HOX Antisense lincRNA HOXA-AS2 Promotes Tumorigenesis of Hepatocellular Carcinoma

Background/Aims: Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world and the third leading cause of cancer-related death. Critical roles for long non-coding RNAs (lncRNAs) have recently been demonstrated for a variety of cancers, including hepatocellular carcinoma. However, the effect and mechanism of lncRNAs in HCC tumorigenesis and chemoresistance have not been extensively characterized. Methods: In the current study, we have identified a HCC-expressed lncRNA termed as HANR (HCC associated long non-coding RNA). We identified HANR by microarray analysis and validated its up-regulated expression by quantitative PCR. RNA pull-down and pathway analyses were conducted to evaluate physical and functional interactions with HANR. In vivo experiments were performed to assess tumorigenesis and increase of chemoresistance. In addition, the HANR expression in HCC specimens was detected by FISH. Xenograft and orthotopic mice model was constructed to observe the effect of HANR on tumorigenesis and chemoresistance in vivo. Results: HANR was demonstrated to be up-regulated in HCC patients and HCC cell lines. Increased HANR expression in HCC predicted short survival of patients. Knock-down of HANR markedly retarded cell proliferation, suppressed HCC xenograft/orthotopic tumor growth, induced apoptosis and enhanced chemosensitivity to doxorubicin, while overexpression of HANR showed the opposite effects. It was found that HANR bind to GSKIP for regulating the phosphorylation of GSK3β in HCC. Conclusion: Our results demonstrate that HANR contributes to the development of HCC and is a promising therapeutic target for chemosensitization of HCC cells to doxorubicin, which may represent a promising therapeutic target in the future.

“…Emerging evidence indicates key regulatory roles of lncRNAs in HCC [29,30]. However, evidence of lncRNAs with clinical prognostic value is still limited.…”

Section: Discussionmentioning

confidence: 99%

LncRNA HANR Promotes Tumorigenesis and Increase of Chemoresistance in Hepatocellular Carcinoma

Xiao

Jin

et al. 2017

“…The lncRNA HOXA cluster antisense RNA 2 (HOXA-AS2) was first reported to be an apoptosis suppressor in NB4 promyelocytic leukemia cells treated with all-trans retinoic acid [12]. Subsequent studies showed that HOXA-AS2 is aberrantly expressed in several human cancers and functions as an oncogene [13, 14]. However, little is known concerning its expression in glioma and its potential role in glioma malignancy and VM.…”

Section: Introductionmentioning

confidence: 99%

Long Non-Coding RNA HOXA-AS2 Regulates Malignant Glioma Behaviors and Vasculogenic Mimicry Formation via the MiR-373/EGFR Axis

Gao

Liu

et al. 2017

Background/Aims: Vasculogenic mimicry (VM) has been reported to be a novel glioma neovascularization process. Anti-VM therapy provides new insight into glioma clinical management. In this study, we revealed the role of the long non-coding RNA HOXA cluster antisense RNA 2 (HOXA-AS2) in malignant glioma behaviors and VM formation. Methods: Quantitative real-time PCR was performed to determine the expression levels of HOXA-AS2 in glioma samples and glioblastoma cell lines. CD34-periodic acid-Schiff dual-staining was performed to assess VM in glioma samples. CCK-8, transwell, and Matrigel tube formation assays were performed to measure the effects of HOXA-AS2 knockdown on cell viability, migration, invasion, and VM tube formation, respectively. RNA immunoprecipitation, dual-luciferase reporter and Western blot assays were performed to explore the molecular mechanisms underlying the functions of HOXS-AS2 in glioblastoma cells. A nude mouse xenograft model was used to investigate the role of HOXA-AS2 in xenograft glioma growth and VM density. Student’s t-tests, one-way ANOVAs followed by Bonferroni posthoc tests, and chi-square tests were used for the statistical analyses. Results: HOXA-AS2 was upregulated in glioma samples and cell lines and was positively correlated with VM. HOXA-AS2 knockdown attenuated cell viability, migration, invasion, and VM formation in glioma cells and inhibited the expression of vascular endothelial-cadherin (VE-cadherin), as well as the expression and activity of matrix metalloproteinase matrix metalloproteinase (MMP)-2 and MMP-9. miR-373 was downregulated in glioma samples and cell lines and suppressed malignancy in glioblastoma cells. HOXA-AS2 bound to miR-373 and negatively regulated its expression. Epidermal growth factor receptor (EGFR), a target of miR-373, increased the expression levels of VE-cadherin, as well as the expression and activity levels of MMP-2 and MMP-9, via activating phosphatidylinositol 3-kinase/serine/threonine kinase pathways. HOXA-AS2 knockdown combined with miR-373 overexpression yielded optimal tumor suppressive effects and the lowest VM density in vivo. Conclusion: HOXA-AS2 knockdown inhibited malignant glioma behaviors and VM formation via the miR-373/EGFR axis.

“…Deregulation of lncRNAs has been shown to contribute to initiation and progression in various human cancer types, including hepatocellular carcinoma, lung cancer, pancreatic cancer, osteosarcoma and colon cancer [13, 15, 16, 20]. Even though more and more lncRNAs have been reported to play crucial roles in osteosarcoma [15, 17, 21], the roles of lncRNAs in osteosarcoma are remain poorly defined.…”

Section: Discussionmentioning

confidence: 99%

“…Evaluation of C-myc staining in tissues was assessed by two independent professional pathologists who were blinded to patient clinical status and outcomes. C-myc expression scores were determined by the area of staining and the percentage of positive cells according to previous work [20]. …”

Section: Methodsmentioning

confidence: 99%

Overexpression of Long Non-Coding RNA NNT-AS1 Correlates with Tumor Progression and Poor Prognosis in Osteosarcoma

Ye¹,

Lin²,

Yao³

et al. 2018

Background/Aims: Increasing evidence demonstrates that long non-coding RNAs (lncRNAs) play critical regulatory roles in cancers, including osteosarcoma. A previous study showed that Nicotinamide Nucleotide Transhydrogenase-antisense RNA1 (NNT-AS1) was aberrantly expressed in several types of cancer. However, the potential biological roles and regulatory mechanisms of NNT-AS1 in osteosarcoma progression remain unknown. Methods: Quantitative RT-PCR was performed to examine the expression of NNT-AS1 in human tissues and cells. The biological functions of NNT-AS1 were determined by CCK-8, colony formation, Flow cytometry and Transwell assays in vitro. A mouse xenograft model was performed to investigate the effect of NNT-AS1 on tumor growth in vivo. Results: In this study, we found the expression of NNT-AS1 was significantly increased in tumor tissues compared to adjacent normal tissues. Furthermore, upregulated NNT-AS1 expression predicted poor prognosis and was an independent and significant risk factor for osteosarcoma patient survival. Further experiments revealed that NNT-AS1 knockdown significantly inhibited cell proliferation by inducing cell cycle arrest and promoting apoptosis in osteosarcoma cells. Moreover, NNT-AS1 silencing suppressed cell migration and invasion in vitro. In a tumor xenograft model, knockdown of NNT-AS1 suppressed tumor growth of OS-732 cells in vivo. Conclusions: Taken together, these findings indicate that NNT-AS1 functions as an oncogene in osteosarcoma and could be a novel diagnostic and therapeutic target for osteosarcoma.