in SKCM is unknown. In this study, a prognostic risk-scoring model for ARG was constructed based on SKCM RNA-seq, mutation, and clinical data in The Cancer Genome Atlas. Our novel prognostic model, which included four ARGs (IRS2, PDGFRA, TFAP2A, and SOD2), could distinguish between low-risk and high-risk groups. Low-risk patients benefited more from immunotherapy and commonly used targeted and chemotherapy drugs than high-risk patients. There were also considerable differences in immunocyte infiltration and tumour microenvironment between the two groups. Furthermore, multivariate Cox regression analysis revealed that age, pT_stage, pM_stage, body mass index, tumour mutation burden, and risk score were independent factors influencing the prognosis of patients with SKCM; therefore, we devised a prognosis nomogram. Last, a long non-coding (lncRNA) NEAT1/miR-33a-5p/IRS2 regulatory axis of the competing endogenous RNA network was built to investigate the mechanisms of SKCM metastasis progression. Grouping based on the scoring system could predict the prognosis of SKCM and predict the sensitivity of patients to immunotherapy, targeted therapy, and chemotherapy. This could facilitate the formulation of individualised treatment strategies and help drug research and development. These findings highlight the regulatory axis of the lncRNA NEAT1/miR-33a-5p/IRS2, which may play a role in SKCM metastasis.

Long non-coding RNAs and melanoma: From diagnosis to therapy

Although extremely rare, malignant melanoma is the deadliest type of skin malignancy with the inherent capability to invade other organs and metastasize to distant tissues. In 2021, it was estimated that approximately 106,110 patients may have received the diagnosis of melanoma, with a mortality rate of 7180. Surgery remains the common choice for treatment in patients with melanoma. Despite many advances in the treatment of melanoma, some patients, such as those who have received cytotoxic chemotherapeutic and immunotherapic agents, a significant number of patients may show inadequate treatment response following initiating these treatments. Non-coding RNAs, including lncRNAs, have become recently popular and attracted the attention of many researchers to make new insights into the pathogenesis of many diseases, particularly malignancies. LncRNAs have been thoroughly investigated in multiple cancers such as melanoma and have been shown to play a major role in regulating various physiological and pathological cellular processes. Considering their core regulatory function, these non-coding RNAs may be appropriate candidates for melanoma patients' diagnosis, prognosis, and treatment. In this review, we will cover all the current literature available for lncRNAs in melanoma and will discuss their potential benefits as diagnostic and/or prognostic markers or potent therapeutic targets in the treatment of melanoma patients.

Exosome-Derived microRNA: Implications in Melanoma Progression, Diagnosis and Treatment

Melanoma is a malignant and aggressive cancer, and its progression is greatly affected by interactions between melanoma cells and their surroundings. Exploration on mechanism of melanoma and improved diagnostic and therapeutic strategies are becoming increasingly important. Unlike extracellular messengers that mainly work on targeted cells through corresponding receptors, exosomes are essential intercellular messengers that deliver biologically active substances such as nucleic acids and proteins to target cells for cell-cell communication. Of them, microRNAs (miRNAs) are common and important exosomal components that can regulate the expression of a wide range of target genes. Accordingly, exosome-derived miRNAs play a significant role in melanoma progression, including invasion and metastasis, microenvironment establishment, angiogenesis, and immune escape. MiRNA signatures of exosomes are specific in melanoma patients compared to healthy controls, thus circulating miRNAs, especially exosomal miRNAs, become potential diagnostic markers and therapeutic targets for melanoma. This review aims to summarize recent studies on the role of exosomal miRNAs in melanoma as well as ongoing efforts in melanoma treatment.

The role of lncRNAs in the tumor microenvironment and immunotherapy of melanoma

Melanoma is one of the most lethal tumors with highly aggressive and metastatic properties. Although immunotherapy and targeted therapy have certain therapeutic effects in melanoma, a significant proportion of patients still have drug resistance after treatment. Recent studies have shown that long noncoding RNAs (lncRNAs) are widely recognized as regulatory factors in cancer. They can regulate numerous cellular processes, including cell proliferation, metastasis, epithelial-mesenchymal transition (EMT) progression and the immune microenvironment. The role of lncRNAs in malignant tumors has received much attention, whereas the relationship between lncRNAs and melanoma requires further investigation. Our review summarizes tumor suppressive and oncogenic lncRNAs closely related to the occurrence and development of melanoma. We summarize the role of lncRNAs in the immune microenvironment, immunotherapy and targeted therapy to provide new targets and therapeutic methods for clinical treatment.

Integration of lncRNAs, Protein-Coding Genes and Pathology Images for Detecting Metastatic Melanoma

Melanoma is a lethal skin disease that develops from moles. This study aimed to integrate multimodal data to predict metastatic melanoma, which is highly aggressive and difficult to treat. The proposed EnsembleSKCM method evaluated the prediction performances of long noncoding RNAs (lncRNAs), protein-coding messenger genes (mRNAs) and pathology images (images) for metastatic melanoma. Feature selection was used to screen for metastatic biomarkers in the lncRNA and mRNA datasets. The integrated EnsembleSKCM model was built based on the weighted results of the lncRNA-, mRNA- and image-based models. EnsembleSKCM achieved 0.9444 in the prediction accuracy of metastatic melanoma and outperformed the single-modal prediction models based on the lncRNA, mRNA and image data. The experimental data suggest the importance of integrating the complementary information from the three data modalities. WGCNA was used to analyze the relationship of molecular-level features and image features, and the results show connections between them. Another cohort was used to validate our prediction.

LncRNA MSC-AS1, as an oncogene in melanoma, promotes the proliferation and glutaminolysis by regulating the miR-330-3p/YAP1 axis

Melanoma is a kind of aggressive skin neoplasms with high mortality. The purpose of this present research was to investigate the effects and potential mechanisms of long-noncoding RNA (lncRNA) MSC antisense RNA 1 (MSC-AS1) in melanoma. MSC-AS1, miR-330-3p and YAP1 expression levels in melanoma tissues and cells were assessed by quantitative real-time polymerase chain reaction. Melanoma cells were evaluated using cell count kit-8, clone formation and ELISA in vitro. The relationship among MSC-AS1, YAP1 and miR-330-3p was validated by pull-down and luciferase reporter assays. Finally, the role of MSC-AS1 in vivo was determined by the xenograft model. Results showed that lncRNA MSC-AS1 was upregulated in melanoma tissues and cells. High expression of MAS-AS1 was positively correlated with a poor prognosis. Pull-down and luciferase reporter demonstrated that miR-330-3p specifically binds directly to YAP1 and MSC-AS1, respectively. MSC-AS1 promoted the expression of YAP1 by downregulating miR-330-3p. Functional experiments suggested that knockdown of MSC-AS1 suppressed the proliferation of melanoma cells and decreased the levels of glutamine, glutamate and α-ketoglutarate, glutaminase and glutamine transporter alanine-serine-cysteine transporter 2. Upregulation of miR-330-3p alleviated the promotion effect of MSC-AS1 overexpression on the proliferation and glutaminolysis of melanoma cells. The above changes could be reversed by YAP1 overexpression. In addition, knockdown of MSC-AS1 dramatically restrained the growth of melanoma cells in xenograft model. In conclusion, our results revealed that MSC-AS1 facilitated the proliferation and glutaminolysis of melanoma cells by regulating miR-330-3p/YAP1 pathway, suggesting that MSC-AS1 could provide a new idea for the treatment of melanoma.

