Division of Pediatric General and Thoracic Surgery, The Center For Molecular Fetal Therapy, Children's Hospital Medical Center, Cincinnati, OH, USA.
J Gene Med. 2010 Jul;12(7):613-23. doi: 10.1002/jgm.1479.
Expression profile analyses of midkine (MDK), a multifunctional protein important in development but repressed postnataly, indicate that it is highly expressed in approximately 80% of adult carcinomas and many childhood cancers including malignant peripheral nerve sheath tumors (MPNST). In the present study, we sought to leverage its selective expression to develop a novel oncolytic herpes simplex virus (oHSV) capable of targeting developmentally primitive cancers that express MDK.
We sought to increase the oncolytic efficacy of the virus by fusing the human MDK promoter to the HSV type 1 neurovirulence gene, gamma(1)34.5, whose protein product increases viral replication.
Tissue-specific MDK promoter activity in human tumor cells and transgene biological activity was confirmed in human MPNST tumor cells. In vitro replication and cytotoxicity in human fibroblasts and MPNST cells by plaque and MTT assays showed that oHSV-MDK-34.5 increased replication and cytotoxicity compared to oHSV-MDK-Luc. By contrast, no significant difference in cytotoxicity was detected between these viruses in normal human fibroblasts. oHSV-MDK-34.5 impaired in vivo tumor growth and increased median survival of MPNST tumor-bearing nude mice.
The transcriptional targeting of HSV lytic infection to MDK-expressing tumor cells is feasible. oHSV-MDK-34.5 shows enhanced anti-tumor effects both in vitro and in vivo. Further studies are warranted and may lead to its use in clinical trials.
中期因子（MDK）是一种在发育过程中发挥多种功能的蛋白，但在出生后受到抑制，其表达谱分析表明，它在大约 80%的成年癌和许多儿童癌中高度表达，包括恶性外周神经鞘瘤（MPNST）。在本研究中，我们试图利用其选择性表达来开发一种新型溶瘤单纯疱疹病毒（oHSV），以靶向表达 MDK 的发育性原始癌症。
我们试图通过将人 MDK 启动子与单纯疱疹病毒 1 神经毒基因γ(1)34.5 融合，来提高病毒的溶瘤效力，其蛋白产物可增加病毒复制。
在人肿瘤细胞中证实了组织特异性 MDK 启动子活性和转基生物活性，在人 MPNST 肿瘤细胞中证实了转基生物活性。通过噬斑和 MTT 测定，在人成纤维细胞和 MPNST 细胞中进行的病毒复制和细胞毒性检测表明，与 oHSV-MDK-Luc 相比，oHSV-MDK-34.5 增加了复制和细胞毒性。相比之下，在正常的人成纤维细胞中，这些病毒之间没有检测到细胞毒性的显著差异。oHSV-MDK-34.5 损害了 MPNST 荷瘤裸鼠体内肿瘤的生长并延长了中位生存期。
将 HSV 溶瘤感染的转录靶向到表达 MDK 的肿瘤细胞是可行的。oHSV-MDK-34.5 在体外和体内均显示出增强的抗肿瘤效果。需要进一步研究，可能会导致其在临床试验中的应用。
