M6A-Mediated Upregulation of LINC00106 Promotes Stemness and Metastasis Properties of Hepatocellular Carcinoma via Sponging Let7f

Background: Hepatocellular carcinoma (HCC) cells exhibit the stemness property, which makes the patient with HCC prone to tumor recurrence and metastasis. Despite the prominent regulatory role of long non-coding RNAs (lncRNAs) in tumor stemness, the roles and molecular mechanisms of LINC00106 in HCC are poorly understood.Methods: LINC00106, let7f and periostin expression levels in tissue specimens and cell lines were assessed through qRT-PCR and immunohistochemistry (IHC). Various in vivo and in vitro assays, namely sphere/colony formation, proportion of side population cells (SP%), invasion, migration, western blot, and murine xenograft model were employed for assessing the stemness and metastatic properties of HCC cells. Luciferase reporter assays, RNA-seq, RNA pull-down, RNA immunoprecipitation (RIP) were conducted to clarificate the target gene and analyze the underlying mechanisms.Results: LINC00106 was prominently upregulated in tissues and cell lines of HCC. Patients having a high LINC00106 level exhibited a poor outcome. Under in vivo and in vitro conditions, the stemness and metastatic properties of HCC cells were augmented by LINC00106. Additionally, LINC00106 was found to sponge let7f to upregulate periostin, which lead to the activation of periostin-associated PI3K-AKT signaling pathway. Moreover, m6A methylation was found to cause LINC00106 upregulation while maintaining LINC00106 RNA transcript stability.Conclusion: m6A methylation triggers the upregulation of LINC00106, which promotes the stemness and metastasis properties in HCC cells by sponging let7f, thereby resulting in periostin activation. The findings indicate the potential of LINC00106 as a diagnostic marker and therapeutic target for HCC.

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M6A-mediated upregulation of LINC00958 increases lipogenesis and acts as a nanotherapeutic target in hepatocellular carcinoma

Journal of Hematology & Oncology ◽

10.1186/s13045-019-0839-x ◽

2020 ◽

Vol 13 (1) ◽

Cited By ~ 24

Author(s):

Xueliang Zuo ◽

Zhiqiang Chen ◽

Wen Gao ◽

Yao Zhang ◽

Jinguo Wang ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Cell Lines ◽

Molecular Mechanisms ◽

Xenograft Model ◽

Systemic Administration ◽

Luciferase Reporter ◽

Loss Of Function ◽

Poor Overall Survival

Abstract Background Long non-coding RNAs (lncRNAs) possess significant regulatory functions in multiple biological and pathological processes, especially in cancer. Dysregulated lncRNAs in hepatocellular carcinoma (HCC) and their therapeutic applications remain unclear. Methods Differentially expressed lncRNA profile in HCC was constructed using TCGA data. LINC00958 expression level was examined in HCC cell lines and tissues. Univariate and multivariate analyses were performed to demonstrate the prognostic value of LINC00958. Loss-of-function and gain-of-function experiments were used to assess the effects of LINC00958 on cell proliferation, motility, and lipogenesis. Patient-derived xenograft model was established for in vivo experiments. RNA immunoprecipitation, dual luciferase reporter, biotin-labeled miRNA pull-down, fluorescence in situ hybridization, and RNA sequencing assays were performed to elucidate the underlying molecular mechanisms. We developed a PLGA-based nanoplatform encapsulating LINC00958 siRNA and evaluated its superiority for systemic administration. Results We identified a lipogenesis-related lncRNA, LINC00958, whose expression was upregulated in HCC cell lines and tissues. High LINC00958 level independently predicted poor overall survival. Functional assays showed that LINC00958 aggravated HCC malignant phenotypes in vitro and in vivo. Mechanistically, LINC00958 sponged miR-3619-5p to upregulate hepatoma-derived growth factor (HDGF) expression, thereby facilitating HCC lipogenesis and progression. METTL3-mediated N6-methyladenosine modification led to LINC00958 upregulation through stabilizing its RNA transcript. A PLGA-based nanoplatform loaded with si-LINC00958 was developed for HCC systemic administration. This novel drug delivery system was controlled release, tumor targeting, safe, and presented satisfactory antitumor efficacy. Conclusions Our results delineate the clinical significance of LINC00958 in HCC and the regulatory mechanisms involved in HCC lipogenesis and progression, providing a novel prognostic indicator and promising nanotherapeutic target.

