LINC00313 suppresses autophagy and promotes stemness of nasopharyngeal carcinoma cells through PTBP1/STIM1 axis.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a kind of malignant head and neck tumor with high mortality. lncRNAs are valuable diagnostic biomarkers and therapeutic targets for various tumors. This study investigated the effects and mechanism of LINC00313 in nasopharyngeal carcinoma. METHODS: Cell Counting Kit-8 (CCK-8) and immunohistochemistry were used for assessing cell proliferation. The levels of autophagy-related proteins, and stem cell markers were detected. Immunofluorescence assay was used for LC3 detection. Methylated RNA Immunoprecipitation (meRIP) of LINC00313 in NPC cells was assessed. The localization of LINC00313 was verified by luorescence in situ hybridization (FIHS). The interaction between LINC00313 and the downstream targets were analyzed and confirmed by immunoprecipitation (RIP). Besides, the tumorigenesis roles of LINC00313 were confirmed in tumor growth mice model. RESULTS: LINC00313 was increased in NPC tissues and cells. LINC00313 knockdown enhanced autophagy, and decreased stemness and cell viability of NPC cells through regulating STIM1. METTL3/IGF2BP1-mediated m6A modification promoted the stabilization and up-regulation of LINC00313. LINC00313 activated AKT/mTOR pathway in NPC cells through PTBP1/STIM1 axis. Moreover, LINC00313 promoted tumor growth and metastasis in xenograft model. CONCLUSION: Upregulation of LINC00313 suppressed autophagy and promoted stemness of NPC cells through PTBP1/STIM1 axis.

Biomarker Potential of LINC00313 in Head and Neck Squamous Cell Carcinoma: Correlation with Epithelial-Mesenchymal Transition and Immune Cell Infiltration.

Although LINC00313 is dysregulated in several tumors, its role in head and neck squamous cell carcinoma (HNSC) is not fully understood. The aim of this study was to analyze the role of LINC00313 in HNSC. The clinical information and LINC00313 expression data of HNSC were mined from the TCGA/GEO/cbioportal database. The correlation between LINC00313 expression and immune cell infiltration in HNSC tumors was analyzed by bioinformatics and gene enrichment analysis was performed. LINC00313 was silenced in HNSC cell lines, and changes at the genetic and molecular levels were verified through qRT-PCR and Western blotting. The researchers also validated its functional phenotype through a series of cell function experiments. The results showed that overexpression and copy number variation of LINC00313 in HNSC were associated with poorer prognosis. In addition, LINC00313 expression was significantly negatively correlated with immune cell infiltration. Silencing of LINC00313 in HNSC cells significantly reduced the rate of cell migration. LINC00313 may affect the progression of HNSC by regulating epithelial-mesenchymal transition. In conclusion, LINC00313 is a potential biomarker of HNSC prognosis and a potential target for immunotherapy.

Revealing underlying regulatory mechanisms of LINC00313 in Osimertinib-resistant LUAD cells by ceRNA network analysis.

BACKGROUND: Osimertinib, a third-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), is the preferred treatment for EGFR-mutated lung cancer. However, acquired resistance inevitably develops. While non-coding RNAs have been implicated in lung cancer through various functions, the molecular mechanisms responsible for osimertinib resistance remain incompletely elucidated. METHODS: RNA-sequencing technology was employed to determine differentially expressed lncRNAs (DE-lncRNAs) and mRNAs (DE-mRNAs) between H1975 and H1975OR cell lines. Starbase 2.0 was utilized to predict DE-lncRNA and DE-mRNA interactions, constructing ceRNA networks. Subsequently, functional and pathway enrichment analysis were performed on target DE-mRNAs to identify pathways associated with osimertinib resistance. Key target DE-mRNAs were then selected as potential risk signatures for lung adenocarcinoma (LUAD) prognostic modeling using multivariate Cox regression analyses. The Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) and immunohistochemistry staining were used for result validation. RESULTS: Functional analysis revealed that the identified DE-mRNAs primarily enriched in EGFR-TKI resistance pathways, especially in the PI3K/Akt signaling pathway, where their concerted actions may lead to osimertinib resistance. Specifically, upregulation of LINC00313 enhanced COL1A1 expression by acting as a miR-218-5p sponge, triggering an upstream response that activates the PI3K/Akt pathway, potentially contributing to osimertinib resistance. Furthermore, the expressions of LINC00313 and COL1A1 were validated by qRT-PCR, and the activation of the PI3K/Akt pathway was confirmed by immunohistochemistry staining. CONCLUSIONS: Our results suggest that the LINC00313/miR-218-5p/COL1A1 axis potentially contributes to osimertinib resistance through the PI3K/Akt signaling pathway, providing novel insights into the molecular mechanisms underlying acquired osimertinib resistance in LUAD. Additionally, our study may aid in the identification of potential therapeutic targets for overcoming resistance to osimertinib.

