LncRNA FOXD3-AS1 promotes proliferation, invasion and migration of cutaneous malignant melanoma via regulating miR-325/MAP3K2

LncRNA LINC00847 Accelerates Melanoma Progression by Regulating MiR-133a-3p/TGFBR1 Axis

AIMS

Growing evidence has suggested that lncRNAs play a regulatory role in tumorigenesis. Dysregulation of a newly identified lncRNA (LINC00847) has been involved in several tumors. Nevertheless, the expression and roles of lncRNAs in skin melanoma remain unclear. Therefore, we attempted to investigate the expressions and roles of lncRNAs in this study.

MATERIALS AND METHODS

Expression levels of LINC00847 were quantified in tissue samples from the TCGA database and clinically recruited participants. LINC00847 was inhibited in cells by transfecting with si-LINC00847 or si-NC. Expressions of LINC00847 and miR-133a-3p were determined using RT-qPCR, and the TGFBR1 level was determined using Western blotting. Targeting sites of LINC00847 with miR-133a-3p and miR-133a-3p with TGFBR1 were predicted by bioinformatic tools and proved by dual-luciferase reporter system and RNA immunoprecipitation. Cell proliferation, invasion, and migration abilities were assessed using CCK8, cell colony formation, cell wound scratch, and transwell assay, respectively.

RESULTS

In both TCGA and clinical cohorts, the expression of LINC00847 was abnormally upregulated in skin melanoma tissues than that of benign nevus. Besides, LINC00847 expression increased more markedly in A375 and SK-MEL-28 cells than in normal epidermal melanocytes (HEMa-LP cells). LINC00847 knockdown remarkably restrained skin melanoma cell proliferation, metastasis, and wound healing rate. Furthermore, miR-133a-3p/TGFBR1 was the downstream target for LINC00847. LINC00847 negatively regulated miR-133a-3p expression in skin melanoma cells. Both miR-133a-3p inhibitors and TGFBR1 vector transfection reversed the effect of LINC00847 silence in skin melanoma cells.

CONCLUSION

LINC00847 was highly expressed in skin melanoma, and its overexpression accelerated the malignant tumor behavior of skin melanoma cells. The miR-133a-3p /TGFBR1 axis was involved in the roles of LINC00847 in skin melanoma.

Upregulation LncRNA MEG3 expression suppresses proliferation and metastasis in melanoma via miR-208/SOX4

Long non-coding RNAs (lncRNAs) regulate gene expression and play a significant role in cancer progression. Previously, downregulation of lncRNA MEG3 was shown to associate with poor clinical outcomes in melanoma patients. The basis for this association has not been described and the aims of this study were to identify a role for lncRNA MEG3 in melanoma and to describe its regulatory mechanism of action. RT-qPCR was used to detect lncRNA MEG3 expression in melanoma cells and tissues. Luciferase reporter assays were used to identify lncRNA MEG3 downstream targets. Melanoma cells were transfected with various expression vectors and these transfected cells were assessed for; migration, colony formation, proliferation, in vivo tumorigenesis, and metastatic potential. Melanoma cell lines were found to be sensitive to lncRNA MEG3 expression levels and overexpression was found to inhibit melanoma cell proliferation and invasion, both in vitro and in vivo. Luciferase reporter assays identified miR-208 and SOX4 as downstream targets of lncRNA MEG3. Overexpression of miR-208 and silencing of SOX4 rescued invasion and proliferation by cells that overexpressed lncRNA MEG3. Moreover, lncRNA MEG3 inhibited cancer stem cell differentiation and suppressed melanoma progression and metastasis through inhibition of miR-208 by SOX4.

KIAA1429 promotes tumorigenesis and gefitinib resistance in lung adenocarcinoma by activating the JNK/ MAPK pathway in an m6A-dependent manner

Non-small cell lung cancer is the leading cause of cancer related mortality worldwide, and lung adenocarcinoma (LUAD) is one of the most common subtypes. The role of N6-methyladenosine (m⁶A) modification in tumorigenesis and drug resistance in LUAD remains unclear. In this study, we evaluated the effects of vir-like m⁶A methyltransferase-associated protein (KIAA1429) depletion on proliferation, migration, invasion, and drug resistance of LUAD cells, and identified m⁶A-dependent downstream genes influenced by KIAA1429. We found that KIAA1429 activated Jun N-terminal kinase (JNK) mitogen-activated protein kinase (MAPK) pathway as a novel signaling event, which is responsible for tumorigenesis and resistance to gefitinib in LUAD cells. KIAA1429 and MAP3K2 showed high expression in LUAD patients' tissues. Knockdown of KIAA1429 inhibited MAP3K2 expression in an m⁶A methylation-dependent manner, restraining the progression of LUAD cells and inhibiting growth of gefitinib-resistant HCC827 cells. KIAA1429 positively regulated MAP3K2 expression, activated JNK/ MAPK pathway, and promoted drug resistance in gefitinib-resistant HCC827 cells. We reproduced the in vitro results in nude mouse xenografted with KIAA1429 knockdown cells. Our study showed that the mechanism of m⁶A KIAA1429-mediated gefitinib resistance in LUAD cells occurs by activating JNK/ MAPK signaling pathway. These findings provide potential targets for molecular therapy and clinical treatment in LUAD patients with gefitinib resistance.

lncRNA-AC130710/miR-129-5p/mGluR1 axis promote migration and invasion by activating PKCα-MAPK signal pathway in melanoma

Invasion and metastasis of melanoma are a series of complicated biological events regulated by multiple factors. The coregulation of many molecules involved in the development and progression of melanoma contributes to invasion and migration. mGluR1 is a metabotropic glutamate receptor that is overexpressed in melanocytes and is sufficient to induce melanoma. In our study, we found that mGluR1 was obviously increased in melanoma. Furthermore, we found that miR-129-5p could directly target and regulate mGluR1 mRNA, which was significantly reduced in A375 cells. Overexpression of miR-129-5p inhibited cell migration, invasion and clonal formation. lncRNA-AC130710 directly targeted and suppressed miR-129-5p in A375 cells. Downregulation of lncRNA-AC130710 suppressed the levels of mGluR1 mRNA by promoting miR-129-5p expression and further inhibiting migration, invasion and colony formation in A375 cells, which was associated with the activation of the PKCα-MAPK signaling pathway. Taken together, our study showed that the lncRNA-AC130710/miR-129-5p/mGluR1 axis plays an important role in the invasion and metastasis of melanoma.

LncRNA FOXD3-AS1 aggravates myocardial ischemia/reperfusion injury by inactivating the Redd1/AKT/GSK3β/Nrf2 signaling pathway via the miR-128/TXNIP axis

Long noncoding RNA forkhead box D3-antisense RNA 1 (FOXD3-AS1) is associated with cardiovascular diseases, but its roles in myocardial ischemia/reperfusion (I/R) injury and the related signaling pathway have not been fully reported. We aimed to investigate the roles and mechanism of action of FOXD3-AS1 in myocardial I/R injury. An in vivo myocardial I/R injury mouse model and an in vitro hypoxia/reoxygenation (H/R) cardiomyocyte model was established. Quantitative reverse transcription-polymerase chain reaction, western blotting, and immunofluorescent assays were performed to examine the expression levels of FOXD3-AS1, microRNA (miR)-128, thioredoxin-interacting protein/regulation of development and DNA damage response 1/protein kinase B/glycogen synthase kinase 3β/nuclear factor erythroid 2-related factor 2 (TXNIP/Redd1/AKT/GSK3β/Nrf2) pathway-related proteins and apoptosis-related proteins. The interactions between FOXD3-AS1 and miR-128 and miR-128 and TXNIP were analyzed by Spearman's correlation test, predicted by ENCORI, and verified by dual-luciferase reporter assay. In addition, the levels of cardiac injury markers and oxidative stress markers were evaluated by corresponding kits. Cell Counting Kit-8 assays and flow cytometry were performed to assess cell viability and apoptosis. Hematoxylin and eosin staining was applied to observe the effect of FOXD3-AS1 on the morphology of myocardial I/R injured tissues. The results showed that the FOXD3-AS1 and TXNIP were highly expressed, whereas miR-128 was expressed at low levels in I/R myocardial tissues and H/R-induced H9c2 cells. FOXD3-AS1 directly targeted miR-128 to reduce its expression. TXNIP was confirmed as a downstream target of miR-128. Knockdown of FOXD3-AS1 led to the alleviation of I/R injury in vivo and in vitro. FOXD3-AS1 enhanced the expression of TXNIP by sponging miR-128, which inhibited the Redd1/AKT/GSK3β/Nrf2 pathway. Both inhibition of miR-128 and overexpression of TXNIP reversed the cardioprotective effect of FOXD3-AS1 small interfering RNA in H/R-induced H9c2 cells.

