Kras activation in p53-deficient myoblasts results in high-grade sarcoma formation with impaired myogenic differentiation.
Kras activation in p53-deficient myoblasts results in high-grade sarcoma formation with impaired myogenic differentiation.
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DOI：
10.18632/oncotarget.3856
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发表时间：
2015-06-10
期刊：
影响因子：
--
通讯作者：
Gladdy RA
中科院分区：
文献类型：
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作者：
McKinnon T;Venier R;Dickson BC;Kabaroff L;Alkema M;Chen L;Shern JF;Yohe ME;Khan J;Gladdy RA
虽然基因组研究提高了我们对肉瘤的分类能力，但许多肉瘤亚型形成和发展的分子机制仍不清楚。为了更好地了解横纹肌肉瘤comagenesis涉及的发育起源和遗传驱动因素，我们描述了一种新的肉瘤模型系统，采用原代鼠p53缺陷型成肌细胞，分离并用KrasG 12 D慢病毒转导。成肌细胞系进行了表征，并进行增殖，锚定非依赖性生长和分化测定，以评估转基因KrasG 12 D表达的影响。KrasG 12 D过表达转化了p53−/−成肌细胞，表现为锚定非依赖性生长增加。在亲本成肌细胞中诱导分化导致关键肌原性调节因子的激活。相反，Kras转导的成肌细胞的终末分化受损。通过KrasG 12 D过表达转化的p53−/−成肌细胞在原位注射到同基因宿主后肢后导致快速、可重复的肿瘤形成。病理分析显示，高级别肉瘤与肌分化的基础上表达的肌肉特异性标志物，如Myod 1和Myog。通过基因集富集分析（GSEA）确定的小鼠肉瘤的基因表达模式与RMS基因集共享生物学途径，并且通过元基因分析确定的小鼠肉瘤的基因表达模式与人类RMS的基因表达模式相似性为61%。因此，我们的新模型系统是一种有效的手段，沿沿着RMS频谱建模高级别肉瘤。
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.