LncRNA NEAT1 Promotes Deterioration of Hepatocellular Carcinoma Based on In Vitro Experiments, Data Mining, and RT-qPCR Analysis
CELLULAR PHYSIOLOGY AND BIOCHEMISTRY
Authors: Ling, Zhi-an; Xiong, Dan-dan; Meng, Rong-mei; Cen, Jie-Mei; Zhao, Na; Chen, Gang; Li, Ruo-lin; Dang, Yi-wu
Abstract
Background/Aims: Accumulated evidence indicates that IncRNA NEAT1 has important roles in various malignant tumors. In this study, we conducted a comprehensive analysis to explore the exact role of NEAT1 in hepatocellular carcinoma (HCC). Methods: The effects of NEAT1 on cell proliferation, apoptosis, migration, and invasion were measured by in vitro experiments. The expression level and clinical value of NEAT1 in HCC was evaluated based on data from The Cancer Genome Atlas (TCGA), Oncomine, and in-house real-time quantitative (RT-qPCR). Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and protein protein interaction (PPI) network analyses were conducted to investigate the potential molecular mechanisms of NEAT1. Results: NEAT1 siRNA not only inhibited proliferation, migration, and invasion of HCC cells but also induced HCC cell apoptosis. A total of four records from TCGA, Oncomine, and RT-qPCR analysis were combined to assess the expression level of NEAT1 in HCC. The pooled standard mean deviation (SMD) indicated that NEAT1 was up regulated in HCC (SMD = 0.54; 95% CI, 0.36-073; P < 0.0001). The area under the curve value of the summary receiver operating characteristic curve was 0.71. NEAT1 expression was also related to race (P = 0.025) and distant metastasis (P = 0.002). Additionally, the results of GO, KEGG pathway, and PPI network analyses suggest that NEAT1 may promote the progression of HCC by interacting with several tumor-related genes (SP1, MDM4, CREBBP, TRAF5, CASP8, TRAF1, KAT2A, and HIST4H4). Conclusions: NEAT1 contributes to the deterioration of HCC and provides a potential biomarker for the diagnosis and therapy of HCC. (C) 2018 The Author(s) Published by S. Karger AG, Basel
Transcriptional activation of histone H4 by C/EBP beta during the mitotic clonal expansion of 3T3-L1 adipocyte differentiation
MOLECULAR BIOLOGY OF THE CELL
Authors: Zhang, You-You; Li, Xi; Qian, Shu-Wen; Guo, Liang; Huang, Hai-Yan; He, Qun; Liu, Yuan; Ma, Chun-Gu; Tang, Qi-Qun
Abstract
CCAAT enhancer binding protein beta (C/EBP beta) is required for both mitotic clonal expansion (MCE) and terminal differentiation during the 3T3-L1 adipocyte differentiation program. Whereas the mechanism of C/EBP beta during terminal differentiation is well understood, the mechanism of C/EBP beta in MCE is not. We provide evidence that histone H4, the most conserved cell cycle-related histone, the change of which is strictly correlated with DNA content change during the cell cycle, is transcriptionally activated by C/EBP beta during MCE. Expression of histone H4 is increased at 16 h after induction when 3T3-L1 preadipocytes synchronously reenter S phase, which is correlated with the sequential phosphorylation and activation of C/EBP beta, and expression was partially suppressed when A-C/EBP (dominant negative for C/EBP protein) was overexpressed. One C/EBP-binding site was identified in one of the histone H4 gene promoters (hist4h4), confirmed by both electrophoretic mobility shift assay and chromatin immunoprecipitation assay. C/EBP-binding sites were also found in 9 of 11 other histone H4 promoters, which can also be transactivated by C/EBP beta. Knockdown of C/EBP beta by stealth small interfering RNA partially decreased H4 gene expression and arrested cells in G1 phase as indicated by bromodeoxyuridine incorporation and fluorescence-activated cell sorting analysis of DNA content. This study provides new insights into why C/EBP beta is required for MCE during 3T3-L1 adipocyte differentiation and why C/EBP beta plays important roles in the proliferation of other cell types.