Gambogenic acid antagonizes the expression and effects of long non-coding RNA NEAT1 and triggers autophagy and ferroptosis in melanoma

In this study, we investigated the molecular mechanism underlying melanoma proliferation, with the aim to discover effective interventions which may markedly improve clinical prognosis. The results showed that gambogenic acid (GNA) could inhibit the proliferation of melanoma cells in vivo (C57BL/6 mice) and in vitro. Long non-coding RNA sequencing was used to identify the most significant long non-coding RNA, i.e., nuclear enriched abundant transcript 1 (NEAT1). NEAT1 was is up-regulated in melanoma, which was found to closely relate to cell proliferation. Melanoma cell lines either over-expressing NEAT1 or with NEAT1 knockdown was established through cloning experiments. A model of transplanted tumors was established to verify the inhibitory effect of GNA on the proliferation of melanoma cells in vitro and in vivo by downregulating NEAT1. Downregulation of NEAT1-induced ferroptosis and autophagy was demonstrated by detecting the effects of NEAT1 overexpressed and downregulated melanoma cell lines and melanoma transplantation model mice. Mechanistically, downregulation of NEAT1 can weaken the direct binding of Slc7a11, indirectly leading to inhibiting GPX-4 activity and subsequent ferroptosis, while, mediating the AMPK/mTOR signal axis-induced autophagy. The levels of Furthermore, NEAT1 decrease under the treatment of Gambogenic acid (GNA), a promising natural anticancer compound, while NEAT1 overexpression suppresses GNA inhibition on cell vitality and eliminates GNA-induced melanoma cell ferroptosis and autophagy.

Circ_HIPK3 Inhibits H2O2-Induced Lens Epithelial Cell Injury in Age-Related Cataract Depending on the Regulation of miR-495-3p/HDAC4 Pathway

Age-related cataract (ARC) is one of the most common chronic diseases. Circular RNA (circ)_HIPK3 is reported to be involved in the advancement of ARC, but its molecular mechanism has not been clarified. Our study provides a new perspective on the clinical treatment of ARC. Our data showed that the expression levels of circ_HIPK3 and histone deacetylase 4 (HDAC4) were downregulated, while microRNA (miR)-495-3p level was increased in ARC tissues and H₂O₂-induced SRA01/04 cells. Functional experiments showed that circ_HIPK3 and HDAC4 overexpression could inhibit H₂O₂-induced lens epithelial cell apoptosis and fibrosis. In terms of mechanism, we found that circ_HIPK3 could sponge miR-495-3p, miR-495-3p could target HDAC4. Besides, we confirmed that circ_HIPK3 sponged miR-495-3p to positively regulate HDAC4. Additionally, miR-495-3p overexpression or HDAC4 knockdown reversed the inhibition effect of circ_HIPK3 on H₂O₂-induced lens epithelial cell injury. In conclusion, our data showed that circ_HIPK3 suppressed H₂O₂-induced lens epithelial cell injury by regulating miR-495-3p/HDAC4 axis.

Molecular Interactions of the Long Noncoding RNA NEAT1 in Cancer

As one of the best-studied long noncoding RNAs, nuclear paraspeckle assembly transcript 1 (NEAT1) plays a pivotal role in the progression of cancers. NEAT1, especially its isoform NEAT1-1, facilitates the growth and metastasis of various cancers, excluding acute promyelocytic leukemia. NEAT1 can be elevated via transcriptional activation or stability alteration in cancers changing the aggressive phenotype of cancer cells. NEAT1 can also be secreted from other cells and be delivered to cancer cells through exosomes. Hence, elucidating the molecular interaction of NEAT1 may shed light on the future treatment of cancer. Herein, we review the molecular function of NEAT1 in cancer progression, and explain how NEAT1 interacts with RNAs, proteins, and DNA promoter regions to upregulate tumorigenic factors.

Silencing LINC00665 inhibits cutaneous melanoma in vitro progression and induces apoptosis via the miR-339-3p/TUBB

Background

LncRNAs are closely related to cutaneous melanoma (CM) tumorigenesis and metastasis, and it can affect the progression of CM by regulating cell proliferation, migration, invasion, apoptosis, and other cellular mechanisms. This study investigated the role of LINC00665 in CM.

Methods

Expressions of LINC00665, miR‐339‐3p, and tubulin beta chain (TUBB) in CM cells were analyzed by qRT‐PCR and/or Western blot. The LINC00665/miR‐339‐3p/TUBB targeting network was predicted by bioinformatics tools, screened out by Venn diagrams and analyzed by Pearson's correlation coefficients, followed by validation via dual‐luciferase reporter assay and/or pull‐down assay. Transfection of siLINC00665 or miR‐339‐3p inhibitor/mimic was conducted with CM cells whose viability, proliferation, migration, invasion, cell cycle progression, and apoptosis were measured by CCK‐8 assay, colony formation assay, wound healing assay, Transwell assay, and flow cytometry. The associations of TUBB with tumor biological characteristics and other proteins were analyzed by CanserSEA and String, respectively.

Results

High‐expressed LINC00665 was detected in CM cells. Silencing LINC00665 decreased CM cell viability; inhibited colony formation, cell cycle progression, migration and invasion; enhanced apoptosis; and upregulated miR‐339‐3p. LINC00665 targeted miR‐339‐3p which targeted TUBB. MiR‐339‐3p upregulation induced effects similar to the LINC00665‐silencing‐induced effects and could downregulate TUBB, which was associated with malignant behaviors and related to other five proteins. MiR‐339‐3p downregulation induced the opposite effects of what miR‐339‐3p upregulation induced, and the miR‐339‐3p downregulation‐induced effects could be reversed by LINC00665 silencing.

Conclusion

Silencing LINC00665 inhibits in vitro CM progression and induces apoptosis via the miR‐339‐3p/TUBB axis.

Identification of Two Exosomal miRNAs in Circulating Blood of Cancer Patients by Using Integrative Transcriptome and Network Analysis

Exosomes carry molecules of great biological and clinical interest, such as miRNAs. The contents of exosomes vary between healthy controls and cancer patients. Therefore, miRNAs and other molecules transported in exosomes are considered a potential source of diagnostic and prognostic biomarkers in cancer. Many miRNAs have been detected in recent years. Consequently, a substantial amount of miRNA-related data comparing patients and healthy individuals is available, which contributes to a better understanding of the initiation, development, malignancy, and metastasis of cancer using non-invasive sampling procedures. However, a re-analysis of available ncRNA data is rare. This study used available data about miRNAs in exosomes comparing healthy individuals and cancer patients to identify possible global changes related to the presence of cancer. A robust transcriptomic analysis identified two common miRNAs (miR-495-3p and miR-543) deregulated in five cancer datasets. They had already been implicated in different cancers but not reported in exosomes circulating in blood. The study also examined their target genes and the implications of these genes for functional processes.