LINC00313 promotes the proliferation and inhibits the apoptosis of chondrocytes via regulating miR-525-5p/GDF5 axis.

BACKGROUND: The present study aimed to explore the potentials of lncRNA LINC00313 in osteoarthritis (OA). METHODS: qRT-PCR was performed to detect the expression of LINC00313 in OA tissues and cells. CCK-8 and EDU were used to detect cell proliferation. The ELISA test kit was conducted to detect the expression of inflammatory factors. Flow cytometry was used to detect the apoptosis rates. Western blot was applied to measure the protein expression. The luciferase reporter gene test was carried out to verify the relationship between miR-525-5p and LINC00313 or GDF5. RESULTS: The data showed that the expression of LINC00313 was significantly down-regulated in OA tissues and cells. Functionally, LINC00313 promoted the proliferation of chondrocytes and suppressed the secretion of inflammatory factors and cell apoptosis. Moreover, LINC00313 functioned as a ceRNA to up-regulate the expression of GDF5 via sponging miR-525-5p. Luciferase and RNA pull-down assays further verified the interaction between miR-525-5p and LINC00313 (or GDF5). Moreover, overexpression of miR-525-5p or down-regulated GDF5 degraded the cellular functions of chondrocyte. Rescue experiments showed that the overexpression of miR-525-5p reversed the increase in cell viability and the decrease in pro-inflammatory factors and apoptosis rate mediated by LINC00313. The knockdown of GDF5 reversed the promotion of miR-525-5p knockdown on cell viability and the inhibition of pro-inflammatory factors and apoptosis rate. CONCLUSIONS: LINC00313 inhibited the development of OA through regulating miR-525-5p/GDF5 axis. LncRNA LINC00313 can be used as a potential target for the treatment of OA.

LINC00313 alleviates osteoarthritis progression in mice through promoting TRAF1 promoter methylation and inhibiting the ASK1/JNK signaling pathway.

OBJECTIVES: This study aimed to explore the underlying role and mechanism of LINC00313 in osteoarthritis (OA) progression. METHODS: CHON-001 chondrocytes were treated with interleukin (IL)-1ß to induce OA in vitro, and then transfected with LINC00313 overexpression plasmids (pcDNA-LINC00313) or small interfering RNA against tumor necrosis factor (TNF) receptor-associated factor 1 (si-TRAF1). Cell viability, apoptosis, levels of inflammatory cytokines tumor necrosis factor-α (TNF-α), IL-6 and IL-8, and expression of extracellular matrix (ECM) degradation related proteins in CHON-001 cells were determined. TRAF1 promoter methylation were was detected with methylation-specific polymerase chain reaction (MSP) assay. Furthermore, a c-Jun N-terminal kinase (JNK) signaling activator was used to confirm whether the apoptosis signal-regulating kinase 1 (ASK1)/JNK signaling pathway was involved in the function of LINC00313/TRAF1 axis in chondrocytes. In addition, an OA mouse model was established and lentivirus LINC00313 overexpression vector (Lv-LINC00313) was injected, and then inflammatory cytokine levels, ECM protein expression, and pathological changes in cartilage tissues were detected. RESULTS: LINC00313 was downregulated and TRAF1 was upregulated in OA cartilage tissues. LINC00313 overexpression or TRAF1 silencing attenuated IL-1ß-induced viability inhibition, apoptosis, inflammation and ECM degradation in CHON-001 cells. Moreover, LINC00313 inhibited TRAF1 expression through promoting DNA methyltransferase 1 (DNMT1) mediated promoter methylation. TRAF1 overexpression reversed the effects of LINC00313 on IL-1ß-induced chondrocyte injury. LINC00313 overexpression inhibited the ASK1/JNK signaling pathway, and JNK activator reversed the effect. In addition, Lv-LINC00313 treatment alleviated cartilage tissue damage and cartilage matrix degradation in OA mice. CONCLUSIONS: LINC00313 alleviated OA progression through inhibiting TRAF1 expression and the ASK1/JNK signaling pathway.

