126 POTENTIAL EFFECTS OF ENGINEERED STEM CELLS TRANSDUCED WITH THERAPEUTIC GENES AGAINST HeLa HUMAN CERVICAL CANCER CELLS VIA A SELECTIVE TUMOR TROPISM CAUSED BY VASCULAR ENDOTHELIAL GROWTH FACTOR

Abstract

According to the World Health Organization, cancer of cervix uteri is the second most common cancer among women worldwide. Recently, cervical cancer still remains a significant public health problem for women despite the development of the human papilloma virus vaccine. The aim of the present study was to investigate the therapeutic efficacy of genetically engineered stem cells (GESTEC) expressing bacterial cytosine deaminase (CD), human interferon-β (IFN-b) gene, or both against HeLa human cervical cancer and the migration factors of the GESTEC toward the cancer cells. A continuously dividing immortalized cell line of neural stem cells (NSC) from a single clone of human fetal brain, HB1.F3, was developed by introducing v-myc. The further introduction of these NSC with bacterial CD and human IFN-b resulted in the generation of HB1.F3.CD and HB1.F3.CD.IFN-b cells. The anticancer effect of these GESTEC was examined in a co-culture with HeLa cells using MTT assay to measure cell viability. A transwell migration assay was performed to assess the migration capability of the stem cells to cervical cancer cells. Next, several chemoattractant ligands and their receptors related to a selective migration of the stem cells towards HeLa cells were determined by real-time PCR. The cell viability of HeLa cells was decreased in response to 5-fluorocytosine (5-FC), a prodrug, indicating that 5-fluorouracil (5-FU), a toxic metabolite, was converted from 5-FC by the CD gene and it caused the cell death in a co-culture system. When IFN-b was additionally expressed with the CD gene by these GESTEC, the anticancer activity was significantly increased. In the migration assay, the GESTEC selectively migrated to HeLa cells. As results of real-time PCR, chemoattractant ligands such as MCP-1, SCF, and VEGF were expressed in HeLa cells, and several receptors such as uPAR, VEGFR2, and c-kit were produced by the GESTEC. These GESTEC transduced with the CD gene and IFN-b may provide the potential of a novel gene therapy for anti-cervical cancer treatments via their selective tumour tropism derived from VEGF and VEGFR2 expressions between HeLa cells and the GESTEC. This work was supported by a grant from the Next-Generation BioGreen 21 Program (No. PJ009599), Rural Development Administration, Republic of Korea.