A noncoding regulatory RNA Gm31932 induces cell cycle arrest and differentiation in melanoma via the miR-344d-3-5p/Prc1 (and Nuf2) axis

Emerging evidence has shown that long non-coding RNAs (lncRNAs) play an important role in inhibiting tumor cell proliferation and inducing differentiation. In this study, integrative analysis of whole transcriptome sequencing data demonstrated that lncRNA-Gm31932 is significantly decreased in all-trans retinoic acid (ATRA)-induced and sodium 4-phenylbutanoate (PB-4)-induced mouse melanoma B16 cells. Silencing lncRNA-Gm31932 could inhibit B16 cell proliferation, with cell cycle arrest at the G0/G1 phase and obvious differentiation characteristics, e.g., increased cell volume, melanin content and tyrosinase (Tyr) activity. Furthermore, a series of experiments (luciferase reporter assay, RNA pull-down assay, and western blotting) showed that lncRNA-Gm3932 down-regulated Prc1 and Nuf2 by competitively sponging miR-344d-3-5p, which subsequently reduced the expression of cell cycle-related proteins CDK2, CDC2, and Cyclin B1, and increased the expression of P21 and P27. Moreover, silencing lncRNA-Gm31932 could significantly inhibit tumor growth in B16 melanoma-bearing mice. Taken together, these results indicate that as a possible signaling pathway for ATRA and PB-4, lncRNA-Gm31932 can induce cell cycle arrest and differentiation via miR-344d-3-5p/Prc1 (and Nuf2) axis.

miR-495-3p depresses cell proliferation and migration by downregulating HMGB1 in colorectal cancer

Background

MicroRNAs play an important role in the genesis and progression of tumours, including colorectal cancer (CRC), which has a high morbidity and mortality rate. In this research, the role of miR-495-3p and HMGB1 in CRC was investigated.

Methods

We performed qRT-PCR to detect the expression of miR-495-3p in colorectal cancer tissues and cell lines. Functional experiments, such as CCK-8, EdU, Transwell and apoptosis assays, were conducted to explore the effects of miR-495-3p on the proliferation, migration and apoptosis of CRC cells in vitro. Then, database prediction, dual-luciferase reporter gene assays and functional experiments verified the role of the miR-495-3p target gene HMGB1 in CRC. Finally, rescue experiments were performed to investigate whether overexpression of HMGB1 could reverse the inhibitory effect of miR-495-3p on CRC cell proliferation in vivo and in vitro.

Results

miR-495-3p was downregulated in colorectal cancer tissues and cell lines, inhibited the proliferation and migration of colorectal cancer cells and promoted cell apoptosis. Database prediction and dual-luciferase reporter gene assays showed that HMGB1 was the downstream target gene of miR-495-3p. We finally demonstrated that miR-495-3p inhibited CRC cell proliferation by targeting HMGB1 in vitro and in vivo.

Conclusion

Our research shows that miR-495-3p inhibits the progression of colorectal cancer by downregulating the expression of HMGB1, which indicates that miR-495-3p may become a potential therapeutic target for colorectal cancer.

Characterization of the microRNA transcriptomes and proteomics of cochlear tissue-derived small extracellular vesicles from mice of different ages after birth

The cochlea is an important sensory organ for both balance and sound perception, and the formation of the cochlea is a complex developmental process. The development of the mouse cochlea begins on embryonic day (E)9 and continues until postnatal day (P)21 when the hearing system is considered mature. Small extracellular vesicles (sEVs), with a diameter ranging from 30 to 200 nm, have been considered a significant medium for information communication in both physiological and pathological processes. However, there are no studies exploring the role of sEVs in the development of the cochlea. Here, we isolated tissue-derived sEVs from the cochleae of FVB mice at P3, P7, P14, and P21 by ultracentrifugation. These sEVs were first characterized by transmission electron microscopy, nanoparticle tracking analysis, and western blotting. Next, we used small RNA-seq and mass spectrometry to characterize the microRNA transcriptomes and proteomes of cochlear sEVs from mice at different ages. Many microRNAs and proteins were discovered to be related to inner ear development, anatomical structure development, and auditory nervous system development. These results all suggest that sEVs exist in the cochlea and are likely to be essential for the normal development of the auditory system. Our findings provide many sEV microRNA and protein targets for future studies of the roles of cochlear sEVs.

YY1-induced long non-coding RNA small nucleolar RNA host gene 8 promotes the tumorigenesis of melanoma via the microRNA-656-3p/SERPINE1 mRNA binding protein 1 axis

Long non-coding (lnc) RNA serves a vital role in the cellular processes of carcinoma. This study aimed to explore the accurate mechanism underlying lncRNA small nucleolar RNA host gene 8 (SNHG8) in melanoma. In this study, lncRNA SNHG8 expression were upregulated in melanoma tissues and cells, and lncRNA SNHG8 knockdown reduced melanoma cell viability, migration and invasion. Moreover, lncRNA SNHG8 expression could be induced by transcription factor YY1. In addition, we found that miR-656 could directly bind to lncRNA SNHG8 and SERPINE1 mRNA binding protein 1 (SERBP1). Rescue assays indicated that miR-656 overexpression inhibited the aforementioned cellular activities in melanoma cells, which were reversed by SERBP1 overexpression. In conclusion, this work elucidated that YY1-induced upregulation of lncRNA SNHG8 boosted the development of melanoma via the miR-656-3p/SERBP1 axis, providing a novel therapeutic strategy for melanoma treatment.

NEAT1 in bone marrow mesenchymal stem cell-derived extracellular vesicles promotes melanoma by inducing M2 macrophage polarization

Bone marrow mesenchymal stem cells (BMSCs)-derived extracellular vesicles (EVs) reportedly play an important role in melanoma pathogenesis. This study aimed to explore the mechanisms of EVs-carried long non-coding RNA (lncRNA) NEAT1 involvement in melanoma. Gain- and loss-of-function experiments were performed to determine biological characteristics of A-375 melanoma cells. Bioinfomatic prediction, RNA immunoprecipitation (RIP), and dual luciferase reporter gene experiments were applied to investigate the roles of NEAT1 and microRNA-374a-5p (miR-374a-5p), and leucine-rich repeat-containing G protein-coupled receptor 4 (LGR4). A subcutaneous tumor model was constructed using nude mice, and in vivo fluorescence imaging was used to observe the effect of NEAT1 on the growth and metastasis of melanoma cells in vivo. The results indicated that BMSC-EVs could be internalized by macrophages to promote the expression of macrophages M2 markers. M2 type macrophages promoted malignancy of melanoma cells. NEAT1 derived from BMSC-EVs promoted the progression of melanoma by promoting M2 polarization of macrophages. NEAT1 inhibits miR-374 expression, while miR-374 could upregulate LGR4-dependent IQGAP1 expression. The tumor-inhibiting effect of NEAT1 silencing was validated in the nude mouse xenograft model. Collectively, the results demonstrated that BMSC-EVs carrying NEAT1 can promote the progression of melanoma by inducing M2 polarization of macrophages, and thus may be considered as a potential target for melanoma therapeutics.

