Laboratory of Oncology, Istituto Giannina Gaslini, Largo G. Gaslini 5, 16147 Genova-Quarto, Italy.
Cell Res. 2011 Oct;21(10):1470-86. doi: 10.1038/cr.2011.38. Epub 2011 Mar 15.
Neuroblastoma (NB)-associated endothelial microvessels (EMs) may be lined by tumor-derived endothelial cells (TECs), that are genetically unstable and chemoresistant. Here we have addressed the identification of TEC progenitors in NB by focusing on Octamer-binding transcription factor 4 (Oct-4) as a putative marker. Oct-4(+) cells were detected in primary NB samples (n = 23), metastatic bone marrow aspirates (n = 10), NB cell lines (n = 4), and orthotopic tumors (n = 10) formed by the HTLA-230 NB cell line in immunodeficient mice. Most Oct-4(+) cells showed a perivascular distribution, with 5% of them homing in perinecrotic areas. All Oct-4(+) cells were tumor-derived since they shared amplification of MYCN oncogene with malignant cells. Perivascular Oct-4(+) cells expressed stem cell-related, neural progenitor-related and NB-related markers, including surface Tenascin C (TNC), that was absent from perinecrotic Oct-4(+) cells and bulk tumor cells. TNC(+) but not TNC(-) HTLA-230 cells differentiated in vitro into endothelial-like cells expressing vascular-endothelial-cadherin, prostate-specific membrane antigen and CD31 upon culture in medium containing vascular endothelial growth factor (VEGF). TNC(+) but not TNC(-) HTLA-230 cells formed neurospheres when cultured in serum-free medium. Both cell fractions were tumorigenic, but only tumors formed by TNC(+) cells contained EMs lined by TECs. In conclusion, we have identified in NB tumors two putative niches containing Oct-4(+) tumor cells. Oct-4(+)/TNC(+) perivascular NB cells displayed a high degree of plasticity and served as progenitors of TECs. Therapeutic targeting of Oct4(+)/TNC(+) progenitors may counteract the contribution of NB-derived ECs to tumor relapse and chemoresistance.
神经母细胞瘤（NB）相关的内皮微血管（EMs）可能由肿瘤衍生的内皮细胞（TECs）排列，这些细胞遗传不稳定且对化疗耐药。在这里，我们通过聚焦于八聚体结合转录因子 4（Oct-4）作为一个潜在的标记物，来确定 NB 中的 TEC 祖细胞。在原发性 NB 样本（n=23）、转移性骨髓抽吸物（n=10）、NB 细胞系（n=4）和由免疫缺陷小鼠中 HTLA-230 NB 细胞系形成的原位肿瘤（n=10）中检测到 Oct-4（+）细胞。大多数 Oct-4（+）细胞呈血管周围分布，其中 5%的细胞归巢于坏死周围区域。所有的 Oct-4（+）细胞均来源于肿瘤，因为它们与恶性细胞一样扩增了 MYCN 癌基因。血管周围的 Oct-4（+）细胞表达干细胞相关、神经祖细胞相关和 NB 相关标志物，包括表面腱糖蛋白 C（TNC），而坏死周围的 Oct-4（+）细胞和大块肿瘤细胞中均不存在 TNC。TNC（+）但不是 TNC（-）的 HTLA-230 细胞在含有血管内皮生长因子（VEGF）的培养基中体外分化为表达血管内皮钙黏蛋白、前列腺特异性膜抗原和 CD31 的内皮样细胞。TNC（+）但不是 TNC（-）的 HTLA-230 细胞在无血清培养基中培养时形成神经球。这两个细胞群均具有致瘤性，但只有 TNC（+）细胞形成的肿瘤含有由 TECs 排列的 EMs。总之，我们在 NB 肿瘤中鉴定出两个含有 Oct-4（+）肿瘤细胞的潜在龛位。Oct-4（+）/TNC（+）血管周围 NB 细胞表现出高度的可塑性，是 TEC 的祖细胞。针对 Oct4（+）/TNC（+）祖细胞的治疗靶向可能会抑制 NB 衍生的 ECs 对肿瘤复发和化疗耐药的贡献。
