Development of iPS cells-derived vector cells for antiangiogenic gene therapy for hepatocellular carcinoma.

在本研究中，我们研究了iPS细胞来源的载体细胞转导可溶性血管内皮生长因子受体-1和2cDNA的抗血管生成基因治疗的抗肿瘤作用。首先，我们试图从小鼠iPS细胞中培养出载体细胞。然而，小鼠iPS细胞来源的平滑细胞表现出比我们预期的更少的增殖活性和对肿瘤组织的归巢。因此，我们改用人iPS细胞构建间充质干细胞。在构建间充质干细胞后，我们将CXCR4基因转移到间充质干细胞，以上调其对肿瘤组织的归巢能力。由于在肿瘤组织缺氧条件下，载体细胞可能通过激活HIF信号产生多种生长因子，因此我们降低了HIF1-？？的表达。用siRNA技术。然后，用腺病毒载体将可溶性VEGFR-1和2cDNA转移到荷瘤小鼠体内，经TIL静脉注射给荷瘤小鼠，每周1×106，共4周。初始治疗4周后，与未治疗的对照组相比，肿瘤生长受到抑制。注射的载体细胞主要位于肿瘤组织的间质中。部分载体细胞在肿瘤组织中分化为内皮细胞和平滑肌细胞。肿瘤组织内微血管密度较对照组降低。很少检测到载体细胞归巢到非癌组织。未发现骨髓抑制、肝功能异常等严重不良反应。

In the present study, we investigated the anti-tumor effects of anti-angiogenic gene therapy with iPS cell-derived vector cells transfected soluble VEGF receptor-1 and 2 cDNAs. At first, we tried to develop the vector cells from mouse iPS cells. However, mouse iPS cell-derived smooth cells showed less proliferative activity and less homing to tumor tissues than we had expected. So, we changed to construct mesenchymal stem cells from human iPS cells. After constructing mesenchymal stem cells, we transferred CXCR4 cDNA to mesenchymal stem cells to up-regulate the ability of homing to tumor tissues. As vector cells might produce several kinds of growth factors through the activation of HIF signaling under hypoxic condition in tumor tissues, we reduced the expression of HIF1-?? with siRNA technique. Then, we transferred soluble VEGFreceptor-1 and 2 cDNAs with adenovirus vector and injected the vector cells (1x106/week for4 weeks) to tumor-bearing mice of hepatoma cells through the til vein. After 4 weeks of initial treatment, tumor growth was suppressed comparing with non-treated control mice. Injected vector cells mainly located in the stroma of tumor tissues. Some of vector cellsdifferentiated to endothelial cells and smooth muscle cells in tumor tissues. The microvascular density in tumor tissues was decreased comparing with control group. The homing of vector cells to non-cancerous tissues was rarely detected. Severe adverse events such as bone marrow suppression or abnormality of liver function test were not observed.