Long noncoding RNA DLX6-AS1 promotes neuroblastoma progression by regulating miR-107/BDNF pathway.

BACKGROUND: Long noncoding RNAs (lncRNAs) play essential roles in tumor progression. However, the functions and targets of lncRNAs in neuroblastoma (NB) progression still remain to be determined. In this study, we aimed to investigate the effect of lncRNA DLX6 antisense RNA 1 (DLX6-AS1) on NB and the underlying mechanism involved. METHODS: Through mining of public microarray datasets, we identify aberrantly expressed lncRNAs in NB. The gene expression levels were determined by quantitative real-time PCR, and protein expression levels were determined by western blot assay. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, colony formation assay, wound-healing assay, transwell invasion assays and flow cytometry analysis were utilized to examine cell proliferation, migration, invasion and apoptosis. Luciferase reporter assay was performed to confirm the interaction between DLX6-AS1and its potential targets. Tumor xenograft assay was used to verify the role of DLX6-AS1 in NB in vivo. RESULTS: We identified DLX6-AS1 was upregulated in NB by using a public microarray dataset. The expression of DLX6-AS1 was increased in NB tissues and derived cell lines, and high expression of DLX6-AS1 was positively correlated with advanced TNM stage and poor differentiation. Knockdown of DLX6-AS1 induced neuronal differentiation, apoptosis and inhibited the growth, invasion, and metastasis of NB cells in vitro and impaired tumor growth in vivo. MiR-107 was the downstream target of DLX6-AS1. MiR-107 was found to target brain-derived neurotrophic factor (BDNF) which is an oncogene in NB. Knockdown of miR-107 or overexpression of BDNF reversed the suppression of NB progression caused by DLX6-AS1 silence. CONCLUSION: Overall, our finding supports that DLX6-AS1 promotes NB progression by regulating miR-107/BDNF pathway, acting as a novel therapeutic target for NB.

LncRNA DLX6-AS1 promoted cancer cell proliferation and invasion by attenuating the endogenous function of miR-181b in pancreatic cancer.

BACKGROUND: Pancreatic cancer, one of the most aggressive malignancies, ranks the fourth cause of cancer-related death worldwide. Aberrantly expressed long non-coding RNAs (lncRNAs) functioned as oncogenes or tumor suppressors in pancreatic cancer. This study aimed to determine the expression of lncRNA DLX6 antisense RNA 1 (DLX6-AS1) in pancreatic cancer tissues and to explore the DLX6-AS1-related pathway in pancreatic cancer. MATERIALS AND METHODS: The gene expression levels were determined by quantitative real-time PCR, and protein expression levels were determined by western blot assay. CCK-8 assay, colony formation assay and Transwell migration and invasion assays were used to examine cell proliferation, migration and invasion. Luciferase reporter assay was used to confirm the binding between DLX6-AS1and its potential targets. In vivo study used the mouse xenograft model to test the anti-tumor effect of DLX6-AS1 knockdown. RESULTS: The high expression of DLX6-AS1 was observed in pancreatic cancer tissues, and high expression of DLX6-AS1 was positively correlated with larger tumor size, advanced TNM stage and lymph node metastasis. Knockdown of DLX6-AS1 dramatically impaired cancer cell proliferation, migration and invasion. MiR-181b was the downstream target of DLX6-AS1. Knockdown of miR-181b reversed the suppression of cell viability, migration and invasion abilities caused by DLX6-AS1 knockdown. MiR-181b was found to target Zinc finger E-box-binding homeobox 2 and to modulate epithelial-mesenchymal transition. Furthermore, DLX6-AS1 knockdown inhibited tumor growth and tumor metastasis in vivo. CONCLUSION: Collectively, our data suggested that DLX6-AS1 promotes cancer cell proliferation and invasion by attenuating the endogenous function of miR-181b in pancreatic cancer.

Expression of long non-coding RNA DLX6-AS1 in lung adenocarcinoma.