Long Non-coding RNA FOXD2-AS1 Promotes Proliferation, Migration, and Invasion in Cholangiocarcinoma Through Regulating miR-760/E2F3 Axis

BACKGROUND

Long non-coding RNA (lncRNA) has been testified to influence the initiation and evolution of sundry carcinomas. Recently, lncRNA FOXD2 adjacent opposite strand RNA 1 (FOXD2-AS1) has been found to display vital regulating functions in various cancers.

METHODS

qRT-PCR was used to verify the dysregulation of FOXD2-AS1 expression in CCA cells and tissues, and the correlation of FOXD2-AS1 expression with clinicopathological characteristics was investigated. The viability, migration, and invasion of CCA cells were verified through CCK-8 assay, colony formation experiment, wound healing assay, and transwell assay. The regulatory networks of FOXD2-AS1 were analyzed by Bioinformatic prediction and dual-luciferase reporter assay.

RESULTS

We discovered that FOXD2-AS1 was significantly upregulated in CCA and its up-regulation was closely correlated with terminal TNM stage, lymph node metastasis and poor survival in the current research. In addition, it was revealed that FOXD2-AS1 was an independent prognostic factor. Functional tests uncovered that the cell viability, migration, and invasion could be restrained through downregulating the expression of FOXD2-AS1, while FOXD2-AS1 overexpression could facilitate the cell viability, migration, and invasion. Mechanistically, FOXD2-AS1 was founded to interact directly with miR-760 and the oncogene E2F3 was the downstream target of miR-760 through bioinformatic prediction and dual-luciferase reporter assays. Finally, we testified that FOXD2-AS1 could competitively sponge miR-760 and further upregulated the E2F3 expression to play a vital part in cholangiocarcinoma.

CONCLUSIONS

This research revealed that lncRNA FOXD2-AS1 could enhance CCA malignant progression through regulating the miR-760/E2F3 axis and was expected to be a prognostic biomarker and therapeutic target for cholangiocarcinoma.

The pleiotropic roles of circular and long noncoding RNAs in cutaneous melanoma

Cutaneous melanoma (CM) is a very aggressive disease, often characterized by unresponsiveness to conventional therapies and high mortality rates worldwide. The identification of the activating BRAFV600 mutations in approximately 50% of CM patients has recently fueled the development of novel small-molecule inhibitors that specifically target BRAFV600 -mutant CM. In addition, a major progress in CM treatment has been made by monoclonal antibodies that regulate the immune checkpoint inhibitors. However, although target-based therapies and immunotherapeutic strategies have yielded promising results, CM treatment remains a major challenge. In the last decade, accumulating evidence points to the aberrant expression of different types of noncoding RNAs (ncRNAs) in CM. While studies on microRNAs have grown exponentially leading to significant insights on CM biology, the role of circular RNAs (circRNAs) and long noncoding RNAs (lncRNAs) in this tumor is less understood, and much remains to be discovered. Here, we summarize and critically review the available evidence on the molecular functions of circRNAs and lncRNAs in BRAFV600 -mutant CM and CM immunogenicity, providing recent updates on their functional role in targeted therapy and immunotherapy resistance. In addition, we also include an evaluation of several algorithms and databases for prediction and validation of circRNA and lncRNA functional interactions.

LINC01224 facilitates the proliferation and inhibits the radiosensitivity of melanoma cells through the miR-193a-5p/NR1D2 axis

Melanoma is a skin cancer characterized by early metastasis and high mortality. Radiotherapy is a common treatment for melanoma in patients. Long noncoding RNAs play pivotal roles in regulating the radiosensitivity of many tumors, including melanomas. In this study, the role of LINC01224 in the radiosensitivity of melanoma cells was explored. The expression of LINC01224 in melanoma was examined by reverse transcription-quantitative polymerase chain reaction, and the results showed that LINC01224 was upregulated in melanoma tissues and cells. The effects of LINC01224 on cell proliferation and apoptosis in melanoma were assessed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT), colony formation, and flow cytometry assays. The effects of LINC01224 on the radiosensitivity of melanoma were analyzed by colony formation assay. The results implied that LINC01224 knockdown inhibited cell viability and proliferation but enhanced cell apoptosis and radiosensitivity. Luciferase reporter and RNA pull-down assays were performed to evaluate the relationships between LINC01224 and miR-193a-5p or miR-193a-5p and nuclear receptor subfamily 1 group D member 2 (NR1D2). We found that LINC01224 binds to miR-193a-5p, which directly targets NR1D2. In addition, we discovered that LINC01224 upregulated NR1D2 expression by sponging miR-193a-5p in melanoma cells. Overall, the data collected in this study suggest that LINC01224 exerts oncogenic effects in melanoma via the miR-193a-5p/NR1D2 axis.

The Role of Long Non-coding RNA, Nuclear Enriched Abundant Transcript 1 (NEAT1) in Cancer and Other Pathologies

Nuclear enriched abundant transcript 1 (NEAT1), consisting of two kinds of lncRNAs of 3.7 kB NEAT1-1 and 23 kB NEAT1-2, can be highly expressed in organs and tissues such as the ovary, prostate, colon, and pancreas, and is involved in paraspeckle formation and mRNA editing and gene expression. Therefore, NEAT1 is a potential biomarker for the treatment of a variety of diseases, which may be caused by two factors (isoforms of NEAT1 and NEAT1 sponging miRNA as ceRNA). However, there is still much confusion about the mechanism and downstream effector between the abnormal expression of NEAT1 and various diseases. This review summarizes recent research progress on NEAT1 in cancer and other pathologies and provides a more reliable theoretical basis for the treatment of related diseases.

The Functional Role of Long Non-Coding RNAs in Melanoma

Melanoma is the most lethal skin cancer, with increasing incidence worldwide. The molecular events that drive melanoma development and progression have been extensively studied, resulting in significant improvements in diagnostics and therapeutic approaches. However, a high drug resistance to targeted therapies and adverse effects of immunotherapies are still a major challenge in melanoma treatment. Therefore, the elucidation of molecular mechanisms of melanomagenesis and cancer response to treatment is of great importance. Recently, many studies have revealed the close association of long noncoding RNAs (lncRNAs) with the development of many cancers, including melanoma. These RNA molecules are able to regulate a plethora of crucial cellular processes including proliferation, differentiation, migration, invasion and apoptosis through diverse mechanisms, and even slight dysregulation of their expression may lead to tumorigenesis. lncRNAs are able to bind to protein complexes, DNA and RNAs, affecting their stability, activity, and localization. They can also regulate gene expression in the nucleus. Several functions of lncRNAs are context-dependent. This review summarizes current knowledge regarding the involvement of lncRNAs in melanoma. Their possible role as prognostic markers of melanoma response to treatment and in resistance to therapy is also discussed.

