Lysine acetyltransferase Tip60 is required for hematopoietic stem cell maintenance
BLOOD
Authors: Numata, Akihiko; Kwok, Hui Si; Zhou, Qi-Ling; Li, Jia; Tirado-Magallanes, Roberto; Angarica, Vladimir Espinosa; Hannah, Rebecca; Park, Jihye; Wang, Chelsia Qiuxia; Krishnan, Vaidehi; Rajagopalan, Deepa; Zhang, Yanzhou; Zhou, Siqin; Welner, Robert S.; Osato, Motomi; Jha, Sudhakar; Bohlander, Stefan K.; Gottgens, Berthold; Yang, Henry; Benoukraf, Touati; Lough, John W.; Bararia, Deepak; Tenen, Daniel G.
Abstract
Hematopoietic stem cells (HSCs) have the potential to replenish the blood system for the lifetime of the organism. Their 2 defining properties, self-renewal and differentiation, are tightly regulated by the epigenetic machineries. Using conditional gene-knockout models, we demonstrated a critical requirement of lysine acetyltransferase 5 (Kat5, also known as Tip60) for murine HSC maintenance in both the embryonic and adult stages, which depends on its acetyltransferase activity. Genome-wide chromatin and transcriptome profiling in murine hematopoietic stem and progenitor cells revealed that Tip60 colocalizes with c-Myc and that Tip60 deletion suppress the expression of Myc target genes, which are associated with critical biological processes for HSC maintenance, cell cycling, and DNA repair. Notably, acetylated H2A.Z (acH2A.Z) was enriched at the Tip60-bound active chromatin, and Tip60 deletion induced a robust reduction in the acH2A.Z/H2A.Z ratio. These results uncover a critical epigenetic regulatory layer for HSC maintenance, at least in part through Tip60-dependent H2A.Z acetylation to activate Myc target genes.
MicroRNA-708 targeting ZNF549 regulates colon adenocarcinoma development through PI3K/AKt pathway
SCIENTIFIC REPORTS
Authors: Zhao, Zhidong; Qin, Xianju
Abstract
Colon adenocarcinoma (COAD) is the most common type of gastrointestinal cancer and is still the third leading cause of cancer-related mortality worldwide. Therefore, finding new and promising drugs to eradicate cancer may be a feasible method to treat COAD patients. Cys2-His2 zinc finger proteins (ZFPs) is one of the largest transcription factor family and many of them are highly involved in regulation of cell differentiation, proliferation, apoptosis, and neoplastic transformation. In this study, we identified a tumor-inhibiting factor, ZNF549, which expressed lowly in COAD tissues and COAD cell lines (HT29, HCT116, SW480, LoVo, and SW620). Overexpression of ZNF549 inhibit the ability of COAD cell proliferation and migration. On the contrary, decreasing the ZNF549 expression level promote the ability of COAD cell proliferation and migration. Through bioinformatics analysis, we found that ZNF549 was a potential target of hsa-miR-708-5p (miR-708-5p). Furthermore, we verified the possibility of miR-708-5p targeting the ZNF549 gene, and miR-708-5p inhibited the expression of ZNF549 by luciferase reporter assays, qRT-PCR and western blot assays. Moreover, the relationship between miR-708-5p and phosphatidylinositol 3-kinase/AKt (PI3K/AKt) signal pathway was elucidated. Overexpression and inhibition of miR-708-5p resulted in increased and decreased expression of p-AKt and p-PI3K in HCT116 cells, respectively. RT-qPCR and western blot assays results demonstrated that miR-708-5p regulated COAD cells development by promoting the process of Epithelial-mesenchymal transition (EMT) through PI3K/AKt signaling pathway. In summary, our findings demonstrated that ZNF549, the target gene of miR-708-5p, functions as a tumor suppressor to inhibit COAD cell lines proliferation and migration through regulate the PI3K/AKt signal pathway.