BACKGROUND: Lung adenocarcinoma (LAC), the primary histological type of non-small cell lung cancer (NSCLC), has displayed an increasing incidence and mortality worldwide. However, therapeutic approaches were limited. Dysregulation of some lncRNAs has been shown in various types of cancers including LAC. The aim of the present study was to vertify lncRNA DLX6-AS1 expression in LAC. METHODS: Microarray assay revealed expression profile of lncRNAs in LAC. qRT-PCR ( quantitative reverse transcription PCR) was performed to identify lncRNA DLX6-AS1 expression level in 72 paired LAC and adjacent normal lung tissues. qRT-PCR and Western blotting were used to verify that down-regulation lncRNA DLX6-AS1 decreased DLX6 (distal-less homeobox 6) mRNA and protein expression. RESULTS: Microarray analysis identified up-regulation of 272 lncRNAs and down-regulation of 635 lncRNAs in LAC tissues. The expression level of lncRNA DLX6-AS1 in LAC tissues was significantly higher compared to paired adjacent normal lung tissues (P< 0.05). In addition, its expression level was closed correlated with both histological differentiation (P = 0.004) and TNM stage (P = 0.033). qRT-PCR and Western blotting analysis showed that DLX6 mRNA and protein levels were lower in si-LncRNA group than in the NC (negative control) and Blank groups. CONCLUSIONS: Microarray analysis identified that lncRNA DLX6-AS1 was up-regulated in LAC tissues. High DLX6-AS1 expression levels were significantly associated with both histological differentiation and TNM stage. Down-regulation of lncRNA DLX6-AS1 expression decreased the DLX6 mRNA and protein levels.

Lipid nanoparticle-encapsulated lncRNA DLX6-AS1 knockdown ameliorates cerebral ischemic injury via the Nrf2/HO-1/NLRP3 axis.

OBJECTIVE: Cerebral ischemia is a neurological disorder that leads to permanent disability. This research focuses on exploring the ameliorative effects of lipid nanoparticle (LNP)-encapsulated lncRNA DLX6-AS1 knockdown in cerebral ischemic injury via the Nrf2/HO-1/NLRP3 axis. METHODS: LNP-encapsulated lncRNA DLX6-AS1 was prepared. Cerebral ischemic injury mouse models were established utilizing middle cerebral artery occlusion (MCAO). The mice were treated by intravenous injection of LNP-encapsulated lncRNA DLX6-AS1. The neurological deficits, Inflammatory factor levels, pathological characteristics were observed. In vitro N2a cell oxygen and glucose deprivation (OGD) models were established, and the cells were treated with LNP-encapsulated lncRNA DLX6-AS1 or Nrf2 inhibitor (ML385). Cell viability and apoptosis were tested. DLX6-AS1, Nrf2, HO-1, and NLRP3 expression levels were assessed. RESULTS: LncRNA DLX6-AS1 levels were elevated in the brain tissues of mice with cerebral ischemic injury and OGD-induced N2a cells. LNP-encapsulated DLX6-AS1 siRNA (si-DLX6-AS1) improved neurological deficit scores, reduced the levels of inflammatory factors, improved brain tissue pathological damage, and raised the number of survival neurons in CA1. LNP-encapsulated si-DLX6-AS1 ameliorated the OGD-induced N2a cell viability decrease and apoptosis rate increase, and ML385 (Nrf2 inhibitor) reversed the ameliorative effects of LNP-encapsulated si-DLX6-AS1. In cerebral ischemic injury mice and OGD-induced N2a cells, Nrf2 and HO-1 levels were reduced and NLRP3 levels were increased. LNP-encapsulated si-DLX6-AS1 raised Nrf2 and HO-1 levels and reduced NLRP3 levels. Nrf2 inhibitor ML385 treatment reversed the ameliorative effects of LNP-encapsulated si-DLX6-AS1 on OGD-induced N2a cell viability and apoptosis. CONCLUSION: Lipid nanoparticle-encapsulated si-DLX6-AS1 ameliorates cerebral ischemic injury via the Nrf2/HO-1/NLRP3 axis.

miR-141-3p Enhanced Radiosensitivity of CRC Cells.

