UPRES EA3535, University of Paris South, Institut Gustave Roussy, 94805 Villejuif, France.
Hum Pathol. 2011 Nov;42(11):1727-39. doi: 10.1016/j.humpath.2011.01.019.
Neuroblastoma is a malignant pediatric tumor with poor survival. The phosphatidylinositol 3'-kinase/AKT pathway is a crucial regulator of cellular processes including apoptosis. Thioredoxin 1, an inhibitor of tumor-suppressor phosphatase and tensin homolog, is overexpressed in many tumors. The objective of this study was to explore phosphatidylinositol 3'-kinase/AKT pathway activation and regulation by thioredoxin 1 to identify potential therapeutic targets. Immunohistochemical analysis was done on tissue microarrays from tumor samples of 101 patients, using antibodies against phosphatidylinositol 3'-kinase, AKT, activated AKT, phosphatase and tensin homolog, phosphorylated phosphatase and tensin homolog, thioredoxin 1, epidermal growth factor receptor, vascular endothelial growth factor and receptors (vascular endothelial growth factor 1 and vascular endothelial growth receptor 2), platelet-derived growth factor receptors, insulin-like growth factor 1 receptor, neurotrophic tyrosine kinase receptor type 2, phosphorylated 70-kd S6 protein kinase, 4E-binding protein 1, and phosphorylated mammalian target of rapamycin. Using 3 neuroblastoma cell lines, we investigated cell viability with AKT-specific inhibitors (LY294002, RAD001) and thioredoxin 1 alone or in combination. We found activated AKT and AKT expressed in 97% and 98%, respectively, of neuroblastomas, despite a high expression of phosphatase and tensin homolog correlated with thioredoxin 1. AKT expression was greater in metastatic than primary tumors. Insulin-like growth factor 1 receptor, tyrosine kinase receptor type 2, vascular endothelial growth receptor 1, and downstream phosphorylated 70-kd S6 protein kinase were correlated with activated AKT. LY294002 and RAD001 significantly reduced AKT activity and cell viability and induced a G(1) cell cycle arrest. Thioredoxin 1 decreased cytotoxicity of AKT inhibitors and doxorubicin, up-regulated AKT activation, and induced cell growth. Thus, vascular endothelial growth receptor 1, tyrosine kinase receptor type 2, insulin-like growth factor 1 receptor, and thioredoxin 1 emerged as preferentially committed to phosphatidylinositol 3'-kinase/AKT pathway activation as observed in neuroblastoma. Thioredoxin 1 is a potential target for therapeutic intervention.
神经母细胞瘤是一种恶性小儿肿瘤，其存活率较差。磷酸肌醇 3'-激酶/AKT 途径是细胞过程（包括细胞凋亡）的关键调节剂。硫氧还蛋白 1 是肿瘤抑制性磷酸酶和张力蛋白同系物的抑制剂，在许多肿瘤中过度表达。本研究的目的是探讨硫氧还蛋白 1 对磷酸肌醇 3'-激酶/AKT 途径的激活和调节作用，以确定潜在的治疗靶点。使用针对磷酸肌醇 3'-激酶、AKT、活化 AKT、磷酸酶和张力蛋白同系物、磷酸化磷酸酶和张力蛋白同系物、硫氧还蛋白 1、表皮生长因子受体、血管内皮生长因子及其受体（血管内皮生长因子 1 和血管内皮生长因子受体 2）、血小板衍生生长因子受体、胰岛素样生长因子 1 受体、神经营养酪氨酸激酶受体 2、磷酸化 70kD S6 蛋白激酶、4E 结合蛋白 1 和磷酸化哺乳动物雷帕霉素靶蛋白的抗体，对 101 例患者的肿瘤样本进行组织微阵列的免疫组织化学分析。我们使用 AKT 特异性抑制剂（LY294002、RAD001）和硫氧还蛋白 1 单独或联合研究了 3 种神经母细胞瘤细胞系的细胞活力。我们发现，尽管磷酸酶和张力蛋白同系物的高表达与硫氧还蛋白 1 相关，但 AKT 的激活和 AKT 的表达分别在 97%和 98%的神经母细胞瘤中表达。与原发肿瘤相比，转移肿瘤中的 AKT 表达更高。胰岛素样生长因子 1 受体、酪氨酸激酶受体 2、血管内皮生长因子受体 1 和下游磷酸化 70kD S6 蛋白激酶与激活的 AKT 相关。LY294002 和 RAD001 显著降低 AKT 活性和细胞活力，并诱导 G1 细胞周期阻滞。硫氧还蛋白 1 降低 AKT 抑制剂和阿霉素的细胞毒性，上调 AKT 激活，并诱导细胞生长。因此，血管内皮生长因子受体 1、酪氨酸激酶受体 2、胰岛素样生长因子 1 受体和硫氧还蛋白 1 作为优先参与神经母细胞瘤中观察到的磷酸肌醇 3'-激酶/AKT 途径激活的因子出现。硫氧还蛋白 1 是治疗干预的潜在靶点。