MiR-325-3p Alleviates Acute Pancreatitis via Targeting RIPK3

BACKGROUND AND AIMS

Acute pancreatitis (AP) is an acute inflammatory disease that can lead to death. Mir-325-3p is strongly and abnormally expressed in many diseases, necessitating exploration of its function and mechanism in AP.

METHODS

Blood samples from AP patients and mice were analyzed. The expression levels of miR-325-3p in AP patients and mouse were detected. Whether miR-325-3p targets RIPK3 gene was predicted by TargetScan online database and dual luciferase reporter assay. In vitro experiments verified the effect of miR-325-3p overexpression on caerulein-induced MPC83 pancreatic acinar cancer cell line. In vivo experiments verified the effect of overexpression of miR-325-3p on the disease degree of pancreatic tissues in AP mice.

RESULTS

Analysis of blood samples from AP patients and experiments in mice demonstrated that expression of miR-325-3p was significantly reduced during the process of AP in humans and mice. Predicted using the TargetScan online database and through dual luciferase reporter assay detection, miR-325-3p directly targets the RIPK3 gene. In vitro experiments revealed that overexpression of miR-325-3p reversed caerulein-induced apoptosis and necroptosis in MPC83 pancreatic acinar cancer cell line. We used Z-VAD-FMK to assess necroptosis and demonstrated that miR-325-3p targets necroptosis to reduce cell damage. In subsequent experiments in mice, we verified that overexpression of miR-325-3p reduces inflammation, edema, hemorrhage, and necrosis in acute pancreatitis. Characteristic western blot, immunohistochemistry, and transmission electron microscopy results revealed that overexpression of miR-325-3p reduces the severity of acute pancreatitis by inhibiting pancreatic necroptosis in AP mice.

CONCLUSIONS

The current research results indicate that miR-325-3p directly targets RIPK3 and exerts a protective role in mouse AP. Necroptosis is still the primary mechanism of RIPK3 regulation. MiR-325-3p inhibits acute pancreatitis by targeting RIPK3-dependent necroptosis, which may represent a novel treatment method for acute pancreatitis.

lncRNA HAGLR modulates myocardial ischemia–reperfusion injury in mice through regulating miR-133a-3p/MAPK1 axis

Acute myocardial infarction is one of the leading causes of morbidity worldwide, but the underlying mechanism responsible for myocardial ischemia–reperfusion (I/R) injury remains elusive. lncRNA plays roles in inflammatory response, cell apoptosis and regulation of myocardial ischemia. However, whether lncRNA HAGLR could regulate myocardial I/R injury and the molecular mechanism need to be further investigated. lncRNA has been shown to bind to miRNAs and compete with endogenous RNAs. miR-133a-3p has been shown to regulate cardiomyocyte apoptosis and ischemic myocardial injury. In this work, it has shown that knockdown of HAGLR could suppress inflammatory response and cell apoptosis induced by I/R and, thus, alleviate myocardial I/R injury. HAGLR promoted myocardial I/R injury by inhibiting miR-133a-3p to promote MAPK1 expression.

DNMT1-mediated demethylation of lncRNA MEG3 promoter suppressed breast cancer progression by repressing Notch1 signaling pathway

Breast carcinoma is one of the common causes of cancer-related mortality in women. Maternally expressed gene 3 (MEG3), a lncRNA located at 14q32, can be involved in carcinogenesis. In this study, we discovered that MEG3 was downregulated by CpG hypermethylation within its gene promoter. Functionally, treatment of breast cancer cells with the DNA methylation inhibitor 5-AzadC as well as silencing of DNA methyltransferase-1 (DNMT1) could decrease the abnormal hypermethylation of the MEG3 promoter, reverse MEG3 expression, inhibit cell proliferation and promote cell apoptosis. In addition, we found that MEG3 expression was negatively correlated with DNMT1. Mechanistically, MEG3 knockdown combined with 5-AzadC or sh-DNMT1 treatment restored the expression of Notch1 receptor, leading to the Notch1 pathway activation, and promoted the progression of epithelial mesenchymal transformation (EMT). Finally, the mice tumor model experiments showed that DNMT1 knockdown can increase MEG3 expression and inhibit tumor growth. Collectively, our findings uncovered that DNMT1-mediated MEG3 demethylation leads to MEG3 upregulation, which in turn inhibits the Notch1 pathway and EMT process in breast cancer.

LncRNA FOXD3-AS1 promotes breast cancer progression by mediating ARF6

BACKGROUND

Breast cancer is one of the most common malignant tumor in women. The high metastatic characteristics cause a high mortality rate of breast cancer. Increasing number of studies have indicated that long non-coding RNAs (lncRNAs) play key roles in the progression of human cancers including breast cancer. In this study, we studied the expression and molecular mechanisms of lncRNA FOXD3-AS1 in breast cancer.

METHODS

The expression of lncRNA FOXD3-AS1 was analyzed by TCGA database and RT-qPCR assay. CCK8 assay was used to measure cell proliferation ability. Cell migration and invasion capacities were detected by transwell assay. Potential targets of lncRNA and miRNA were predicted by bioinformatic tools. The targeting relationship between genes was verified by dual-luciferase reporter assay. The nude mice tumor model was performed to study the effect of FOXD3-AS1 on breast cancer in vivo. Protein expression was detected by western blot.

RESULTS

In the present study, we found that the FOXD3-AS1 expression was significantly increased in breast cancer tissues compared with normal tissues and involved in the poor prognosis of patients. Functionally, knockdown of FOXD3-AS1 suppressed cell proliferation and metastasis abilities in vitro, and tumor growth in vivo. Mechanistically, FOXD3-AS1 functioned as a competing endogenous RNA (ceRNA) to upregulate ARF6 expression by targeting miR-127-3p. In addition, the roles of FOXD3-AS1 on cell proliferation and metastasis were achieved through miR-127-3p/ARF6 axis.

CONCLUSION

In summary, our results reported the regulatory mechanism of FOXD3-AS1 in breast cancer progression by targeting miR-127-3p/ARF6 axis to affect cell proliferation, migration, invasion and tumor growth.

The Multiple Pharmacologic Functions and Mechanisms of Action of Guizhi Fuling Formulation

Objectives

Guizhi Fuling Formulation (GZFL), a traditional Chinese medical formulation, consists of Cinnamomi Ramulus, Paeoniae Radix Alba (or Paeoniae Radix Rubra), Moutan Cortex, Persicae Semen, and Poria, with multiple therapeutic functions such as sedation, antitumor activity, anti-inflammation, and neuroprotection. However, its clinical applications remain relatively fragmented, and the underlying mechanisms of GZFL in different diseases are still not very certain. Further research and summary in both application and mechanisms remain to be needed for human health and the best use of GZFL. Therefore, we summarized the multiple pharmacologic effects and possible mechanisms of action of GZFL according to recent 17 years of research.

