LncRNA NEAT1 promotes docetaxel resistance in prostate cancer by regulating ACSL4 via sponging miR-34a-5p and miR-204-5p

Docetaxel resistance remains one of the main problems in clinical treatment of metastatic prostate cancer (PCa). Previous studies identified differently expressed lncRNAs in docetaxel-resistant PCa cell lines, while the potential mechanisms were still unknown. In the present study, we found NEAT1 was expressed at high levels in docetaxel-resistant PCa clinical samples and related cell lines. When knockdown NEAT1, cell proliferation and invasion in docetaxel-resistant PCa cells in vitro and in vivo were downregulated. Our further researches explained that NEAT1 exerts oncogenic function in PCa by competitively ‘sponging’ both miR-34a-5p and miR-204-5p. Inhibition of miR-34a-5p or miR-204-5p expression mimics the docetaxel-resistant activity of NEAT1, whereas ectopic expression of miR-34a-5p or miR-204-5p attenuates the anti-drug function of NEAT1 in PCa cells. Besides, we also found ACSL4 is a target of both miR-34a-5p and miR-204-5p, and ACSL4 was also inhibited by miR-34a-5p and miR-204-5p. Moreover, suppression of miR-34a-5p or/and miR-204-5p greatly restrained the expression of ACSL4 upon NEAT1 overexpression. Joint expression of miR-34a-5p and miR-204a-5p synergistically decreased the expression of ASCL4, indicating miR-34a-5p and miR-204a-5p collaboratively inhibit the expression of ACSL4. Innovatively, we concluded that NEAT1 contributes to the docetaxel resistance by increasing ACSL4 via sponging miR-34a-5p and miR-204-5p in PCa cells.     

MiR-483-5p suppresses the proliferation of glioma cells via directly targeting ERK1

MicroRNAs (miRNAs) exhibit tumor-specific expression signatures and play crucial roles in tumorigenesis by targeting oncogenes. Here, through analyzing the miRNA-array profiles of human glioblastoma tissues and the adjacent normal brain tissues, we found miR-483-5p was significantly down-regulated in gliomas, which was confirmed in both human glioma specimens and cell lines. The overexpression of miR-483-5p suppressed glioma cell proliferation and induced a G0/G1 arrest. In contrast, miR-483-5p inhibition promoted cell proliferation. Furthermore, by a dual-luciferase reporter assay and expression analysis, we identified extracellular signal-regulated kinase 1 (ERK1) as a direct target of miR-483-5p. ERK1 knockdown can block cell proliferation induced by miR-483-5p inhibition. Thus, our findings provide the first evidence that miR-483-5p can serve as a tumor suppressor in gliomas.     

RELA/NEAT1/miR-302a-3p/RELA feedback loop modulates pancreatic ductal adenocarcinoma cell proliferation and migration

Pancreatic ductal adenocarcinoma (PDAC) remains a challenging malignancy due to distant metastasis. RELA, a major component of the NF-κB pathway, could serve as an oncogene through activating proliferation or migration-related gene expression, including NEAT1, a well-known oncogenic long noncoding RNA. In the current study, the expression and function of RELA and NEAT1 in PDAC were examined. The potential upstream regulatory microRNAs of RELA were screened and verified for their correlation with RELA and NEAT1. The expression and function of the selected miR-302a-3p were evaluated. RELA and NEAT1 expression were upregulated in PDAC tissues, particularly in PDAC tissues with lymph node metastasis, and their expression correlated with clinical parameters. RELA overexpression promoted PDAC cell proliferation and migration, which could be partially attenuated by the NEAT1 knockdown. By binding to RELA, miR-302a-3p inhibited RELA expression, as well as PDAC cell proliferation and migration. RELA downstream NEAT1 expression was negatively regulated by miR-302a-3p; the suppressive effect of NEAT1 knockdown on PDAC cell proliferation and migration was partially attenuated by miR-302a-3p inhibition. Moreover, through direct binding, the expression of miR-302a-3p was also negatively regulated by NEAT1. The expression of miR-302a-3p was downregulated and negatively correlated with RELA or NEAT1 in tissue samples, indicating that rescuing miR-302a-3p expression may inhibit PDAC cell proliferation and migration through RELA/NEAT1. In summary, RELA, NEAT1, and miR-302a-3p form a feedback loop in PDAC to modulate PDAC cell proliferation and migration.     

