Oncogenic KSHV-encoded interferon regulatory factor upregulates HMGB2 and CMPK1 expression to promote cell invasion by disrupting a complex lncRNA-OIP5-AS1/miR-218-5p network.
ABSTRACT: Kaposi's sarcoma (KS), a highly disseminated tumor of hyperproliferative spindle endothelial cells, is the most common AIDS-associated malignancy caused by infection of Kaposi's sarcoma-associated herpesvirus (KSHV). KSHV-encoded viral interferon regulatory factor 1 (vIRF1) is a viral oncogene but its role in KSHV-induced tumor invasiveness and motility remains unknown. Here, we report that vIRF1 promotes endothelial cell migration, invasion and proliferation by down-regulating miR-218-5p to relieve its suppression of downstream targets high mobility group box 2 (HMGB2) and cytidine/uridine monophosphate kinase 1 (CMPK1). Mechanistically, vIRF1 inhibits p53 function to increase the expression of DNA methyltransferase 1 (DNMT1) and DNA methylation of the promoter of pre-miR-218-1, a precursor of miR-218-5p, and increases the expression of a long non-coding RNA OIP5 antisense RNA 1 (lnc-OIP5-AS1), which acts as a competing endogenous RNA (ceRNA) of miR-218-5p to inhibit its function and reduce its stability. Moreover, lnc-OIP5-AS1 increases DNA methylation of the pre-miR-218-1 promoter. Finally, deletion of vIRF1 from the KSHV genome reduces the level of lnc-OIP5-AS1, increases the level of miR-218-5p, and inhibits KSHV-induced invasion. Together, these results define a novel complex lnc-OIP5-AS1/miR-218-5p network hijacked by vIRF1 to promote invasiveness and motility of KSHV-induced tumors.
Project description:Long non-coding RNAs have been reported to be involved in non-small cell lung cancer (NSCLC) progression. However, whether Opa-interacting protein 5 antisense RNA 1 (OIP5-AS1) serves a role in NSCLC remains unclear. Bioinformatics analysis of The Cancer Genome Atlas datasets showed clinical significance and relevance of OIP5-AS1 in NSCLC. Western blotting and reverse transcription-quantitative PCR revealed protein and RNA expression levels of the genes [including OIP5-AS1, microRNA (miR)-140-5p, histone deacetylase 7 (HDAC7) and vascular endothelial growth factor A (VEGFA)]. Direct associations between the genes (miR-140-5p and OIP5-AS1, or miR-140-5p and HDAC7) were confirmed using a dual-luciferase reporter assay. Lymphatic vessel formation and invasion ability were detected using a lymphatic vessel formation assay and Transwell invasion assay. OIP5-AS1 knockdown attenuated lymphatic vessel length and invasion. The role of OIP5-AS1 was reverted by miR-140-5p. HDAC7 and VEGFA are downstream effectors of miR-140-5p-mediated NSCLC metastasis. OIP5-AS1, miR-140-5p, HDAC7 and VEGFA were all dysregulated in human clinical NSCLC tumor tissues. In conclusion, the present results demonstrated a novel mechanism for OIP5-AS1-induced metastatic phenotypes of NSCLC via the miR-140-5p/HDAC7/VEGFA axis.
Project description:Several studies have shown an important role for long non-coding RNA (lncRNA) in breast cancer progression. The present study investigated the role of lncRNA Opa interacting protein 5-antisense RNA 1 (OIP5-AS1) in the progression of breast cancer. OIP5-AS1 was significantly upregulated in breast cancer tissues and in breast cancer cell lines, and OIP5-AS1 downregulation inhibited the malignant behavior of breast cancer in vitro and in vivo. For in-depth exploration of the mechanism of OIP5-AS1 in breast cancer, we found that expression of microRNA-129-5p(miR-129-5p), which was found to bind sites in the sequence of OIP5-AS1, in breast cancer tissues was negatively correlated with OIP5-AS1. Also, luciferase assays indicated that OIP5-AS1 acted as a miR-129-5p sponge, resulting in upregulated expression of the sex-determining region Y-box 2 (SOX2) transcription factor. Our study showed that OIP5-AS1 plays a critical role in promoting breast cancer progression and that OIP5-AS1 downregulation targets SOX2 by miR-129-5p upregulation.
