Structural basis of the Integrator complex assembly and association with transcription factors.

Integrator is a multi-subunit protein complex responsible for premature transcription termination of coding and non-coding RNAs. This is achieved via two enzymatic activities, RNA endonuclease and protein phosphatase, acting on the promoter-proximally paused RNA polymerase Ⅱ (RNAPⅡ). Yet, it remains unclear how Integrator assembly and recruitment are regulated and what the functions of many of its core subunits are. Here, we report the structures of two human Integrator sub-complexes: INTS10/13/14/15 and INTS5/8/10/15, and an integrative model of the fully assembled Integrator bound to the RNAPⅡ paused elongating complex (PEC). An in silico protein-protein interaction screen of over 1,500 human transcription factors (TFs) identified ZNF655 as a direct interacting partner of INTS13 within the fully assembled Integrator. We propose a model wherein INTS13 acts as a platform for the recruitment of TFs that could modulate the stability of the Integrator's association at specific loci and regulate transcription attenuation of the target genes.

ZNF655 promotes the progression of hepatocellular carcinoma through PSMB8.

Hepatocellular carcinoma (HCC) is a type of liver cancer that is associated with high mortality rates. This study aims to investigate the role of ZNF655, a member of the zinc finger protein family, in the development of HCC. Immunohistochemical staining analysis was conducted to evaluate the expression of ZNF655 in HCC patient samples. Lentivirus-mediated ZNF655 knockdown was established in HCC cell lines (BEL-7402 and HCCLM3). The effects of ZNF655 on different aspects of HCC cell behavior such as proliferation, apoptosis, cycle, migration and tumor formation were examined. Downstream targets of ZNF655 in HCC were identified and verified through loss/gain-of-function experiments. Clinically, ZNF655 expression was elevated in HCC and increased with the severity of the disease. Functionally, inhibition of ZNF655 expression reduced the progression of HCC cells by decreasing proliferation, causing apoptosis, arresting cell cycle retention in G2, suppressing migration, and attenuating tumor formation in mice. Mechanistically, the proteasome subunit beta type-8 (PSMB8) was found to be co-expressed with ZNF655 in HCC, and PSMB8 knockdown weakened the promotion of ZNF655 overexpression on HCC. In summary, these findings suggest that ZNF655 promotes the progression of HCC through PSMB8, and inhibition of its expression may be a promising therapeutic target for HCC.

ZNF655 mediated by LINC01210/miR-124-3p axis promotes the progression of gastric cancer.

Gastric cancer (GC) is a common malignant tumor that usually originates from the epithelium of the gastric mucosa. ZNF655 was a suppressor gene of many cancers. However, the mechanism of ZNF655 in GC remains unknown. Quantitative polymerase chain reaction was used to assess the expression of ZNF655, LINC01210, and miR-124-3p. Western blotting was used to monitor ZNF655 protein expression. MTT, clone formation, transwell, and flow cytometry were all used to investigate the functions of GC cells. The interactions between ZNF655, LINC01210, and miR-124-3p were confirmed using the dual-luciferase reporter gene assay and the RIP assay. ZNF655 was highly expressed in GC cells. ZNF655 knockdown reduced GC cell viability, proliferation, migration, invasion, and induced apoptosis. The level of miR-124-3p was significantly reduced in GC cells. Besides, miR-124-3p targeted ZNF655 and inhibited its expression. MiR-124-3p mimics inhibited GC cell progression, but ZNF655 overexpression reversed these effects. Moreover, LINC01210 was found to be highly expressed in GC cells and to be able to sponge miR-124-3p. Furthermore, inhibiting miR-124-3p or increasing ZNF655 could counteract the effects of LINC01210 knockdown on GC cell development. Finally, ZNF655 promoted GC cell progression and was regulated by the LINC01210/miR-124-3p axis.

ZNF655 Promotes the Progression of Glioma Through Transcriptional Regulation of AURKA.

Objectives: Glioma has a high degree of malignancy, strong invasiveness, and poor prognosis, which is always a serious threat to human health. Previous studies have reported that C2H2 zinc finger (ZNF) protein is involved in the progression of various cancers. In this study, the clinical significance, biological behavior, and molecule mechanism of ZNF655 in glioma were explored. Methods: The expression of ZNF655 in glioma and its correlation with prognosis were analyzed through public datasets and immunohistochemical (IHC) staining. The shRNA-mediated ZNF655 knockdown was used to explore the effects of ZNF655 alteration on the phenotypes and tumorigenesis of human glioma cell lines. Chromatin immunoprecipitation (ChIP)-qPCR and luciferase reporter assays were performed to determine the potential mechanism of ZNF655 regulating Aurora kinase A (AURKA). Results: ZNF655 was abundantly expressed in glioma tissue and cell lines SHG-44 and U251. Knockdown of suppressed the progression of glioma cells, which was characterized by reduced proliferation, enhanced apoptosis, cycle repression in G2, inhibition of migration, and weakened tumorigenesis. Mechanistically, transcription factor ZNF655 activated the expression of AURKA by directly binding to the promoter of AURKA. In addition, downregulation of AURKA partially reversed the promoting effects of overexpression of ZNF655 on glioma cells. Conclusions: ZNF655 promoted the progression of glioma by binding to the promoter of AURKA, which may be a promising target for molecular therapy.

