Knockdown of lncRNA HULC inhibits proliferation,migration, invasion,and promotes apoptosis by sponging miR‐122 in osteosarcoma

Osteosarcoma is a rare malignant bone tumor with high degree of malignancy. HULC (highly upregulated in liver cancer), a long noncoding RNA (lncRNA) was involved in hepatocellular carcinoma development and progression, but its underlying mechanism in osteosarcoma is unknown. The aim of this study was to explore the functional role of HULC in osteosarcoma. The study was conducted in human osteosarcoma cell lines and the expression of HULC in the cell lines was detected by qRT‐PCR. Furthermore, the effects of HULC on tumorigenicity of osteosarcoma cells were evaluated by in vitro assays. Results revealed that HULC was highly expressed in osteosarcoma MG63 and OS‐732 cells compared to osteoblast hFOB1.19 cells. Suppression of HULC in osteosarcoma cells inhibited cell viability, migration, invasion, and promoted apoptosis. HULC functioned as an endogenous sponge for miR‐122, and its silence functioned through upregulating miR‐122. HNF4G was a target of miR‐122, and the effect of HNF4G on OS‐732 cells was the same as HULC. Furthermore, overexpression of miR‐122 inactivated PI3K/AKT, JAK/STAT, and Notch pathways by downregulation of HNF4G. These findings suggest that knockdown of HULC inhibited proliferation, migration, and invasion by sponging miR‐122 in osteosarcoma cells. HULC may act as a novel therapeutic target for management of osteosarcoma.     

Long noncoding RNA HAND2-AS1 inhibits cancer cell proliferation,migration, and invasion in esophagus squamous cell carcinoma by regulating microRNA-21

Long noncoding RNA (lncRNA) HAND2-AS1 is a well-characterized tumor suppressor in several types of malignancies, while its role in esophagus squamous cell carcinoma (ESCC) is unknown. In this study, we found that lncRNA HAND2-AS1 was downregulated, while microRNA-21 ( miRNA-21) was upregulated in tumor tissues than in adjacent healthy tissues of ESCC patients. Expression levels of lncRNA HAND2-AS1 and miRNA-21 were significantly and inversely correlated in tumor tissues but not in healthy tissues. Plasma levels of lncRNA HAND2-AS1 were lower in ESCC patients than in healthy controls, and downregulation of plasma lncRNA HAND2-AS1 distinguished early stage ESCC patients from healthy controls. lncRNA HAND2-AS1 overexpression resulted in downregulation of miRNA-21 in cells of ESCC cell lines and inhibited cell proliferation, migration, and invasion. miRNA-21 overexpression failed to affect lncRNA HAND2-AS1 expression but significantly attenuated the inhibitory effect of lncRNA HAND2-AS1 overexpression on cancer cell proliferation, migration, and invasion. Therefore, lncRNA HAND2-AS1 may inhibit cancer cell proliferation, migration, and invasion in ESCC by regulating miRNA-21.     

lncRNA MIR503HG functioned as a tumor suppressor and inhibited cell proliferation,metastasis and epithelial-mesenchymal transition in bladder cancer

Bladder cancer is the most common malignancy with high recurrence. Currently, the long noncoding RNAs (lncRNAs) have been suggested to play vital roles in the pathogenesis of bladder cancer. The present study investigated the role of lncRNA MIR503 host gene (MIR503HG) in the pathogenesis of bladder cancer by using both in vitro and in vivo functional assays. The expression of MIR503HG was downregulated in bladder cancer tissues and cell lines. Low expression of MIR503HG was associated with advanced tumor stage, advanced histological grade, and lymph node metastasis. Ectopic expression of MIR503HG inhibited cell proliferation, cell growth, cell invasion, and migration, and also promoted cell apoptosis and inhibited cell cycle progression in SW780 cells. In parallel, T24 cells were used for loss-of-function studies. Knockdown of MIR503HG promoted the cancer cell proliferation and increased the migration and invasion abilities of T24 cells. In addition, knockdown of MIR503HG reduced the cell apoptotic rate in cancer cells and promoted cell cycle progression. Furthermore, MIR503HG overexpression decreased the epithelial-mesenchymal transition-related mRNA and protein levels of ZEB1, Snail, N-cadherin, and vimentin, with an increase in E-cadherin level. Consistently, knockdown of MIR503HG showed the opposite effects. In vivo xenograft, nude mice results showed that overexpression of MIR503HG suppressed the tumor growth and tumor metastasis. In conclusion, our results identified a novel lncRNA MIR503HG that exhibited significant antiproliferation, antimigration/invasion effects on bladder cancer cells both in vitro and in vivo, which may hold a therapeutic promise to treat bladder cancer.     

