Cancer Investigation, 27:140–148, 2009 ISSN: 0735-7907 print / 1532-4192 online Copyright c  Informa Healthcare USA, Inc. DOI: 10.1080/07357900802189832 ORIGINAL ARTICLE Cellular and Molecular Biology Human Cytokine-Induced Killer Cells Specifically Infiltrated and Retarded the Growth of the Inoculated Human Cholangiocarcinoma Cells in SCID Mice Adisak Wongkajornsilp, 1 Theera Somchitprasert, 1 Raywadee Butraporn, 4 Valla Wamanuttajinda, 1 Kanda Kasetsinsombat, 1 Sukit Huabprasert, 1 Kittipong Maneechotesuwan, 1,2 and Suradej Hongeng 1,3 Department of Pharmacology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand, 1 Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand, 2 Department of Pediatrics, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand 3 and Laboratory Animal Center, Department of Medical Sciences, Ministry of Public Health, Nonthaburi 11000, Thailand. 4 ABSTRACT Cytokine-induced killer (CIK) cells were examined for safety and efficacy for cholangiocarci- noma treatment. Several conditions of human CIK cells were examined using ex vivo cytotoxic assay and SCID mice pre-inoculated with cholangiocarcinoma cells. We monitored the ex vivo cytotoxicity, tumor sizes and immunohistochemistry. Optimal tumor suppression was observed when CIK cells were pre-exposed to dendritic cells (DCs). Unexpectedly, pulsing of tumor RNA to DCs rendered the co-culturing CIK cells ineffective and raised the proportion of CD4 + CD25 + subset. The use of CD3 + CD56 + subset instead of the whole population of CIK cells for the co- culture with RNA-pulsed DCs restored the efficacy. Tumor-infiltrating human CD3 + cells were observed from day 2 – 14. The CD3 + CD56 + cells are logical candidates for clinical trial while the DC-co-cultured CIK cells produced similar efficacy and more feasible for clinical application. The RNA pulsation of DCs up-regulated the regulatory subset of CIK cells and abrogated the anti-tumor efficacy. INTRODUCTION Cholangiocarcinoma (CCA), is a bile duct epithelial cancer endemic in the Northeast of Thailand (1) , with an increasing in- cidence discernible in Europe and North America. Conventional treatments including surgery, chemotherapy, and radiation do not bring satisfactory survival due to anatomic location, presence of metastases, and high recurrent rates (2). These unsatisfactory Keywords: Cytokine-induced killer cells, Cholangiocarcinoma, Animal experiment Correspondence to: Suradej Hongeng, M.D. Department of Pediatrics Faculty of Medicine Ramathibodi Hospital Mahidol University Bangkok 10400 Thailand email: rashe@mahidol.ac.th outcomes underling the importance of the search for innovative treatments such as immunotherapy. Cytokine-induced killer (CIK) exhibit high proliferation rate and cytotoxic activity in vitro (3) . The major effector cells are the CD3 + CD56 + subset (4). The cytolytic activity of CIK cells being independent of MHC restriction (5, 6) implies feasibility in using CIK cells allogeneic to the tumors. The safety of CIK cells was demonstrated by the lack of cytotoxicity toward au- tologous as well as allogeneic normal cells (3). Co-culture of CIK cells with dendritic cells (DCs) has been reported in a few models of cancer (e.g., multiple myeloma (7), hepatocellular carcinoma (8, 9), osteosarcoma (3), glioma (10, 11), pancreatic carcinoma (12, 13), renal and colon carcinoma (14, 15), and murine leukemia and lymphoma(16)) showing enhancement of anti-tumor cytotoxicity of CIK cell in all. The transfection of DCs with tumor RNA also further en- hanced the anti-tumor cytotoxicity in osteosarcoma (3) and glioblastoma multiforme (11). Experiments to block the MHC class-I and -II pathways on tumors-RNA transfected DCs showed that only MHC class-I blocking led to a significant 140 Cancer Invest Downloaded from informahealthcare.com by Mahidol University ,Faculty of Medicine on 04/17/13 For personal use only.