The VHL tumor suppressor protein regulates tumorigenicity of U87-derived glioma stem-like cells by inhibiting the JAK/STAT signaling pathway
The VHL tumor suppressor protein regulates tumorigenicity of U87-derived glioma stem-like cells by inhibiting the JAK/STAT signaling pathway
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DOI：
10.3892/ijo.2013.1773
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发表时间：
2013-03-01
影响因子：
5.2
通讯作者：
Yamada, Sachiko
中科院分区：
文献类型：
--
作者：
Kanno, Hiroshi;Sato, Hidemitsu;Yamada, Sachiko
信号转导和转录激活因子3（STAT 3）在肿瘤干细胞的致瘤性中起重要作用。本研究的目的是探讨该途径通过肿瘤抑制因子von Hippel-Lindau（VHL）蛋白在胶质瘤干细胞中的抑制机制。我们通过MACS方法分离了漂浮的神经球形成CD 133（+）细胞作为胶质瘤干细胞样细胞（GSLCs）。此外，我们还检测了这些细胞的生长速率、在软琼脂中形成集落和神经球的能力、植入SCID小鼠的能力以及CD 133、STAT 3、JAK 2、延伸蛋白A、PTEN和VHL的表达。此外，我们使用腺病毒载体将STAT 3抑制剂VHL基因转移到GSLCs中，并将这些转染子与对照载体转染的GSLCs进行比较。GSLCs被证明是可植入的，并在SCID小鼠的皮下组织中形成肿瘤，其组织学类似于人类胶质母细胞瘤。此外，GSLCs显示出高的软琼脂集落和神经球形成能力，几乎所有的GSLCs均为CD 133阳性。大多数GSLC对STAT 3、JAK 2和Elongin A呈免疫阳性，但对PTEN和VHL呈免疫阴性。当VHL基因被转移到GSLCs并将这些细胞移植到SCID小鼠中时，它们不会导致肿瘤形成。它们的软琼脂集落和神经球形成的能力被显着抑制，虽然它们的增殖只有中度抑制。关于各种因子的表达，在VHL转染子中CD 133的表达降低，而STAT 3、JAK 2和Elongin A的表达被消除。然而，PTEN和VHL的表达上调。这些结果表明，VHL通过抑制JAK/STAT信号通路调节胶质瘤肿瘤干细胞的致瘤性和自我更新能力。
The signal transducer and activator of transcription 3 (STAT3) factor plays an important role in the tumorigenicity of cancer stem cells. The purpose of this study was to investigate the inhibitory mechanism of this pathway acting through the tumor suppressor von Hippel-Lindau (VHL) protein in glioma cancer stem cells. We isolated floating neurosphere-forming CD133(+) cells as glioma stem-like cells (GSLCs) by the MACS method. Furthermore, we examined these cells for their growth rate, ability to form colonies and neurospheres in soft agar, capacity for implantation into SCID mice and expression of CD133, STAT3, JAK2, Elongin A, PTEN and VHL. Furthermore, we transferred the VHL gene, an inhibitor of STAT3, into GSLCs using an adenovirus vector and compared these transfectants with control vector-transfected GSLCs. GSLCs proved to be implantable and formed a tumor in the subcutaneous tissue of SCID mice, the histology of which was similar to that of human glioblastomas. In addition, GSLCs exhibited a high capacity for soft agar colony and neurosphere formation, nearly all of which were CD133 positive. The majority of GSLCs were immunopositive for STAT3, JAK2 and Elongin A, but immunonegative for PTEN and VHL. When the VHL gene was transferred to GSLCs and these cells were transplanted into SCID mice, they did not result in tumor formation. Their capacity for soft agar colony and neurosphere formation was significantly inhibited, although their proliferation was only moderately inhibited. Regarding the expression of various factors, that of CD133 was decreased in the VHL transfectants and those of STAT3, JAK2 and Elongin A were eliminated. However, the expression of PTEN and of VHL was upregulated. These findings suggest that VHL regulated the tumorigenicity and self-renewal ability of glioma cancer stem cells by inhibiting the JAK/STAT signaling pathway.