Methods

We retrieved four English and two Chinese databases using these keywords (the formulation name or its synonyms) and searched articles written in English from January 2006 up to February 2022. Key Findings. GZFL exhibits multiple pharmacologic advantages in gynecologic diseases and other expanding diseases such as cancer, blood, and vascular disease, renal failure, inflammation, and brain injury. Possibly due to its diverse bioactive components and pharmacologic activities, GZFL could target the multiple signaling pathways involved in regulating blood circulation, inflammatory and immune factors, proliferation, apoptosis, and so on.

Conclusion

This review suggests that GZFL displays promising therapeutic effects for many kinds of diseases, which have been beyond the scope of the original prescription for gynecologic diseases. In this way, we wish to provide a reference and recommendation for further preclinic and clinic studies.

hsa-miR-340-5p inhibits epithelial–mesenchymal transition in endometriosis by targeting MAP3K2 and inactivating MAPK/ERK signaling

Increasing evidence has verified the indispensable effect of microRNAs (miRNAs) in the biological processes of human diseases, including endometriosis. hsa-miR-340-5p was reported to display a low level in patients with endometriosis, but the detailed function of miR-340-5p in endometriosis is unclarified. RT-qPCR was used for the assessment of RNA levels of miR-340-5p and its downstream target genes in endometrial stromal cells (ESCs). Western blotting and Transwell assays revealed that upregulation of miR-340-5p suppressed the migration, invasiveness, and epithelial–mesenchymal transition (EMT) in ESCs. Bioinformatics tools were used to predict miR-340-5p downstream genes. Luciferase reporter assay displayed that miR-340-5p could bind to messenger RNA mitogen-activated protein kinase kinase kinase 2 (MAP3K2). MAP3K2 was targeted by miR-349-5p and could reverse the influence of miR-340-5p. miR-340-5p exerted its impact on the invasive characters of ESCs by inactivating the MAP3K2-mediated MAPK/ERK signaling. In conclusion, miR-340-5p restrains cell migration, invasiveness, and EMT in ESCs by targeting MAP3K2 and inactivating MAPK/ERK signaling.

Emerging Roles and Mechanisms of lncRNA FOXD3-AS1 in Human Diseases

Numerous long noncoding RNAs (lncRNAs) have been identified as powerful regulators of human diseases. The lncRNA FOXD3-AS1 is a novel lncRNA that was recently shown to exert imperative roles in the initialization and progression of several diseases. Emerging studies have shown aberrant expression of FOXD3-AS1 and close correlation with pathophysiological traits of numerous diseases, particularly cancers. More importantly, FOXD3-AS1 was also found to ubiquitously impact a range of biological functions. This study aims to summarize the expression, associated clinicopathological features, major functions and molecular mechanisms of FOXD3-AS1 in human diseases and to explore its possible clinical applications.

Oncogenic Forkhead box D3 antisense RNA 1 promotes cell survival and confers temozolomide resistance in glioblastoma cells through the miR-128-3p/WEE1 G2 checkpoint kinase axis

Although temozolomide (TMZ) is recommended for glioblastoma (GBM) treatment, patients treated with TMZ usually develop TMZ resistance. Thus, there is an urgent need to elucidate the mechanism through which GBM cells acquire TMZ resistance. FOXD3-AS1, a recently discovered lncRNA, shows high expression in diverse cancer types. Nonetheless, its role in GBM remains unclear. This study found that FOXD3-AS1 was overexpressed in GBM cells and associated with dismal prognostic outcome in GBM patients. Functional studies revealed that depletion of FOXD3-AS1 inhibited cell growth and induced apoptosis of GBM cells. Results also showed that FOXD3-AS1 participates in the tolerance of GBM cells to TMZ. Specifically, TMZ-resistant cells exhibited higher FOXD3-AS1 expression compared to parental cells. Overexpression of FOXD3-AS1 increased TMZ tolerance in TMZ sensitive cells, whereas depletion of FOXD3-AS1 sensitized TMZ-resistant cells to TMZ treatment. Mechanistically, WEE1 was positively expressed with FOXD3-AS1. Given that both FOXD3-AS1 and WEE1 contain a binding site for miR-128-3p, FOXD3-AS1 could act as a competing endogenous RNA (ceRNA) to promote WEE1 expression by sponging miR-128-3p. Furthermore, we demonstrated that WEE1 was upregulated in TMZ-resistant GBM cells. Overexpression of WEE1 increased TMZ tolerance in TMZ sensitive cells, whereas deletion of FOXD3-AS1 promoted TMZ-resistant cells to be more sensitive to TMZ. Importantly, depletion of WEE1 could reverse TMZ resistant phenotype in FOXD3-AS1-overexpressed GBM cells. Collectively, our findings reveal a critical role of FOXD3-AS1 in the survival of GBM cells and TMZ resistance, which suggests that FOXD3-AS1 is a potential biomarker for the diagnosis and treatment of GBM.

Taraxasterol attenuates melanoma progression via inactivation of reactive oxygen species-mediated PI3K/Akt signaling pathway

Background: Taraxasterol (TX), a pentacyclic triterpene, is one of the main active constituents isolated from Taraxacum officinale. A growing number of studies have reported that TX exhibits a wide range of biological activities such as anti-oxidative, anti-inflammatory, and neuro-protective effects. Recently, TX has been demonstrated to be a potential drug candidate for treatment of some types of cancers. However, the specific role of TX in melanoma remains unclear.Purpose: In this study, we aimed at exploration of the effect of TX on melanoma cell viability, apoptosis, migration, invasion, and epithelial-mesenchymal transition (EMT) as well as the underlying mechanisms.Research design: A375 and SK-MEL-28 cells were treated with various concentrations of TX for different times. Cell viability was measured using CCK-8 assay. Cell apoptosis was determined by flow cytometry. Transwell assays were performed to measure cell migration and invasion. The expression of E-cadherin, α-catenin, N-cadherin, vimentin, p-PI3K, PI3K, p-Akt and Akt was detected using western blot.Results: The study showed that TX induced A375 and SK-MEL-28 cell apoptosis. Furthermore, exposure to TX inhibited A375 and SK-MEL-28 cell migration and invasion. Besides, the EMT process was reversed in A375 and SK-MEL-28 cells after TX treatment. We also observed that TX reduced the protein expression of p-PI3K and p-Akt; thus, inhibiting activity of the PI3K/Akt pathway in A375 and SK-MEL-28 cells. In addition, TX treatment increased the levels of reactive oxygen species (ROS) in A375 and SK-MEL-28 cells, and treatment with the ROS scavenger NAC significantly rescued TX-induced down-regulation of p-PI3K and p-Akt in A375 and SK-MEL-28 cells.Conclusions: In conclusion, our study demonstrated that TX induced ROS accumulation followed by inactivation of the PI3K/Akt pathway and subsequently attenuated melanoma progression, suggesting that TX may be a potential candidate for treatment of melanoma.

Regulation of LncRNAs in Melanoma and Their Functional Roles in the Metastatic Process

Long non-coding RNAs (lncRNAs) are key regulators of numerous intracellular processes leading to tumorigenesis. They are frequently deregulated in cancer, functioning as oncogenes or tumor suppressors. As they act through multiple mechanisms, it is not surprising that they may exert dual functions in the same tumor. In melanoma, a highly invasive and metastatic tumor with the propensity to rapidly develop drug resistance, lncRNAs play different roles in: (i) guiding the phenotype switch and leading to metastasis formation; (ii) predicting the response of melanoma patients to immunotherapy; (iii) triggering adaptive responses to therapy and acquisition of drug resistance phenotypes. In this review we summarize the most recent findings on the lncRNAs involved in melanoma growth and spreading to distant sites, focusing on their role as biomarkers for disease diagnosis and patient prognosis, or targets for novel therapeutic approaches.