Pathogenic roles of long noncoding RNAs in melanoma: Implications in diagnosis and therapies

Melanoma is one of the most dangerous types of cutaneous neoplasms, which are pigment-producing cells of neuroectodermal origin found all over the body. A great deal of research is focused on the mechanisms of melanoma to promote better diagnostic and treatment options for melanoma in its advanced stages. The progression of melanoma involves alteration in different levels of gene expression. With the successful implementation of next-generation sequencing technology, an increasing number of long noncoding RNAs (lncRNAs) sequences have been discovered, and a significant number of them have phenotypic effects in both in vitro and in vivo studies, implying that they play an important role in the occurrence and progression of human cancers, particularly melanoma. A number of evidence indicated that lncRNAs are important regulators in tumor cell proliferation, invasion, apoptosis, immune escape, energy metabolism, drug resistance, epigenetic regulation. To better understand the role of lncRNAs in melanoma tumorigenesis, we categorize melanoma-associated lncRNAs according to their cellular functions and associations with gene expression and signaling pathways in this review. Based on the mechanisms of lncRNA, we discuss the possibility of lncRNA-target treatments, and the application of liquid biopsies to detect lncRNAs in melanoma diagnosis and prognosis.

Long non-coding RNA (lncRNA) nuclear enriched abundant transcript 1 (NEAT1) regulates fibroblast growth factor receptor substrate 2 (FRS2) by targeting microRNA (miR)-29-3p in hypertrophic scar fibroblasts

Long non-coding RNAs (lncRNAs) play crucial roles in human diseases. However, the detailed role of lncRNAs in hypertrophic scar fibroblasts (HSFs) is inadequately understood. This study aimed to investigate the potential role of lncRNA nuclear enriched abundant transcript 1 (NEAT1) in hypertrophic scarring. Expression of lncRNAs, miRNAs, and genes were detected by polymerase chain reaction; protein expression was evaluated using western blotting. Cellular function was determined using the CCK-8 assay. The interaction between microRNA (miR)-29-3p and NEAT1 or fibroblast growth factor receptor substrate 2 (FRS2) was verified by luciferase and RNA pull-down assays. The results showed that NEAT1 was overexpressed in the hypertrophic dermis and in HSFs. However, knockdown of NEAT1 suppressed the proliferation and extracellular matrix (ECM) production of HSFs. Moreover, NEAT1 functioned as a competing endogenous RNA to upregulate FRS2 by sponging miR-29-3p. Downregulation of miR-29-3p or overexpression of FRS2 antagonized the effects of NEAT1 knockdown and promoted HSF proliferation and ECM release. In conclusion, NEAT1 knockdown protected against hypertrophic scarring by modulating the miR-29-3p/FRS2 axis, which is a viable target in scar treatment.

SNHG10 Promotes Cell Proliferation and Migration in Gastric Cancer by Targeting miR-495-3p/CTNNB1 Axis

BACKGROUND

Long non-coding RNAs have been acknowledged as the crucial regulators in the progression of human cancers, including gastric cancer (GC). Small nucleolar RNA host gene 10 (SNHG10) has been identified as an oncogene in several cancer types. Nonetheless, it is unclear whether SNHG10 exerts functions in GC cells.

AIMS

The aims of the current study were to explore the function and underlying mechanism of SNHG10 in GC.

METHODS

The expression levels of SNHG10, miR-495-3p and catenin beta 1 (CTNNB1) were detected by RT-qPCR. Loss-of-function assays, including CCK-8, colony formation assay, flow cytometry analysis and transwell assays, were conducted to verify the effect of SHNG10 on the proliferation, apoptosis, migration and invasion of GC cells. Mechanism experiments were performed to identify the downstream molecular mechanism of SNHG10.

RESULTS

SNHG10 was expressed at a high level in GC cells. Knockdown of SNHG10 inhibited the proliferation, migration and invasion of GC cells. Silencing of SNHG10 led to the downregulation of core factors of WNT signaling pathway. Knockdown of SNHG10 could decline the expression of CTNNB1 through sequestering miR-495-3p.

CONCLUSIONS

SNHG10 promotes the procession of GC through targeting miR-495-3p/CTNNB1 and activating WNT signaling pathway.

NCK1-AS1 promotes the progression of melanoma by accelerating cell proliferation and migration via targeting miR-526b-5p/ADAM15 axis

Background

Long non-coding RNAs (lncRNAs) are vital regulators of gene expression and cellular processes in multiple cancers, including melanoma. Nevertheless, the function of lncRNA NCK1-antisense 1 (NCK1-AS1) in melanoma remains unknown.

Methods

RT-qPCR was used to analyze the expression of NCK1-AS1, microRNA-526b-5p (miR-526b-5p) and ADAM metallopeptidase domain 15 (ADAM15). Cell proliferation was determined by CCK-8, colony formation and EdU assays. Cell migration was assessed by transwell migration and wound healing assays. Mechanism experiments including luciferase reporter, RIP and RNA pull down assays were conducted to demonstrate the interactions between RNAs. Xenograft model was established to verify the function of NCK1-AS1 and miR-526b-5p in melanoma in vivo.

Results

NCK1-AS1 was overexpressed in melanoma cell lines and NCK1-AS1 knockdown hampers the proliferation and migration of melanoma cells. Besides, miR-526b-5p binds to NCK1-AS1 in melanoma and ADAM15 was validated as its downstream target. Further, the inhibitory effects of NCK1-AS1 knockdown on cell proliferation and migration in melanoma were reversed by the depletion of miR-526b-5p and further counteracted by ADAM15 knockdown. The growth of melanoma tumors was hindered by the down-regulation of NCK1-AS1 or up-regulation of miR-526b-5p.

Conclusion

NCK1-AS1 facilitates cell proliferation and migration in melanoma via targeting miR-526b-5p/ADAM15 axis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02055-y.

circTLK1 facilitates the proliferation and metastasis of renal cell carcinoma by regulating miR-495-3p/CBL axis

Renal cell carcinoma (RCC) is a common urological malignancy. Circular RNAs (circRNAs) have been confirmed to play an important regulatory role in various cancers. This study aimed to investigate the role and potential mechanism of circTLK1 (hsa_circ_0004442) in RCC. The levels of circTLK1, Cbl proto-oncogene (CBL), and microRNA-495-3p (miR-495-3p) were detected by quantitative reverse transcription polymerase chain reaction or western blot. Cell proliferation, cycle arrest and apoptosis, migration, and invasion were assessed by colony formation, flow cytometry, scratch, and transwell assays. The levels of E-cadherin and Vimentin were measured by western blot. The targeting relationship between miR-495-3p and miR-495-3p or CBL was verified by dual-luciferase reporter assay. Tumor growth in vivo was evaluated by xenograft assay. The results found that circTLK1 and CBL were up-regulated in RCC tissues and cells. Silencing of circTLK1 or CBL inhibited proliferation and metastasis and accelerated apoptosis in RCC cells. In addition, circTLK1 directly bound to miR-495-3p, and CBL was the target of miR-495-3p. circTLK1 sponged miR-495-3p to increase CBL expression. Moreover, knockdown of circTLK1 suppressed tumor growth in vivo. In conclusion, down-regulation of circTLK1 restrained proliferation and metastasis and promoted apoptosis in RCC cells by modulating miR-495-3p/CBL axis.