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Downregulation of CRABP2 Inhibit the Tumorigenesis of Hepatocellular Carcinoma In Vivo and In Vitro

BioMed Research International ◽

10.1155/2020/3098327 ◽

2020 ◽

Vol 2020 ◽

pp. 1-12

Author(s):

Qingmin Chen ◽

Ludong Tan ◽

Zhe Jin ◽

Yahui Liu ◽

Ze Zhang

Keyword(s):

Hepatocellular Carcinoma ◽

Retinoic Acid ◽

Cell Lines ◽

Molecular Mechanisms ◽

Tumor Stage ◽

Migration And Invasion ◽

Hcc Cells

Cellular retinoic acid-binding protein 2 (CRABP2) binds retinoic acid (RA) in the cytoplasm and transports it into the nucleus, allowing for the regulation of specific downstream signal pathway. Abnormal expression of CRABP2 has been detected in the development of several tumors. However, the role of CRABP2 in hepatocellular carcinoma (HCC) has never been revealed. The current study aimed to investigate the role of CRABP2 in HCC and illuminate the potential molecular mechanisms. The expression of CRABP2 in HCC tissues and cell lines was detected by western blotting and immunohistochemistry assays. Our results demonstrated that the expression levels of CRABP2 in HCC tissues were elevated with the tumor stage development, and it was also elevated in HCC cell lines. To evaluate the function of CRABP2, shRNA-knockdown strategy was used in HCC cells. Cell proliferation, metastasis, and apoptosis were analyzed by CCK-8, EdU staining, transwell, and flow cytometry assays, respectively. Based on our results, knockdown of CRABP2 by shRNA resulted in the inhibition of tumor proliferation, migration, and invasion in vitro, followed by increased tumor apoptosis-related protein expression and decreased ERK/VEGF pathway-related proteins expression. CRABP2 silencing in HCC cells also resulted in the failure to develop tumors in vivo. These results provide important insights into the role of CRABP2 in the development and development of HCC. Based on our findings, CRABP2 may be used as a novel diagnostic biomarker, and regulation of CRABP2 in HCC may provide a potential molecular target for the therapy of HCC.

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Epigenetic regulation of ferroptosis via ETS1/miR-23a-3p/ACSL4 axis mediates sorafenib resistance in human hepatocellular carcinoma

Journal of Experimental & Clinical Cancer Research ◽

10.1186/s13046-021-02208-x ◽

2022 ◽

Vol 41 (1) ◽

Author(s):

Yuanjun Lu ◽

Yau-Tuen Chan ◽

Hor-Yue Tan ◽

Cheng Zhang ◽

Wei Guo ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Drug Resistance ◽

Molecular Mechanisms ◽

Luciferase Reporter ◽

Dependent Manner ◽

Bioinformatics Analyses ◽

Sorafenib Treatment ◽

Hcc Cells

Abstract Background Drug resistance to sorafenib greatly limited the benefits of treatment in patients with hepatocellular carcinoma (HCC). MicroRNAs (miRNAs) participate in the development of drug resistance. The key miRNA regulators related to the clinical outcome of sorafenib treatment and their molecular mechanisms remain to be identified. Methods The clinical significance of miRNA-related epigenetic changes in sorafenib-resistant HCC was evaluated by analyzing publicly available databases and in-house human HCC tissues. The biological functions of miR-23a-3p were investigated both in vitro and in vivo. Proteomics and bioinformatics analyses were conducted to identify the mechanisms that regulating miR-23a-3p. Luciferase reporter assay and chromatin immunoprecipitation (ChIP) assay were used to validate the binding relationship of miR-23a-3p and its targets. Results We found that miR-23a-3p was the most prominent miRNA in HCC, which was overexpressed in sorafenib non-responders and indicated poor survival and HCC relapse. Sorafenib-resistant cells exhibited increased miR-23a-3p transcription in an ETS Proto-Oncogene 1 (ETS1)-dependent manner. CRISPR-Cas9 knockout of miR-23a-3p improved sorafenib response in HCC cells as well as orthotopic HCC tumours. Proteomics analysis suggested that sorafenib-induced ferroptosis was the key pathway suppressed by miR-23a-3p with reduced cellular iron accumulation and lipid peroxidation. MiR-23a-3p directly targeted the 3′-untranslated regions (UTR) of ACSL4, the key positive regulator of ferroptosis. The miR-23a-3p inhibitor rescued ACSL4 expression and induced ferrotoptic cell death in sorafenib-treated HCC cells. The co-delivery of ACSL4 siRNA and miR-23a-3p inhibitor abolished sorafenib response. Conclusion Our study demonstrates that ETS1/miR-23a-3p/ACSL4 axis contributes to sorafenib resistance in HCC through regulating ferroptosis. Our findings suggest that miR-23a-3p could be a potential target to improve sorafenib responsiveness in HCC patients.

