Abstract B13: A growth of human choriocarcinoma cells was selectively inhibited by therapeutic neural stem cells expressing cytosine deaminase and interferon-β in cellular and xenograft models

Abstract

Abstract In this study, human neural stem cells (hNSCs) expressing Escherichia coli cytosine deaminase (CD) and human interferon-β (IFN-β) was used to cancer treatment strategy for human choriocarcinoma cancer. Prodrug 5-fluorocytosine (5-FC) is converted to 5-fluorouacil (5-FU) by CD, which induces an effect of killing the tumor cells through DNA synthesis inhibition. Also, IFN-β suppresses tumor growth through the apoptotic process. To manufacture animal models xenografted with choriocarcinoma, CMFDA pre-labeled JEG-3 cells (2×106) were injected intravenously (i.v.) into the tail vein of athymic nude mice (group A) and injected subcutaneously (s.c.) into the back of the mice (group B). Subcutaneously injected cancer cells were mixed with Matrigel (BD Biosciences, Bedford, MA, USA) at 1:1 volume ratio of Matrigel to PBS in 100 μl. On group A, CM-dil pre-labeled hNSCs (2×106) were injected intravenously after a week. On group B, when the tumor volume reached at 100mm3, CM-Dil pre-labeled hNSCs (2×106) were injected subcutaneously adjacent to the tumor mass. Every mice received i.p. injections of 5-FC (500 mg/kg/day) every day for 21 days. In a modified trans-well migration assay, NSCs selectively migrated to JEG-3 choriocarcinoma cells. It was revealed that the tumor-tropic properties of engineered NSCs were attributed to chemoattractant factors (CXCR4, SCF, SDF-1a, VEGF) secreted by JEG-3 cells. When JEG-3 cells co-cultured with engineered NSCs in the presence of 5-FC, the viability of JEG-3 cells was markedly decreased. The present results suggested that NSCs expressing CD gene and IFN-β gene have a potential therapeutic effect against choriocarcinoma. Consequently, hNSC therapy may be a clinically effective tool for the treatment of human choriocarcinoma cancer. In addition, we are currently studying on an in vivo model to demonstrate that selective anti-tumor effect of NSCs. Note: This abstract was not presented at the conference. Citation Format: Gyu-Sik Kim, Kyung-Chul Choi. A growth of human choriocarcinoma cells was selectively inhibited by therapeutic neural stem cells expressing cytosine deaminase and interferon-β in cellular and xenograft models [abstract]. In: Proceedings of the AACR International Conference: New Frontiers in Cancer Research; 2017 Jan 18-22; Cape Town, South Africa. Philadelphia (PA): AACR; Cancer Res 2017;77(22 Suppl):Abstract nr B13.