Prognostic role of long noncoding RNA ZFAS1 in cancer patients: a systematic review and meta-analysis

Non-coding RNAs: a promising target for early metastasis intervention

ABSTRACT

Metastases account for the overwhelming majority of cancer-associated deaths. The dissemination of cancer cells from the primary tumor to distant organs involves a complex process known as the invasion-metastasis cascade. The underlying biological mechanisms of metastasis, however, remain largely elusive. Recently, the discovery and characterization of non-coding RNAs (ncRNAs) have revealed the diversity of their regulatory roles, especially as key contributors throughout the metastatic cascade. Here, we review recent progress in how three major types of ncRNAs (microRNAs, long non-coding RNAs, and circular RNAs) are involved in the multistep procedure of metastasis. We further examine interactions among the three ncRNAs as well as current progress in their regulatory mechanisms. We also propose the prevention of metastasis in the early stages of cancer progression and discuss current translational studies using ncRNAs as targets for metastasis diagnosis and treatments. These studies provide insights into developing more effective strategies to target metastatic relapse.

High-throughput sequencing approach for the identification of lncRNA biomarkers in hepatocellular carcinoma and revealing the effect of ZFAS1/miR-150-5p on hepatocellular carcinoma progression

Aims

To screen abnormal lncRNAs and diagnostic biomarkers in the progression of hepatocellular carcinoma through high-throughput sequencing and explore the underlying mechanisms of abnormal lncRNAs in the progression of hepatocellular carcinoma.

Methods

The transcriptome sequencing was used to analyze the RNA expression profile and identify differentially expressed RNAs. Hub lncRNAs were screened by combining (WGCNA, ceRNA regulatory network, PPI, GO and KEGG analyses, Kaplan-Meier curve analysis, Cox analysis, risk model construction and qPCR). Thereafter, the correlation between the expression of hub lncRNAs and tumor clinicopathological parameters was analyzed, and the hub lncRNAs were analyzed by GSEA. Finally, the effects of hub RNAs on the proliferation, migration and invasion of HepG2 cells were investigated in vitro.

Results

Compared with the control group, a total of 610 lncRNAs, 2,593 mRNAs and 26 miRNAs were screened in patients with hepatocellular carcinoma. Through miRNA target prediction and WGCNA, a ceRNA was constructed, comprising 324 nodes and 621 edges. Enrichment analysis showed that mRNAs in ceRNA were involved mainly in cancer development progression. Then, the ZFAS1/miR-150-5p interaction pair was screened out by Kaplan Meier curve analysis, Cox analysis and qPCR analysis. Its expression was related to tumor stage, TNM stage and patient age. ROC curve analysis showed that it has a good predictive value for the risk of hepatocellular carcinoma. GSEA showed that ZFAS1 was also enriched in the regulation of immune response, cell differentiation and proliferation. Loss-of-function experiments revealed that ZFAS1 inhibition could remarkably suppress HepG2 cell proliferation, migration and invasion in vitro. Bioinformatic analysis and luciferase reporter assays revealed that ZFAS1 directly interacted with miR-150-5p. Rescue experiments showed that a miR-150-5p inhibitor reversed the cell proliferation, migration and invasion functions of ZFAS1 knockdown in vitro.

Conclusion

ZFAS1 is associated with the malignant status and prognosis of patients with hepatocellular carcinoma, and the ZFAS1/miR-150-5p axis is involved in hepatocellular carcinoma progression.

LncRNA ZFAS1: Role in tumorigenesis and other diseases

Residing on chromosome 20q13.13, Zinc Finger NFX1-Type Containing 1 (ZNFX1) antisense RNA 1 (ZFAS1) is a transcript which has been primarily recognized as a modulator of differentiation of alveolar and epithelial cell in the mammary gland. This long non-coding RNA (lncRNA) partakes in the molecular cascades leading to several non-neoplastic conditions such as osteoarthritis, epilepsy, rheumatoid arthritis, atherosclerosis, pulmonary fibrosis, myocardial infarction, and cardiac dysfunction. More importantly, ZFAS1 is considered as an oncogene in almost all types of cancers. Using expression amounts of ZFAS1, it is possible to forecast the clinical outcome of patients with different neoplasms such as colorectal cancer, gastric cancer, cholangiocarcinoma, hepatoblastoma, and other types of cancer. We describe the role of ZFAS1 in the development of neoplastic and non-neoplastic disorders.

