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Membrane-to-nucleus signaling links insulin-like growth factor-1- and stem cell factor-activated pathways. PLoS One 2013;8(10):e76822

Date

10/12/2013

Pubmed ID

24116170

Pubmed Central ID

PMC3792098

DOI

10.1371/journal.pone.0076822

Scopus ID

2-s2.0-84885041041   10 Citations

Abstract

Stem cell factor (mouse: Kitl, human: KITLG) and insulin-like growth factor-1 (IGF1), acting via KIT and IGF1 receptor (IGF1R), respectively, are critical for the development and integrity of several tissues. Autocrine/paracrine KITLG-KIT and IGF1-IGF1R signaling are also activated in several cancers including gastrointestinal stromal tumors (GIST), the most common sarcoma. In murine gastric muscles, IGF1 promotes Kitl-dependent development of interstitial cells of Cajal (ICC), the non-neoplastic counterpart of GIST, suggesting cooperation between these pathways. Here, we report a novel mechanism linking IGF1-IGF1R and KITLG-KIT signaling in both normal and neoplastic cells. In murine gastric muscles, the microenvironment for ICC and GIST, human hepatic stellate cells (LX-2), a model for cancer niches, and GIST cells, IGF1 stimulated Kitl/KITLG protein and mRNA expression and promoter activity by activating several signaling pathways including AKT-mediated glycogen synthase kinase-3I? inhibition (GSK3i). GSK3i alone also stimulated Kitl/KITLG expression without activating mitogenic pathways. Both IGF1 and GSK3i induced chromatin-level changes favoring transcriptional activation at the Kitl promoter including increased histone H3/H4 acetylation and H3 lysine (K) 4 methylation, reduced H3K9 and H3K27 methylation and reduced occupancy by the H3K27 methyltransferase EZH2. By pharmacological or RNA interference-mediated inhibition of chromatin modifiers we demonstrated that these changes have the predicted impact on KITLG expression. KITLG knock-down and immunoneutralization inhibited the proliferation of GIST cells expressing wild-type KIT, signifying oncogenic autocrine/paracrine KITLG-KIT signaling. We conclude that membrane-to-nucleus signaling involving GSK3i establishes a previously unrecognized link between the IGF1-IGF1R and KITLG-KIT pathways, which is active in both physiologic and oncogenic contexts and can be exploited for therapeutic purposes.

Author List

Hayashi Y, Asuzu DT, Gibbons SJ, Aarsvold KH, Bardsley MR, Lomberk GA, Mathison AJ, Kendrick ML, Shen KR, Taguchi T, Gupta A, Rubin BP, Fletcher JA, Farrugia G, Urrutia RA, Ordog T

Authors

Gwen Lomberk PhD Professor in the Surgery department at Medical College of Wisconsin
Angela Mathison PhD Assistant Professor in the Surgery department at Medical College of Wisconsin
Raul A. Urrutia MD Center Director, Professor in the Surgery department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Aminophenols
Animals
Blotting, Western
Cell Line
Cell Line, Tumor
Cell Membrane
Cell Nucleus
Cells, Cultured
Gastrointestinal Stromal Tumors
Glycogen Synthase Kinase 3
Hepatic Stellate Cells
Histones
Humans
Insulin-Like Growth Factor I
Interstitial Cells of Cajal
Maleimides
Methylation
Mice
Mice, Inbred BALB C
Mice, Knockout
Proto-Oncogene Proteins c-kit
Receptor, IGF Type 1
Reverse Transcriptase Polymerase Chain Reaction
Signal Transduction
Stem Cell Factor
Transcription, Genetic