Kim Gyu-Sik, Heo Jae-Rim, Kim Seung U, Choi Kyung-Chul
Laboratory of Biochemistry and Immunology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea.
Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
Transl Oncol. 2018 Feb;11(1):74-85. doi: 10.1016/j.tranon.2017.11.003. Epub 2017 Dec 5.
Cancer treatments using stem cells expressing therapeutic genes have been identified for various types of cancers. In this study, we investigated inhibitory effects of HB1.F3.CD and HB1.F3.CD.IFN-β cells expressing Escherichia coli cytosine deaminase (CD) and human interferon-β (IFN-β) genes in intravenously (i.v.) injected mice with a metastasis model. In this treatment, pro-drug 5-fluorocytosine (5-FC) is converted to cytotoxic drug 5-fluorouracil by hNSCs expressing the CD gene, which inhibits DNA synthesis in cancer cells. Moreover, IFN-β induces apoptosis and reduces the growth of cancer cells. Upon MTT assay, proliferation of choriocarcinoma (JEG-3) cells decreased when co-cultured with hNSCs expressing CD and IFN-β genes. To confirm the cancer-tropic effect of these stem cells, chemoattractant factors (VEGF, CXCR4, and C-kit) secreted from JEG-3 cells were identified by polymerase chain reaction. hNSCs migrate toward JEG-3 cells due to ligand-receptor interactions of these factors. Accordingly, the migration capability of hNSCs toward JEG-3 cells was confirmed using an in vitro Trans-well assay, in vivo subcutaneously (s.c.) injected mice groups (xenograft model), and metastasis model. Intravenously injected hNSCs migrated freely to other organs when compared to s.c. injected hNSCs. Thus, we confirmed the inhibition of lung and ovarian metastasis of choriocarcinoma by i.v. injected HB1.F3.CD or HB1.F3.CD.IFN-β cells in the presence of 5-FC. Treatment of these stem cells also increased the survival rates of mice. In conclusion, this study showed that metastatic cancer was diminished by genetically engineered hNSCs and noncytotoxic drug 5-FC. This is the first report of the therapeutic potential of i.v. injected hNSCs in a metastasis model; therefore, the results indicate that this stem cell therapy can be used as an alternative novel tool to treat metastatic choriocarcinoma.
已确定针对各种类型癌症的使用表达治疗性基因的干细胞的癌症治疗方法。在本研究中，我们调查了静脉注射（i.v.）到具有转移模型的小鼠体内的表达大肠杆菌胞嘧啶脱氨酶（CD）和人干扰素-β（IFN-β）基因的HB1.F3.CD和HB1.F3.CD.IFN-β细胞的抑制作用。在这种治疗中，前药5-氟胞嘧啶（5-FC）被表达CD基因的人神经干细胞（hNSCs）转化为细胞毒性药物5-氟尿嘧啶，从而抑制癌细胞中的DNA合成。此外，IFN-β诱导细胞凋亡并减少癌细胞的生长。经MTT测定，与表达CD和IFN-β基因的hNSCs共培养时，绒毛膜癌细胞（JEG-3）的增殖减少。为了确认这些干细胞的癌趋化作用，通过聚合酶链反应鉴定了JEG-3细胞分泌的趋化因子（VEGF、CXCR4和C-kit）。由于这些因子的配体-受体相互作用，hNSCs向JEG-3细胞迁移。因此，使用体外Trans-well测定、体内皮下（s.c.）注射小鼠组（异种移植模型）和转移模型确认了hNSCs向JEG-3细胞的迁移能力。与皮下注射的hNSCs相比，静脉注射的hNSCs可自由迁移至其他器官。因此，我们证实在5-FC存在的情况下，静脉注射HB1.F3.CD或HB1.F3.CD.IFN-β细胞可抑制绒毛膜癌的肺转移和卵巢转移。这些干细胞治疗还提高了小鼠的存活率。总之，本研究表明基因工程改造的hNSCs和非细胞毒性药物5-FC可减少转移性癌症。这是关于静脉注射hNSCs在转移模型中的治疗潜力的首次报道；因此，结果表明这种干细胞疗法可作为治疗转移性绒毛膜癌的一种新型替代工具。