ARID1B/SUB1-activated lncRNA HOXA-AS2 drives the malignant behaviour of hepatoblastoma through regulation of HOXA3

It has been becoming increasingly evident that long non‐coding RNAs (lncRNAs) play important roles in various human cancers. However, the biological processes and clinical significance of most lncRNAs in hepatoblastoma (HB) remain unclear. In our previous study, genome‐wide analysis with a lncRNA microarray found that lncRNA HOXA‐AS2 was up‐regulated in HB. Stable transfected cell lines with HOXA‐AS2 knockdown or overexpression were constructed in HepG2 and Huh6 cells, respectively. Our data revealed knockdown of HOXA‐AS2 increased cell apoptosis and inhibited cell proliferation, migration and invasion in HB. Up‐regulation of HOXA‐AS2 promoted HB malignant biological behaviours. Mechanistic investigations indicated that HOXA‐AS2 was modulated by chromatin remodelling factor ARID1B and transcription co‐activator SUB1, thereby protecting HOXA3 from degradation. Therefore, HOXA‐AS2 positively regulates HOXA3, which might partly demonstrate the involvement of HOXA3 in HOXA‐AS2‐mediated HB carcinogenesis. In conclusion, HOXA‐AS2 is significantly overexpressed in HB and the ARID1B/HOXA‐AS2/HOXA3 axis plays a critical role in HB tumorigenesis and development. These results might provide a potential new target for HB diagnosis and therapy.

Circular RNA circ_0000372 contributes to the proliferation, migration and invasion of colorectal cancer by elevating IL6 expression via sponging miR-495

Circular RNAs are thought to play a vital function in the progression of various cancers, including colorectal cancer (CRC). However, the biological function and mechanism of circ_0000372 in CRC are still not clear. The expression of circ_0000372 and microRNA (miR)-495 was examined by quantitative real-time PCR. Cell proliferation was evaluated using cell counting kit 8 and colony formation assays. Further, cell migration and invasion were assessed using transwell assay. Additionally, western blot analysis was used to detect the expression of proteins associated with proliferation, metastasis, Janus kinase 2 (JAK2)/signal transducers and activators of transcription (STAT3) signaling pathway and interleukin 6 (IL6). Dual-luciferase reporter assay and RNA immunoprecipitation assay were employed to verify the interaction between miR-495 and circ_0000372 or IL6. Furthermore, the effect of circ_0000372 on CRC tumor growth in vivo was explored using the mice xenograft models. Circ_0000372 was markedly upregulated in CRC, and its high expression was associated with the poor prognosis of CRC patients. Silenced circ_0000372 was able to suppress CRC cell proliferation, migration and invasion in vitro and CRC tumor growth in vivo. Bioinformatics prediction and experimental verification proposed that circ_0000372 could sponge miR-495, and miR-495 could target IL6. Besides, the JAK2/STAT3 signaling pathway activation could be regulated by circ_0000372, miR-495 and IL6. Rescue assay results confirmed that the inhibition effect of circ_0000372 knockdown on the proliferation and metastasis of CRC could be reversed by miR-495 inhibitor or IL6 overexpression. In short, we concluded that circ_0000372 promoted CRC progression by regulating the miR-495/IL6 axis, suggesting that circ_0000372 could be used as a new prognostic biomarker and therapeutic target for CRC.

The LINC00477/miR-128 axis promotes the progression of polycystic ovary syndrome by regulating ovarian granulosa cell proliferation and apoptosis

BACKGROUND

Long noncoding RNAs (lncRNAs) participate in the pathogenesis of various human diseases. This study aims to investigate the roles of lncRNA LINC00477 in polycystic ovary syndrome (PCOS), especially the impacts of LINC00477 on the proliferation and migration of human granulosa cells and the related mechanisms.

METHODS

qRT-PCR analysis was performed to examine the expression pattern of LINC00477 in serum samples of PCOS patients as well as PCOS animal models. The effect of LINC00477 on the viability and apoptosis of ovarian granulosa cells was detected by MTT and flow cytometry assays. The correlation between LINC00477 and miR-128 was verified by bioinformatics analysis and dual-luciferase reporter and RNA pull-down assays. Finally, rescue assays were performed to analyze the effects of the LINC00477-miR-128 axis on the biological behaviors of granulosa cells.

RESULTS

LINC00477 was significantly upregulated in the serum of PCOS patients as well as PCOS mouse models. LINC00477 overexpression inhibited the proliferation and promoted the apoptosis of granulosa cells, whereas knockdown of LINC00477 yielded the opposite effects. Moreover, miR-128 mimics partially abrogated the effect of LINC00477 on granulosa cells.

CONCLUSION

LINC00477 may function as a ceRNA to inhibit proliferation and apoptosis of granulosa cells by modulating miR-128 expression.

Circular RNA CDR1as promotes tumor progression by regulating miR-432-5p/E2F3 axis in pancreatic cancer

BACKGROUND

Pancreatic cancer (PC), characterized with high growth rate and metastatic rate. It's urgently necessary to explore new mechanism of PC. Circular RNA/miRNA/mRNA network was widely reported to participate in the cancer progression.

METHODS

In this research, circular RNA CDR1as (circCDR1as) was identified by microarray analysis and detected in pancreatic cancer (PC) tissues and cells. Transwell, colony-forming assay, nude mouse tumorigenicity assay were used to determine the function of circCDR1as in PC. Western blot, dual luciferase reporting test were applied to investigate the mechanism.

RESULTS

We found that circCDR1as was highly expressed in PC tissues. The levels of circCDR1as in PC tissues and cells were higher than those in controls. CircCDR1as promoted the migration, invasion and proliferation of PC cells in vitro and tumor growth in vivo via mediating E2F3 expression by sponging miR-432-5p.

CONCLUSIONS

In conclusion, circCDR1as could promote the development of PC and might be a novel diagnostic target for PC.

Comprehensive Review on the Clinical Relevance of Long Non-Coding RNAs in Cutaneous Melanoma

Cutaneous melanoma is considered a rare tumor, although it is one of the most common cancers in young adults and its incidence has risen in the last decades. Targeted therapy, with BRAF and MEK inhibitors, and immunotherapy revolutionized the treatment of metastatic melanoma but there is still a considerable percentage of patients with primary or acquired resistance to these therapies. Recently, oncology researchers directed their attention at the role of long non-coding RNAs (lncRNAs) in different types of cancers, including melanoma. lncRNAs are RNA transcripts, initially considered "junk sequences", that have been proven to have a crucial role in the fine regulation of physiological and pathological processes of different tissues. Furthermore, they are more expressed in tumors than protein-coding genes, constituting perfect candidates either as biomarkers (diagnostic, prognostic, predictive) or as therapeutic targets. In this work, we reviewed all the literature available for lncRNA in melanoma, elucidating all the potential roles in this tumor.