LncRNA Linc00511 promotes osteosarcoma cell proliferation and migration through sponging miR-765

Long noncoding RNA (lncRNA) Linc00511 is a novel lncRNA, and it was reported to play important roles in the progression and carcinogenesis of several tumors. However, the expression and biological roles of Linc00511 in osteosarcoma were still unknown. In this research, we showed that the expression of Linc00511 was upregulated in osteosarcoma samples and cell lines. Ectopic expression of Linc00511 promoted osteosarcoma cell growth, colony formation, and migration. Moreover, overexpression of Linc00511 enhanced the epithelial-mesenchymal transition progression in osteosarcoma cell. In addition, we showed that elevated expression of Linc00511 suppressed microRNA-765 (miR-765) expression and promoted apurinic/apyrimidinic endonuclease 1 (APE1) expression in osteosarcoma cell. The expression of miR-765 was downregulated in osteosarcoma cells and samples and was negatively related to Linc00511 expression in osteosarcoma tissues. Ectopic expression of miR-765 inhibited osteosarcoma cell growth and migration. Furthermore, we showed that Linc00511 overexpression promoted MG-63 cells proliferation, colony formation, and migration via downregulation of miR-765. These results suggested that Linc00511 played as an oncogene in the development of osteosarcoma.     

LncRNA PTCSC3 inhibits triple-negative breast cancer cell proliferation by downregulating lncRNA H19

Long noncoding RNA (lncRNA) PTCSC3 (hereafter PTCSC3 is used to represent lncRNA PTCSC3) inhibits glioma and thyroid cancer, indicating its potential tumor suppression function in other types of cancers. We explored the potential involvement of PTCSC3 in triple-negative breast cancer (TNBC). In the current study, we found that PTCSC3 was downregulated in tumor tissues of patients with TNBC. PTCSC3 expression was positively correlated with plasma levels of PTCSC3. LncRNA H19 was upregulated and was inversely correlated with PTCSC3 in tumor tissues. PTCSC3 overexpression led to downregulated H19 in TNBC cells, while H19 overexpression did not affect PTCSC3 expression. PTCSC3 inhibited and H19 promoted proliferation of TNBC cells. H19 overexpression attenuated the effects of PTCSC3 overexpression. Cancer cell migration and invasion were not significantly affected by PTCSC3 overexpression. Therefore, lncRNA PTCSC3 inhibits TNBC cell proliferation by downregulating lncRNA H19.     

外泌体介导长链非编码RNA H19促进肝癌细胞增殖与转移

外泌体是由细胞分泌的直径为30～150 nm的小囊泡,含有丰富的mRNA、microRNA和长链非编码RNA(lncRNA)。目前,大多数外泌体研究都集中在mRNA和microRNA,而对lncRNA的生物学功能并不十分清楚。研究表明,肿瘤细胞外泌体 lncRNA H19在肿瘤细胞的增殖、迁移和侵袭中发挥了重要作用。本研究将筛选到的lncRNA H19高表达的肝癌细胞HCCLM3,分别收集其高表达lncRNA H19的外泌体和其下调lncRNA H19表达后的外泌体。然后,将收集到的外泌体分别添加到lncRNA H19低表达的肝癌细胞Hep3B和HepG2孵育液中。孵育24 h后,检测其对肿瘤细胞的增殖、迁移和侵袭能力的影响。结果显示,肝癌细胞HCCLM3可分泌大量的外泌体,且能被其他肿瘤细胞大量摄取;与下调lncRNA H19表达的外泌体相比,lncRNA H19高表达的外泌体能显著增强Hep3B和HepG2细胞的增殖、迁移和侵袭能力。而这一作用可通过激活PI3K/AKT/mTOR通路实现。上述结果表明,lncRNA H19高表达的肝癌细胞以外泌体方式,增强邻近肝癌细胞的增殖、迁移和侵袭能力,促进肝癌的发生与发展。     