BACKGROUND: Colorectal cancer (CRC) is recognized as one of the frequently diagnosed malignancies, and numerous microRNAs (miRs) are identified to be active in CRC. OBJECTIVE: This work aimed to clarify the effect of miR-141-3p on the radiosensitivity of CRC cells. METHODS: Firstly, CRC cell lines were cultured and applied to construct radiation-resistant CRC cells via X-ray treatment. The expression levels of miR-141-3p and long non-coding RNA DLX6 antisense RNA 1 (lncRNA DLX6-AS1) in CRC cells were measured using real-time quantitative polymerase chain reaction. After transfection with miR-141-3p mimics and 24 h treatment with 6- MV X-ray (0, 2, 4, 6 Gy), the survival fraction (SF) and the colony formation ability of CRC cells were determined using the cell counting kit-8 and colony formation methods. The interactions between miR-141-3p and DLX6-AS1 were analyzed using the dual-luciferase assay. The impact of miR-141-3p on DLX6-AS1 stability was detected after adding actinomycin-D. The role of DLX6- AS1 in the radiosensitivity of CRC cells was explored by transfecting oe-DLX6-AS1 into radiation- resistant CRC cells overexpressing miR-141-3p. RESULTS: The relative expression levels of miR-141-3p were downregulated in CRC cells and further declined in radiation-resistant cells. Upregulation of miR-141-3p relative expression reduced SF and the colony formation ability while amplifying the radiosensitivity of radiation-resistant CRC cells. miR-141-3p directly bound to DLX6-AS1 to reduce DLX6-AS1 stability, and therefore downregulated DLX6-AS1 expression. DLX6-AS1 overexpression counteracted the role of miR- 141-3p overexpression in amplifying the radiosensitivity of radiation-resistant CRC cells. CONCLUSION: miR-141-3p binding to DLX6-AS1 significantly decreased DLX6-AS1 stability and expression, promoting the radiosensitivity of CRC cells.

The lncRNA DLX6-AS1/miR-16-5p axis regulates autophagy and apoptosis in non-small cell lung cancer: A Boolean model of cell death.

Long non-coding RNA (lncRNA) distal-less homeobox 6 antisense RNA 1 (DLX6-AS1) is elevated in a variety of cancers, including non-small cell lung cancer (NSCLC) and cervical cancer. Although it was found that the microRNA-16-5p (miR-16), which is known to regulate autophagy and apoptosis, had been downregulated in similar cancers. Recent research has shown that in tumors with similar characteristics, DLX6-AS1 acts as a sponge for miR-16 expression. However, the cell death-related molecular mechanism of the DLX6-AS1/miR-16 axis has yet to be investigated. Therefore, we propose a dynamic Boolean model to investigate gene regulation in cell death processes via the DLX6-AS1/miR-16 axis. We found the finest concordance when we compared our model to many experimental investigations including gain-of-function genes in NSCLC and cervical cancer. A unique positive circuit involving BMI1/ATM/miR-16 is also something we predict. Our results suggest that this circuit is essential for regulating autophagy and apoptosis under stress signals. Thus, our Boolean network enables an evident cell-death process coupled with NSCLC and cervical cancer. Therefore, our results suggest that DLX6-AS1 targeting may boost miR-16 activity and thereby restrict tumor growth in these cancers by triggering autophagy and apoptosis.

Strategies of LncRNA DLX6-AS1 on Study and Therapeutics.

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

LncRNA DLX6-AS1 promotes microglial inflammatory response in Parkinson's disease by regulating the miR-223-3p/NRP1 axis.

