Augmented Antitumor Effects of Killer Cells Induced by Tumor Necrosis Factor Gene-Transduced Autologous Tumor Cells from Gastrointestinal Cancer Patients

Abstract

The purpose of this study was to determine the feasibility of a vaccine therapy using tumor necrosis factor (TNF) gene-transduced autologous tumor cells for the treatment of human gastrointestinal cancers, which tend to have lower immunogenicity than other cancers such as melanoma and renal cell carcinoma. We succeeded in establishing primary cultured tumor cells from 12/54 carcinomatous effusions (4 liver cancer patients, 5 gastric cancer patients, 1 pancreatic cancer patient, and 2 colon cancer patients) and in transducing the TNF gene to the tumor cells by using the retrovirus vector MFG-TNF. Even after irradiation, TNF production (0.3-3.5 U/ml per 10(6) cells per 72 hr) was confirmed for 10 of 12 transfectants, and the other two transduced cells were found to have approximately one TNF gene copy. In 7 of the 12 patients, the cytotoxic activity of killer cells to nontransduced autologous tumor cells incubated with these TNF gene transfectants was augmented. This activity was blocked with anti-HLA class I antibody or BrefeldinA (BFA), suggesting that the killer cells were cytotoxic T lymphocytes (CTL) and tumor antigens are presented with HLA class I molecules. Indeed, enhanced expression of HLA class I and/or ICAM-1 molecules on the surface of the TNF gene-transduced tumor cells were observed by fluorescence-activated cell sorting (FACS) analysis. Furthermore, natural killer (NK) and/or lymphokine-activated killer (LAK) activities determined by using K562 or Daudi cells as targets were also enhanced in some of these cases when they were incubated with TNF gene-transduced tumor cells. These findings indicate the feasibility of using TNF gene-transduced tumor cells as a vaccine in gastrointestinal cancer patients.

Gene Therapy: Basic Concepts and Applications in Gastrointestinal Diseases

“…TNF-secreting tumorcells elicit in the host an antitu mor immune response, involving cytotoxic T lympho cytes (CTLs), natural killer cells, and lymphokine-acti-vated killer cells, capable of eliminating tumors in mouse models. Data consistent with this concept have also been obtained with TNF gene transduced autologous tumor cells from GI cancer patients [55].…”

Tumor necrosis factor as an antineoplastic agent: pitfalls and promises

“…The cytotoxic activity of killer cells to nontransduced autologous tumor cells incubated with these TNF gene transfectants was augmented. These and other findings indicate the potential for using TNF gene-transduced tumor cells as a vaccine [113]. Others transfected fibroblasts with the TNF gene and showed that these cells started to produce TNF and had antitumor activities [114].…”

Synergistic Suppressive Effect of Double Transfection of Tumor Necrosis Factor‐α and Interleukin 12 Genes on Tumorigenicity of Meth‐A Cells

“…We previously reported that the transfection of TNF gene could enhance the expression of MHC class I and ICAM I on tumor cells. 14,15) Then, we examined the expression of surface antigens on double transfectants by flow cytometry. Transfection with IL-12 gene enhanced MHC class I expression and furthermore, slightly enhanced the expression of MHC class II and B7.1.…”

“…Moreover, we demonstrated that TNF gene transfection of tumor cells freshly isolated from the ascitic fluids of patients with gastrointestinal cancers enhanced the expression of MHC class I and/or intercellular adhesion molecule-I (ICAM I), and we suggested that this would be involved in augmentation of the killer activity of tumor-infiltrating lymphocytes (TIL) induced by coculturing with autologous tumor cells transfected with TNF gene. 15) On the other hand, IL-12 is a cytokine which potently induces Th1-type cell-mediated immunity 16) and enhances the activities of natural killer T (NKT), 17) NK/ LAK 18) and CTL. 19) Through these immunostimulatory actions, IL-12 is reported to exert potent antitumor and antimetastatic effects via systemic administration 20,21) or upon local production induced by cancer vaccines.…”