Exosomal MicroRNA-325 Enhances Trophoblast Migration and Invasion Through Downregulation of Lethal-7b and Upregulation of Forkhead Box Protein O1 Expression in Preeclampsia

We aimed to explore the mechanism by how microRNA (miRNA)-325 derived from marrow mesenchymal stem cell exosomes (MSC-exos) affects the trophoblast progression in preeclampsia (PE). RT-qPCR detected the level of miRNA let-7b and FOXO1 in the placenta tissue of PE patients. Functional experiment was performed to analyze the effect of FOXO1 inhibitor and let-7b mimics on cell migration, invasion and apoptosis through Transwell assay and TUNEL staining. The trophoblast cell was co-cultured with overexpressed-miR-325 MSC-exos to measure gene expression and cell progression. let-7b was highly and FOXO1 was lowly expressed in PE placenta tissue. let-7b directly targeted and inhibited FOXO1 expression. Importantly, as miR-325 was internalized by trophoblast cells through MSC-exos, MSC-exos overexpressing miR-325 inhibited let-7b expression in trophoblasts, up-regulated FOXO1 and activated AKT signaling pathway. Further, MSC-exos treatment promoted invasion and migration of trophoblast cell and inhibited apoptosis. In conclusion, miR-325 derived from MSC-exos promotes the invasion and migration of trophoblast cells in PE through inhibition of let7b and upregulation of FOXO1.

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.

LncRNA FOXD3-AS1 Promotes Tumorigenesis of Glioma via Targeting miR-128-3p/SZRD1 Axis

Background

The aim of the current study was to investigate the roles of LncRNA FOXD3-AS1 (FOXD3-AS1) in the glioma progression, and its underlying mechanism of competing endogenous RNA (ceRNA) network of FOXD3-AS1/miR-128-3p/SZRD1.

Materials and Methods

The FOXD3-AS1 expression and its prognostic relation were detected by bioinformatics tool. Next, glioma cell lines (HS683, U251, T98G, and SNB-19) were used to verify the FOXD3-AS1 expression. Furthermore, the roles of the FOXD3-AS1/miR-128-3p/SZRD1 axis on the glioma development in vitro and in vivo were examined.

Results

Bioinformatics analysis showed that FOXD3-AS1 was upregulated in the glioma and linked with poor prognosis. Consistently, FOXD3-AS1 level was overexpressed in the glioma cell lines (HS683 and U251). Subsequently, we verified that silencing of FOXD3-AS1 (si-FOXD3-AS1) restrained the cell proliferation, invasion, and tumor growth in vivo, and induced G0/G1 arrest, and promoted apoptosis. Further study also stated that FOXD3-AS1 interacted with miR-128-3p and SZRD1 was the target gene of miR-128-3p. Moreover, overexpression of miR-128-3p restrained the cell proliferation and metastasis of glioma, and reduced the SZRD1 level. Rescue assay illustrated that miR-128-3p inhibitor could reverse the suppressive impact of si-FOXD3-AS1 on the glioma progression. Similarly, SZRD1 overexpression could neutralize the influences of miR-128-3p mimic on glioma progression.

Conclusion

FOXD3-AS1 promoted the tumorigenesis of glioma, and exerted its function to modulate SZRD1 by targeting miR-128-3p.

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.

Exosomal lncRNA FOXD3-AS1 upregulates ELAVL1 expression and activates PI3K/Akt pathway to enhance lung cancer cell proliferation, invasion, and 5-fluorouracil resistance

Long non-coding RNA (lncRNA) FOXD3-AS1 expression is upregulated in lung cancer; however, its effect and mechanism on 5-fluorouracil (5-FU) resistance remain unclear. In this study, we determined the effects of FOXD3-AS1-enriched exosomes derived from lung cancer cells on the proliferation, invasion, and 5-FU resistance of lung cancer cells. Online bioinformatics database analysis showed that FOXD3-AS1 was upregulated in lung cancer progression. Real-time quantitative PCR results confirmed that FOXD3-AS1 expression was upregulated in lung cancer tissues and cell lines, and FOXD3-AS1 was greatly enriched in lung cancer cell-derived exosomes. ELAV-like RNA-binding protein 1 (ELAVL1) was identified as an RNA-binding protein of FOXD3-AS1. The lung cancer cell-derived exosomes promoted A549 cell proliferation and invasion and inhibited apoptosis caused by 5-FU, and transfection of si-FOXD3-AS1 or si-ELAVL1 in exosome-incubated A549 cells reversed these effects. Moreover, exosome-incubated A549 cells were co-transfected with si-FOXD3-AS1 and pcDNA-ELAVL1, showing the same cell proliferation, invasion, and 5-FU resistance as those of A549 cells treated with lung cancer cell-derived exosomes alone. Mechanistic studies identified that lung cancer cell-derived exosomes activated the PI3K/Akt pathway, and transfection of si-FOXD3-AS1 or treatment with the PI3K inhibitor LY294002 reversed the activation of the PI3K/Akt axis induced by exosomes. In conclusion, our study revealed that lung cancer cell-derived exosomal FOXD3-AS1 upregulated ELAVL1 expression and activated the PI3K/Akt pathway to promote lung cancer progression. Our findings provide a new strategy for lung cancer treatment.

lncRNA FOXD3-AS1 promotes the progression of non-small cell lung cancer by regulating the miR-135a-5p/CDK6 axis

Long non-coding RNA (lncRNA) is essential to the development and progression of malignant human cancer. Growing evidence suggests that the lncRNA forkhead box D3 antisense 1 (FOXD3-AS1) is a crucial regulatory effector for multiple cancer types and is closely associated with poor prognosis. However, in most cases, the molecular mechanism underlying the role of FOXD3-AS1 in cancer development has not yet been fully elucidated. The present study focused on non-small cell lung cancer (NSCLC) in order to gain insight into how FOXD3-AS1 drives cancer progression. First, FOXD3-AS1 expression in NSCLC tissue samples was detected using reverse transcription-quantitative (RT-qPCR). Moreover, cell proliferation and apoptosis were determined using Cell Counting Kit-8 assays and flow cytometry, respectively. A luciferase reporter assay was then performed to determine whether there was a direct binding association between FOXD3-AS1 and microRNA (miR)-135a-5p. Lastly, a tumor subcutaneous xenograft model was established to examine the role of FOXD3-AS1 in tumor growth. FOXD3-AS1 was significantly overexpressed in NSCLC tissue samples and cell lines compared with normal tissue samples and cells. FOXD3-AS1 silencing expression significantly inhibited A549 and H1229 cell proliferation while inducing apoptosis compared with sh-NC group. The luciferase reporter assay demonstrated the direct binding interaction between FOXD3-AS1 and miR-135a-5p. Moreover, FOXD3-AS1 silencing led to the upregulation of miR-135a-5p in A549 and H1229 cells compared with sh-NC group. It was also demonstrated that miR-135a-5p could bind to the 3′ untranslated region of cyclin-dependent kinase 6 (CDK6) and negatively modulate its transcription. miR-135a-5p knockdown or CDK6 overexpression reversed the inhibition on cell proliferation and apoptosis following FOXD3-AS1 knockdown. Altogether, the present study suggests that FOXD3-AS1 sponges miR-135a-5p to promote cell proliferation and concomitantly inhibit apoptosis by regulating CDK6 expression in NSCLC cells.

lncRNA TINCR attenuates the proliferation and invasion, and enhances the apoptosis of cutaneous malignant melanoma cells by regulating the miR‑424‑5p/LATS1 axis