Parkinson's disease (PD) is a prevailing neurodegenerative disorder. This study discussed the mechanism of lncRNA distal-less homeobox 6 antisense 1 (DLX6-AS1) on inflammatory responses in PD. With healthy male C57BL/6 mice (8-10 weeks) and BV2 microglia as study subjects, we established PD models in vivo/in vitro by injection of 1-methyl-4-phenyl-2, 3, 6-tetrahydropyridine (MPTP) for 4 weeks and treatment of lipopolysaccharide (LPS) for 24 h, respectively. DLX6-AS1 expression in PD mice and BV2 microglia was examined using reverse transcription quantitative-polymerase chain reaction and then down-regulated via stereotaxic catheter injection or cell transfection to evaluate its effect on neurological function. Meanwhile, the cell number of TH+ /Caspase3 + /IBA1 + in substantia nigra, cell viability, and apoptosis rate of BV2 microglia, inflammatory levels, and NLR family pyrin domain containing 3 (NLRP3) inflammasome were determined using immunohistochemistry, MTT assay, flow cytometry, ELIZA assay, and Western blot. The binding relationship between miR-223-3p and DLX6-AS1/Neuropilin-1 (NRP1) was verified by dual-luciferase assay and RNA immunoprecipitation assay. After down-regulation of DLX6-AS1, we down-regulated/overexpressed miR-223-3p/NRP1 levels in BV2 microglia. DLX6-AS1 was overexpressed in PD mice. Silencing DLX6-AS1 improved neurological function and alleviated microglial inflammation in PD mice. Specifically, the latency of mice falling from the rotating rod was longer, and the latency of climbing rod test was shorter; TH+ cells increased, while Caspase3 + /IBA1 + cells decreased; the levels of inflammatory were lowered. Silencing DLX6-AS1 inhibited LPS-induced inflammation of BV2 microglia. DLX6-AS1 acted as the ceRNA of miR-223-3p to promote NRP1. Down-regulation of miR-223-3p or overexpression of NRP1 partially annulled the effect of silencing DLX6-AS1 on BV2 microglial inflammation. Overall, DLX6-AS1 promotes the microglial inflammatory response in PD through the ceRNA mechanism of miR-223-3p/NRP1.

Long non-coding RNA DLX6-AS1 knockdown suppresses the tumorigenesis and progression of non-small cell lung cancer through microRNA-16-5p/BMI1 axis.

BACKGROUND: Non-small cell lung cancer (NSCLC) is a huge threat to sufferers' life and overall health. Long non-coding RNA (lncRNA) distal-less homeobox 6 antisense RNA 1 (DLX6-AS1) has been revealed to function as a carcinogenesis factor in some cancers. This research aimed to scrutinize the role and mechanism underlying DLX6-AS1 in NSCLC tumorigenesis and progression. METHODS: The levels of DLX6-AS1, microRNA-16-5p (miR-16-5p), and BMI1 mRNA were estimated via reverse transcription-quantitative PCR (RT-qPCR) assay. The protein levels were disclosed by western blot assay. Cell proliferative potential was estimated by colony formation and Cell Counting Kit-8 (CCK-8) assays. Cell migration was estimated by Transwell and wound healing assay. A Transwell assay was executed to estimate cell invasion. The relationships of DLX6-AS1, miR-16-5p, and BMI1 were forecasted by bioinformatics analysis, and confirmed by luciferase reporter assay and RNA immunoprecipitation (RIP) assay. A xenograft mice model was employed to to inspect the function of DLX6-AS1 knockdown on NSCLC tumorigenesis in vivo. RESULTS: DLX6-AS1 was overexpressed in NSCLC tissues and cells, and was inextricably linked with the poor prognosis of NSCLC patients. Depletion of DLX6-AS1 oppressed cell proliferation, migration, invasion, epithelial-mesenchymal transition (EMT) but promoted apoptosis in NSCLC. MiR-16-5p is a target of DLX6-AS1 and directly targets BMI1. Moreover, the anti-tumor impacts of miR-16-5p were overturned by overexpression of DLX6-AS1 or BMI1 in NSCLC cells. Additionally, DLX6-AS1 silencing inhibited tumor growth of NSCLC in vivo. CONCLUSIONS: In conclusion, lncRNA DLX6-AS1 downregulation suppressed the tumorigenesis and progression of NSCLC via miR-16-5p/BMI1 axis in vitro and in vivo, elucidating the vital roles and downstream targets of DLX6-AS1 in NSCLC.