Silencing long non-coding RNA NEAT1 attenuates rheumatoid arthritis via the MAPK/ERK signalling pathway by downregulating microRNA-129 and microRNA-204

The participation of long noncoding RNAs (lncRNAs) and microRNAs (miRs) in the progression of rheumatoid arthritis (RA) is a key area of investigation. The current study aimed to investigate the action of lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) in fibroblast-like synoviocyte (FLS) proliferation and synovitis in RA. A rat model of RA was established. LncRNA NEAT1 expression in the synovial tissues of patients with RA and FLSs from the RA rat model was determined using RT-qPCR. Next, dual luciferase reporter gene assay was applied to investigate the relationship between miR-129/204 and mitogen-activated protein kinase (MAPK)/extracellular regulated protein kinase (ERK). A putative binding relationship between miR-204 and lncRNA NEAT1 was evaluated by RIP assay, and miR-129 promoter methylation was determined using MSP. After the expression of lncRNA NEAT1, miR-129 or miR-204 was altered in FLSs, the extent of ERK1/2 phosphorylation was assessed. In addition, FLS synovitis and proliferation were determined by ELISA and EdU assay, respectively. In RA rats, lncRNA NEAT1 was silenced and miR-129/miR-204 was overexpressed to explore their roles in vivo. LncRNA NEAT1 was upregulated, while miR-129 and miR-204 were downregulated in RA synovial tissues and FLSs. MAPK1 was target gene of both miR-129 and miR-204. LncRNA NEAT1 bound to miR-204 and promoted miR-129 promoter methylation. Silencing lncRNA NEAT1 or overexpressing miR-129/miR-204 enhanced miR-129/miR-204 expression, but reduced the extent of ERK1/2 phosphorylation, proliferation of FLSs, and synovitis in RA. Collectively, silencing lncRNA NEAT1 promoted miR-129 and miR-204 to inhibit the MAPK/ERK signalling pathway, reducing FLS synovitis in RA.Abbreviations: ACR: American College of Rheumatology; ELISA: Enzyme-linked immunosorbent assay; ERK: extracellular signal-regulated kinase; FLS: fibroblast-like synoviocyte; GADPH: glyceraldehyde-3-phosphate dehydrogenase; HRP: horseradish peroxidase; IFA: Incomplete Freund's Adjuvant; lncRNAs: long noncoding RNAs; MSP: Methylation-specific PCR; NC: negative control; NEAT1: nuclear paraspeckle assembly transcript 1; OD: optical density; RA: rheumatoid arthritis; RIPA: Radio Immunoprecipitation Assay; RLU: relative light units; RT-qPCR: reverse transcription quantitative polymerase chain reaction; UTR: untranslated region.

CircularRNA_0119872 regulates the microRNA-582-3p/E2F transcription factor 3 pathway to promote the progression of malignant melanoma

OBJECTIVES

Malignant melanoma (MM) is an invasive tumor that poses a threat to patient health. Circular RNAs (circRNAs) are important regulators of MM carcinogenesis. In this study, we investigated the expression characteristics and biological functions of, and mechanism underlying, circ_0119872 expression in MM.

METHODS

Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was employed to examine the circ_0119872, microRNA (miR)-582-3p, and E2F transcription factor 3 (E2F3) mRNA expression levels in MM tissues and cell lines. Western blotting was performed to quantify E2F3 protein expression. MM cells with circ_0119872 knockdown were established, and cell counting kit 8 (CCK-8) and transwell assays were utilized to examine the function of circ_0119872 and its effects on the malignant characteristics of MM cells. The MiRDB and TargetScan databases were used to predict the target genes of miR-582-3p. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was used to explore the biological functions of the target genes of miR-582-3p. Additionally, a dual-luciferase reporter gene experiment was performed to verify the targeting relationship between circ_0119872 and miR-582-3p as well as that between miR-582-3p and E2F3.

RESULTS

Circ_0119872 was remarkably upregulated in MM tissues and cell lines. Circ_0119872 knockdown suppressed the cell proliferation and metastasis In addition, miR-582-3p was identified as a downstream target of circ_0119872. The target genes of miR-193a-3p are involved in melanogenesis and cancer-related signaling pathways. Mechanistically, circ_0119872 facilitated MM progression by adsorbing miR-582-3p and upregulating E2F3 expression.

CONCLUSION

Circ_0119872 is an oncogenic circRNA that participates in the promotion of MM progression by regulating the miR-582-3p/E2F3 axis.

Identification of lncRNA-mRNA Regulatory Module to Explore the Pathogenesis and Prognosis of Melanoma

Skin cutaneous melanoma (SKCM) is an aggressive form of skin cancer that results in high mortality rate worldwide. It is vital to discover effective prognostic biomarkers and therapeutic targets for the treatment of melanoma. Long non-coding RNA (lncRNA) has been verified to play an essential role in the regulation of gene expression in diseases and tumors. Therefore, it is significant to explore the function of lncRNAs in the development and progression of SKCM. In this paper, a set of differentially expressed lncRNAs (DElncRNAs) and mRNAs (DEmRNAs) were first screened out using 471 cutaneous melanoma samples and 813 normal skin samples. Gene Ontology and KEGG pathway enrichment analysis were performed to obtain the significant function annotations and pathways of DEmRNAs. We also ran survival analysis on both DElncRNAs and DEmRNAs to identify prognostic-related lncRNAs and mRNAs. Next, a set of hub genes derived from protein-protein interaction (PPI) network analysis and lncRNA target genes screened from starbase-ENCORI database were integrated to construct a lncRNA-mRNA regulatory module, which includes 6 lncRNAs 4 target mRNAs. We further checked the capacity of these lncRNA and mRNA in the diagnosis of melanoma, and found that single lncRNA can effectively distinguish tumor and normal tissue. Moreover, we ran CMap analysis to select a list of small molecule drugs for SKCM, such as EGFR inhibitor AG-490, growth factor receptor inhibitor GW-441756 and apoptosis stimulant betulinic-acid, which have shown therapeutic effect in the treatment of melanoma.

Regulation of melanoma malignancy by the RP11-705C15.3/miR-145-5p/NRAS/MAPK signaling axis

Melanoma is a common lethal skin cancer. Dissecting molecular mechanisms driving the malignancy of melanoma may uncover potential therapeutic targets. We previously identified miR-145-5p as an important tumor-suppressive microRNA in melanoma. Here, we further investigated the roles of long non-coding RNAs (lncRNAs) in melanoma. We identified RP11-705C15.3, a regulator of miR-145-5p, as an oncogenic lncRNA in melanoma. RP11-705C15.3 competitively bound miR-145-5p, relieved the repressive roles of miR-145-5p on its target NRAS, upregulated NRAS expression, and activated MAPK signaling. In vitro functional assays revealed that ectopic expression of RP11-705C15.3 promoted melanoma cell proliferation, inhibited apoptosis, and promoted migration and invasion. Silencing of RP11-705C15.3 repressed melanoma cell proliferation, induced apoptosis, and repressed migration and invasion. Notably, the roles of RP11-705C15.3 in melanoma cell proliferation, apoptosis, migration and invasion are reversed by miR-145-5p overexpression. In vivo functional assays revealed that RP11-705C15.3 promoted melanoma tumor growth and metastasis, which were also reversed by miR-145-5p overexpression. Furthermore, we investigated the expression of RP11-705C15.3 in clinical melanoma tissues and found that RP11-705C15.3 was increased in melanoma tissues. High expression of RP11-705C15.3 was positively correlated with thickness, ulceration, metastasis, and inferior overall survival. Taken together, our findings suggest RP11-705C15.3 as a novel oncogene in melanoma, and highlight that the RP11-705C15.3/miR-145-5p/NRAS/MAPK signaling axis may be potential therapeutic targets for melanoma.