Long noncoding RNA FOXD2-AS1 promotes glioma malignancy and tumorigenesis via targeting miR-185-5p/CCND2 axis

Glioma is the most aggressive malignant tumor in the adult central nervous system. Abnormal long noncoding RNA (lncRNA) FOXD2-AS1 expression was associated with tumor development. However, the possible role of FOXD2-AS1 in the progression of glioma is not known. In the present study, we used in vitro and in vivo assays to investigate the effect of abnormal expression of FOXD2-AS1 on glioma progression and to explore the mechanisms. FOXD2-AS1 was upregulated in glioma tissue, cells, and sphere subpopulation. Upregulation of FOXD2-AS1 was correlated with poor prognosis of glioma. Downregulation of FOXD2-AS1 decreased cell proliferation, migration, invasion, stemness, and epithelial-mesenchymal transition (EMT) in glioma cells and inhibited tumor growth in transplanted tumor. We also revealed that FOXD2-AS1 was mainly located in cytoplasm and microRNA (miR)-185-5p both targeted FOXD2-AS1 and CCND2 messenger RNA (mRNA) 3′-untranslated region (3′-UTR). miR-185-5p was downregulated in glioma tissue, cells, and sphere subpopulation. Downregulation of miR-185-5p was closely correlated with poor prognosis of glioma patients. In addition, miR-185-5p mimics decreased cell proliferation, migration, invasion, stemness, and EMT in glioma cells. CCND2 was upregulated in glioma tissue, cells, and sphere subpopulation. Upregulation of CCND2 was closely correlated with poor prognosis of glioma patients. CCND2 knockdown decreased cell proliferation, migration, invasion, and EMT in glioma cells. In glioma tissues, CCND2 expression was negatively associated with miR-185-5p, but positively correlated with FOXD2-AS1. FOXD2-AS1 knockdown and miR-185-5p mimics decreased CCND2 expression. Inhibition of miR-185-5p suppressed FOXD2-AS1 knockdown-induced decrease of CCND2 expression. Overexpression of CCND2 suppressed FOXD2-AS1 knockdown-induced inhibition of glioma malignancy. Taken together, our findings highlight the FOXD2-AS1/miR-185-5p/CCND2 axis in the glioma development.     

Long noncoding RNA FLVCR1-AS1 aggravates biological behaviors of glioma cells via targeting miR-4731-5p/E2F2 axis

Long noncoding RNAs (lncRNAs) display essential roles in cancer progression. FLVCR1-AS1 is a rarely investigated lncRNAs involved in various human cancers, such as hepatocellular carcinoma and lung cancer. However, its function in glioma has not been clarified. In our study, we found that FLVCR1-AS1 was highly expressed in glioma tissues and cell lines. And upregulation of FLVCR1-AS1 predicted poor prognosis in patients with glioma. Moreover, FLVCR1-AS1 knockdown inhibited proliferation, migration and invasion of glioma cells. Through bioinformatics analysis, we identified that FLVCR1-AS1 was a sponge for miR-4731-5p to upregulate E2F2 expression. Moreover, rescue assays indicated that FLVCR1-AS1 modulated E2F2 expression to participate in glioma progression. Altogether, our research demonstrates that the FLVCR1-AS1/miR-4731-5p/E2F2 axis is a novel signaling in glioma and may be a potential target for tumor therapy.     