Long noncoding RNA lnc-ABCA12-3 promotes cell migration,invasion, and proliferation by regulating fibronectin 1 in esophageal squamous cell carcinoma

Long noncoding RNAs (lncRNAs) have been shown to play important roles in human cancers, including esophageal squamous cell carcinoma (ESCC). We previously demonstrated that a novel lncRNA, lnc-ABCA12-3, was overexpressed in ESCC tissues. However, the exact function of lnc-ABCA12-3 is unknown. In the current study, we aimed to evaluate the expression of lnc-ABCA12-3 in ESCC and to explore the potential mechanism of lnc-ABCA12-3 in cell migration, invasion, and proliferation. We showed that lnc-ABCA12-3 was upregulated in ESCC tumor tissues and cell lines. The increased expression of lnc-ABCA12-3 was positively associated with advanced tumor-node-metastasis stages and poor prognosis. The knockdown of lnc-ABCA12-3 inhibited the cell migration, invasion, and proliferation abilities of KYSE-510 and Eca-109 cells. We also found that fibronectin 1 (FN1) was upregulated in ESCC tumor tissues. The expression of FN1 messenger RNA was positively correlated with the expression of lnc-ABCA12-3 in ESCC tumor tissues. After lnc-ABCA12-3 knockdown, the expression of FN1 was downregulated. In addition, the overexpression of FN1 restored the abilities of cell migration, invasion and proliferation in Eca-109 cells. Further studies indicated that lnc-ABCA12-3 acted as a competing endogenous RNA for miR-200b-3p to regulate FN1 expression. In conclusion, these results suggest that lnc-ABCA12-3 is a novel oncogene in tumorigenesis and that its high expression is related to a poor prognosis for patients with ESCC. lnc-ABCA12-3 promotes cell migration, invasion, and proliferation via the regulation of FN1 in ESCC. Our data suggest that lnc-ABCA12-3 might serve as a potential prognostic biomarker and therapeutic target for ESCC.     

MiR-138 Acts as a Tumor Suppressor by Targeting EZH2 and Enhances Cisplatin-Induced Apoptosis in Osteosarcoma Cells

Chemotherapeutic insensitivity remains a major obstacle to treating osteosarcoma effectively. Recently, increasing evidence has suggested that microRNAs (miRNAs) are involved in drug resistance. However, the effect of miR-138 on cisplatin chemoresistance in osteosarcoma has not been reported. We used real-time PCR to detect the expression of mature miR-138 in osteosarcoma tissues and cell lines. Cell proliferation, invasion, and migration assays were used to observe changes to the osteosarcoma malignant phenotype. MiR-138 was downregulated in osteosarcoma tissues and cell lines, and miR-138 overexpression negatively regulated osteosarcoma cell proliferation, migration, and invasion. We also verified that EZH2 is a direct target of miR-138. Furthermore, enhancing EZH2 expression reduced the inhibitory effects of miR-138 on osteosarcoma. Proliferation, apoptosis assays and caspase-3 activity assay confirmed that elevated miR-138 expression enhanced osteosarcoma cell chemosensitivity to cisplatin by targeting EZH2. In conclusion, the present study demonstrates that miR-138 acts as a tumor suppressor by enhancing osteosarcoma cell chemosensitivity and supports its potential application for treating osteosarcoma in the future.     

