LINC00680 Promotes the Progression of Non-Small Cell Lung Cancer and Functions as a Sponge of miR-410-3p to Enhance HMGB1 Expression

Non-Coding RNAs as Key Regulators in Lung Cancer

For several decades, most lung cancer investigations have focused on the search for mutations in candidate genes; however, in the last decade, due to the fact that most of the human genome is occupied by sequences that do not code for proteins, much attention has been paid to non-coding RNAs (ncRNAs) that perform regulatory functions. In this review, we principally focused on recent studies of the function, regulatory mechanisms, and therapeutic potential of ncRNAs including microRNA (miRNA), long ncRNA (lncRNA), and circular RNA (circRNA) in different types of lung cancer.

Circ_LRP6 facilitates osteosarcoma progression via the miR-122-5p/miR-204-5p/HMGB1 axis

Circ_LRP6 is participated in the occurrence and development of numerous tumors. Nevertheless, its roles and mechanism in osteosarcoma (OS) is unknown. This study aims to illustrate this point. With the use of qRT-PCR, the level of circ_LRP6, miR-122-5p, miR-204-5p and HMGB1 was identified. To observe cell proliferation, migration and invasion, we adopted CCK-8 and Transwell assays in the present study. Besides, to prove the existing interaction, bioinformatics analysis and dual luciferase reporting assays were employed. The influence of circ_LRP6 on osteosarcoma in vivo was evaluated by subcutaneous tumor formation model in nude mice. In osteosarcoma tissues, circ_LRP6 and HMGB1 are strongly denoted, whereas miR-122-5p and miR-204-5p are under-expressed. Circ_LRP6 knockdown could significantly hinder the proliferation, migration and invasion of osteosarcoma cells. Circ_LRP6 hindered the proliferation of osteosarcoma in vivo. Bioinformatics predicted that miR-122-5p and miR-204-5p functioned as direct targets of circ_LRP6, and HMGB1 were possible target genes of miR-122-5p and miR-204-5p. The findings indicated that the low level of miR-122-5p and miR-204-5p and the overexpression of HMGB1 could partially restore and reduce the inhibitory impact of circ_LRP6 on the proliferation, migration and invasion of osteosarcoma cells. Circ_LRP6 affects osteosarcoma progression via the miR-122-5p/miR-204-5p/HMGB1 axis, and is shown to be a molecular biomarker.

Plasma-Derived Small Extracellular Vesicles From VKH Patients Suppress T Cell Proliferation Via MicroRNA-410-3p Modulation of CXCL5 Axis

Purpose

Circulating exosomes regulate immune responses and induce immune tolerance in immune-mediated diseases. This study aimed to investigate the role of circulating small extracellular vesicles (sEVs) derived from patients with Vogt-Koyanagi-Harada (VKH) syndrome, in T-cell responses.

Methods

The sEVs were isolated from the plasma of healthy controls, patients with VKH, and other uveitis patients. The effects of autologous and allogeneic sEVs on the proliferation of circulating CD4+ T cells were evaluated. Microarray analysis of sEVs was performed to determine their differential miRNA expression profiles. The target genes of the candidate miRNA were predicted and verified. The role of both the candidate miRNA and target genes in T-cell proliferation was tested.

Results

Plasma-derived sEVs from patients with VKH inhibited the proliferation of autologous CD4+ T cells. Among all the miRNAs that might be associated with inflammatory activity, we found that miR-410-3p had the largest number of T-cell proliferation target genes. MiR-410-3p mimics inhibited the proliferation of Jurkat cells and CD4+ T cells. C-X-C motif chemokine ligand 5 (CXCL5) was confirmed to be a potential target gene of miR-410-3p, and siRNA-mediated CXCL5 knockdown inhibited cell proliferation.

Conclusions

Circulating sEVs exert an inhibitory effect on autologous CD4+ T cells mediated by miR-410-3p by targeting CXCL5, supporting the possibility of using autogenic sEVs to inhibit ocular inflammation.