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Exosomal hsa_circ_0004658 derived from RBPJ overexpressed-macrophages inhibits hepatocellular carcinoma progression via miR-499b-5p/JAM3

Cell Death and Disease ◽

10.1038/s41419-021-04345-9 ◽

2022 ◽

Vol 13 (1) ◽

Author(s):

Lei Zhang ◽

Jing Zhang ◽

Pengfei Li ◽

Ting Li ◽

Zhiqin Zhou ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Xenograft Model ◽

Circular Rna ◽

Luciferase Reporter ◽

Mouse Xenograft Model ◽

Rna Immunoprecipitation ◽

And Migration ◽

Hcc Cells

AbstractMacrophage-derived exosomes (Mφ-Exo) have multidimensional involvement in tumor initiation, progression, and metastasis, but their regulation in hepatocellular carcinoma (HCC) is not fully understood. RBPJ has been implicated in macrophage activation and plasticity. In this study we assess the role of exosomes derived from RBPJ-overexpressed macrophages (RBPJ+/+ Mφ-Exo) in HCC. The circular RNA (circRNA) profiles in RBPJ+/+ Mφ-Exo and THP-1-like macrophages (WT Mφ)-Exo was evaluated using circRNA microarray. CCK-8, Transwell, and flow cytometry analyses were used to evaluate the function of Mφ-Exo-circRNA on HCC cells. Luciferase reporter assays, RNA immunoprecipitation, and Pearson’s correlation analysis were used to confirm interactions. A nude mouse xenograft model was used to further analyze the functional significance of Mφ-Exo-cirRNA in vivo. Our results shown that hsa_circ_0004658 is upregulated in RBPJ+/+ Mφ-Exo compared to WT Mφ-Exo. RBPJ+/+ Mφ-Exo and hsa_circ_0004658 inhibits proliferation and promotes apoptosis in HCC cells, whereas hsa_circ_0004658 knockdown stimulated cell proliferation and migration but restrained apoptosis in vitro and promotes tumor growth in vivo. The effects of RBPJ+/+ Mφ-Exo on HCC cells can be reversed by the hsa_circ_0004658 knockdown. Mechanistic investigations revealed that hsa_circ_0004658 acts as a ceRNA of miR-499b-5p, resulting in the de-repression of JAM3. These results indicate that exosome circRNAs secreted from RBPJ+/+ Mφ inhibits tumor progression through the hsa_circ_0004658/miR-499b-5p/JAM3 pathway and hsa_circ_0004658 may be a diagnostic biomarker and potential target for HCC therapy.

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LncRNA HOXD-AS1 functions as a ceRNA to promote hepatocellular carcinoma metastasis in zebrafish xenograft models

10.21203/rs.3.rs-232919/v1 ◽

2021 ◽

Author(s):

Ying Zhang ◽

Xiaolu Wang ◽

Feng Qin ◽

Shaochang Jia

Keyword(s):

Hepatocellular Carcinoma ◽

Cell Lines ◽

Noncoding Rna ◽

Xenograft Model ◽

Cerna Network ◽

Xenograft Models ◽

Proliferation And Invasion ◽

Hcc Cells

Abstract Background: A few studies have shown that long noncoding RNA (lncRNA) HOXD cluster antisense RNA 1 (HOXD-AS1) plays an important role in hepatocellular carcinoma (HCC) metastasis as a competing endogenous RNA (ceRNA), but there is little in vivo evidence. This study aims to explore the zebrafish HCC xenograft as an in vivo metastasis model to verify the ceRNA network of HOXD-AS1. Methods: The quantitative reverse transcription PCR (qRT-PCR) assay was used to assess the expression level of HOXD-AS1 in HCC cell lines. Knockdown of HOXD-AS1 or miR-130a-3p was performed by transfecting small interfering RNA (siRNA) or microRNA (miRNA) inhibitor, respectively. The proliferation and invasion of HCC cells in vitro were analyzed by CCK-8 and transwell assays. The growth and metastasis of HCC cells in vivo were assessed by zebrafish xenograft models.Results: We verified that HOXD-AS1 was overexpressed in all tested HCC cell lines than the normal hepatic cells. Silence of HOXD-AS1 suppressed cell proliferation and invasion in Hep3B and Huh7 HCC cell lines in vitro. In zebrafish xenograft models, knockdown of HOXD-AS1 also reduced the growth and metastasis of the two HCC cells. Moreover, downregulation of miR-130a-3p not only increased the HCC metastasis, but also rescued the metastasis which inhibited by silence of HOXD-AS1 in vitro and in vivo.Conclusions: Our study demonstrates the metastasis role of the HOXD-AS1/miR-130a-3p ceRNA network in HCC cells in vitro and in vivo, and these findings suggest that zebrafish xenograft model could be used for ceRNA mechanism verification in tumor metastasis.

