The aim of the present study was to investigate the therapeutic efficacy of genetically engineered stem cells (GESTECs) expressing bacterial cytosine deaminase (CD) and/or human interferon-beta (IFN-) gene against HeLa cervical cancer and the migration factors of the GESTECs toward the cancer cells. cancer 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 GESTECs. These GESTECs transduced with CD gene and IFN- may provide a potential of a novel gene therapy for anti-cervical cancer treatments their selective tumor tropism derived from VEGF and VEGFR2 expressions between HeLa cells and the GESTECs. and (Kim et al., 2012a; 2012b; Niess et al., 2011). For example, human neural stem cells (hNSCs) are one of the candidate stem cells showing a therapeutic PD0325901 kinase inhibitor potential introduction of suicide genes and tumor tropism for the treatment of malignant tumors in the human brain including medulloblastomas and gliomas (Aboody et al., 2000; 2006; Kim et al., 2006). In this study, authors PD0325901 kinase inhibitor used several kinds of stem cells; HB1.F3, HB1.F3.CD, and HB1.F3. CD.IFN- cells. CD gene expressed by these stem cells as a suicide gene can convert a non-toxic prodrug, 5-fluorocytosine (5-FC), to the toxic agent, 5-fluorouracil (5-FU). IFN- is usually a powerful cytokine with anti-viral and anti-cancer effects. In cervical cancer therapy, IFNs have been used to treat mucosal lesions caused by human papilloma computer virus (HPV) infection, such PD0325901 kinase inhibitor as intraepithelial precursor lesions to cancer of the uterine cervix, genital warts or recurrent respiratory papillomatosis, by potentially reducing or eliminating the replication of HPV plasmid genomes (Lace et al., 2009). The use of nontoxic pro-drugs PD0325901 kinase inhibitor seems to minimize side effects compared to using active anti-cancer drugs, but there is a difficulty in delivering the gene that converts a non-toxic pro-drug to its active metabolite to the exact tumor site for a selective activity. In this respect, these GESTECs are suitable for delivering the converting enzymes because of tumor tropism of hNSC. Stem cells carrying CD and/or IFN- migrate to tumor sites and convert pro-drugs to toxic drugs. The tumor tropism of stem cells is known to be caused by a response to several chemoattractants secreted by cancer cells the action of related receptors produced by them (Kang et al., 2012a; 2012b; 2012c; Kim et al., 2012a; 2012b). It can be hypothesized that GESTECs may have an anti-cancer effect against HeLa cervical cancer cells by expressing the therapeutic genes such as CD and IFN- gene and induce a selective cancer cell death by migrating the right tumor site owing to the specific interactions of chemoattractant ligands and their receptors between the stem cells and HeLa cancer cells. MATERIALS AND METHODS Cell culture A human cervical cancer cell line, HeLa, was purchased from the American Tissue Type Culture Collection (ATCC, USA) and cultured in DMEM (Hyclone Laboratories Inc., USA) supplemented with 10% (v/v) fetal bovine serum (FBS; Hyclone Laboratories), 1% HEPES (Invitrogen Life Technologies, USA), 1% penicillin/streptomycin (Cellgro Mediatech, USA), and 0.1% anti-mycoplasmal plasmocin (Invivogen, USA) at 37C in a humidified atmosphere of 5% CO2-95% air. In addition, hNSCs such as HB1.F3, HB1.F3.CD, and HB1.F3.CD.IFN- cells were obtained from Chungang University (Korea). HB1.F3 is an immortalized hNSC line derived from human fetal brain at 15 weeks of gestation by an amphotropic and replication-incompetent retroviral vector v-myc. The clonal HB1.F3.CD and HB1. F3.CD.IFN- cell lines were derived from parental HB1.F3 cell line by CD3D transducing CD and human IFN- genes. All hNSCs such as HB1.F3, HB1.F3.CD, and HB1.F3.CD.IFN- cells and human dermal fibroblasts (HDF ; OBM Lab., Korea) were cultured in DMEM supplemented with 10% FBS, 1% penicillin G and streptomycin, 1% HEPES, and 0.1% plasmocin at 37C in a humidified atmosphere of 5% CO2-95% air. Cells were trypsinized with 0.05% trypsin/0.02% EDTA in Mg2+/Ca2+? free HBSS (Hyclone Laboratories). Cell viability assay MTT assay was performed to measure the cytotoxic effect of 5-FC and 5-FU on cervical cancer cells (5,000 cells/well). HeLa cells, a cervical cancer cell line, were seeded in.