Multi-hallmark long noncoding RNA maps reveal non-small cell lung cancer vulnerabilities

Long noncoding RNAs (lncRNAs) are widely dysregulated in cancer, yet their functional roles in cancer hallmarks remain unclear. We employ pooled CRISPR deletion to perturb 831 lncRNAs detected in KRAS-mutant non-small cell lung cancer (NSCLC) and measure their contribution to proliferation, chemoresistance, and migration across two cell backgrounds. Integrative analysis of these data outperforms conventional "dropout" screens in identifying cancer genes while prioritizing disease-relevant lncRNAs with pleiotropic and background-independent roles. Altogether, 80 high-confidence oncogenic lncRNAs are active in NSCLC, which tend to be amplified and overexpressed in tumors. A follow-up antisense oligonucleotide (ASO) screen shortlisted two candidates, Cancer Hallmarks in Lung LncRNA 1 (CHiLL1) and GCAWKR, whose knockdown consistently suppressed cancer hallmarks in two- and three-dimension tumor models. Molecular phenotyping reveals that CHiLL1 and GCAWKR control cellular-level phenotypes via distinct transcriptional networks. This work reveals a multi-dimensional functional lncRNA landscape underlying NSCLC that contains potential therapeutic vulnerabilities.

LncRNA LINC00680 Acts as a Competing Endogenous RNA and Is Associated With the Severity of Myasthennia Gravis

Background and Purpose

Myasthenia gravis (MG) is a T cell-dependent antibody-mediated autoimmune disorder that can seriously affect patients' quality of life. However, few studies have focused on the severity of MG. Moreover, existing therapeutic efforts, including those targeting biomarkers for MG, remain unsatisfactory. Therefore, it is vital that we investigate the pathogenesis of MG and identify new biomarkers that can not only evaluate the severity of the disease but also serve as potential therapeutic targets. Long noncoding RNA LINC00680 has been found to be associated with the progression of a variety of diseases as a competing endogenous RNA (ceRNA). However, the specific role of LINC00680 in MG has yet to be clarified. Here, we aimed to investigate the association between LINC00680 and the severity of MG.

Methods

Bioinformatics tools, quantitative real-time PCR, Western blotting, and luciferase assays were selected to investigate key signaling pathways and RNA expression in patients with MG. The Quantitative MG Score scale and the MG Composite scale were used to evaluate the severity of MG in the included patients. Cell viability assays and flow cytometry analysis were selected to analyze cell proliferation and apoptosis.

Results

Compared with control subjects, the expression levels of LINC00680 and mitogen-activated protein kinase 1 (MAPK1) in peripheral blood mononuclear cells of patients with MG were both upregulated; the levels of miR-320a were downregulated. A positive correlation was detected between LINC00680 expression and the severity of MG. Luciferase reporter assays identified that LINC00680 acts as a target for miR-320a. The in vitro analysis confirmed that LINC00680 regulates the expression of MAPK1 by sponging miR-320a. Finally, the functional analysis indicated that LINC00680 promoted Jurkat cell proliferation and inhibited cellular apoptosis by sponging miR-320a.

Conclusion

LINC00680 may be associated with the severity of MG as a ceRNA by sponging miR-320a to upregulate MAPK1. These findings suggest that LINC00680 may represent a potential biomarker which evaluates the severity of MG and may serve as a therapeutic target.

Major Role for Cellular MicroRNAs, Long Noncoding RNAs (lncRNAs), and the Epstein-Barr Virus-Encoded BART lncRNA during Tumor Growth In Vivo

This study assessed the effects of Epstein-Barr virus (EBV) and one form of virally encoded BART long noncoding RNAs (lncRNAs) on cellular expression in epithelial cells grown in vitro and as tumors in vivo determined by high-throughput RNA sequencing of mRNA and small RNAs. Hierarchical clustering based on gene expression distinguished the cell lines from the tumors and distinguished the EBV-positive tumors and the BART tumors from the EBV-negative tumors. EBV and BART expression also induced specific expression changes in cellular microRNAs (miRs) and lncRNAs. Multiple known and predicted targets of the viral miRs, the induced cellular miRs, and lncRNAs were identified in the altered gene set. The changes in expression in vivo indicated that the suppression of growth pathways in vivo reflects increased expression of cellular miRs in all tumors. In the EBV and BART tumors, many of the targets of the induced miRs were not changed and the seed sequences of the nonfunctional miRs were found to have homologous regions within the BART lncRNA. The inhibition of these miR effects on known targets suggests that these induced miRs have reduced function due to sponging by the BART lncRNA. This composite analysis identified the effects of EBV on cellular miRs and lncRNAs with a functional readout through identification of the simultaneous effects on gene expression. Major shifts in gene expression in vivo are likely mediated by effects on cellular noncoding RNAs. Additionally, a predicted property of the BART lncRNA is to functionally inhibit the induced cellular miRs.

