Down-regulation of ATF1 leads to early neuroectoderm differentiation of human embryonic stem cells by increasing the expression level of SOX2

ATF1 promotes the malignancy of lung adenocarcinoma cells by transcriptionally regulating ZNF143 expression

The clinical oncogenic functions and mechanisms of activating transcription factor 1 (ATF1) in the progression of lung adenocarcinoma have not been completely elucidated. In this study, by employing human lung adenocarcinoma tissues and cells, we detect the correlation of ATF1 expression with the clinicopathological features and prognosis of patients with lung adenocarcinoma and find that ATF1 promotes lung adenocarcinoma cell proliferation and migration by transcriptionally enhancing zinc finger protein 143 (ZNF143) expression. ATF1 and ZNF143 are strongly expressed in lung adenocarcinoma tissues compared with those in the adjacent normal tissues, and high ATF1 and ZNF143 expressions are related to poor disease-free survival of lung adenocarcinoma patients. ATF1 overexpression results in increased proliferation and migration of lung adenocarcinoma cells, whereas knockdown of ATF1 inhibits cell proliferation and migration. Furthermore, ATF1 transcriptionally regulates the expression of ZNF143, and ATF1 and ZNF143 expressions are positively correlated in lung adenocarcinoma tissues. ZNF143 knockdown blocks lung adenocarcinoma cell migration, which is mediated by ATF1 upregulation. Hence, this study provides a potential therapeutic candidate for the treatment of lung adenocarcinoma.

EWSR1-ATF1 dependent 3D connectivity regulates oncogenic and differentiation programs in Clear Cell Sarcoma

Oncogenic fusion proteins generated by chromosomal translocations play major roles in cancer. Among them, fusions between EWSR1 and transcription factors generate oncogenes with powerful chromatin regulatory activities, capable of establishing complex gene expression programs in permissive precursor cells. Here we define the epigenetic and 3D connectivity landscape of Clear Cell Sarcoma, an aggressive cancer driven by the EWSR1-ATF1 fusion gene. We find that EWSR1-ATF1 displays a distinct DNA binding pattern that requires the EWSR1 domain and promotes ATF1 retargeting to new distal sites, leading to chromatin activation and the establishment of a 3D network that controls oncogenic and differentiation signatures observed in primary CCS tumors. Conversely, EWSR1-ATF1 depletion results in a marked reconfiguration of 3D connectivity, including the emergence of regulatory circuits that promote neural crest-related developmental programs. Taken together, our study elucidates the epigenetic mechanisms utilized by EWSR1-ATF1 to establish regulatory networks in CCS, and points to precursor cells in the neural crest lineage as candidate cells of origin for these tumors.

The relationship between cellular histogenesis and molecular phenotypes for the EWSR1- ATF1 fusion in clear cell sarcoma (CCS) requires further characterization. Here, the authors investigate the EWSR1-ATF1 gene regulation networks in CCS cell lines, primary tumors, and mesenchymal stem cells.

Editing SOX Genes by CRISPR-Cas: Current Insights and Future Perspectives

Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and its associated proteins (Cas) is an adaptive immune system in archaea and most bacteria. By repurposing these systems for use in eukaryote cells, a substantial revolution has arisen in the genome engineering field. In recent years, CRISPR-Cas technology was rapidly developed and different types of DNA or RNA sequence editors, gene activator or repressor, and epigenome modulators established. The versatility and feasibility of CRISPR-Cas technology has introduced this system as the most suitable tool for discovering and studying the mechanism of specific genes and also for generating appropriate cell and animal models. SOX genes play crucial roles in development processes and stemness. To elucidate the exact roles of SOX factors and their partners in tissue hemostasis and cell regeneration, generating appropriate in vitro and in vivo models is crucial. In line with these premises, CRISPR-Cas technology is a promising tool for studying different family members of SOX transcription factors. In this review, we aim to highlight the importance of CRISPR-Cas and summarize the applications of this novel, promising technology in studying and decoding the function of different members of the SOX gene family.

Molecular signatures of selection on the human GLI3 associated central nervous system specific enhancers

The zinc finger-containing transcription factor Gli3 is a key mediator of Hedgehog (Hh) signaling pathway. In vertebrates, Gli3 has widespread expression pattern during early embryonic development. Along the anteroposterior axes of the central nervous system (CNS), dorsoventral neural pattern elaboration is achieved through Hh mediated spatio-temporal deployment of Gli3 transcripts. Previously, we and others uncovered a set of enhancers that mediate many of the known aspects of Gli3 expression during neurogenesis. However, the potential role of Gli3 associated enhancers in trait evolution has not yet received any significant attention. Here, we investigate the evolutionary patterns of Gli3 associated CNS-specific enhancers that have been reported so far. A subset of these enhancers has undergone an accelerated rate of molecular evolution in the human lineage in comparison to other primates/mammals. These fast-evolving enhancers have acquired human-specific changes in transcription factor binding sites (TFBSs). These human-unique changes within subset of Gli3 associated CNS-specific enhancers were further validated as single nucleotide polymorphisms through 1000 Genome Project Phase 3 data. This work not only infers the molecular evolutionary patterns of Gli3 associated enhancers but also provides clues for putative genetic basis of the population-specificity of gene expression regulation.