Alterations in ALK/ROS1/NTRK/MET drive a group of infantile hemispheric gliomas

© The Author(s) 2019. Open Access. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.Infant gliomas have paradoxical clinical behavior compared to those in children and adults: low-grade tumors have a higher mortality rate, while high-grade tumors have a better outcome. However, we have little understanding of their biology and therefore cannot explain this behavior nor what constitutes optimal clinical management. Here we report a comprehensive genetic analysis of an international cohort of clinically annotated infant gliomas, revealing 3 clinical subgroups. Group 1 tumors arise in the cerebral hemispheres and harbor alterations in the receptor tyrosine kinases ALK, ROS1, NTRK and MET. These are typically single-events and confer an intermediate outcome. Groups 2 and 3 gliomas harbor RAS/MAPK pathway mutations and arise in the hemispheres and midline, respectively. Group 2 tumors have excellent long-term survival, while group 3 tumors progress rapidly and do not respond well to chemoradiation. We conclude that infant gliomas comprise 3 subgroups, justifying the need for specialized therapeutic strategies.info:eu-repo/semantics/publishedVersio

The Regulation of Muscle Structure and Metabolism by Mio/dChREBP in Drosophila.

All cells require energy to perform their specialized functions. Muscle is particularly sensitive to the availability of nutrients due to the high-energy requirement for muscle contraction. Therefore the ability of muscle cells to obtain, store and utilize energy is essential for the function of these cells. Mio, the Drosophila homolog of carbohydrate response element binding protein (ChREBP), has recently been identified as a nutrient responsive transcription factor important for triglyceride storage in the fly fat body. However, the function of Mio in muscle is unknown. In this study, we characterized the role of Mio in controlling muscle function and metabolism. Decreasing Mio levels using RNAi specifically in muscle results in increased thorax glycogen storage. Adult Mio-RNAi flies also have a flight defect due to altered myofibril shape and size in the indirect flight muscles as shown by electron microscopy. Myofibril size is also decreased in flies just before emerging from their pupal cases, suggesting a role for Mio in myofibril development. Together, these data indicate a novel role for Mio in controlling muscle structure and metabolism and may provide a molecular link between nutrient availability and muscle function

Mio affects myofibril size.

<p>Scanning Electron Microscopy of Indirect Flight Muscles of adult Mef2-Gal4>Mio^dsRNA and Mef2-Gal4>Mio-IR females compared to Mef2-Gal4>GFP controls. Panels (A), (B) and (C) show cross sections of the myofibrils; bars indicate 0.5μm. f, myofibril; c, mitochondrion; g, glycogen granules. (D) Average myofibril area of Mef2-Gal4>Mio^dsRNA and Mef2-Gal4>Mio-IR flies compared to Mef2-Gal4>GFP control flies (n = 3–5). All values represent average myofibril area ±SEM. *p<0.05 Kruskal-Wallis One-way ANOVA with post hoc all pairwise multiple comparison pooled sample median test.</p

Decreasing Mio levels results in abnormal myofibril organization.

<p>Scanning Electron Microscopy of longitudinal sections of Indirect Flight Muscles of adult Mef2-Gal4>Mio^dsRNA and Mef2-Gal4>Mio-IR females compared to Mef2-Gal4>GFP controls. f, myofibril; g, glycogen granules. Each arrow points to a single longitudinal myofibril. Scale bar = 20μm.</p

Mio affects myofibril size in pharate adults.

<p>Transmission Electron Microscopy of Indirect Flight Muscles of Mef2-Gal4>Mio^dsRNA and Mef2-Gal4>Mio-IR pharate adults compared to Mef2-Gal4>GFP controls. Panels (A), (B) and (C) show cross sections of the myofibrils. Bars indicate 0.5μm. f, myofibril; c, mitochondrion; g, glycogen granules. (D) Average myofibril area of Mef2-Gal4>Mio^dsRNA and Mef2-Gal4>Mio-IR pharate adults compared to Mef2-Gal4>GFP controls (n = 3–5). Values represent average myofibril area ±SEM. *p<0.05 by One-way ANOVA with post hoc Tukey test.</p

Decreasing Mio levels results in abnormal myofibril ultrastructure.

<p>Transmission Electron Microscopy of Indirect Flight Muscles of adult Mef2-Gal4>Mio^dsRNA and Mef2-Gal4>Mio-IR females compared to Mef2-Gal4>GFP controls. Panels (A), (B) and (C) show cross sections of the myofibrils; panels (D), (E) and (F) show longitudinal sections of myofibrils. f, myofibril; c, mitochondrion; g, glycogen granules; m, m-line; z, z-line. Scale bar = 0.5μm.</p

Mio is not necessary for normal expression of structural genes in adult fly muscle.

<p>Expression of Actin 88F (Act88F, n = 8), Myosin Heavy Chain (MHC, n = 11), and Myosin light chain-2 (Mlc-2, n = 8) was measured by performing quantitative PCR on thorax cDNA from 5–7 day old Mef2-Gal4>Mio^dsRNA and Mef2-Gal4>Mio-IR flies and compared to Mef2-Gal4>GFP controls. mRNA levels of Mef2-Gal4>GFP controls were set to 1.0 and mRNA levels of Mef2-Gal4>Mio^dsRNA and Mef2-Gal4>Mio-IR animals were then normalized to their respective control. Values represent mean±SEM. *p<0.05 by One-way ANOVA with post hoc Tukey test.</p

Mio in muscle is necessary for normal flight.

<p>Flight tests were performed on Mef2-Gal4>Mio^dsRNA (n = 144) and Mef2-Gal4>Mio-IR (n = 296) flies and compared to Mef2-Gal4>GFP (n = 179) controls and scored based on flight ability (See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0136504#sec002" target="_blank">methods</a>). Values represent average flight score ±SEM. *p<0.05 Kruskal-Wallis One-way ANOVA with post hoc all pairwise multiple comparison pooled sample median test.</p

Mio expression in muscle is necessary for normal glycogen storage.

<p>(A) Analysis of Mio expression from thoraxes of 5–7 day old Mef2-Gal4>Mio^dsRNA and Mef2-Gal4>Mio-IR flies compared to Mef2-Gal4>GFP controls (n = 8). Mio levels of the Mef2-Gal4>GFP controls were set to 1.0 and Mio levels of Mef2-Gal4>Mio^dsRNA and Mef2-Gal4>Mio-IR animals were then calculated relative to their respective control. Values represent mean <i>Mio</i> expression±SEM. *p<0.05 by One-way ANOVA with post hoc Tukey test. (B) Glycogen/protein and (C) triglyceride/protein of thoraxes dissected from 5–8 day old Mef2-Gal4>Mio^dsRNA and Mef2-Gal4>Mio-IR male and female flies compared to their respective Mef2-Gal4>GFP controls (n = 6). Values represent mean±SEM. *p<0.05 by One-way ANOVA with post hoc Tukey test.</p

The Regulation of Muscle Structure and Metabolism by Mio/dChREBP in <i>Drosophila - Table 1 </i>

<p>The Regulation of Muscle Structure and Metabolism by Mio/dChREBP in <i>Drosophila - Table 1 </i></p