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Linc-SCRG1 accelerates progression of hepatocellular carcinoma as a ceRNA of miR26a to derepress SKP2

Journal of Experimental & Clinical Cancer Research ◽

10.1186/s13046-020-01825-2 ◽

2021 ◽

Vol 40 (1) ◽

Author(s):

Jun-Jie Hu ◽

Cui Zhou ◽

Xin Luo ◽

Sheng-Zheng Luo ◽

Zheng-Hong Li ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Cell Lines ◽

Colony Formation ◽

S Phase ◽

Luciferase Reporter ◽

And Migration ◽

Hcc Cells ◽

Proliferation And Migration

Abstract Background Increasing evidence has demonstrated that long noncoding RNAs (lncRNAs) have regulatory functions in hepatocellular carcinoma (HCC). The link between lincSCRG1 and HCC remains unclear. Methods To explore the lincSCRG1 regulation axis, bioinformatics, RIP and luciferase reporter assay were performed. The expressions of lincSCRG1-miR26a-SKP2 were detected in HCC tissues and cell lines through qPCR and western blot. The functions of HCC cells were investigated through in vitro assays (MTT, colony formation, transwell and flow cytometry) and the inner effect of lincSCRG1-miR26a in vivo was evaluated by xenografts and liver metatstatic nude mice models. Results LincSCRG1 was found to be strongly elevated in human HCC tissues and cell lines. MiR26a and S phase kinase-related protein 2 (SKP2) were predicted as the target miRNA for lincSCRG1 and the target gene for miR26a with direct binding sites, respectively. LincSCRG1 was verified as a competing endogenous RNA (ceRNA) via negative regulation of miR26a and derepression of SKP2 in HCC cells. Both overexpression of lincSCRG1 (ov-lincSCRG1) and inhibition of miR26a (in-miR26a) obviously stimulated cellular viability, colony formation, migration and proliferation of S phase cells and also significantly increased the protein levels of cyclinD1, CDK4, MMP2/3/9, Vimentin, and N-cadherin or inhibited the protein level of E-cadherin of HCC cells, while knockdown of lincSCRG1 (sh-lincSCRG1) and upregulation of miR26a (mi-miR26a) had the opposite effects on HCC cells. Cotransfection of in-miR26a or overexpression of SKP2 (ov-SKP2) with sh-lincSCRG1 could rescue the anticancer functions of sh-lincSCRG1, including suppressing proliferation and migration of HCC cells. Additionally, sh-lincSCRG1 could effectively inhibit the growth of subcutaneous xenograft tumours and lung metastasis, while the anticancer effect of sh-lincSCRG1 could be reversed by cotransfection of in-miR26a. Conclusions LincSCRG1 acts as a ceRNA of miR26a to restrict its ability to derepress SKP2, thereby inducing the proliferation and migration of HCC cells in vitro and in vivo. Depletion of lincSCRG1 could be used as a potential therapeutic approach in HCC.

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LINC00680 Enhances Hepatocellular Carcinoma Stemness Behavior and Chemoresistance by Sponging miR-568 to Upregulate AKT3

10.21203/rs.3.rs-86054/v1 ◽

2020 ◽

Author(s):