Cutaneous malignant melanoma (CMM) is responsible for ≥1/2 of skin cancer‑related mortalities. The aberrant expression of long non‑coding RNAs (lncRNAs) has been associated with the development of CMM. However, to the best of our knowledge, the role of the lncRNA TINCR ubiquitin domain containing (TINCR) in CMM has not been previously investigated, and thus, the current study aimed to evaluate this in vitro and in vivo. Reverse transcription‑quantitative PCR (RT‑qPCR) was used to analyze microRNA (miR)‑424‑5p expression, and RT‑qPCR and western blotting were used to measure TINCR, large tumor suppressor kinase 1 (LATS1), cellular communication network factor 2 (CTGF), cellular communication network factor 1 (CCN1) and AXL receptor tyrosine kinase (AXL) mRNA and protein expression levels, respectively. Cell Counting Kit‑8, flow cytometry and Transwell assays were used to detect the proliferation, apoptosis and invasion of CMM cell lines, respectively. The binding sites between TINCR and miR‑424‑5p were predicted using the miRDB database. A dual luciferase reporter assay and RT‑qPCR were used to identify the relationship between TINCR and miR‑424‑5p in CMM cell lines. The bioinformatics analysis revealed that TINCR was one of the most significantly downregulated lncRNAs in CMM, and advanced stage CMM tissues showed the greatest decrease in TINCR expression. Moreover, in the collected CMM tissues and tested cell lines of the current study, TINCR expression was found to be downregulated compared with the respective controls. Notably, TINCR overexpression inhibited the expression levels of CTGF, CCN1 and AXL, decreased the proliferation and invasion, and induced the apoptosis of CMM cell lines. In addition, a mutual binding association was identified between miR‑424‑5p and TINCR in CMM cells. LATS1, a target of miR‑424‑5p, was found to be positively regulated by TINCR. TINCR activated Hippo signaling and repressed the activity of Yes 1 associated transcriptional regulator by regulating LATS1 expression, while LATS1 knockdown reversed the effect of TINCR overexpression on CMM cells. Collectively, the findings of the present study suggested that TINCR may attenuate the progression of CMM by regulating the miR‑424‑5p/LATS1 signaling axis. These results indicated that TINCR may play a tumor suppressive role in CMM.

KCNQ1OT1: An Oncogenic Long Noncoding RNA

Long noncoding RNAs (lncRNAs) are transcripts greater than 200 nucleotides that do not code for proteins but regulate gene expression. Recent studies indicate that lncRNAs are involved in the modulation of biological functions in human disease. KCNQ1 Opposite Strand/Antisense Transcript 1 (KCNQ1OT1) encodes a lncRNA from the opposite strand of KCNQ1 in the CDKN1C/KCNQ1OT1 cluster that is reported to play a vital role in the development and progression of cancer. KCNQ1OT1 regulates cancer cell proliferation, cell cycle, migration and invasion, metastasis, glucose metabolism, and immune evasion. The aberrant expression of KCNQ1OT1 in cancer patients is associated with poor prognosis and decreased survival. This review summarizes recent literature related to the biological functions and molecular mechanisms of KCNQ1OT1 in various human cancers, including colorectal, bladder, breast, oral, melanoma, osteosarcoma, lung, glioma, ovarian, liver, acute myeloid leukemia, prostate, and gastric. We also discuss the role of KCNQ1OT1 as a promising diagnostic biomarker and a novel therapeutic target in human cancers.

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.

Long non-coding RNA FOXD3 antisense RNA 1 augments anti-estrogen resistance in breast cancer cells through the microRNA-363/ trefoil factor 1/ phosphatidylinositol 3-kinase/protein kinase B axis

Long non-coding RNA (lncRNA) FOXD3 antisense RNA 1 (FOXD3-AS1) has been reported to participate in multiple processes that contribute toward the development of cancer. The present study aimed to explore the effect of lncRNA FOXD3-AS1 on anti-estrogen resistance in breast cancer (BC) cells. FOXD3-AS1 was found to be highly expressed in BC cell lines. Moreover, FOXD3-AS1 was highly expressed in estrogen receptor-negative (ER^-) cells compared to the ER-positive (ER⁺) cells. FOXD3-AS1 overexpression in T47D and MCF-7 (ER⁺) cells enhanced the resistance of cells to tamoxifen (TMX), whereas FOX3-AS1 downregulation reduced the TMX resistance in MDA-MB-231 (ER^-) cells. Similar results were reproduced in vivo that FOXD3-AS1 inhibition reduced the growth of xenograft tumors formed by MDA-MB-231 cells following TMX treatment whereas FOXD3-AS1 overexpression in T47D cells facilitated tumor growth. The bioinformatic analysis and luciferase assays indicated that FOXD3-AS1 sponged microRNA-363 (miR-363) to restore expression of trefoil factor 1 (TFF1) mRNA. Overexpression of miR-363 reduced T47D cell proliferation induced by FOXD3-AS1, whereas overexpression of TFF1 restored growth of MDA-MB-231 cells reduced after FOXD3-AS1 silencing. The phosphorylation of phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) was increased by FOXD3-AS1 but attenuated by miR-363. Inhibition of PI3K/Akt blocked the role of FOXD3-AS1 and reduced the TMX resistance in T47D and MCF-7 cells. Taken together, the present study suggested that FOXD3-AS1 sponges miR-363 to upregulate TFF1 expression, leading to PI3K/Akt signaling activation and anti-estrogen resistance in BC cells.

LncRNA FOXD3-AS1 Promotes the Malignant Progression of Nasopharyngeal Carcinoma Through Enhancing the Transcription of YBX1 by H3K27Ac Modification

BACKGROUND

Long noncoding RNAs (lncRNAs) can affect the progression of various tumors, including nasopharyngeal carcinoma (NPC). Here, lncRNA FOXD3-AS1 is highly expressed in NPC tissues through bioinformatics analysis and related to the malignant progression of NPC.

METHODS

Bioinformatics analysis and real-time reverse transcription quantitative PCR(RT-qPCR) assay were applied to identify the expression of FOXD3-AS1 in NPC tissues and cells. Specific short hairpin RNAs (shRNAs) or overexpression plasmids were used to knockdown or upregulate FOXD3-AS1 in NPC cells. The effect of FOXD3-AS1 on proliferation and metastasis of NPC was confirmed by CCK8, colony formation, transwell assays in vitro and mouse tumor growth and metastasis models in vivo, of which the mechanism was explored by RNA pull down, mass spectrometry (MS), RNA Immunoprecipitation (RIP), chromatin immunoprecipitation (CHIP) and luciferase assays.

RESULTS

FOXD3-AS1 was highly expressed in NPC tissues and cells. Knockdown of FOXD3-AS1 significantly inhibited proliferation, migration, and invasion of NPC cells in vitro and vivo. FOXD3-AS1 could specifically bind to YBX1 and have a positive effect on the expression of YBX1. Bioinformatics analysis showed that the promoter of YBX1 had a high enrichment of H3K27ac, which promote mRNA transcription and protein translation of YBX1. Moreover, overexpression of YBX1 could reverse the proliferation, migration and invasion arrest caused by FOXD3-AS1 knockdown.

CONCLUSION

LncRNA FOXD3-AS1 is highly expressed and promotes malignant phenotype in NPC, which may provide a new molecular mechanism for NPC.

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.

ILF3-AS1 promotes the aerobic glycolysis and proliferation of melanoma cells by regulating miR-493-5p/PDK1 pathway

BACKGROUND

To investigate the role of ILF3-AS1 in regulating the survival of melanoma and its molecular mechanism.

