title: Kras activation in p53-deficient myoblasts results in high-grade sarcoma formation with impaired myogenic differentiation.
abstract: While genomic studies have improved our ability to classify sarcomas, the molecular mechanisms involved in the formation and progression of many sarcoma subtypes are unknown. To better understand developmental origins and genetic drivers involved in rhabdomyosarcomagenesis, we describe a novel sarcoma model system employing primary murine p53-deficient myoblasts that were isolated and lentivirally transduced with KrasG12D. Myoblast cell lines were characterized and subjected to proliferation, anchorage-independent growth and differentiation assays to assess the effects of transgenic KrasG12D expression. KrasG12D overexpression transformed p53-/- myoblasts as demonstrated by an increased anchorage-independent growth. Induction of differentiation in parental myoblasts resulted in activation of key myogenic regulators. In contrast, Kras-transduced myoblasts had impaired terminal differentiation. p53-/- myoblasts transformed by KrasG12D overexpression resulted in rapid, reproducible tumor formation following orthotopic injection into syngeneic host hindlimbs. Pathological analysis revealed high-grade sarcomas with myogenic differentiation based on the expression of muscle-specific markers, such as Myod1 and Myog. Gene expression patterns of murine sarcomas shared biological pathways with RMS gene sets as determined by gene set enrichment analysis (GSEA) and were 61% similar to human RMS as determined by metagene analysis. Thus, our novel model system is an effective means to model high-grade sarcomas along the RMS spectrum.
authors.affiliation: Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada.
authors.forename: Timothy
authors.initials: T
authors.lastname: McKinnon
authors.affiliation: Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada.
authors.forename: Rosemarie
authors.initials: R
authors.lastname: Venier
authors.affiliation: Department of Pathology & Laboratory Medicine, Mount Sinai Hospital, Toronto, Canada.
authors.forename: Brendan C
authors.initials: BC
authors.lastname: Dickson
authors.affiliation: Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada.
authors.forename: Leah
authors.initials: L
authors.lastname: Kabaroff
authors.affiliation: Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada.
authors.forename: Manon
authors.initials: M
authors.lastname: Alkema
authors.affiliation: Genetics Branch, Oncogenomics Section, Center for Cancer Research, National Institute of Health, Gaithersburg, MD, USA.
authors.forename: Li
authors.initials: L
authors.lastname: Chen
authors.affiliation: Genetics Branch, Oncogenomics Section, Center for Cancer Research, National Institute of Health, Gaithersburg, MD, USA.
authors.forename: Jack F
authors.initials: JF
authors.lastname: Shern
authors.affiliation: Genetics Branch, Oncogenomics Section, Center for Cancer Research, National Institute of Health, Gaithersburg, MD, USA.
authors.forename: Marielle E
authors.initials: ME
authors.lastname: Yohe
authors.affiliation: Genetics Branch, Oncogenomics Section, Center for Cancer Research, National Institute of Health, Gaithersburg, MD, USA.
authors.forename: Javed
authors.initials: J
authors.lastname: Khan
authors.affiliation: Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada.|Ontario Institute for Cancer Research, Cancer Stem Cell Program, Toronto, Canada.|Department of Surgery, University of Toronto, Toronto, Canada.
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Gladdy
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D002460:Cell Line; D049109:Cell Proliferation / Q000502:physiology; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D032446:Myoblasts / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology*; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics / Q000378:metabolism*; D012509:Sarcoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology
chemical_list: C117307:KRAS protein, human; C495971:Hras protein, mouse; D016283:Proto-Oncogene Proteins p21(ras)
keywords: Kras; mouse models of cancer; myogenic differentiation; rhabdomyosarcoma; sarcoma