Synergistic Effect of Stereotactic Radiotherapy Combined with Karelizumab on Patients with Advanced NSCLC

In this paper, synergistic effects of stereotactic radiotherapy (SRS) combined with karelizumab on the patients with advanced NSCLC have been analyzed through extensive experiments. For this purpose, 100 patients with advanced NSCLC in our hospital from December 2018 to December 2020 were selected and divided into control group and observation group. The control group was treated with SRS, while the observation group was treated with karelizumab at the same time. The data of age, gender, BMI, pathological type, and clinical stage were collected and recorded. After 3 months of treatment, the short-term efficacy of the two groups was evaluated according to RECIST solid tumor efficacy evaluation standard. Fasting venous blood of all patients before and 3 months after treatment was collected. The serum levels of matrix metalloproteinase-9 (MMP-9), cytokeratin 19 fragment (CY211), carcinoembryonic antigen (CEA), and vascular endothelial growth factor (VEGF) were detected by the enzyme-linked immunosorbent assay. The KPS score was used to evaluate the quality of life before and after treatment. The incidence of fatigue, diarrhea, and other adverse reactions were compared between the two groups. The patients were followed up for 3 years, and the survival of all patients was recorded. The total effective rate of the observation group was 50.00% (23/46), which was evidently higher than that (27.78% (15/54)) of the control group (P < 0.05). After treatment, the parameters of CY211, MMP-9, VEGF, and CEA in the two groups were evidently lower than those before treatment, and the parameters of CY211, MMP-9, VEGF, and CEA in the observation group were evidently lower than those in the control group after treatment (P < 0.05). After treatment, KPS parameters of the two groups were evidently higher than those before treatment, and KPS parameters of the observation group were evidently higher than those of the control group after treatment (P < 0.05). The 1-year, 2-year, and 3-year survival rates of the observation group were 95.64% (44/46), 89.13% (41/46), and 80.43% (37/46), respectively, and the 2-year and 3-year survival rates of the observation group were evidently higher than those of the control group (P < 0.05). SRS combined with karelizumab in the treatment of patients with advanced NSCLC has good curative effect, can evidently inhibit the angiogenesis and tumor growth and metastasis, can evidently improve the quality of life of patients, has a good synergistic effect, and can be widely used in clinic.

Long non-coding RNA LINC00680 functions as a ceRNA to promote esophageal squamous cell carcinoma progression through the miR-423-5p/PAK6 axis

Background

Esophageal squamous cell carcinoma (ESCC) is a common invasive malignancy worldwide with poor clinical outcomes. Increasing amount of long non-coding RNAs (lncRNAs) have been reported to be involved in cancer development. However, lncRNAs that are functional in ESCC and the underlying molecular mechanisms remain largely unknown.

Methods

Transcriptomic analysis was performed to identify dysregulated lncRNAs in ESCC tissue samples. The high expression of LINC00680 in ESCC was validated by RT-qPCR, and the oncogenic functions of LINC00680 was investigated by cell proliferation, colony formation, migration and invasion assays in ESCC cells in vitro and xenografts derived from ESCC cells in mice. RNA-seq, competitive endogenous RNA (ceRNA) network analysis, and luciferase reporter assays were carried out to identify LINC00680 target genes and the microRNAs (miRNAs) bound to LINC00680. Antisense oligonucleotides (ASOs) were used for in vivo treatment.

Results

Transcriptome profiling revealed that a large number of lncRNAs was dysregulated in ESCC tissues. Notably, LINC00680 was highly expressed, and upregulation of LINC00680 was associated with large tumor size, advanced tumor stage, and poor prognosis. Functionally, knockdown of LINC00680 restrained ESCC cell proliferation, colony formation, migration, and invasion in vitro and inhibited tumor growth in vivo. Mechanistically, LINC00680 was found to act as a ceRNA by sponging miR-423-5p to regulate PAK6 (p21-activated kinase 6) expression in ESCC cells. The cell viability and motility inhibition induced by LINC00680 knockdown was significantly reversed upon PAK6 restoration and miR-423-5p inhibition. Furthermore, ASO targeting LINC00680 substantially suppressed ESCC both in vitro and in vivo.