METHODS

The relative expression level of ILF3-AS1 in melanoma was assessed by qPCR. The effect of ILF3-AS1 and PDK1 on the cell viability was tested by MTT assay. Glucose uptake colorimetric assay, lactate assay, the measurements of extracellular acidification rate (ECAR) and Oxygen consumption rate (OCR) were performed to test the effect of ILF3-AS1 and PDK1 on the cellular glycolysis. Luciferase assay was conducted to detect the interactions of ILF3-AS1, miR-493-5p and PDK1. RNA immunoprecipitation chip (RIP) assay was used to detect the enrichments of ILF3-AS1 and miR-493-5p in the complex. Protein level of PDK1 was detected by western blot analysis.

RESULTS

qPCR revealed that ILF3-AS1 was upregulated in human melanoma cell lines. MTT assay showed that ILF3-AS1 knockdown blunted cell proliferation, which was rescued by the overexpression of PDK1. Glucose uptake colorimetric assay, lactate assay, the measurements of ECAR and OCR indicated that ILF3-AS1 promoted glycolysis through PDK1. Western blotting results showed that ILF3-AS1 overexpression promoted PDK1 expression, which was prevented by miR-493-5p overexpression in SK-MEL-1 cells.

CONCLUSIONS

ILF3-AS1 promotes the aerobic glycolysis and survival of melanoma cells involving miR-493-5p/PDK1 pathway.

Competing Endogenous RNA Networks in Glioma

Gliomas are the most common and malignant primary brain tumors. Various hallmarks of glioma, including sustained proliferation, migration, invasion, heterogeneity, radio- and chemo-resistance, contribute to the dismal prognosis of patients with high-grade glioma. Dysregulation of cancer driver genes is a leading cause for these glioma hallmarks. In recent years, a new mechanism of post-transcriptional gene regulation was proposed, i.e., "competing endogenous RNA (ceRNA)." Long non-coding RNAs, circular RNAs, and transcribed pseudogenes act as ceRNAs to regulate the expression of related genes by sponging the shared microRNAs. Moreover, coding RNA can also exert a regulatory role, independent of its protein coding function, through the ceRNA mechanism. In the latest glioma research, various studies have reported that dysregulation of certain ceRNA regulatory networks (ceRNETs) accounts for the abnormal expression of cancer driver genes and the establishment of glioma hallmarks. These achievements open up new avenues to better understand the hidden aspects of gliomas and provide new biomarkers and potential efficient targets for glioma treatment. In this review, we summarize the existing knowledge about the concept and logic of ceRNET and highlight the emerging roles of some recently found ceRNETs in glioma progression.

COPS8 in cutaneous melanoma: an oncogene that accelerates the malignant development of tumor cells and predicts poor prognosis

This study aimed to investigate the roles of COP9 signalosome subunit 8 (COPS8) and its underlying mechanism in cutaneous melanoma. Bioinformatics tools were utilized to analyze the expression of COPS8 in cutaneous melanoma, while Kaplan-Meier analysis was employed to assess the correlation between COPS8 and patients' overall survival. The proliferation, migration, and invasion of cells were estimated by CCK8, colony formation, and Transwell assays. Western blot was used to check the expression of epithelial-mesenchymal transition (EMT)-related proteins. Results showed that COPS8 was up-regulated and predicted a poor clinical outcome for cutaneous melanoma patients. Knockdown of COPS8 inhibited cutaneous melanoma cell proliferation, migration and invasion, whereas overexpression of COPS8 resulted in the opposite outcomes. The up-regulation of E-cadherin and down-regulation of N-cadherin, vimentin, and snail were caused by silencing COPS8 while their expression showed contrary trends in cells with overexpressed COPS8. Collectively, COPS8 is up-regulated and promotes cutaneous melanoma progression via regulating EMT.

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.

LncRNA LOXL1-AS1 promotes esophageal squamous cell carcinoma progression by targeting DESC1

Recently, ample evidence indicated that numerous aberrantly expressed long non-coding RNAs (lncRNAs) participated in the development of multiple malignancies. However, the expression and function of lncRNA LOXL1-AS1 in mediating esophageal squamous cell carcinoma (ESCC) carcinogenesis remains largely elusive. Here we validated that LOXL1-AS1 was significantly upregulated in ESCC tissues compared with the corresponding adjacent non-neoplastic tissues, and LOXL1-AS1 expression was positively correlated with ESCC patients' lymph node metastasis. Besides, LOXL1-AS1 knockdown impaired ESCC cells proliferation, migration and invasion capabilities in vitro. Furthermore, inhibiting LOXL1-AS1 in ESCC cells increased the percentage of cells at the G1 phase, accompanied by reducing in S phase in contrast to scramble control, and silencing of LOXL1-AS1 evoked ESCC cell apoptosis. From high throughput RNA sequencing (RNA-seq) analysis, we identified that differentially expressed in squamous cell carcinoma 1 (DESC1) was a critical downstream target of LOXL1-AS1. Taken together, we demonstrated the function and mechanism of LOXL1-AS1 in contributing ESCC progression for the first time, and indicated LOXL1-AS1 may be a novel therapeutic biomarker of ESCC.

Long non-coding RNA LINC00665 promotes melanoma cell growth and migration via regulating the miR-224-5p/VMA21 axis

Melanoma is an aggressive malignant skin tumor endangering the health of patients. Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been increasingly reported to be implicated in the carcinogenesis of melanoma. Long intergenic non-coding RNA 00665 (LINC00665) has been found to exert important regulatory roles in some cancers, yet its function in melanoma remains to be investigated. QRT-PCR analysis was conducted to evaluate the relative expression of RNAs. Functional experiments in vitro including colony formation, EdU, wound-healing and transwell assays, as well as in vivo xenograft assays, were utilized to study the role of LINC00665 in melanoma. Mechanical experiments were implemented to probe into the molecular linkage of LINC00665, miR-224-5p and VMA21. LINC00665 was abnormally highly expressed in melanoma cells. Silencing LINC00665 could inhibit the proliferation and migration of melanoma cells. LINC00665 sponged miR-224-5p to upregulate VMA21. VMA21 knockdown exerted similarly interfering effects on above biological processes in melanoma cells. However, VMA21 overexpression abolished the in vitro and in vivo outcomes of LINC00665 silencing. LINC00665 promotes proliferative and migrating abilities of melanoma cells via targeting miR-224-5p/VMA21 axis.

LncRNA FOXD3-AS1/miR-135a-5p function in nasopharyngeal carcinoma cells

This research aimed to illustrate the biological function and associated regulatory mechanism of lncRNA FOXD3-AS1 (FOXD3-AS1) in nasopharyngeal carcinoma (NPC). This research initially found that FOXD3-AS1 was obviously upregulated in NPC cell lines by quantitative reverse transcription polymerase chain reaction (qRT-PCR) detection. Next, the direct target of FOXD3-AS1 was predicted by bioinformatics and further verified by dual-luciferase reporter assay. MiroRNA-135a-5p (miR-135a-5p) was identified as the target gene of FOXD3-AS1 and down-expressed in C666-1 cells compared to NP69. In addition, function assays were conducted in C666-1 cells, including methyl tetrazolium assay, flow cytometry, Caspase3 activity detection, and western blot assay. Our results suggested that miR-135a-5p upregulation inhibited NPC cell growth, enhanced cell apoptosis, promoted Caspase3 activity, increased cleaved-Caspase3, and reduced pro-Caspase3 level. Moreover, we found that FOXD3-AS1 knockdown notably inhibited C666-1 cell proliferation, increased cell apoptosis, enhanced Caspase3 activity, enhanced cleaved-Caspase3 expression, and suppressed pro-Caspase3 level in C666-1 cells. However, these findings were reversed in C666-1 cells by miR-135a-5p mimic co-transfection. To sum up, our data showed that FOXD3-AS1 knockdown regulated cell growth and apoptosis in NCP cells via altering miR-135a-5p expression, suggesting that FOXD3-AS1 might be a therapeutic target for NPC diagnosis and treatment.