An upstream open reading frame regulates vasculogenic mimicry of glioma via ZNRD1-AS1/miR-499a-5p/ELF1/EMI1 pathway

Increasing evidence has suggested that gliomas can supply blood through vasculogenic mimicry. In this study, the expression and function of ZNRD1-AS1-144aa-uORF (144aa-uORF) and some non-coding RNAs in gliomas were assessed. Real-time quantitative PCR or Western blot was used to discover the expression of 144aa-uORF, ZNRD1-AS1, miR-499a-5p, ELF1 and EMI1 in gliomas. In addition, RIP and RNA pull-down assays were applied to explore the interrelationship between 144aa-uORF and ZNRD1-AS1. The role of the 144aa-uORF\ZNRD1-AS1\miR-499a-5p\ELF1\EMI1 axis in vasculogenic mimicry formation of gliomas was analysed. This study illustrates the reduced expression of the 144aa-uORF in glioma tissues and cells. Up-regulation of 144aa-uORF inhibits proliferation, migration, invasion and vasculogenic mimicry formation within glioma cells. The up-regulated 144aa-uORF can increase the degradation of ZNRD1-AS1 through the nonsense-mediated RNA decay (NMD) pathway. Knockdown of ZNRD1-AS1 inhibits vasculogenic mimicry in glioma cells by modulating miR-499a-5p. At the same time, miR-499a-5p is down-regulated and has a tumour-suppressive effect in gliomas. In addition, ZNRD1-AS1 serves as a competitive endogenous RNA (ceRNA) and regulates the expression of ELF1 by binding to miR-499a-5p. Notably, ELF1 binds to the promoter region of EMI1 and up-regulates EMI1 expression, while simultaneously promoting vasculogenic mimicry in glioma cells. This study suggests that the 144aa-uORF\ZNRD1-AS1\miR-499a-5p\ELF1\EMI1 axis takes key part in regulating the formation of vasculogenic mimicry in gliomas and may provide a potential target for glioma treatment.     

Hsa_circ_0076931 suppresses malignant biological properties,down-regulates miR-6760-3p through direct binding,and up-regulates CCBE1 in glioma

The function of circular RNAs (circRNAs) in gliomas is as yet unknown. The present study explored role of hsa_circ_0076931 in glioma. circRNA expression profiles were identified via RNA-seq followed by qRT-PCR validation in three pairs of glioma and normal brain tissues (NBT). The function of hsa_circ_0076931 was investigated in vitro using cell lines as well as in vivo using a xenograft tumor. Hsa_circ_0076931 was up-regulated by overexpression and an mRNA profile compared with wild-type was identified by RNA-seq. The relationship between miR-6760-3p and hsa_circ_0076931 or CCBE1 was confirmed via luciferase reporter or AGO2-RIP assays. A total of 507 circRNAs were identified in glioma tissues that were differentially expressed compared with that in NBT, and the sequencing data were deposited in BioProject (ID: PRJNA746438). Hsa_circ_0007694 and hsa_circ_0008016 were memorably increased whereas hsa_circ_0076931 and hsa_circ_0076948 decreased in glioma compared with those in NBT. Additionally, hsa_circ_0076931 expression was negatively correlated with histological grade. Overexpression of hsa_circ_0076931 inhibited proliferation, migration, and invasion while promoting apoptosis of glioma cells. A total of 4383 and 537 aberrantly expressed genes were identified between the hsa_circ_0076931-overexpressed and control groups in H4 and U118-MG cells, respectively; the sequencing data were deposited in BioProject (ID: PRJNA746438). These differentially expressed genes were mainly enriched in cancer-related pathways. In addition, elevated hsa_circ_0076931 levels induced the expression of CCBE1 while suppressing miR-6760-3p expression. miR-6760-3p can bind to hsa_circ_0076931. The experimental evidence supports using hsa_circ_0076931 as a marker for glioma and to help prevent malignant progression. The mechanism might be relevant to miR-6760-3p and CCBE1.     