Conclusions

An oncogenic lncRNA, LINC00680, was identified in ESCC, which functions as a ceRNA by sponging miR-423-5p to promote PAK6 expression and ESCC. LINC00680/miR-423-5p/PAK6 axis may serve as promising diagnostic and prognostic biomarkers and therapeutic targets for ESCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-022-01539-3.

circ‑LRP6 contributes to osteosarcoma progression by regulating the miR‑141‑3p/HDAC4/HMGB1 axis

Circular RNA-lipoprotein receptor 6 (circ-LRP6) serves a role in promoting the tumorigenesis of retinoblastoma, esophageal squamous cell cancer and oral squamous cell carcinoma; however, whether circ-LRP6 demonstrates the same effect in osteosarcoma (OS) is yet to be fully elucidated. The present study aimed to analyze the expression, role and potential molecular mechanism of circ-LRP6 in OS. The expression levels of circ-LRP6, microRNA (miR)-141-3p, histone deacetylase 4 (HDAC4) and high mobility group protein 1 (HMGB1) were evaluated by reverse transcription- quantitative PCR in OS tissues and cell lines. Cell Counting Kit-8, Transwell and Matrigel assays were conducted to evaluate cell proliferation, migration and invasion, respectively. Western blotting was also performed to determine HDAC4 and HMGB1 protein expression levels. Bioinformatics and dual-luciferase reporter assays were used to predict and analyze the interactions between circ-LRP6 and miR-141-3p, miR-141-3p and HDAC4, as well as between miR-141-3p and HMGB1. Additionally, RNA immunoprecipitation was performed to verify the association between circ-LRP6 and miR-141-3p. The results confirmed that circ-LRP6 was highly expressed in OS tissues and cell lines. In addition, circ-LRP6 negatively regulated the expression of miR-141-3p and, in turn, miR-141-3p negatively regulated HDAC4 and HMGB1 expression. Functional assays revealed that circ-LRP6 knockdown inhibited the proliferation, migration and invasion of OS cells, whereas the inhibition of miR-141-3p or the overexpression of either HDAC4 or HMGB1 partly reversed the inhibitory effect of circ-LRP6 knockdown. In summary, the present study determined that circ-LRP6 knockdown inhibited the proliferation, migration and invasion of OS cells by regulating the miR-141-3p/HDAC4/HMGB1 axis.

LINC00680 modulates docetaxel resistance in breast cancer via the miR-320b/CDKL5 axis

Introduction: Increasing evidence has indicated that LINC00680 represents an oncogenic factor in cancer; however, the mechanism by which LINC00680 contributes to breast cancer (BC) remains unknown. Methods: A dual-luciferase reporter assay was used to explore the relationship between LINC00680, miR-320b, and cyclin-dependent kinase 5 (CDKL5). A CCK-8 assay and transwell assay were utilized to evaluate the proliferation and invasion in docetaxel-resistant BC cells, respectively. Results: LINC00680 and CDKL5 protein levels were both upregulated when induced by different concentrations of docetaxel. LINC00680 knockdown decreased the expression level of drug resistance-related genes, proliferation, and invasion of BC cells. Bioinformatics prediction and dual-luciferase assays revealed that miR-320b targeted the 3^′-unstranslated regions (UTR) of both LINC00680 and CDKL5, suggesting that the modulation of LINC00680 on CDKL5 occurred via sequestering miR-320b. Conclusion: Overall, this study highlights the important role of LINC00680 in docetaxel resistance through the miR-320b/CDKL5 pathway and provides a novel therapeutic strategy for BC drug resistance.

Long non-coding RNA VCAN-AS1 promotes the malignant behaviors of breast cancer by regulating the miR-106a-5p-mediated STAT3/HIF-1α pathway

An accumulating number of studies have found that long noncoding RNAs (lncRNAs) participate in breast cancer (BC) development. LncRNA VCAN-AS1, a novel lncRNA, has been confirmed to regulate the progression of gastric cancer, while its role in BC is elusive. Here, our results illustrate that VCAN-AS1 is overexpressed in BC tissues and cells, while miR-106a-5p was downregulated and negatively correlated with VCAN-AS1. In addition, high VCAN-AS1 expression and low miR-106a-5p expression were closely correlated with poor overall survival in BC patients. Functional experiments confirmed that VCAN-AS1 overexpression notably accelerated BC cell proliferation, migration, invasion, and epithelial–mesenchymal transition (EMT) and enhanced tumor cell growth while also suppressing cell apoptosis. However, overexpression of miR-106a-5p had the opposite effects. In addition, rescue experiments confirmed that overexpression of VCAN-AS1 inhibited the tumor-suppressive effects mediated by miR-106a-5p. Mechanistically, through bioinformatics analysis, we found that VCAN-AS1 functions as a competitive endogenous RNA (ceRNA) of miR-106a-5p, which targets the 3ʹ untranslated region (UTR) of signal transducer and activator of transcription 3 (STAT3). Further experiments indicated that miR-106a-5p downregulated the STAT3/hypoxia-inducible factor-1alpha (HIF-1α) pathway, while activating the STAT3 pathway reversed miR-106a-5p-mediated antitumor effects. Collectively, our data suggest that VCAN-AS1 is upregulated in breast cancer and promotes its progression by regulating the miR-106a-5p-mediated STAT3/HIF-1α pathway. This study provides a new target for BC therapy.

