EWS/FLI-1 oncoprotein subtypes impose different requirements for transformation and metastatic activity in a murine model
EWS/FLI-1 oncoprotein subtypes impose different requirements for transformation and metastatic activity in a murine model
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DOI：
10.1007/s00109-007-0202-5
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发表时间：
2007-09-01
影响因子：
4.7
通讯作者：
Lecanda, Fernando
中科院分区：
文献类型：
--
作者：
Gonzalez, Iranzu;Vicent, Silvestre;Lecanda, Fernando
尤文肉瘤/原始神经外胚层肿瘤(EWS/PNET)以特定的染色体易位为特征，最常见的是产生EWS/FLI-1嵌合基因。根据装配的并列外显子的数量，几种融合类型被描述为具有不同的发生率和预后。为了评估每种融合类型对EWS/PNET的特定表型、致瘤和转移特征的影响，我们利用小鼠间充质多能细胞系C3H10T1/2开发了一种顺应性系统。在转导EWS/FLI-1后，细胞在体外获得了显著的形态变化，包括较小的尺寸和“轴突样”的膜延长。嵌合融合蛋白在体外具有致癌特性，包括非锚定生长和增殖率增加。此外，EWS/FLI-1的表达阻止了矿化，伴随着成骨基因的抑制，并诱导了对脂肪细胞分化程序的戏剧性抑制。此外，EWS/FLI-1通过特定神经基因的从头表达促进了异常的神经表型。肌肉注射转导细胞导致肿瘤的发展和明显的溶骨性损害。与在人类肿瘤中观察到的情况类似，2型EWS/FLI-1细胞在免疫缺陷小鼠中形成原发肿瘤，与携带1型和3型融合的细胞相比，发病率更高，潜伏期更短。相比之下，与表达1型的细胞相比，表达2型和3型融合的细胞显示出特异性的转移活性，软组织和四肢溶骨性病变的肉眼转移数量更多。因此，每种癌蛋白的结构强烈影响其致瘤性和转移性。因此，该模型为了解尤文肿瘤发展和转移活动中涉及的遗传决定因素提供了基础，并代表了一个分析参与人类肉瘤形成的其他癌蛋白的细胞系统。
Ewing sarcoma/primitive neuroectodermal tumors (EWS/PNET) are characterized by specific chromosomal translocations most often generating a chimeric EWS/FLI-1 gene. Depending on the number of juxtaposed exons assembled, several fusion types have been described with different incidences and prognoses. To assess the impact of each fusion type on the specific phenotypic, tumorigenic, and metastatic features of EWS/PNET, we developed an amenable system using a murine mesenchymal multipotent C3H10T1/2 cell line. Upon transduction of EWS/FLI-1, cells acquired dramatic morphological changes in vitro, including a smaller size and "neurite-like" membrane elongations. Chimeric fusion proteins conferred oncogenic properties in vitro, including anchorage-independent growth and an increased rate of proliferation. Furthermore, EWS/FLI-1 expression blocked mineralization, with concomitant repression of osteoblastic genes, and induced a dramatic repression of the adipocytic differentiation program. Moreover, EWS/FLI-1 promoted an aberrant neural phenotype by the de novo expression of specific neural genes. The intramuscular injection of transduced cells led to tumor development and the induction of overt osteolytic lesions. Analogously, to what was observed in human tumors, type 2 EWS/FLI-1 cells formed primary tumors in immunodeficient mice with a higher incidence and a lower latency than cells bearing types 1 and 3 fusions. By contrast, cells expressing types 2 and 3 fusions showed specific metastatic activity with a higher number of macroscopic metastases in soft tissues and osteolytic lesions in the limbs as compared to type-1-expressing cells. Therefore, the structure of each oncoprotein strongly influenced its tumorigenicity and metastagenicity. Thus, this model provides a basis for understanding the genetic determinants involved in Ewing tumor development and metastatic activity and represents a cellular system to analyze other oncoproteins involved in human sarcomagenesis.