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

Melanoma contributes a lot to skin cancer-related deaths. lncRNAs are implicated in various diseases, including melanoma. lncRNA NEAT1 is frequently dysregulated and can play important roles in multiple cancers. Nevertheless, little has been studied about the function of NEAT1 in melanoma progression. In our present research, we displayed NEAT1 was overexpressed in melanoma cells. A series of functional assays showed that overexpression of NEAT1 promoted the proliferation, migration, and invasion of melanoma cells. By contrast, NEAT1 knockdown obviously restrained melanoma cell progression. Mechanistically, it was revealed that NEAT1 could directly bind with miR-495-3p, which led to a negative effect on miR-495-3p levels. In addition, miR-495-3p was significantly decreased in melanoma cells. Furthermore, E2F3 was postulated as the target of miR-495-3p and overexpression of this miR could suppress the levels of E2F3. Meanwhile, it was exhibited that melanoma cell proliferation, migration, and invasion induced by E2F3 silence was abrogated by miR-495-3p. Moreover, an in vivo xenograft nude mice model was established using A375 cells and it was indicated that NEAT1 promoted melanoma progression in vivo via regulating the miR-495-3p/E2F3 axis. In conclusion, we suggest that NEAT1 exerts an oncogenic effect on melanoma development via inhibition of miR-495-3p and induction of E2F3. NEAT1 might serve as a crucial prognostic biomarker of melanoma.     

FtMt promotes glioma tumorigenesis and angiogenesis via lncRNA SNHG1/miR-9-5p axis

ObjectiveThis study is to investigate the effects and the mechanisms of mitochondrial ferritin (FtMt) on the glioma tumorigenesis and angiogenesis.MethodsFtMt expression was detected in glioma tissues and cells as well as in nude mouse tissues. Cell proliferation and apoptosis rate were observed following transfection of LV-FtMt or sh-FtMt in glioma cell line. Moreover, glioma cells with FtMt over-expression/knockdown were co-cultured with human umbilical vein endothelial cells (HUVECs) to observe its function on HUVEC proliferation, angiogenic ability and the vascular endothelial growth factor (VEGF) content. Gain and loss of function of small nucleolar RNA host gene 1 (SNHG1) and miR-9-5p were performed in glioma cells and GBM nude mice to observe its effect on glioma cell proliferation and HUVEC angiogenic ability. Luciferase reporter gene and RIP assay were employed to inspect the interactions among SNHG1, FtMt and miR-9-5p. Additionally, a xenograft mouse model was applied to determine the role of FtMt in glioma.ResultsIn this work, FtMt was strongly expressed in glioma tissues and cells as well as in nude mouse tumor tissues. The employment of the loss-of and gain-of functions assays illustrated that FtMt enhanced glioma tumorigenesis and angiogenesis. Mechanistically, our findings showed that FtMt positively related to SNHG1 while negatively correlated with miR-9-5p, and both SNHG1 and FtMt can competitively bind with miR-9-5p. Besides, the inhibition effects of sh-FtMt on glioma were surveyed in vivo experiments.ConclusionEvidence in this study suggested that FtMt promotes glioma tumorigenesis and angiogenesis via SNHG1 mediated miR-9-5p expression, which may provide a theoretical basis for glioma treatment.     

LncRNA SNHG1 regulates immune escape of renal cell carcinoma by targeting miR-129-3p to activate STAT3 and PD-L1