The role of exosomes in lung cancer metastasis and clinical applications: an updated review

Lung cancer is the leading cause of cancer-associated deaths accounting for 24% of all cancer deaths. As a crucial phase of tumor progression, lung cancer metastasis is linked to over 70% of these mortalities. In recent years, exosomes have received increasing research attention in their role in the induction of carcinogenesis and metastasis in the lung. In this review, recent studies on the contribution of exosomes to lung cancer metastasis are discussed, particularly highlighting the role of lung tumor-derived exosomes in immune system evasion, epithelial-mesenchymal transition, and angiogenesis, and their involvement at both the pre-metastatic and metastatic phases. The clinical application of exosomes as therapeutic drug carriers, their role in antitumor drug resistance, and their utility as predictive biomarkers in diagnosis and prognosis are also presented. The metastatic activity, a complex multistep process of cancer cell invasion, survival in blood vessels, attachment and subsequent colonization of the host's organs, is integrated with exosomal effects. Exosomes act as functional mediating factors in cell-cell communication, influencing various steps of the metastatic cascade. To this end, lung cancer cell-derived exosomes enhance cell proliferation, angiogenesis, and metastasis, regulate drug resistance, and antitumor immune activities during lung carcinogenesis, and are currently being explored as an important component in liquid biopsy assessment for diagnosing lung cancer. These nano-sized extracellular vesicles are also being explored as delivery vehicles for therapeutic molecules owing to their unique properties of biocompatibility, circulatory stability, decreased toxicity, and tumor specificity. The current knowledge of the role of exosomes highlights an array of exosome-dependent pathways and cargoes that are ripe for exploiting therapeutic targets to treat lung cancer metastasis, and for predictive value assessment in diagnosis, prognosis, and anti-tumor drug resistance.

LncRNA LINC00680 promotes lung adenocarcinoma growth via binding to GATA6 and canceling GATA6-mediated suppression of SOX12 expression

Lung adenocarcinoma (LUAD) is a major subtype of non-small-cell lung cancers (NSCLC). LINC00680 has been characterized as a novel oncogenic lncRNA in LUAD, but its regulatory mechanisms remain largely unclear. This study aimed to explore the subcellular localization of LINC00680 in LUAD and its regulation on the transcriptional process. LUAD cell lines (A549, H1650, and H1299) were used for in vitro and in vivo studies. Results showed LINC00680 depletion resulted in G0/G1 phase arrest of LUAD cells and reduced CDK4 and cyclin D1 expression in H1650 and H1299 cells. LINC00680 overexpression promoted A549 cell proliferation and increased CDK4 and cyclin D1 expression. RNA-fluorescence in situ hybridization (FISH) assay showed that LINC00680 has both cytoplasmic and nuclear distribution in LUAD cells. RNA pulldown and western blotting assays confirmed a physical interaction between LINC00680 and GATA6. In LUAD cells, GATA6 overexpression only slightly suppressed SOX12 transcription. ChIP-qPCR and dual-luciferase assay showed that GATA6 only weakly bound to the SOX12 promoter and decreased its activity. However, when LINC00680 was depleted, these transcriptional suppressive effects were significantly enhanced. These findings suggested that LINC00680 forms a complex with GATA6 and weakens its transcriptional suppressive effect on SOX12 expression. In the nude mice model, LINC00680 overexpression partly abrogated the growth-suppressive effects of GATA6 on A549 derived tumors. In summary, this study revealed a novel LINC00680-GATA6-SOX12 axis in promoting LUAD cell cycle progression and proliferation. Future studies should be conducted for a better understanding of the complex networking of LINC00680 in LUAD.