Twist2 amplification in rhabdomyosarcoma represses myogenesis and promotes oncogenesis by redirecting MyoD DNA binding

Abstract

Rhabdomyosarcoma (RMS) is an aggressive pediatric cancer composed of myoblast-like cells. Recently, we discovered a unique muscle progenitor marked by the expression of the Twist2 transcription factor. Genomic analyses of 258 RMS patient tumors uncovered prevalent copy number amplification events and increased expression of TWIST2 in fusion-negative RMS. Knockdown of TWIST2 in RMS cells results in up-regulation of MYOGENIN and a decrease in proliferation, implicating TWIST2 as an oncogene in RMS. Through an inducible Twist2 expression system, we identified Twist2 as a reversible inhibitor of myogenic differentiation with the remarkable ability to promote myotube dedifferentiation in vitro. Integrated analysis of genome-wide ChIP-seq and RNA-seq data revealed the first dynamic chromatin and transcriptional landscape of Twist2 binding during myogenic differentiation. During differentiation, Twist2 competes with MyoD at shared DNA motifs to direct global gene transcription and repression of the myogenic program. Additionally, Twist2 shapes the epigenetic landscape to drive chromatin opening at oncogenic loci and chromatin closing at myogenic loci. These epigenetic changes redirect MyoD binding from myogenic genes toward oncogenic, metabolic, and growth genes. Our study reveals the dynamic interplay between two opposing transcriptional regulators that control the fate of RMS and provides insight into the molecular etiology of this aggressive form of cancer. Article published online ahead of print. Article and publication date are online at http://www.genesdev.org/cgi/doi/10.1101/gad.324467.119. © 2019 Li et al. This article is distributed exclusively by Cold Spring Harbor Laboratory Press for the first six months after the full-issue publication date (see http://genesdev.cshlp.org/site/misc/terms.xhtml). After six months, it is available under a Creative Commons License (Attribution-NonCommercial 4.0 International), as described at http://creativecommons.org/licenses/by-nc/4.0/.

Twist regulates Yorkie to guide lineage reprogramming of syncytial alary muscles

“…Altogether, our results show that a Twist/Yki/FGFR axis plays a central role in the regulatory network that mediates syncytial muscle cell fate plasticity and initiates a lineage switch during cellular reprogramming. Of note, vertebrate orthologs of Twist, Yki and FGFR are well known to be involved in the reprogramming processes that transform myogenic cells into rhabdomyosarcoma (Goldstein et al, 2007;Li et al, 2019;Tremblay et al, 2014). Our results connect the function of this set of regulators within a naturally occurring muscle lineage reprogramming event.…”

“…Twist function and cellular plasticity have been connected in the literature mainly due to its role as one of the transcriptional master regulators during the transition from epithelial to mesenchymal states (EMT), crucially required for embryonic morphogenesis and often linked to metastasis in various cancer models (Lu and Kang, 2019). In terms of myogenic cell fate plasticity it is known that prolonged Twist expression negatively regulates muscle cell differentiation during embryonic myogenesis as well as adult flight muscle development in Drosophila (Anant et al, 1998;Cripps and Olson, 1998;Domsch et al, 2020), whereas forced expression of vertebrate Twist proteins can even reverse myogenic differentiation in vitro by unwiring the myogenic regulatory network from its targets (Hjiantoniou et al, 2008;Li et al, 2019;Liu et al, 2017;Mastroyiannopoulos et al, 2013) and appear to play a role during the regeneration of craniofacial muscles (Zhao et al, 2020). Here we provide evidence that (Pan, 2010;Wang et al, 2016).…”

Interaction between SNAI2 and MYOD enhances oncogenesis and suppresses differentiation in Fusion Negative Rhabdomyosarcoma

“…MYOD function can also be disrupted by competition for functional E2A co-factor with non-functional E2A splice variants and other expressed factors including TWIST1, TWIST2, and HEY1 9 , 10 , 23 , 41 . However, in the case of TWIST1 and HEY1 this disruption occurs by competition for co-factor E2A and not at the chromatin level 11 , 22 .…”

Dissecting myogenin-mediated retinoid X receptor signaling in myogenic differentiation

“…At the structural level, MRFs are a family of basic helix-loop-helix (bHLH) transcription factors that bind to a conserved core hexanucleotide motif (CANNTG) known as E-box 5 . MRF binding is modulated by E-box accessibility, central dinucleotide pair and flanking sequences, which may vary between biological systems and conditions [6][7][8] . As such, the myogenic program is genetically governed by E-box components, whereas E-box accessibility is controlled epigenetically 6,9 .…”