LINC00313 facilitates osteosarcoma carcinogenesis and metastasis through enhancing EZH2 mRNA stability and EZH2-mediated silence of PTEN expression.

BACKGROUND: Osteosarcoma is one of the five leading causes of cancer death among all pediatric malignancies. Recent advances in non-coding RNAs suggested that many long noncoding RNAs (lncRNAs) are dysregulated in cancer tissues and play important roles in carcinogenesis. We aimed to further explore the mechanisms of Long Intergenic Non-Protein Coding RNA 313 (LINC00313)-promoted malignant phenotypes of osteosarcoma. METHODS: The mRNA expressions were determined by quantitative real-time PCR. Protein levels were detected using Western blotting or immunohistochemistry staining. Protein binding to genomic DNA and RNA were measured using chromatin and RNA immunoprecipitation assay, respectively. CCK-8 and EdU incorporation assay were adopted to detect cell proliferation. Transwell assay was employed to assess the capacity of cell migration and invasion. The roles of LINC00313 and its target genes in tumorigenesis and metastasis of osteosarcoma were evaluated using subcutaneous xenograft models and tail vein inoculation models. RESULTS: LINC00313 was elevated in osteosarcoma tissues compared with adjacent normal tissues. Higher LINC00313 was associated with advanced grades of osteosarcoma. LINC00313 promoted cell proliferation, migration, invasion in vitro and tumor growth as well as metastasis in vivo through inhibiting PTEN expression to promote AKT phosphorylation. Mechanistically, LINC00313 favored the interaction between FUS and EZH2, leading to the prolonged half-life of EZH2 mRNA, thereby in turn up-regulating EZH2 proteins and increasing EZH2-mediated epigenetic silence of PTEN. CONCLUSION: LINC00313 exerted oncogene-like actions through increasing EZH2 mRNA stability, leading to PTEN deficiency in osteosarcoma.

LINC00313 regulates the metastasis of testicular germ cell tumors through epithelial-mesenchyme transition and immune pathways.

Testicular germ cell tumor (TGCT) is a relatively rare entity tumor, accounting for only 1% of all male cancers. However, it is the most common solid tumor in young men between 15 and 34 years old. Long noncoding RNAs (lncRNAs) are involved in various physiological and pathological processes. However, the functions of lncRNAs in TGCT have only rarely been investigated. LncRNAs associated with TGCT were identified using Gene Expression Omnibus (GEO) database and UCSC XENA database data mining. The effects of LINC00313 on NCCIT cell migration and invasion were evaluated in transwell assays. The expression levels of epithelial-mesenchyme transition (EMT)-related proteins in cells knockdown of LINC00313 were analyzed by Western blot. Correlation analyses between lncRNA LINC00313 expression and copy number variation (CNV) and immune cell infiltration were carried out using The Cancer Genome Atl as (TCGA) data. The effect of Panobinostatin targeting LINC00313 in TGCT cells was investigated. We observed higher LINC00313 expression in TGCT. The migratory and invasive properties of TGCT cells were augmented by LINC00313, likely via its effects on modulating the expression of epithelial-mesenchyme transition (EMT) related proteins: CTNNB1, ZEB1, CDH2, Snail and VIM. Moreover, LINC00313 expression and CNV correlated negatively with the infiltration of immune cells. In addition, Panobinostat might be a possible candidate drug to target LINC00313 in TGCT. LINC00313 performs important pro-migration and invasion functions in the pathogenesis of TGCT. LINC00313 could be used as diagnostic, prognostic, immune marker and therapeutic target to develop effective treatment of TGCT.