DLX6-AS1 promotes cell proliferation, migration and EMT of gastric cancer through FUS-regulated MAP4K1.

Gastric cancer (GC) is the second most prevalent carcinoma resulting in cancer-related deaths in the world, with differences among geographic areas. Although the incidence and mortality rates of GC in Asia are decreasing, the search for diverse and effective therapies of GC is still needed to be fully inquired. The present research explored the expression pattern, functional role and underlying mechanism of DLX6-AS1 in GC. Firstly, we measured DLX6-AS1 expression in GC and then found the elevated level of DLX6-AS1. To further inspect the function role of DLX6-AS1 involved in GC, we performed lost-of-function assays. The silencing of DLX6-AS1 suppressed cell proliferation, migration and EMT process of GC cells. Subsequently, we uncovered that MAP4K1 was also up-regulated in GC and could be positively regulated by DLX6-AS1. Moreover, MAP4K1 down-regulation similarly inhibited GC progression. In addition, DLX6-AS1 stabilized MAP4K1 via modulating FUS. In summary, DLX6-AS1 modulated GC progression through FUS-regulated MAP4K1. Our paper exposed the role and regulatory mechanism of DLX6-AS1 in GC, which suggested a novel and valid therapy for GC patients.

Down-regulated lncRNA DLX6-AS1 inhibits tumorigenesis through STAT3 signaling pathway by suppressing CADM1 promoter methylation in liver cancer stem cells.

BACKGROUND: Liver cancer stem cells (LCSCs) are a small subset of cells characterized by unlimited self-renewal, cell differentiation, and uncontrollable cellular growth. LCSCs are also resistant to conventional therapies and are thus believed to be held responsible for causing treatment failure of hepatocellular carcinoma (HCC). It has been recently found that long non-coding RNAs (lncRNAs) are important regulators in HCC. This present study aims to explore the underlying mechanism of how lncRNA DLX6-AS1 influences the development of LCSCs and HCC. METHODS: A microarray-based analysis was performed to initially screen differentially expressed lncRNAs associated with HCC. We then analyzed the lncRNA DLX6-AS1 levels as well as CADM1 promoter methylation. The mRNA and protein expression of CADM1, STAT3, CD133, CD13, OCT-4, SOX2, and Nanog were then detected. We quantified our results by evaluating the spheroid formation, proliferation, and tumor formation abilities, as well as the proportion of tumor stem cells, and the recruitment of DNA methyltransferase (DNMT) in LCSCs when lncRNA DLX6-AS1 was either overexpressed or silenced. RESULTS: LncRNA DLX6-AS1 was upregulated in HCC. The silencing of lncRNA DLX6-AS1 was shown to reduce and inhibit spheroid formation, colony formation, proliferation, and tumor formation abilities, as well as attenuate CD133, CD13, OCT-4, SOX2, and Nanog expression in LCSCs. Furthermore, downregulation of lncRNA DLX6-AS1 contributed to a reduction in CADM1 promoter methylation via suppression of DNMT1, DNMT3a, and DNMT3b in LCSCs and inactivating the STAT3 signaling pathway. CONCLUSION: This study demonstrated that down-regulated lncRNA DLX6-AS1 may inhibit the stem cell properties of LCSCs through upregulation of CADM1 by suppressing the methylation of the CADM1 promoter and inactivation of the STAT3 signaling pathway.