Immune escape of renal cell carcinoma (RCC) impacts patient survival. However, the molecular mechanism of long noncoding RNA (lncRNA) small nucleolar RNA host gene 1 (SNHG1) in RCC immune escape remains unclear. Quantitative real-time PCR and western blotting results revealed that the expression of lncRNA SNHG1 and STAT3 were upregulated in RCC tissues and cells and that the expression of miR-129-3p was downregulated. Enzyme-linked immunosorbent assay results revealed the increased levels of immune-related factors (interferon-γ, tumour necrosis factor α, and interleukin-2) in RCC tissues. SNHG1 knockdown or miR-129-3p overexpression inhibited the proliferation and invasion of A498 and 786-O cells, while the proliferation and cytotoxicity of CD8⁺ T cells increased, which promoted the secretion of immune-related factors. STAT3 overexpression decreased the protective effect of miR-129-3p overexpression on RCC cell immune escape. In addition, miR-129-3p knockdown and STAT3 overexpression decreased the protective effect of lncRNA SNHG1 knockdown on RCC cell immune escape. In addition, PD-L1 expression was downregulated after lncRNA SNHG1 knockdown but upregulated after miR-129-3p knockdown and STAT3 overexpression. Dual-luciferase assays showed that lncRNA SNHG1 targets miR-129-3p, and miR-129-3p targets STAT3. RNA pull-down and RNA immunoprecipitation assays verified the regulatory relationship between SNHG1 and STAT3. In vivo, shSNHG1 prolonged the overall survival of RCC tumour model mice and inhibited RCC tumour growth and immune escape but increased CD8⁺ T cell infiltration in mice. Our findings provide an experimental basis for elucidating the molecular mechanisms of immune escape by RCC and reveal a novel target to treat this disease.     

Involvement of NEAT1/miR-133a axis in promoting cervical cancer progression via targeting SOX4

NEAT1 is an important tumor oncogenic gene in various tumors. Nevertheless, its involvement remains poorly studied in cervical cancer. Our study explored the functional mechanism of NEAT1 in cervical cancer. NEAT1 level in several cervical cancer cells was quantified and we found NEAT1 was greatly upregulated in vitro. NEAT1 knockdown inhibited cervical cancer development through repressing cell proliferation, colony formation, capacity of migration, and invasion and also inducing the apoptosis. For another, microRNA (miR)-133a was downregulated in cervical cancer cells and NEAT1 negatively modulated miR-133a expression. Subsequently, we validated that miR-133a functioned as a potential target of NEAT1. Meanwhile, SOX4 is abnormally expressed in various cancers. SOX4 was able to act as a downstream target of miR-133a and silencing of SOX4 can restrain cervical cancer progression. In addition, in vivo assays were conducted to prove the role of NEAT1/miR-133a/SOX4 axis in cervical cancer. These findings implied that NEAT1 served as a competing endogenous RNA to sponge miR-133a and regulate SOX4 in cervical cancer pathogenesis. To sum up, it was implied that NEAT1/miR-133a/SOX4 axis was involved in cervical cancer development.     

miR-9-5p靶向Ambra1促进舌癌细胞增殖

miRNAs在肿瘤中异常表达,且与肿瘤的发生发展密切相关。目前发现,miR-9-5p在肿瘤中可能发挥原癌或抑癌效应,功能尚未完全阐述清楚。本文拟探讨miR-9-5p在舌癌中的作用。前期研究中收集10例舌癌组织及配对的癌旁组织,实时荧光定量PCR技术检测后发现,miR-9-5p在舌癌组织中的表达量显著高于癌旁组织,且其在舌癌细胞中的表达量也明显高于正常舌上皮细胞。此外,在舌癌细胞Tca8113中过表达miR-9-5p显著增加细胞的增殖能力。生物信息学预测及双荧光素酶报告基因实验证实,miR-9-5p可直接结合在自噬/苄氯素1调节因子1（activating molecule in beclin1-regulated autophagy, Ambra1）的 3′-UTR区域,靶向抑制Ambra1表达。Western印迹结果证实过表达miR-9-5p降低Ambra1的表达,反之亦然。Ambra1在舌癌细胞中的表达量显著低于正常舌上皮细胞。BrdU实验证实在舌癌细胞SCC-25中过表达Ambra1可显著抑制其增殖能力;相反,使用siRNA技术沉默Ambra1能够显著促进Tca8113细胞的增殖。在干预miR-9-5p的细胞中同时干预Ambra1的表达,结果发现Ambra1可显著逆转miR-9-5p对舌癌细胞增殖的促进作用。总之,miR-9-5p在舌癌中可能发挥原癌基因样作用,通过直接靶向抑制Ambra1表达进而促进舌癌细胞发生增殖。