ELF1-activated FOXD3-AS1 promotes the migration, invasion and EMT of osteosarcoma cells via sponging miR-296-5p to upregulate ZCCHC3

Osteosarcoma (OS) is a malignant carcinoma often occurring in adolescents. The critical function of long non-coding RNAs (lncRNAs) in cancer arouses increasing attention. Nevertheless, the specific function of FOXD3 Antisense RNA 1 (FOXD3-AS1) in OS has not been understood yet. In this research, FOXD3-AS1 showed strengthened level in OS specimens and cell lines, and its deficiency restrained cell migration, invasion and epithelial-to-mesenchymal transition (EMT) in OS. Then, we confirmed the interaction of FOXD3-AS1 with microRNA-296-5p (miR-296-5p) and that miR-296-5p overexpression blocked OS cell migration, invasion and EMT. Besides, miR-296-5p targeted zinc finger CCHC-type containing 3 (ZCCHC3), and FOXD3-AS1 released ZCCHC3 via sequestering miR-296-5p. Moreover, rescue assays delineated that ZCCHC3 upregulation neutralized the inhibitory effect of FOXD3-AS1 depletion on in vitro behaviors and in vivo tumorigenesis in OS. In addition, E74 like ETS transcription factor 1 (ELF1) stimulated FOXD3-AS1 transcription, and ELF1 silence-suppressed malignant phenotypes of OS cells were offset by FOXD3-AS1 upregulation. Overall, present work elucidated that ELF1-activated FOXD3-AS1 aggravated cell migration, invasion and EMT in OS via absorbing miR-296-5p to augment ZCCHC3 expression, which might provide potential guidance for researchers to find effective targets for OS treatment.

The critical roles of lncRNAs in the pathogenesis of melanoma

Long non-coding RNAs (lncRNAs) embrace a huge fraction of human transcripts and participate in the pathogenesis of human disorders especially malignant conditions. Malignant melanoma, as the most fatal type of cutaneous malignnacies, is associated with dysregulation of several lncRNAs including PVT1, H19, MALAT1, and CCAT1. Moreover, a portion of lncRNAs are exclusively expressed in melanoma cell lines. Expression levels of several lncRNAs are associated with TNM stage, tumor size and progression of melanoma. Thus, these lncRNAs are regarded as biomarkers for this malignancy. Peripheral transcript levels of a number of lncRNAs, such as PVT1, SNHG5 and SPRY4-IT1, could distinguish melanoma patients from unaffected persons with appropriate sensitivity and specificity values. Moreover, expression levels of numerous lncRNAs in tissue biopsies could differentiate malignant samples from benign samples. Based on the results of both cell line and in vivo studies, lncRNAs regulate critical pathways in the carcinogenesis of melanoma, such as the PI3K/Akt and NF-κB signaling pathways, and are involved in the modulation of response to chemotherapeutic agents. Here we review the existing information on the role of lncRNAs in malignant melanoma.

Predicting miRNA-lncRNA-mRNA network in ultraviolet A-induced human skin photoaging

BACKGROUND/OBJECTIVE

Recent researches had reported that microRNAs (miRNAs) played a role in skin photoaging. Our previous study found that long noncoding RNA (lncRNA) expression was changed in the UVA-irradiated skin fibroblasts, but the regulating network of noncoding RNA in UV-induced skin changes has not been elucidated well. Here, we investigated the interactions of miRNA-lncRNA-mRNAs in skin photoaging mechanisms.

METHODS

Human dermal fibroblasts (HDFs) were irradiated with UVA at 10 J/cm² once a day lasting for 14 days. miRNA expression profiles were detected by high-throughput sequencing. miRNAs changed significantly were identified by qRT-PCR. Functional annotation analysis and pathway enrichment were carried out using Gene Ontology and KEGG, and predicted miRNA-lncRNA-mRNA interactions were performed via bioinformatic analysis.

RESULTS

34 differentially expressed miRNAs (>1.5-fold changes, P < .05) after UVA irradiation were identified to interact with distinct lncRNAs. miRNA-lncRNA-mRNA network prediction and regulatory role analysis showed that the gene expression of cellular process, cell part, and binding was mainly coordinated in UVA-irradiated fibroblasts. miRNA-lncRNA-mRNA-signal transduction pathway analysis showed that TNF signaling pathway, thyroid hormone signaling pathway, and lysosome were mainly affected after UVA irradiation.

CONCLUSION

miRNA-lncRNA-mRNA network played a critical part in skin photoaging. Our research provided novel insights into the repeated UVA-induced skin damage in noncoding RNA regulatory field and might help to further understand the delicate interplay of gene regulation at the noncoding RNA level in photoaged skin and UV-induced skin cancers in future researching and provide novel insights into the repeated UVA-damaging pathology and potential targets for preventing human skin photoaging.

LncRNA FOXD3-AS1 knockdown protects against cerebral ischemia/reperfusion injury via miR-765/BCL2L13 axis

AIMS

Long non-coding RNAs (lncRNAs) FOXD3-AS1 was reported to be increased in cardiomyocyte ischemic injury. However, its role and underlying molecular mechanism in ischemic stroke remain unknown. This study was to investigate the role of FOXD3-AS1 in cerebral ischemia/reperfusion injury.

METHODS

The expression of FOXD3-AS1 and miR-765 were measured with qRT-PCR. The shared putative miR-765 binding sites both in BCL2L13 and FOXD3-AS1 were identified with bioinformatics, luciferase reporter assay and RNA immunoprecipitation. Apoptosis and its related proteins were detected by TUNEL assay, Hoechst 33,258 staining, flow cytometry and western blot. Infarct volume and the neurological status were evaluated with TTC staining and neurologic deficit score, respectively.

RESULTS

The up-regulation of FOXD3-AS1 and down-regulation of miR-765 were found in both mouse brains after cerebral ischemia/reperfusion (I/R) and neuroblastoma cells of neuro-2A (N2a) after oxygen-glucose deprivation/reoxygenation (OGD/R). Moreover, the overexpression of miR-765 reduced N2a cell apoptosis caused by OGD/R. MiR-765 could target BCL2L13 directly. In addition, we found that FOXD3-AS1 bound to miR-765 directly, acting as a ceRNA to modulate the expression of BCL2L13. Overexpression of FOXD3-AS1 antagonized the inhibitory impact of miR-765 on the expression of BCL2L13 and the apoptosis of N2a cells treated with OGD/R, while FOXD3-AS1 knockdown promoted the inhibitory impact of miR-765 on the expression of BCL2L13 and the apoptosis of N2a cells treated with OGD/R. Furthermore, we found that neurological deficits and brain injury induced by I/R in vivo were attenuated by FOXD3-AS1 knockdown.

CONCLUSIONS

We verified a critical signaling pathway of FOXD3-AS1/miR-765/BCL2L13 in regulating cerebral ischemia/reperfusion injury.

