Expression profiling of medulloblastoma: PDGFRA and the RAS/MAPK pathway as therapeutic targets for metastatic disease
Expression profiling of medulloblastoma: PDGFRA and the RAS/MAPK pathway as therapeutic targets for metastatic disease
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DOI：
10.1038/ng731
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发表时间：
2001-10-01
期刊：
影响因子：
30.8
通讯作者：
Stephan, DA
中科院分区：
文献类型：
--
作者：
MacDonald, TJ;Brown, KM;Stephan, DA
髓母细胞瘤播散的遗传调控机制目前知之甚少，但转移性髓母细胞瘤与不良预后高度相关。我们获得了23个原发性髓母细胞瘤的表达谱，临床上被指定为转移性（M+）或非转移性（M0），并确定了85个基因的表达显着不同类之间。使用基于这些基因的类别预测算法和留一法，我们以72%的准确度将样本类别分配给这些肿瘤（M+或M0），并以100%的准确度将样本类别分配给另外四个独立肿瘤。我们还将转移性髓母细胞瘤细胞系Daoy分配到转移性类别。值得注意的是，血小板衍生生长因子受体α（PDGFRA）和下游RAS/促分裂原活化蛋白激酶（MAPK）信号转导途径的成员在M+肿瘤中上调。对一组独立肿瘤的免疫组织化学验证显示，与MO肿瘤相比，M+肿瘤中PDGFRA显著过表达。使用体外试验，我们表明，血小板衍生生长因子α（PDGFA）增强髓母细胞瘤迁移和增加下游的MAPK 2K 1（MEK 1），MAPK 2K 2（MEK 2），MAPK 1（p42 MAPK）和MAPK 3（p44 MAPK）磷酸化的剂量依赖性方式。PDGFRA的中和抗体阻断了MAP 2K 1、MAP 2K 2和MAPK 1/3的磷酸化，而高度特异性的MAP 2K 1和MAP 2K 2抑制剂U 0126也阻断了MAPK 1/3。两者均抑制迁移并防止PDGFA刺激的迁移。这些结果提供了第一次深入了解髓母细胞瘤转移的遗传调控，并首次提出PDGFRA和RAS/MAPK信号通路在髓母细胞瘤转移中的作用。因此，PDGFRA和RAS蛋白的抑制剂应考虑作为可能的新的治疗策略对髓母细胞瘤的调查。
Little is known about the genetic regulation of medulloblastoma dissemination, but metastatic medulloblastoma is highly associated with poor outcome. We obtained expression profiles of 23 primary medulloblastomas clinically designated as either metastatic (M+) or non-metastatic (M0) and identified 85 genes whose expression differed significantly between classes. Using a class prediction algorithm based on these genes and a leave-one-out approach, we assigned sample class to these tumors (M+ or M0) with 72% accuracy and to four additional independent tumors with 100% accuracy. We also assigned the metastatic medulloblastoma cell line Daoy to the metastatic class. Notably, platelet-derived growth factor receptor alpha (PDGFRA) and members of the downstream RAS/mitogen-activated protein kinase (MAPK) signal transduction pathway are upregulated in M+ tumors. Immunohistochemical validation on an independent set of tumors shows significant overexpression of PDGFRA in M+ tumors compared to MO tumors. Using in vitro assays, we show that platelet-derived growth factor alpha (PDGFA) enhances medulloblastoma migration and increases downstream MAP2K1 (MEK1), MAP2K2 (MEK2), MAPK1 (p42 MAPK) and MAPK3 (p44 MAPK) phosphorylation in a dose-dependent manner. Neutralizing antibodies to PDGFRA blocks MAP2K1, MAP2K2 and MAPK1/3 phosphorylation, whereas U0126, a highly specific inhibitor of MAP2K1 and MAP2K2, also blocks MAPK1/3. Both inhibit migration and prevent PDGFA-stimulated migration. These results provide the first insight into the genetic regulation of medulloblastoma metastasis and are the first to suggest a role for PDGFRA and the RAS/MAPK signaling pathway in medulloblastoma metastasis. Inhibitors of PDGFRA and RAS proteins should therefore be considered for investigation as possible novel therapeutic strategies against medulloblastoma.