Gege Shu ◽

Huizhao Su ◽

Zhiqian Wang ◽

Shihui Lai ◽

Yan Wang ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Cell Lines ◽

Xenograft Model ◽

Luciferase Reporter ◽

Loss Of Function ◽

Mechanism Study ◽

Mouse Xenograft Model ◽

High Level

Abstract Background: Hepatocellular carcinoma (HCC) has an extremely poor prognosis due to the development of chemoresistance, coupled with inherently increased stemness properties. Long non-coding RNAs (LncRNAs) are key regulators for tumor cell stemness and chemosensitivity. Currently the relevance between LINC00680 and tumor progression was still largely unknown, with only one study showing its significance in glioblastoma. The study herein was aimed at identifying the role of LINC00680 in the regulation HCC stemness and chemosensitivity. Methods: QRT-PCR was used to detect the expression of LINC00680, miR-568 and AKT3 in tissue specimen and cell lines. Gain- or loss-of function assays were applied to access the function of LINC00680 in HCC cells, including cell proliferation and stemness properties. HCC stemness and chemosensitivity were determined by sphere formation, cell viability and colony formation. Luciferase reporter, RNA immunoprecipitation (RIP), and RNA pull down assays were performed to examine the interaction between LINC00680 and miR-568 as well as that between miR-568 and AKT3. A nude mouse xenograft model was established for the in vivo study.Results: We found that LINC00680 was remarkably upregulated both in HCC tissue and cell lines. Patients with high level of LINC00680 had poorer prognosis. LINC00680 overexpression significantly enhanced HCC cell stemness and decreased in vitro and in vivo chemosensitivity to 5-fluorouracil (5-Fu), whereas LINC00680 knockdown led to opposite results. Mechanism study revealed that LINC00680 regulated HCC stemness and chemosensitivity through sponging miR-568, thereby expediting the expression of AKT3, which further activated its downstream signaling molecules, including mTOR, elF4EBP1, and p70S6K.Conclusion: LINC00680 promotes HCC stemness properties and decreases chemosensitivity through sponging miR-568 to activate AKT3, suggesting that LINC00680 might be a potentially important HCC diagnosis marker and therapeutic target.

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A Novel lncRNA loc339803 acts as CeRNA of miR-30a-5p to promote the migration and invasion of hepatocellular carcinoma cells

10.21203/rs.3.rs-56090/v1 ◽

2020 ◽

Author(s):

cailin xue ◽

xudong zhang ◽

peng gao ◽

weiwei yu ◽

xiaohan cui ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Cell Lines ◽

Luciferase Reporter ◽

Migration And Invasion ◽

Advanced Tumor Stage ◽

Qrt Pcr ◽

Advanced Tumor ◽

Hcc Cells

Abstract Background Hepatocellular carcinoma (HCC) is one of the most common malignant tumors, and has an unfavorable clinical outcome. Emerging evidences have demonstrated that long noncoding RNAs (lncRNAs) play an important role in the carcinogenesis and progression of HCC. However, the clinical significances, the biological roles of most lncRNAs in HCC remain poorly understood. Methods The expression levels of lncRNA loc339803 in HCC tissues and cell lines were determined by quantitative real-time polymerase chain reaction(qRT-PCR) assay. The cellular sublocalization of loc339803 were determined by fluorescence in situ hybridization and nuclear & cytoplasmic RNA isolation assay. Western blot, CCK-8, Edu, colony formation, migration and invasion assays were used to investigate the roles of loc339803 in progression of HCC in vitro. A mouse model for lung metastasis was constructed to evaluate the role of loc339803 in HCC development in vivo. The correlations among loc339803, miR-30a-5p and SNAIL1 were validated by qRT-PCR and a dual- luciferase reporter assay. Results The expression of loc339803 was upregulated in HCC tissues and cell lines, and positively correlated with tumor size, advanced tumor stage, higher serum AFP level and poor prognosis of HCC patients. loc339803 can promote the migration and invasion of HCC cells in vivo and in vitro. Further studies demonstrated the loc339803 functioned as a competing endogenous RNA (ceRNA) by directly binding to miR-30a-5p, thus up-regulating the expression of snai1, a target gene of miR-30a-5p. Moreover, miR-30a-5p upregulation blocked the enhancement of migration and invasion of HCC cells induced by loc339803 overexpression. Conclusions Loc339803 may be oncogenic in HCC and associated with poor clinical outcomes. LncRNA loc339803 might promote the invasion and migration of HCC cells through regulating miR-30a-5p/ SNAIL1 axis.

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KLF7/VPS35 axis contributes to hepatocellular carcinoma progression through CCDC85C-activated β-catenin pathway

Cell & Bioscience ◽

10.1186/s13578-021-00585-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Yarong Guo ◽

Bao Chai ◽

Junmei Jia ◽

Mudan Yang ◽

Yanjun Li ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Cell Proliferation ◽