Long Non-Coding RNA LINC00313 Accelerates Cervical Carcinoma Progression by miR-4677-3p/CDK6 Axis.

BACKGROUND: Cervical cancer is one of the most common gynecologic tumors. Evidence is accumulating that long non-coding RNAs participate in the pathogenesis of cancers, but the expression and role of lncRNA LINC00313 in cervical carcinoma is not reported. METHODS: We measured the expression levels of LINC00313 in clinical samples of cervical carcinoma and investigated the function of LINC00313 in the regulation of proliferation, metastasis, and EMT. Luciferase reporter assay was employed to explore the molecular regulation process of LINC00313. RESULTS: Our data showed that the levels of LINC00313 in cervical carcinoma tissues and cells were significantly up-regulated. Functionally, LINC00313 accelerated the progression, migration, and EMT of SiHa and Hela cells. Luciferase reporter assay confirmed that miR-4677-3p/CDK6 regulatory axis is the direct downstream of LINC00313. Functional gain- and loss-of-function strategies further showed that LINC00313 induced the up-regulation of CDK6 expression through competitive binding with miR-4677-3p, leading to promote the progression of cervical carcinoma. CONCLUSION: Our results demonstrated that LINC00313 accelerated the progression of cervical cancer through the miR-4677-3p/CDK6 regulatory axis. LncRNA LINC00313 may serve as a potential target for the diagnosis and treatment of cervical carcinoma.

LncRNA LINC00313 Knockdown Inhibits Tumorigenesis and Metastasis in Human Osteosarcoma by Upregulating FOSL2 through Sponging miR-342-3p.

PURPOSE: Osteosarcoma (OS) is the most common primary bone tumor, with high morbidity in infants and adolescents. Long noncoding RNA LINC00313 has been found to modulate papillary thyroid cancer tumorigenesis and to be dysregulate in lung cancer. However, the role of LINC00313 in OS has not yet been addressed. MATERIALS AND METHODS: We evaluated mRNA and protein expression using real-time quantitative PCR and Western blotting. Cell proliferation was evaluated using MTT; apoptosis and autophagy were assessed with flow cytometry, Western blotting, and/or GFP-LC3 assay. Transwell assay was conducted to measure cell migration and invasion. Potential target sites for LINC00313 and miR-342-3p were predicted with starBase v.2.0 and TargetScan Human, and verified using luciferase reporter assay, RNA immunoprecipitation, and RNA pull-down assay. In vivo, xenogeneic tumors were induced with U2OS and MG-63 cells, separately. RESULTS: LINC00313 was upregulated and miR-342-3p was downregulated in OS tissues and cells. High expression of LINC00313 was associated with shorter overall survival. FOSL2 downregulation and miR-342-3p overexpression suppressed cell proliferation and migratory and invasive abilities while promoting apoptosis and autophagy, all of which were consistent with the effects of LINC00313 knockdown. miR-342-3p, sponged by LINC00313, inversely modulated FOSL2 by targeting MG-63 cells, and FOSL2 expression was positively controlled by LINC00313. LINC00313 knockdown suppressed tumor growth in vivo. CONCLUSION: LINC00313 is upregulated in OS, and LINC00313 knockdown plays a vital anti-tumor role in OS cell progression through a miR-342-3p/FOSL2 axis. Our study suggests that LINC00313 may be a novel, promising biomarker for diagnosis and prognosis of OS.