Project description:The function of the vast majority of mammalian long noncoding (lnc) RNAs remains unknown. Here, analysis of a highly abundant mammalian lncRNA, OIP5-AS1, known as cyrano in zebrafish, revealed that OIP5-AS1 reduces cell proliferation. In human cervical carcinoma HeLa cells, the RNA-binding protein HuR, which enhances cell proliferation, associated with OIP5-AS1 and stabilized it. Tagging OIP5-AS1 with MS2 hairpins to identify associated microRNAs revealed that miR-424 interacted with OIP5-AS1 and competed with HuR for binding to OIP5-AS1. We further identified a 'sponge' function for OIP5-AS1, as high levels of OIP5-AS1 increased HuR-OIP5-AS1 complexes and prevented HuR interaction with target mRNAs, including those that encoded proliferative proteins, while conversely, lowering OIP5-AS1 increased the abundance of HuR complexes with target mRNAs. We propose that OIP5-AS1 serves as a sponge or a competing endogenous (ce)RNA for HuR, restricting its availability to HuR target mRNAs and thereby repressing HuR-elicited proliferative phenotypes.
Project description:Breast cancer is the most common invasive cancer in women with the highest number of related deaths which is caused by distal metastasis. Recently, integrated analysis of gene expression profile suggested widespread gene dysregulation in various types of cancer. Research in the past decade has focused on long non?coding RNAs (lncRNAs), particularly in cell proliferation, tumor progression and metastasis. OPA?interacting protein 5 antisense transcript 1 (OIP5?AS1) is an evolutionarily conserved long non?coding RNA that has been linked to oncogenesis in multiple cancers. In breast cancer, dysregulation of OIP5?AS1 was reported but the precise role in cancer development and progression remains unclear. In the present study, using small interfering RNA (siRNA) targeting OIP5?AS1, it was shown that knockdown of OIP5?AS1 was associated with alteration of EMT markers and suppressed migration and invasion of breast cancer cells. Among the EMT?related transcription factors, ZEB1 and ZEB2 were significantly downregulated with OIP5?AS1 knockdown. Computational analysis and a dual?luciferase reporter system identified miR?340?5p was the target gene for OIP5?AS1. Further experiments verified the function of OIP5?AS1 in cell invasion was dependent on miR?340a?5p through regulating target gene ZEB2. In vivo study demonstrated that overexpressing OIP5?AS1 in breast cancer cells promoted lung metastasis in nude mice. The findings of the present study revealed the mechanism of OIP5?AS1 in breast cancer metastasis. Overall, our study may provide a potential therapeutic target for breast cancer metastasis.
Project description:Kaposi's sarcoma (KS), caused by Kaposi's sarcoma-associated herpesvirus (KSHV), is a highly angioproliferative disseminated tumor of endothelial cells commonly found in AIDS patients. We have recently shown that KSHV-encoded viral interferon regulatory factor 1 (vIRF1) mediates KSHV-induced cell motility (PLoS Pathog. 2019 Jan 30;15(1):e1007578). However, the role of vIRF1 in KSHV-induced cellular transformation and angiogenesis remains unknown. Here, we show that vIRF1 promotes angiogenesis by upregulating sperm associated antigen 9 (SPAG9) using two in vivo angiogenesis models including the chick chorioallantoic membrane assay (CAM) and the matrigel plug angiogenesis assay in mice. Mechanistically, vIRF1 interacts with transcription factor Lef1 to promote SPAG9 transcription. vIRF1-induced SPAG9 promotes the interaction of mitogen-activated protein kinase kinase 4 (MKK4) with JNK1/2 to increase their phosphorylation, resulting in enhanced VEGFA expression, angiogenesis, cell proliferation and migration. Finally, genetic deletion of ORF-K9 from KSHV genome abolishes KSHV-induced cellular transformation and impairs angiogenesis. Our results reveal that vIRF1 transcriptionally activates SPAG9 expression to promote angiogenesis and tumorigenesis via activating JNK/VEGFA signaling. These novel findings define the mechanism of KSHV induction of the SPAG9/JNK/VEGFA pathway and establish the scientific basis for targeting this pathway for treating KSHV-associated cancers.
