Long noncoding RNA MEG3 silencing protects against hypoxia-induced pheochromocytoma-12 cell injury through inhibition of TIMP2 promoter methylation

Hypoxia is a common pathological process caused by insufficient oxygen. Long noncoding RNAs (lncRNAs) have been proven to participate in this pathology. Hypoxia is reported to significantly reduce the secretion of tissue inhibitor of metalloproteinase 2 (TIMP2) and TIMP2 induces pheochromocytoma-12 (PC12) cell cycle arrest. Thus, our study aimed to explore the mechanism by which lncRNA maternally expressed gene 3 (MEG3) was implicated in hypoxia-induced PC12 cell injury through TIMP2 promoter methylation. To elucidate the potential biological significance of MEG3 and the regulatory mechanism between MEG3 and TIMP2, a hypoxia-induced PC12 cell injury model was generated. The hypoxia-exposed cells were subjected to a series of overexpression plasmids and short hairpin RNAs, followed by the measurement of levels of MEG3, TIMP2, lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), reactive oxygen species (ROS), Bcl-2-associated X protein, B-cell lymphoma-2, and caspase-3, as well as the changes in MMP, cell proliferation, apoptosis, and cell cycle progression. On the basis of the findings, MEG3 was upregulated in hypoxia-injured PC12 cells. MEG3 recruited methylation proteins DNMT3a, DNMT3b, and MBD1 and accelerated TIMP2 promoter methylation, which in turn inhibited its expression. Moreover, PC12 cells following MEG3 silencing and TIMP2 overexpression exhibited significantly decreased levels of LDH, MDA, and ROS along with cell apoptosis, yet increased SOD and MMP levels, as well as cell cycle entry to the S phase and cell proliferation. In conclusion, MEG3 silencing suppresses hypoxia-induced PC12 cell injury by inhibiting TIMP2 promoter methylation. This study may provide novel therapeutic targets for hypoxia-induced injury.     

Long noncoding RNA CASC9 promotes LIN7A expression via miR-758-3p to facilitate the malignancy of ovarian cancer

The long noncoding RNA cancer susceptibility 9 (CASC9) has been reported to be a pivot modulator in growth and metastasis of breast cancer, liver cancer, esophageal squamous cell carcinoma, lung adenocarcinoma, gastric cancer, and nasopharyngeal cancer. However, its potential roles in ovarian cancer remain unclear. In this study, we aimed at its functions and molecular mechanism in ovarian cancer progression. We showed that CASC9 was highly expressed in ovarian cancer tissues and cell lines. An elevated level of CASC9 predicts an unfavorable prognosis in patients with ovarian cancer. Loss-of-function and gain-of-function assays illustrated that CASC9 promotes ovarian cancer cell proliferation, migration, and invasion in vitro, and accelerates tumor growth in vivo. We showed that CASC9 works as a competing endogenous RNA (ceRNA) for miR-758-3p which targets LIN7A. CASC9 inhibits the level of miR-758-3p, and in turn stimulates LIN7A expression in ovarian cancer. Overexpression of LIN7A reverses the suppressive roles of CASC9 depletion on ovarian cancer. In sum, our findings reveal a novel undefined regulatory signaling pathway, namely CASC9/miR-758-3p/LIN7A axis, involved in ovarian cancer progression.     

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.     

长非编码 RNA ILF3-AS1 通过调控 miR-130a-3p/PTEN轴抑制宫颈癌细胞的增殖

ILF3反义 RNA 1(ILF3 antisense RNA 1,ILF3-AS1)是一条定位于染色体 19p13.2的lncRNA,它是白介素增强子结合因子3(interleukin enhancer binding factor 3,ILF3)的反义 RNA.ILF3-AS1在多种肿瘤发生发展中发挥关键作用,但其...     

Long noncoding RNA FOXD3-AS1 promotes colon adenocarcinoma progression and functions as a competing endogenous RNA to regulate SIRT1 by sponging miR-135a-5p

More and more documents have proved that the abnormal expression of long noncoding RNAs (lncRNAs) are correlated with the initiation and progression of colorectal cancer (CRC). lncRNA FOXD3-AS1 has been reported in glioma for its oncogenic property. According to the survival analysis of The Cancer Genome Atlas database, FOXD3-AS1 upregulation implied lower survival rate of patients with CRC. Quantitative real-time polymerase chain reaction showed the overexpression of FOXD3-AS1 in both CRC tissues and cells. The Kaplan–Meier method demonstrated the prognostic value of FOXD3-AS1 for patients with CRC. To explore the effect of FOXD3-AS1 on CRC progression, loss-of-function experiments were carried out, whose results indicated that knockdown of FOXD3-AS1 suppressed cell proliferation, migration, and invasion, inhibited cell cycle and promoted cell apoptosis in vitro. In vivo experiments affirmed that FOXD3-AS1 affected tumor growth. FOXD3-AS1 expression was enriched in the cytoplasm of CRC cells. Mechanism experiments revealed that FOXD3-AS1 served as a competing endogenous RNA to upregulate SIRT1 by sponging miR-135a-5p. In addition, SIRT1 silencing also restrained cell proliferation and motility. Rescue assays revealed the biological function of FOXD3-AS1/miR-135a-5p/SIRT1 axis in CRC progression. In conclusion, FOXD3-AS1 promotes CRC progression by regulating miR-135a-5p/SIRT1 axis, shedding lights on the way to CRC treatments.     