ZNF655 is involved in development and progression of non-small-cell lung cancer.

AIMS: Non-small cell lung cancer (NSCLC) is a malignant tumor with high mortality, which seriously endangers human health. The clinical significance, biological function and potential mechanism of Zinc finger protein 655 (ZNF655) in NSCLC are discussed in this study. MATERIALS AND METHODS: The expression level of ZNF655 in NSCLC was clarified by immunohistochemical (IHC) staining. Subsequently, lentivirus-mediated shRNA was used to construct ZNF655 knock down NSCLC cells NCI-H1299 and A549. In vitro and in vivo loss of function assays were used to evaluate the malignant behaviors of the cells. KEY FINDINGS: The expression level of ZNF655 was abnormally abundant in NSCLC. The decrease of ZNF655 expression led to the inhibition of the malignant behaviors of NSCLC, which was manifested by weakened proliferation, increased sensitivity to apoptosis, cycle repression at G2 and weakened migration. Consistently, downregulation of ZNF655 reduced tumorigenesis in mouse xenograft model. Moreover, decreased expression of ZNF655 resulted in upregulated expression of Bad, Bax, Fas, p21, p27, Caspase 3 and Caspase 8 in NSCLC cells. NCI-H1299 cells with ZNF655 knockdown resulted in decreased phosphorylation of Akt, downregulation of CDK6 and PIK3CA, and upregulation of MAPK9. Collectively, ZNF655 may regulate apoptosis of NSCLC cells through PI3K/Akt and p53 signaling pathways. SIGNIFICANCE: ZNF655 possessed a promoting effect in the progression of NSCLC, which may serve as a promising molecular target for clinical treatment.

Role of ANKHD1/LINC00346/ZNF655 Feedback Loop in Regulating the Glioma Angiogenesis via Staufen1-Mediated mRNA Decay.

Accumulating evidence shows that long noncoding RNA (lncRNA) dysregulation plays a critical role in tumor angiogenesis. Glioma is characterized by abundant angiogenesis. Herein, we investigated the expression and function of LINC00346 in the regulation of glioma angiogenesis. The present study first demonstrated that ANKHD1 (ankyrin repeat and KH domain-containing protein 1) and LINC00346 were significantly increased in glioma-associated endothelial cells (GECs), whereas ZNF655 (zinc finger protein 655) was decreased in GECs. Meanwhile, ANKHD1 inhibition, LINC00346 inhibition, or ZNF655 overexpression impeded angiogenesis of GECs. Moreover, ANKHD1 targeted LINC00346 and enhanced the stability of LINC00346. In addition, LINC00346 bound to ZNF655 mRNA through their Alu elements so that LINC00346 facilitated the degradation of ZNF655 mRNA via a STAU1 (Staufen1)-mediated mRNA decay (SMD) mechanism. Futhermore, ZNF655 targeted the promoter region of ANKHD1 and formed an ANKHD1/LINC00346/ZNF655 feedback loop that regulated glioma angiogenesis. Finally, knockdown of ANKHD1 and LINC00346, combined with overexpression of ZNF655, resulted in a significant decrease in new vessels and hemoglobin content in vivo. The results identified an ANKHD1/LINC00346/ZNF655 feedback loop in the regulation of glioma angiogenesis that may provide new targets and strategies for targeted therapy against glioma.

ADAR1 up-regulates ZNF655 expression via RNA editing and enhances HBV replication in HepG2 cell line / 基础医学与临床

Objective To explore the effect of ADAR1 on ZNF655 and the regulation of ZNF655 on the expression of HBV. Methods Sanger sequencing was used to validate the 3′UTR region of ZNF655 in ADAR1. The expression of ADAR1 and ZNF655 mRNA as well as HBV RNA were detected by RT-qPCR. Dual luciferase report plasmid assay was used to detect the expression of luciferase. To detect the expression of ADAR1 and ZNF655 pro-tein by Western blot. HBsAg and HBeAg was detected by ELISA. Results The chr7:99575277 loci on ZNF655 3′UTR was homozygous in DNA level and hybrid in RNA level. On the 3′UTR editing site of ZNF655,the luciferase activity of the edited G allele was significantly higher than that of the normal A allele (P＜0.001). The expression of ZNF655 was upregulated by ADAR1 in the level of transcription and translation(P＜0.01).ZNF655 significantly promoted the expression of HBV. Conclusions The chr7:99575277 loci on ZNF655 3′UTR is edited by ADAR1, promoting the expression of ZNF655,which upregulated the expression of HBV.