Downregulation of lncRNA CASC2 facilitates osteosarcoma growth and invasion through miR‐181a

Objectives

Long non‐coding RNA cancer susceptibility candidate 2 (CASC2) is a novel lncRNA and has been indicated as playing tumour suppressor gene in several tumours. However, the role of CASC2 in osteosarcoma is still uncovered.

Materials and methods

The CASC2 and miR‐181a expressions were measured via qRT‐PCR. CCK‐8 assay and colony formation assay were performed to determine the cell growth, and transwell assay was performed to assess the cell invasion.

Results

We showed that CASC2 expression was downregulated in osteosarcoma samples and cell lines. Moreover, we showed that downregulated expression of CASC2 was correlated with advanced TNM stage. Furthermore, overexpression of CASC2 inhibited osteosarcoma cell proliferation, colony formation, and invasion. In addition, we indicated that ectopic expression of CASC2 suppressed miR‐181a expression and enhanced the expression of Ras association domain family member 6 (RASSF6), PTEN and ATM in osteosarcoma cell, which were the direct target gene of miR‐181a. Moreover, we indicated that RASSF6 expression was downregulated in osteosarcoma samples and cell lines and downregulated expression of RASSF6 was correlated with advanced TNM stage. We found that the expression of RASSF6 was positively correlated with the expression of CASC2 in osteosarcoma tissues. Ectopic expression of CASC2 suppressed the osteosarcoma cell proliferation, colony formation and invasion through regulating RASSF6 expression.

Conclusions

Our data illuminated that CASC2 acted as a tumour suppressor in osteosarcoma progression.     

The Downregulation of MiR-182 Is Associated with the Growth and Invasion of Osteosarcoma Cells through the Regulation of TIAM1 Expression

BackgroundOsteosarcoma is the most common primary bone malignancy in children and young adults. Increasing results suggest that discovery of microRNAs (miRNAs) might provide a novel therapeutical target for osteosarcoma.MethodsMiR-182 expression level in osteosarcoma cell lines and tissues were assayed by qRT-PCR. MiRNA mimics or inhibitor were transfected for up-regulation or down-regulation of miR-182 expression. Cell function was assayed by CCK8, migration assay and invasion assay. The target genes of miR-182 were predicated by bioinformatics algorithm (TargetScan Human).ResultsMiR-182 was down-regulated in osteosarcoma tissues and cell lines. Overexpression of miR-182 inhibited tumor growth, migration and invasion. Subsequent investigation revealed that TIAM1 was a direct and functional target of miR-182 in osteosarcoma cells. Overexpression of miR-182 impaired TIAM1-induced inhibition of proliferation and invasion in osteosarcoma cells.ConclusionsDown-expression of miR-182 in osteosarcoma promoted tumor growth, migration and invasion by targeting TIAM1. MiR-182 might act as a tumor suppressor gene whose down-regulation contributes to the progression and metastasis of osteosarcoma, providing a potential therapy target for osteosarcoma patients.     

CT45A1 promotes the metastasis of osteosarcoma cells in vitro and in vivo through β-catenin

Increased expression of cancer/testis antigens (CTAs) is reported in various tumors. However, the unique role of CTAs in tumor genesis has not yet been verified. Here, we first report the functional role of CT45A1 in the carcinogenesis of osteosarcoma. RNA sequencing and immunohistochemistry confirmed that elevated expression of CT45A1 was detected in osteosarcoma, especially in metastatic tissues of osteosarcoma. Furthermore, osteosarcoma patients with poorer prognosis showed high expression of CT45A1. In cell tests, CT45A1 overexpression was shown to strengthen the proliferation, migration, and invasion abilities of osteosarcoma cells, while silencing CT45A1 markedly elicited the opposite effects in these tests by disrupting the activation of β-catenin. In summary, we identify a novel role of CT45A1 in osteosarcoma. Furthermore, our results suggested that CT45A1 may contribute to the development of osteosarcoma and could be a possible therapeutic target for osteosarcoma patients.Subject terms: Epithelial-mesenchymal transition, Sarcoma     