LncRNA ZFAS1, as a poor prognostic indicator, promotes cell proliferation and epithelial-mesenchymal transition in endometrial carcinoma

Background: Long noncoding RNA Zinc finger nuclear transcription factor, X-box binding 1-type containing 1 antisense RNA 1 (ZFAS1) has been reported to be an oncogene in various tumors. However, the role of ZFAS1 in endometrial carcinoma (EC) are not fully determined. Methods & results: Here, we found ZFAS1 expression was significantly upregulated in EC patients, which was significantly associated with International Federation of Gynecology and Obstetrics stage, histological grade, myometrial invasion and poor prognosis. The loss-of-function assays showed that knockdown of ZFAS1 significantly suppressed the proliferation, G1/S transition, migration and invasion in EC cells. Moreover, knockdown of ZFAS1 obviously downregulated the expression of CDK4, Cyclin D1 and N-cadherin, but upregulated E-cadherin expression. Conclusion: Collectively, these results suggest that ZFAS1 might be used as potential therapeutic targets for EC treatment.

Long non-coding RNA ZFAS1 promotes the expression of EPAS1 in gastric cardia adenocarcinoma

LncRNA (Long non-coding RNA) ZFAS1 (zinc finger antisense 1) functions as the oncogene in multiple cancers, including gastric cancer. However, its function and underlying mechanism in the GCA (gastric cardia adenocarcinoma), the most aggressive type of gastric cancer, remain unknown. We demonstrated here that the LncRNA ZFAS1 was up-regulated in GCA tissues. Furthermore, the elevated level of ZFAS1 was significantly associated with the GCA metastasis and cancer recurrence. It was also demonstrated to be an independent prognostic indicator of disease-free survival and overall survival for GCA patients. RNA sequencing showed that the up-regulated ZFAS1 was tightly associated with the down-regulated hypoxia inducible factor 1 (HIF1) and up-regulated EPAS1 (Endothelial PAS domain protein 1, also known as HIF2). In vitro studies showed that the ZFAS1 could bind to EPAS1, enhance its abilities to epigenetically silence the HIF1, and promote its own expression in GCA cell lines. In the animal model, co-delivering the EPAS1 and the ZFAS1 antisense oligos could significantly boost up their therapeutic effects on tumor growth. Thus, targeting ZFAS1 and EPAS1 might be an alternative therapeutic option in GCA.

Knockdown of ZFAS1 suppresses the progression of acute myeloid leukemia by regulating microRNA-150/Sp1 and microRNA-150/Myb pathways

Leukemia is the most frequent malignancy in children with acute myeloid leukemia (AML) as the second commonest type. Long non-coding RNA zinc finger antisense 1 (ZFAS1) has been widely reported as an oncogenic factor in multiple malignancies including AML. However, the roles and molecular mechanisms of ZFAS1 in the tumorigenesis of AML are poor defined till now. In the present study, RT-qPCR assay showed that ZFAS1 was highly expressed in bone marrow of acute leukemia patients and AML cell lines. Loss-of-function analyses revealed that ZFAS1 knockdown inhibited proliferation and promoted apoptosis in AML cells and curbed AML xenograft growth in vivo. Bioinformatics analysis and luciferase reporter assay unveiled that microRNA-150 (miR-150) could interact with ZFAS1, Myb 3' UTR and Sp1 3' UTR. Moreover, ZFAS1 acted as a molecular sponge of miR-150, giving rise to the downregulation of miR-150 level and upregulation of Myb and Sp1 levels. Moreover, miR-150 overexpression resulted in the reduction of AML cell proliferative ability and the increase of cell apoptotic rate. Additionally, the inhibition of miR-150 abrogated ZFAS1 loss-mediated anti-leukemia effects. In summary, our data demonstrated that ZFAS1 knockdown hampered AML progression by regulating miR-150/Myb and miR-150/Sp1 pathways, providing some potential biomarkers or targets for the diagnosis and treatment of leukemia.