Circ_0016760 Acts as a Sponge of MicroRNA-4295 to Enhance E2F Transcription Factor 3 Expression and Facilitates Cell Proliferation and Glycolysis in Nonsmall Cell Lung Cancer

Background: Circular RNAs (circRNAs) have been validated as important regulators of nonsmall cell lung cancer (NSCLC), but the role and potential mechanism of circ_0016760 in NSCLC remain largely unclear. Materials and Methods: Quantitative real-time polymerase chain reaction was performed to detect the levels of circ_0016760, microRNA-4295 (miR-4295), and E2F transcription factor 3 (E2F3). The cell proliferation was measured by methyl-thiazolyl diphenyl-tetrazolium bromide assay. The protein levels of proliferating cell nuclear antigen and E2F3 were examined by Western blot. Xenograft mice model was constructed to explore the effect of circ_0016760 on tumor growth in vivo. The relationship among circ_0016760, miR-4295, and E2F3 was evaluated using dual-luciferase reporter assay. Glucose consumption of NSCLC cells was assessed by the glucose assay kit. Results: Circ_0016760 and E2F3 expression levels were upregulated in NSCLC tissues and cells, while miR-4295 was downregulated. Circ_0016760 could bind to miR-4295, and negatively modulate its expression in NSCLC cells. Besides, miR-4295 directly targeted E2F3 and inversely regulated E2F3 expression. More importantly, Circ_0016760 facilitated proliferation and glycolysis of NSCLC cells by increasing E2F3 by sponging miR-4295 as well as promoted the tumor growth in vivo. Conclusion: Circ_0016760 served as a growth-promoting circRNA in NSCLC by facilitating cell proliferation and glycolysis by regulating the miR-4295/E2F3 axis, providing a novel potential target for NSCLC treatment.

NEAT1/miR-200b-3p/SMAD2 axis promotes progression of melanoma

Melanoma is a skin malignancy with a high mutation frequency of genetic alterations. MicroRNA (miR)-200b-3p is involved in various cancers, while in melanoma its bio-function remains unknown. In this study, we found that miR-200b-3p was down-regulated in melanoma tissues and cell lines compared to benign nevus cells. Overexpression of miR-200b-3p significantly inhibited the proliferation and invasion of melanoma cells. According to bioinformatics analysis and sequencing data, we supposed that SMAD family member 2 (SMAD2) was the target gene and nuclear enriched abundant transcript 1 (NEAT1) was the upstream long non-coding RNA (lncRNA) of miR-200b-3p. These predictions were verified by western blotting and quantitative real-time reverse transcription PCR (RT-qPCR). Luciferase reporter assays revealed that NEAT1 up-regulated SMAD2 by directly sponging miR-200b-3p. In vitro and in vivo, we demonstrated that both NEAT1 and SMAD2 could promote the proliferation and invasion of melanoma cells, and these effects were reversed by up-regulating miR-200b-3p. In addition, NEAT1/miR-200b-3p/SMAD2 axis promoted melanoma progression by activating EMT signaling pathway and immune responses. Taken together, the NEAT1/miR-200b-3p/SMAD2 signaling pathway promotes melanoma via activation of EMT, cell invasion and is related with immune responses, which provides new insights into the molecular mechanisms and therapeutic targets for melanoma.

Long non‑coding RNA TTN‑AS1 regulates the proliferation, invasion and migration of triple‑negative breast cancer by targeting miR‑211‑5p

Increasing evidence has demonstrated that long non-coding RNAs (lncRNAs) serve important roles in numerous malignancies, including triple-negative breast cancer (TNBC). The lncRNA titin-antisense RNA1 (TTN-AS1) has previously been reported to promote tumorigenesis in various types of cancer. The present study aimed to investigate the potential role of TTN-AS1 in breast cancer and the associated underlying mechanisms. Following prediction by Starbase and confirmation by dual-luciferase reporter assay, TINCR was demonstrated to be a target gene for microRNA (miR)-211-5p. The expression levels of TTN-AS1 and miR-211-5p, which was predicted to be targeted by TTN-AS1, in TNBC tissues and in the breast cancer cell lines MDA-MB-453 and MDA-MB-231 were measured using reverse transcription-quantitative PCR. Following TTN-AS1-knockdown, cell proliferation was measured using a Cell Counting Kit-8 assay and colony formation assay, whereas cell invasion and migration were measured using Transwell and wound healing assays, respectively. Luciferase reporter assay was performed to verify the potential interaction between TTN-AS1 and miR-211-5p. In addition, rescue assays were conducted to investigate the effects of TTN-AS1 and miR-211-5p on TNBC development. The results demonstrated that TTN-AS1 expression was significantly upregulated, whereas that of miR-211-5p was found to be downregulated in TNBC tissues and cell lines compared with the matched adjacent normal tissues and normal breast epithelial cell line MCF-10A, respectively. Furthermore, TTN-AS1-knockdown inhibited the proliferation and invasive and migratory abilities of MDA-MB-453 and MDA-MB-231 cells, which was reversed following co-transfection with the miR-211-5p inhibitor. The results from luciferase reporter assay confirmed that miR-211-5p was a direct target of TTN-AS1, suggesting that TTN-AS1 may bind directly to miR-211-5p to negatively regulate its expression. In conclusion, the findings from the present study demonstrated that TTN-AS1 regulated the proliferation and invasive and migratory abilities of TNBC by targeting miR-211-5p. This study may provide some insights into the regulatory mechanism of TNBC and help the development of novel therapeutic interventions for TNBC.

Immune Microenvironment Related Competitive Endogenous RNA Network as Powerful Predictors for Melanoma Prognosis Based on WGCNA Analysis

Cutaneous melanoma is the most life-threatening skin malignant tumor due to its increasing metastasis and mortality rate. The abnormal competitive endogenous RNA network promotes the development of tumors and becomes biomarkers for the prognosis of various tumors. At the same time, the tumor immune microenvironment (TIME) is of great significance for tumor outcome and prognosis. From the perspective of TIME and ceRNA network, this study aims to explain the prognostic factors of cutaneous melanoma systematically and find novel and powerful biomarkers for target therapies. We obtained the transcriptome data of cutaneous melanoma from The Cancer Genome Atlas (TCGA) database, 3 survival-related mRNAs co-expression modules and 2 survival-related lncRNAs co-expression modules were identified through weighted gene co-expression network analysis (WCGNA), and 144 prognostic miRNAs were screened out by univariate Cox proportional hazard regression. Cox regression model and Kaplan-Meier survival analysis were employed to identify 4 hub prognostic mRNAs, and the prognostic ceRNA network consisting of 7 lncRNAs, 1 miRNA and 4 mRNAs was established. After analyzing the composition and proportion of total immune cells in cutaneous melanoma microenvironment through CIBERSORT algorithm, it is found through correlation analysis that lncRNA-TUG1 in the ceRNA network was closely related to the TIME. In this study, we first established cutaneous melanoma’s TIME-related ceRNA network by WGCNA. Cutaneous melanoma prognostic markers have been identified from multiple levels, which has important guiding significance for clinical diagnosis, treatment, and further scientific research on cutaneous melanoma.