MicroRNA‑224 promotes the sensitivity of osteosarcoma cells to cisplatin by targeting Rac1

Osteosarcoma is the most common primary bone tumour in children and adolescents. Accumulating evidence has shown that microRNAs (miRNAs) participate in the development of almost all types of cancer. Here, we investigated the role of miR‐224 in the development and progression of osteosarcoma. We demonstrated that miR‐224 was down‐regulated in osteosarcoma cell lines and tissues. Lower miR‐224 levels were correlated with shorter survivalin osteosarcoma patients. Furthermore, overexpression of miR‐224 suppressed osteosarcoma cell proliferation, migration and invasion and contributed to the increased sensitivity of MG‐63 cells to cisplatin. We identified Rac1 as a direct target gene of miR‐224 in osteosarcoma. Rac1 expression was up‐regulated in the osteosarcoma cell lines and tissues, and there was an inverse correlation between Rac1 and miR‐224 expression in osteosarcoma tissues. Furthermore, rescuing Rac1 expression decreased the sensitivity of miR‐224‐overexpressing MG‐63 cells to cisplatin. We also demonstrated that ectopic expression of Rac1 promoted the proliferation, migration and invasion of miR‐224‐overexpressing MG‐63 cells. These data suggest that miR‐224 plays a tumour suppressor role in the development of osteosarcoma and is related to the sensitivity of osteosarcoma to cisplatin.     

miR-203 Acts as a Tumor Suppressor Gene in Osteosarcoma by Regulating RAB22A

microRNAs (miRNAs), small noncoding RNAs of 19–25 nt, play an important roles in the pathological processes of tumorigenesis. The object of this study was to study the expression and function of miR-203 and to found its target gene in osteosarcoma. In our study, we found the expression level of miR-203 was significantly downregulated in osteosarcoma cell lines and tissues. In addition, overexpression of miR-203 inhibited the osteosarcoma cell proliferation and migration and inhibited Mesenchymal-to-Epithelial reversion Transition (MErT). Moreover, we identified RAB22A as a direct target of miR-203 and RAB22A overexpression blocks the roles of miR-203 in osteosarcoma cell. Furthermore, we demonstrated that RAB22A expression was upregulated in human osteosarcoma cell lines and tissues. Take together, our results demonstrated that miR-203 act as a tumor suppressor miRNA through regulating RAB22A expression and suggested its involvement in osteosarcoma progression and carcinogenesis.     

Long noncoding RNA PCAT-1 acts as an oncogene in osteosarcoma by reducing p21 levels

Long non-coding RNA (lncRNA) is emerging as a critical regulator in multiple cancers. Recently, lncRNA PCAT-1 was found to be up-regulated in prostate cancer and hepatocellular carcinoma, exerting oncogenic effects. However, the biological function and regulatory mechanism of PCAT-1 remain unclear in osteosarcoma (OS). In this study, we reported that PCAT-1 expression was also upregulated in OS tissues, and its overexpression was remarkably associated with tumor size, Enneking stage, tumor node metastasis (TNM) stage and metastasis in patients with OS. Knockdown of PCAT-1 suppressed OS cells proliferation, migration and invasion in vitro, and inhibited the tumorigenicity of OS cells in vivo. Mechanistic investigations revealed that PCAT-1 could interact with EZH2, thereby repressing p21 expression. Additionally, rescue experiments indicated that PCAT-1 functioned as an oncogene partly via suppressing p21 in OS cells. Collectively, our findings demonstrate that PCAT-1 is a new candidate for use in OS diagnosis, prognosis and therapy.     

miR-497-5p inhibits tumor cell growth and invasion by targeting SOX5 in non–small-cell lung cancer