ZFAS1: A novel vital oncogenic lncRNA in multiple human cancers

Long noncoding RNAs (lncRNAs) are a class of noncoding, endogenous, single‐stranded RNAs longer than 200 nucleotides in length that are transcribed by RNA polymerase II. Mounting evidence has indicated that lncRNAs play key roles in several physiological and pathological processes by modifying gene expression at the transcriptional, posttranscriptional, epigenetic, and translation levels. Many reports have demonstrated that lncRNAs function as potential oncogene or tumour suppressors and thus play vital regulatory roles in tumourigenesis and tumour progression. ZNFX1 antisense RNA 1 (ZFAS1), a novel lncRNA transcribed in the antisense orientation of zinc finger NFX1‐type containing 1(ZNFX1), was found to be increased in multiple cancers, such as gastric cancer and hepatocellular carcinoma, contributing to cancer development and progression. In the present review, we summarized recent progression on study of the functions and underlying molecular mechanisms of ZFAS1 related to occurrence and development of multiple cancers.

Long noncoding RNA FOXD2-AS1 accelerates the gemcitabine-resistance of bladder cancer by sponging miR-143

Increasing evidences have proved that long noncoding RNAs (lncRNAs) modulate the tumorigenesis of bladder cancer involved in multiple pathophysiological processes. In the study, we investigate the role of lncRNA FOXD2-AS1 in the gemcitabine (GEM) resistant bladder cancer and explore its potential mechanism. Results showed that lncRNA FOXD2-AS1 was high-expressed in gemcitabine-resistant bladder cancer cells. In vitro experiments, FOXD2-AS1 knockdown suppressed the 50% inhibitive concentration (IC50) of gemcitabine, drug-resistance related genes (MDR1, MRP2, LRP1) expression, invasion and ABCC3 protein expression in gemcitabine-resistant bladder cancer cells (T24/GEM, 5637/GEM). In vivo of xenograft assay, FOXD2-AS1 knockdown inhibited the tumor growth of bladder cancer cells. Bioinformatics program and validation experiments confirmed that FOXD2-AS1 positively regulated ABCC3 protein through targeting miR-143, acting as a competing endogenous RNA (ceRNA). In summary, our results revealed the vital roles of FOXD2-AS1/miR-143/ABCC3 axis in gemcitabine resistance of bladder cancer cells, providing a novel therapeutic strategy for bladder cancer.

ZFAS1 functions as an oncogenic long non-coding RNA in bladder cancer

Long non-coding RNA (lncRNA) ZFAS1 (zinc finger antisense 1) has been suggested to have an oncogenic role in the tumorigenesis of human malignant tumors. However, the expression status and biological function of ZFAS1 in bladder cancer is still unknown. Thus, the purpose of the present study is to explore the clinical value of ZFAS1 in bladder cancer patients, and the biological function of ZFAS1 in bladder cancer cell. In the present study, we found ZFAS1 expression was increased in bladder cancer tissues compared with paired adjacent normal tissues through analyzing the Cancer Genome Atlas (TCGA) database. Furthermore, we confirmed that levels of ZFAS1 expression were elevated in bladder cancer tissues and cell lines compared with normal bladder tissues and normal uroepithelium cell line, respectively. Then, we observed that the expression level of ZFAS1 was positively associated with clinical stag, muscularis invasion, lymph node metastasis, and distant metastasis in bladder cancer patients. The experiments in vitro suggested that knockdown of ZFAS1 repressed bladder cancer cell proliferation via up-regulating KLF2 and NKD2 expression, and inhibited cell migration and invasion via down-regulating ZEB1 and ZEB2 expression. In conclusion, ZFAS1 is overexpressed in bladder cancer, and functions as an oncogenic lncRNA in regulating bladder cancer cell proliferation, migration, and invasion.