ABSTRACT
BACKGROUND AND AIM: Circular ubiquitin-like, containing PHD and ring finger domains 1 (circUHRF1) is aberrantly upregulated in human hepatocellular carcinoma (HCC) tissues. However, the underlying molecular mechanisms remain obscure. The present study aimed at elucidating the interactive function of circUHRF1-G9a-ubiquitin-like, containing PHD and ring finger domains 1 (UHRF1) mRNA-eukaryotic translation initiation factor 4A3 (EIF4A3)-PDZ and LIM domain 1 (PDLIM1) network in HCC. METHODS: Expression of circUHRF1, mRNAs of G9a, UHRF1, PDLIM1, epithelial-mesenchymal transition (EMT)-related proteins, and Hippo-Yap pathway components was determined by quantitative polymerase chain reaction (Q-PCR), immunofluorescence, or Western blot analysis. Tumorigenic and metastatic capacities of HCC cells were examined by cellular assays including Cell Counting Kit-8, colony formation, wound healing, and transwell assays. Molecular interactions between EIF4A3 and UHRF1 mRNA were detected by RNA pull-down experiment. Complex formation between UHRF1 and PDLIM1 promoter was detected by chromatin immunoprecipitation assay. Co-immunoprecipitation was performed to examine the binding between UHRF1 and G9a. RESULTS: Circular ubiquitin-like, containing PHD and ring finger domains 1, G9a, and UHRF1 were upregulated, while PDLIM1 was downregulated in HCC tissue samples and cell lines. Cellular silencing of circUHRF1 repressed HCC proliferation, invasion, migration, and EMT. G9a formed a complex with UHRF1 and inhibited PDLIM1 transcription. CONCLUSION: Eukaryotic translation initiation factor 4A3 regulated circUHRF1 expression by binding to UHRF1 mRNA promoter. circUHRF1 increased the stability of G9a and UHRF1 mRNAs through recruiting EIF4A3. Overexpression of circUHRF1 aggravated HCC progression through Hippo-Yap pathway and PDLIM1 inhibition. By elucidating the molecular function of circUHRF1-G9a-UHRF1 mRNA-EIF4A3-PDLIM1 network, our data shed light on the HCC pathogenesis and suggest a novel therapeutic strategy for future HCC treatment.
Subject(s)
Carcinoma, Hepatocellular , DEAD-box RNA Helicases , Liver Neoplasms , Humans , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/drug therapy , RNA, Messenger/genetics , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Homeodomain Proteins/therapeutic use , Ubiquitin/genetics , Ubiquitin/metabolism , Ubiquitin/therapeutic use , RING Finger Domains , Liver Neoplasms/genetics , Liver Neoplasms/pathology , Ubiquitin-Protein Ligases/genetics , Ubiquitin-Protein Ligases/metabolism , Ubiquitin-Protein Ligases/therapeutic use , CCAAT-Enhancer-Binding Proteins/chemistry , CCAAT-Enhancer-Binding Proteins/genetics , CCAAT-Enhancer-Binding Proteins/metabolism , Peptide Initiation Factors/genetics , Peptide Initiation Factors/metabolism , Peptide Initiation Factors/therapeutic use , Cell Proliferation/genetics , Cell Line, Tumor , Gene Expression Regulation, Neoplastic/genetics , Eukaryotic Initiation Factor-4A/genetics , Eukaryotic Initiation Factor-4A/metabolismABSTRACT
ß-Thalassemia (ß-thal) is a common hematological disorder in the Guangxi Zhuang Autonomous Region of Southern China. Heterozygous ß-thal is usually associated with reduced hematological indices and increased Hb A2 levels. However, the preventive program of the regional government only conducts the screening of hematological indices [complete blood count (CBC)] especially at primary hospitals. In this study, we describe a male ß-thal patient presenting normal hematological indices but with a high Hb A2 level. We proposed that hemoglobin (Hb) analysis and CBC should be performed together in the preventive screening program in regions with a high thalassemia incidence to avoid misdiagnosis.