Long noncoding RNA ABHD11-AS1 promote cells proliferation and invasion of colorectal cancer via regulating the miR-1254-WNT11 pathway

The purpose of our study was to investigate the effects of the long noncoding RNA (lncRNA) ABHD11-AS1 on colorectal cancer (CRC) progression and further explore its possible underlying mechanisms. In the study, we found that ABHD11-AS1 was highly expressed in CRC tissues and cell lines. High ABHD11-AS1 expression was correlated with poor overall survival of patients with CRC. ABHD11-AS1 knockdown reduced CRC cell proliferation, in vitro invasion, and in vivo tumor growth. Investigation of the underlying mechanism showed that ABHD11-AS1 could act as a molecular sponge of miR-1254, and WNT11 was a downstream target of miR-1254 in CRC. Moreover, there was a negative association between ABHD11-AS1 expression (or WNT11) and miR-1254 in CRC tissues. The rescue assays showed that WNT11 overexpression partially rescued the effects of ABHD11-AS1 inhibition on CRC progression. Thus, we demonstrated that ABHD11-AS1 promotes CRC progression through the miR-1254-WNT11 pathway, which provides a new insight into the therapeutic strategies for CRC.     

Long noncoding RNA DINO (damage induced noncoding) represses the development of gastric cancer by modulating p21 and Bcl-2 Associated X Protein (Bax) expression

lncRNAs are responsible for a variety of diseases, including gastric cancer (GC). Many recent studies have reported that lncRNAs can serve as crucial regulators of various genes. Nevertheless, the biological function of lncRNA damage induced noncoding (DINO) remained poorly investigated in GC. Therefore, in our present study, the detailed role of DINO was investigated. It was manifested that DINO was significantly downregulated in GC tissues. Then, DINO was modulated by infecting LV-DINO or by LV-shRNA in BGC-823 and MGC-803 cells. Moreover, it was displayed that GC cell proliferation was suppressed by DINO overexpression, whereas silencing DINO increased cell proliferation significantly. For another, it was indicated that DINO dramatically induced apoptotic ratios of BGC-823 and MGC-803 cells, whereas the decrease of DINO depressed GC cell apoptosis. Apart from these, GC cell cycle progression was greatly blocked by LV-DINO. Furthermore, Western blot results displayed that upregulation of DINO elevated p21 expression and Bax expression. Oppositely, inhibition of DINO greatly suppressed p21 and Bax protein expression level. Taken these, DINO might exert a tumor inhibitory role in the progression of GC through modulating p21 and Bax.     

Long noncoding RNA PTPRG-AS1 acts as a microRNA-194-3p sponge to regulate radiosensitivity and metastasis of nasopharyngeal carcinoma cells via PRC1

Protein regulator of cytokinesis 1 (PRC1) has been reported in correlation with various malignancies. Functionality of PRC1 in nasopharyngeal carcinoma (NPC) was investigated, in perspective of long noncoding RNA (lncRNA) regulatory circuitry. Aberrant expressed messenger RNA and lncRNA were screened out from the Gene Expression Omnibus microarray database. NPC cell line CNE-2 was adopted for in vitro study and transfected with mimic or short hairpin RNA of miR-194-3p and PTPRG-AS1. The radioactive sensitivity, cell viability, migration, invasion, and apoptosis were detected. PTPRG-AS1 and PRC1 were upregulated in NPC, whereas miR-194-3p was downregulated. PTPRG-AS1 was found to specifically bind to miR-194-3p as a competing endogenous RNA and miR-194-3p targets and negatively regulates PRC1. Overexpressed miR-194-3p or silenced PTPRG-AS1 resulted in enhanced sensitivity to radiotherapy and cell apoptosis along with suppressed cell migration, invasion and proliferation in NPC. Furthermore, impaired tumor formation was also caused by miR-194-3p overexpression or PTPRG-AS1 suppression through xenograft tumor in nude mice. In our study, PTPRG-AS1/miR-194-3p/PRC1 regulatory circuitry was revealed in NPC, the mechanism of which can be of clinical significance for treatment of NPC.     

Long noncoding RNA HOXA-AS2 regulates the expression of SCN3A by sponging miR-106a in breast cancer

Breast cancer is the most commonly diagnosed cancer that affects women worldwide. This study aimed to investigate the competing endogenous RNAs (ceRNAs) mechanism in breast cancer. Microarray data were downloaded from the University of California Santa Cruz (UCSC) Xena database. The limma package was used to screen the differentially expressed messenger RNAs (DEMs) and differentially expressed long noncoding RNAs (DELs). Subsequently, functional analysis was performed using DAVID tool. After constructing the protein-protein interaction (PPI) network, we identified the major gene modules using the Cytoscape software. Univariate survival analysis in the survival package was performed. Finally, the ceRNA regulatory network was constructed to identify the critical genes. A total of 1380 DEMs and 345 DELs were identified in breast cancer samples compared with normal samples. Functional enrichment analysis showed that DEMs were mainly involved in cell division, and cell cycle. We screened four major gene modules and identified the hub nodes in these functional modules. Several DEMs (including FABP7, C4BPA, and LAMB3) and three long noncoding RNAs (lncRNAs) (LINC00092, SLC26A4.AS1, and COLCA1) exhibited significant correlation with patients' survival outcomes. In the ceRNA network, the lncRNA HOXA-AS2 regulated the expression level of SCN3A by interacting with hsa-miR-106a-5p. Thus, our study investigated the ceRNA mechanism in breast cancer. The results showed that lncRNA HOXA-AS2 might modulate the expression of SCN3A by sponging miR-106a in breast cancer.