Project description:BACKGROUND:Although OIP5-AS1 has been characterized as an oncogenic lncRNA in many types of cancer, its role and underlying mechanism in ovarian carcinoma (OC) remains unknown. This study aimed to investigate the role of OIP5-AS1 in OC. METHODS:OC tissues and non-tumor tissues (ovary tissues within 3 cm around tumors) were collected from 58 OC patients (age range 36 to 67 years old, mean age 51.4?±?5.9 years old). The expression of OIP5-AS1 and snail in paired tissues were determined by RT-qPCR. The interaction between OIP5-AS1 and miR-34a was predicted by IntaRNA2.0 and confirmed by dual luciferase reporter assay. The effects of overexpression of OIP5-AS1 and miR-34a on the expression of snail were analyzed by RT-qPCR and Western blotting. Cell invasion and migration were analyzed by Transwell assay. RESULTS:We observed that the expression of OIP5-AS1 and snail was upregulated and positively correlated with each other in OC. RNA-RNA interaction analysis showed that OIP5-AS1 might sponge miR-34a. In OC cells, overexpression of OIP5-AS1 resulted in the upregulated expression of snail, while overexpression of miR-34a downregulated the expression of snail. In addition, overexpression of miR-34a reduced the effects of overexpression of OIP5-AS1 on the expression of snail. In cell invasion and migration assay, overexpression of OIP5-AS1 and snail resulted in increased OC cell invasion and migration, while overexpression of miR-34a decreased OC cell invasion and migration. Moreover, overexpression of miR-34a attenuated the effects of OIP5-AS1 overexpression on OC cell invasion and migration. CONCLUSIONS:Therefore, OIP5-AS1 may upregulate snail expression in OC by sponging miR-34a to promote OC cell invasion and migration.
Project description:Background:Multiple myeloma (MM) is a prevalent hematological malignancy. Long noncoding RNAs are correlated with the development of MM. In this project, the function of lncRNA opa interacting protein 5-antisense 1 (OIP5-AS1) in MM and the potential mechanistic pathway were explored. Methods:The expression of OIP5-AS1, microRNA (miR)-27a-3p and tuberous sclerosis 1 (TSC1) was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) assay. Cell proliferation was assessed by Cell Counting Kit-8 (CCK-8) assay, colony formation assay and Bromodeoxyuridine (BrdU) staining. And cell apoptosis was evaluated by flow cytometry assay. Cell metastasis was assessed utilizing transwell assay. Western blot analysis was employed to detect protein level. The target relation between miR-27a-3p and OIP5-AS1 or TSC1 was confirmed via dual-luciferase reporter assay and RNA immunoprecipitation assay. Tumor xenograft assay was conducted to measure the function of OIP5-AS1 in vivo. Results:The expression levels of OIP5-AS1 and TSC1 were decreased in MM, whereas miR-27a-3p was upregulated. High level of OIP5-AS1 could predict favourable prognosis of MM patients. Overexpression of OIP5-AS1 inhibited cell viability, colony formation ability, migration and invasion, induced cell cycle arrest in G1 phase and apoptosis of MM cells in vitro as well as repressed tumorigenesis in vivo. MiR-27a-3p was a target of OIP5-AS1, and reversed the impact of OIP5-AS1 on MM cells. MiR-27a-3p directly targeted TSC1. Silencing of miR-27a-3p repressed MM progression by elevating TSC1 expression. OIP5-AS1 upregulated TSC1 by sponging miR-27a-3p. Conclusion:OIP5-AS1 repressed multiple myeloma progression by regulating miR-27a-3p/TSC1 axis.