Tumor Growth ◽

Luciferase Reporter ◽

Aberrant Expression ◽

Proliferation And Invasion ◽

Hcc Cells

Abstract Objective Dysregulation of KLF7 participates in the development of various cancers, but it is unclear whether there is a link between HCC and aberrant expression of KLF7. The aim of this study was to investigate the role of KLF7 in proliferation and migration of hepatocellular carcinoma (HCC) cells. Methods CCK8, colony growth, transwell, cell cycle analysis and apoptosis detection were performed to explore the effect of KLF7, VPS35 and Ccdc85c on cell function in vitro. Xenografted tumor growth was used to assess in vivo role of KLF7. Chip-qPCR and luciferase reporter assays were applied to check whether KLF7 regulated VPS35 at transcriptional manner. Co-IP assay was performed to detect the interaction between VPS35 and Ccdc85c. Immunohistochemical staining and qRT-PCR analysis were performed in human HCC sampels to study the clinical significance of KLF7, VPS35 and β-catenin. Results Firstly, KLF7 was highly expressed in human HCC samples and correlated with patients’ differentiation and metastasis status. KLF7 overexpression contributed to cell proliferation and invasion of HCC cells in vitro and in vivo. KLF7 transcriptional activation of VPS35 was necessary for HCC tumor growth and metastasis. Further, co-IP studies revealed that VPS35 could interact with Ccdc85c in HCC cells. Rescue assay confirmed that overexpression of VPS35 and knockdown of Ccdc85c abolished the VPS35-medicated promotion effect on cell proliferation and invasion. Finally, KLF7/VPS35 axis regulated Ccdc85c, which involved in activation of β-catenin signaling pathway, confirmed using β-catenin inhibitor, GK974. Functional studies suggested that downregulation of Ccdc85c partly reversed the capacity of cell proliferation and invasion in HCC cells, which was regulated by VPS35 upregulation. Lastly, there was a positive correlation among KLF7, VPS35 and active-β-catenin in human HCC patients. Conclusion We demonstrated that KLF7/VPS35 axis promoted HCC cell progression by activating Ccdc85c-medicated β-catenin pathway. Targeting this signal axis might be a potential treatment strategy for HCC.

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LncRNA SNHG15 contributes to doxorubicin resistance of osteosarcoma cells through targeting the miR-381-3p/GFRA1 axis

Open Life Sciences ◽

10.1515/biol-2020-0086 ◽

2020 ◽

Vol 15 (1) ◽

pp. 871-883

Author(s):

Jinshan Zhang ◽

Dan Rao ◽

Haibo Ma ◽

Defeng Kong ◽

Xiaoming Xu ◽

...

Keyword(s):

Cell Lines ◽

Noncoding Rna ◽

Xenograft Model ◽

Inhibitory Effect ◽

Cell Counting ◽

Luciferase Reporter ◽

Osteosarcoma Cell ◽

Osteosarcoma Cells

AbstractBackgroundOsteosarcoma is a common primary malignant bone cancer. Long noncoding RNA small nucleolar RNA host gene 15 (SNHG15) has been reported to play an oncogenic role in many cancers. Nevertheless, the role of SNHG15 in the doxorubicin (DXR) resistance of osteosarcoma cells has not been fully addressed.MethodsCell Counting Kit-8 assay was conducted to measure the half-maximal inhibitory concentration value of DXR in osteosarcoma cells. Western blotting was carried out to examine the levels of autophagy-related proteins and GDNF family receptor alpha-1 (GFRA1). Quantitative reverse transcription-polymerase chain reaction was performed to determine the levels of SNHG15, miR-381-3p, and GFRA1. The proliferation of osteosarcoma cells was measured by MTT assay. The binding sites between miR-381-3p and SNHG15 or GFRA1 were predicted by Starbase bioinformatics software, and the interaction was confirmed by dual-luciferase reporter assay. Murine xenograft model was established to validate the function of SNHG15 in vivo.ResultsAutophagy inhibitor 3-methyladenine sensitized DXR-resistant osteosarcoma cell lines to DXR. SNHG15 was upregulated in DXR-resistant osteosarcoma tissues and cell lines. SNHG15 knockdown inhibited the proliferation, DXR resistance, and autophagy of osteosarcoma cells. MiR-381-3p was a direct target of SNHG15, and GFRA1 bound to miR-381-3p in osteosarcoma cells. SNHG15 contributed to DXR resistance through the miR-381-3p/GFRA1 axis in vitro. SNHG15 depletion contributed to the inhibitory effect of DXR on osteosarcoma tumor growth through the miR-381-3p/GFRA1 axis in vivo.ConclusionsSNHG15 enhanced the DXR resistance of osteosarcoma cells through elevating the autophagy via targeting the miR-381-3p/GFRA1 axis. Restoration of miR-381-3p expression might be an underlying therapeutic strategy to overcome the DXR resistance of osteosarcoma.

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