Long non-coding RNA FOXD3-AS1 regulates the expression and secretion of IL-25 in nasal epithelial cells to inhibit Th2 type immunoreaction in allergic rhinitis

Long non-coding RNA FOXD3-AS1 is associated with allergic rhinitis (AR). This article aims to demystify the role of FOXD3-AS1 in AR. We compared FOXD3-AS1 expression in nasal mucosas between AR patients and healthy control. Next, nasal epithelial cells (NECs) were incubated with lipopolysaccharide or recombinant IL-25, and then the supernatant of the NECs was incubated with CD4⁺ T cells. Th2 cell proportions were assessed by flow cytometry. The levels of gene and cytokines were detected by real-time quantitative PCR or enzyme linked immunosorbent assay. FOXD3-AS1 was downregulated in nasal mucosas of AR patients, whereas Th2 cell proportions and the levels of IL-25, IL-4, and IL-13 were enhanced in peripheral blood of AR patients. FOXD3-AS1 overexpression inhibited the expression and secretion of IL-25 in NECs. The levels of IL-4 and IL-13 and Th2 cell proportions in CD4⁺ T cells were enhanced by recombinant IL-25, which was effectively abolished by the supernatant of FOXD3-AS1-overexpressed NECs treatment. Our study demonstrates that FOXD3-AS1 is downregulated in nasal mucosas of AR patients, and FOXD3-AS1 represses the expression and secretion IL-25 in NECs, thereby inhibiting Th2 type immunoreaction in AR. Thus, our data provide a novel target gene for AR treatment.

Long Noncoding RNA CAR10 Contributes to Melanoma Progression By Suppressing miR-125b-5p to Induce RAB3D Expression

Background

Melanoma is a very malignant skin cancer with high mortality and unsatisfactory prognosis. Many long noncoding RNAs (lncRNAs) have been reported to be aberrantly expressed in melanoma. How lncRNA regulates melanoma progression is poorly defined. LncRNA CAR10 has been shown to regulate the progression of several cancers and its role in melanoma remains unclear. This study aims to determine the role and mechanism of lncRNA CAR10 in the regulation of melanoma progression.

Methods

qRT-PCR was utilized to analyze CAR10 in melanoma human tissues and cell lines while Kaplan–Meier curve was used to examine the survival rate. CCK8 assay and EdU assay were used to assess cell proliferation when Transwell assay was conducted to determine migration and invasion. And tumor xenograft assay was performed to evaluate tumor growth in vivo. Additionally, luciferase assay and RNA pulldown assay were performed to analyze the interactions among CAR10, miR-125b-5p and RAB3D.

Results

LncRNA CAR10 was upregulated in melanoma tissues and cell lines. Upregulation of CAR10 predicted a poor prognosis in patients with melanoma. CAR10 knockdown suppressed proliferation, migration and invasion of melanoma cells in vitro. CAR10 silencing attenuated tumor growth in vivo. CAR10 inhibited miR-125b-5p activity to upregulate RAB3D expression. And miR-125b-5p/RAB3D signaling is crucial for CAR10-dependent melanoma progression.

Conclusion

Our work suggests that lncRNA CAR10 promotes melanoma growth and metastasis through modulating miR-125b-5p/RAB3D axis.

LncRNA FOXD3-AS1 Mediates AKT Pathway to Promote Growth and Invasion in Hepatocellular Carcinoma Through Regulating RICTOR

Background: Hepatocellular carcinoma (HCC) has high morbidity and mortality, but current therapeutic methods cannot effectively improve patient's prognosis. FOXD3-AS1, a new identified long noncoding RNA, is dysregulated in several cancers and functions as a carcinogenic or tumor-suppressor factor. However, the function of FOXD3-AS1 in HCC has not been reported. Materials and Methods: Quantitative real time-polymerase chain reaction was applied to evaluate the expression of FOXD3-AS1 in HCC tissues and cell lines. miRDB and TargetScan websites were utilized to predict the interaction network of FOXD3-AS1 as a competing endogenous RNA. The interaction was confirmed by luciferase reporter assay and RNA binding protein immunoprecipitation (RIP) assay. The effect of FOXD3-AS1 on HCC cells (Huh6) were measured by cell counting kit (CCK)-8, BrdU cell proliferation assay, Transwell invasion assay, and wound healing assay. Results: FOXD3-AS1 was overexpressed in HCC, and HCC patients with the high level of FOXD3-AS1 had a poor prognosis. In addition, FOXD3-AS1 knockdown considerably inhibited the proliferation, migration, and invasion of Huh6 cells. Besides, FOXD3-AS1 functioned as a sponge of miR-335, and RICTOR was a direct target gene of miR-335. Furthermore, FOXD3-AS1 could enhance the level of RICTOR through sponging miR-335. Moreover, the knockdown of FOXD3-AS1 could competitively bind with miR-335 to suppress RICTOR expression, thereby inhibiting the growth of Huh6 cells through the deactivation of AKT signaling pathway. Conclusions: FOXD3-AS1 is crucial for the tumorigenesis and progression of HCC. The interaction among FOXD3-AS1, miR-335, and RICTOR provides a novel insight for understanding the molecular mechanism of HCC, and FOXD3-AS1, miR-335, and RICTOR can be regarded as the potential targets for HCC treatment.

miR-335 Acts as a Tumor Suppressor and Enhances Ionizing Radiation-Induced Tumor Regression by Targeting ROCK1

Recent development of integrative therapy against melanoma combines surgery, radiotherapy, targeted therapy, and immunotherapy; however, the clinical outcomes of advanced stage and recurrent melanoma are poor. As a skin cancer, melanoma is generally resistant to radiotherapy. Hence, there is an urgent need for evaluation of the mechanisms of radioresistance. The present study identified miR-335 as one of the differential expression of miRNAs in recurrent melanoma biopsies post-radiotherapy. The expression of miR-335 declined in melanoma tissues compared to the adjacent tissues. Moreover, miR-335 expression correlated with advanced stages of melanoma negatively. Consistent with the prediction of STARBASE and miRDB database, miR-335 targeted ROCK1 via binding with 3′-UTR of ROCK1 directly, resulting in attenuation of proliferation, migration, and radioresistance of melanoma cells. The authors validated that overexpression of miR-335 enhanced X-ray-induced tumor regression by B16 mouse models. Briefly, the present findings gained insights into miR-335/ROCK1-mediated radiosensitivity and provided a promising therapeutic strategy for improving radiotherapy against melanoma.

Downregulated Long Non-Coding RNA MSC-AS1 Inhibits Osteosarcoma Progression and Increases Sensitivity to Cisplatin by Binding to MicroRNA-142

Background

Osteosarcoma (OS) is the most prevalent malignant primary bone tumor, resulting from severe transformation of primitive mesenchymal cells, which induces osteogenesis. Long non-coding RNA (lncRNA) MSC-AS1 triggers osteogenic differentiation by sponging microRNA (miR)-140-5p. The present study assessed the mechanism of lncRNA MSC-AS1 in OS biological features and sensitivity to cisplatin (DDP) by binding to miR-142.

Material/Methods

Firstly, lncRNA MSC-AS1 expression in OS tissues and cells was analyzed. OS cells were transfected with silenced MSC-AS1 to determine its role in OS biological behaviors, and we also assessed the effect of MSC-AS1 on OS sensitivity to DDP. Then, website prediction and dual-luciferase reporter gene assay were utilized for verification of the binding site between MSC-AS1 and miR-142. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis were performed to determine the effect of MSC-AS1 on expression of miR-142, cyclin-dependent kinase 6 (CDK6), and the PI3K/AKT signaling pathway. Xenograft transplantation was also applied to confirm the in vitro experiments.

Results

Overexpressed MSC-AS1 was associated with poor prognosis of OS patients. OS cell proliferation, invasion, and migration were reduced after silencing MSC-AS1, while cell apoptosis was enhanced. Moreover, silencing MSC-AS1 made OS cells more sensitive to DDP. Interestingly, MSC-AS1 knockdown induced miR-142 expression and reduced CDK6 levels, thereby decreasing the protein expression of p-PI3K/t-PI3K and p-AKT/t-AKT. Silencing MSC-AS1 repressed OS progression in vivo.

Conclusions

Our study demonstrated that silencing MSC-AS1 inhibited OS biological behaviors by enhancing miR-142 to decrease CDK6 and inactivating the PI3K/AKT axis. Our results may provide new insights for OS treatment.