MicroRNAs plays an important role in the ccurrence and development of non–small-cell lung cancer (NSCLC). miR-497-5p has been reported to function as a tumor suppressor in various cancers. However, the role of miR-497-5p in NSCLC remains poorly understood. In this study, we aimed to investigate the biological role and potential molecular mechanism of miR-497-5p in NSCLC. Our results showed that the messenger RNA (mRNA) expression level of miR-497-5p was notably downregulated in human NSCLC tissues and cell lines. miR-497-5p overexpression remarkably inhibited NSCLC cell proliferation and increased cell apoptosis in A549 and H460 cells, whereas inhibition of miR-497-5p had an opposite effect. The ability of cell migration and invasion was inhibited by miR-497-5p overexpression but was increased by miR-497-5p inhibition. Moreover, our findings indicated that SOX5 was a direct target of miR-497-5p. The protein and mRNA expression levels of SOX5 in A549 cells were remarkably inhibited by miR-497-5p overexpression but was upregulated by miR-497-5p inhibition. Furthermore, SOX5 overexpression notably reversed the effect of miR-497-5p mimic on NSCLC cell proliferation, cell apoptosis, cell migration, and invasion. Taken together, these results indicated that miR-497-5p overexpression inhibited NSCLC cell proliferation, migration and invasion, and induced cell apoptosis through inhibiting SOX5 gene expression. It was conceivable that miR-497-5p might serve as a potential molecular target for NSCLC treatment.     

LUCAT1 as an oncogene in tongue squamous cell carcinoma by targeting miR-375 expression

Emerging studies suggested that lncRNAs play a crucial molecular role in cancer development and progression. LncRNA LUCAT1 has been proved as oncogenic molecular in lung cancer, glioma, osteosarcoma, renal carcinoma and oesophageal squamous cell carcinoma. However, its roles and function mechanisms in tongue squamous cell carcinoma (TSCC) are still unknown. We showed that the expression of LUCAT1 was up-regulated in the TSCC cells and tissues and the higher LUCAT1 expression was associated with the poor overall survival (OS). Knockdown expression of LUCAT1 suppressed TSCC cell proliferation, cycle and migration. In addition, we demonstrated that miR-375 overexpression inhibited the luciferase activity of LUCAT1 wild-type and knockdown LUCAT1 promoted the miR-375 expression in TSCC cell. Furthermore, we indicated that miR-375 expression was down-regulated in the TSCC cell lines and tissues and the lower expression of miR-375 was associated with poor OS. The expression of miR-375 was inversely correlated with LUCAT1 expression in the TSCC tissues. Knockdown LUCAT1 promoted TSCC cell proliferation, cell cycle and migration partly through regulating miR-375 expression. In summary, this study suggested the tumorigenic effect of lncRNA LUCAT1 in TSCC cells by targeting miR-375 expression.     

LncRNA SNHG12 promotes tumorigenesis and metastasis in osteosarcoma by upregulating Notch2 by sponging miR-195-5p

Osteosarcoma is the most common primary malignant bone tumor and has a high fatality rate in children and adolescents. Recently, an increasing amount of evidence has demonstrated that lncRNAs have crucial roles in regulating biological characteristics in malignant tumors. Therefore, this research was carried out to uncover the biological function and the potential molecular mechanism of SNHG12 in osteosarcoma. In this study, we found that SNHG12 was significantly upregulated in both osteosarcoma tissues and cell lines and osteosarcoma patients with high levels of SNHG12 tended to have a poor prognosis. We evaluated the biological function of SNHG12 in 143B and U2OS cells and show that the downregulation of SNHG12 suppressed cell proliferation by blocking cell cycle progression at the G0/G1 phase and weakened cell invasion and migration abilities. Dual-luciferase reporter and RIP assays were conducted to confirm that SNHG12 functioned as a ceRNA, modulating the expression of Notch2 by sponging miR-195-5p in osteosarcoma. We further demonstrate that Notch2 played a crucial role in activating the Notch signaling pathway. In conclusion, SNHG12 might serve as a valuable biomarker and prognosis factor in osteosarcoma patients. The SNHG12/miR-195-5p/Notch2-Notch signaling pathway axis might become a novel therapeutic for osteosarcoma.