Project description:The present study aimed to identify novel intervertebral disc degeneration (IDD)‑associated long noncoding (lnc)RNAs and genes. The lncRNA and mRNA microarray dataset GSE56081 was downloaded from the Gene Expression Omnibus database and included 5 samples from patients with degenerative lumbar nucleus pulposus and 5 normal controls. Differentially expressed lncRNAs or differentially expressed genes (DEGs) were identified and co‑expression network analysis was performed followed by functional analysis for genes in the network. Additionally, a microRNA (miRNA)‑lncRNA‑mRNA competing endogenous RNA (ceRNA) regulatory network was constructed based on DEGs and lncRNAs in the co‑expression network. Furthermore, a literature search was performed to identify specific miRNAs that had been previously associated with IDD and a specific miRNA‑associated ceRNA network was extracted from the co‑expression network. A total of 967 genes and 137 lncRNAs were differentially expressed between IDD samples and controls. A co‑expression network was constructed and contained 39 differentially expressed lncRNAs and 209 DEGs, which were primarily involved in 'skeletal system development', 'response to mechanical stimulus' and 'bone development'. Furthermore, a ceRNA network was established, including 79 miRNAs, 9 downregulated lncRNAs and 148 DEGs. The identified miRNAs included a previously reported disease‑associated miRNA, hsa‑miR‑140. The present study demonstrated that hsa‑miR‑140 was regulated by three lncRNAs in the hsa‑miR‑140‑associated ceRNA network, including KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1), OIP5 antisense RNA 1 (OIP5‑AS1) and UGDH antisense RNA 1 (UGDH‑AS1). KCNQ1OT1 was co‑expressed with neurochondrin (NCDN) and lon peptidase 2, peroxisomal. In addition, the lncRNAs OIP5‑AS1 and UGDH‑AS1 targeted several overlapping co‑expressed genes, including forkhead box F1 (FOXF1) and polycystin 1, transient receptor potential channel interacting (PKD1). Therefore, KCNQ1OT1 may regulate the expression of NCDN, and OIP5‑AS1 and UGDH‑AS1 may affect the expression of FOXF1 and PKD1 in IDD. Further experiments are required to validate the results of the present study, which may provide valuable insights into the identification of novel biomarkers associated with IDD.
Project description:Numerous studies have suggested that dysregulated long noncoding RNAs (lncRNAs) contributed to the development and progression of many cancers. lncRNA OIP5 antisense RNA 1 (OIP5-AS1) has been reported to be increased in several cancers. However, the roles of OIP5-AS1 in liver hepatocellular carcinoma (LIHC) remain to be investigated. In this study, we demonstrated that OIP5-AS1 was upregulated in LIHC tissue specimens and its overexpression was associated with the poor survival of patients with LIHC. Furthermore, loss-of function experiments indicated that OIP5-AS1 promoted cell proliferation and inhibited cell apoptosis both in vitro and in vivo. Moreover, binding sites between OIP5-AS1 and hsa-miR-26a-3p as well as between hsa-miR-26a-3p and EPHA2 were confirmed by luciferase assays. Finally, a rescue assay was performed to prove the effect of the OIP5-AS1/hsa-miR-26a-3p/EPHA2 axis on LIHC cell biological behaviors. Based on all of the above findings, our results suggested that OIP5-AS1 promoted LIHC cell proliferation and invasion via regulating the hsa-miR-26a-3p/EPHA2 axis.
Project description:Long non-coding RNAs (lncRNAs) play an important role in the regulation of key cellular processes in early development and cancer. LncRNA Oip5-as1 facilitates stem cell self-renewal in mouse by sponging mmu-miR-7 and modulating NANOG level, yet its role in cancer is less understood. We analyzed OIP5-AS1 expression in oral tumors and in TCGA datasets. We observed overexpression of OIP5-AS1 in oral tumors (P?<?0.001) and in tumors of epithelial origin from TCGA. OIP5-AS1 expression was strongly associated with undifferentiated tumors (P?=?0.0038). In silico analysis showed miR-7 binding site is conserved in mouse and human OIP5-AS1. However, human NANOG 3'-UTR lost the binding site for hsa-miR-7a-3. Therefore, we screened for other miRNAs that can be sponged by OIP5-AS1 and identified six potential miRNAs and their downstream target genes. Expression analysis showed downregulation of miRNAs and upregulation of downstream target genes, particularly in undifferentiated tumors with high-level of OIP5-AS1 suggesting OIP5-AS1 could post-transcriptionally modulate the downstream target genes. Further, systematic epigenomic analysis of OIP5-AS1 promoter revealed binding motifs for MYC, NANOG and KLF4 suggesting that OIP5-AS1 could be transactivated by stemness-associated transcription factors in cancer. OIP5-AS1 overexpression in undifferentiated oral tumors may be suggestive of enhanced cancer stemness, and consequently, poor clinical outcome.