Combination of Fas ligand and GM-CSF in immunotherapy of lung cancer
2004
Hochschulschrift
Zugriff:
92
Lung cancer has the highest mortality among the neoplastic diseases in Taiwan. Since conventional therapeutic methods may not completely cure this disease, gene therapy, a novel therapeutic strategy, is developed to induce specific immune responses to eliminate the tumor cells. It has been reported that Fas ligand (FasL) or granulocyte-macrophage colony stimulating factor (GM-CSF) may induce tumor rejection responses and delay tumor growth. This study was designed to investigate whether the combination of FasL and GM-CSF may efficiently suppress cell growth in lung tumor. FasL was cloned using the tetracycline-regulated RevTet-off system and the expression of FasL was mediated with and without doxcycline. The GM-CSF gene expression was mediated using the pZeoSV vector. The Lewis lung carcinoma-1 cell line (LLC-1 cells) isolated from non-small- cell lung carcinoma was then transfected with FasL and/or GM-CSF. The expressions of FasL and GM-CSF were then evaluated in vitro by RT-PCR, Western blotting, and bioassay using the GM-CSF dependent cell line M-NFS-60. To examine the tumorgenicity effects in vivo, B57BL/6 mice were subcutaneously injected with tumor cells. Mice administrated with GM-CSF transduced LLC-1 (LLC-1/GM-CSF) showed a delay tumor onset. Moreover, complete suppression of tumor growth was observed in those administrated with FasL transduced LLC-1 cells (LLC-1/FasL/ pZeoSV) and LLC-1 cells with co-expression of FasL and GM-CSF (LLC-1/FasL/mGM-CSF). Spleen cells from mice injected with LLC-1/FasL/mGM-CSF showed significantly higher cytotixic activity against LLC-1 (higher CTL activity) than those with LLC-1/FasL/ pZeoSV or LLC-1/mGM-CSF. To determine the role of FasL in tumorgenicity, B57BL/6 mice were subcutaneously injected with LLC-1/FasL/pZeoSV and LLC-1/FasL/ mGM-CSF before oral administration of doxcycline for three days. Although the mice injected with parental LLC-1 cells, and LLC-1/FasL/ mGM-CSF showed mild suppression of tumor growth, no tumor growth suppression was observed in the LLC-1/FasL/pZeoSV group with doxcycline treatment. Tumor cells transfected with FasL and/or GM-CSF were tested in the mice as tumor vaccines. After injection of LLC-1 cells, memory immune response and delayed tumor growth were generated in the group treated with LLC-1/FasL/pZeoSV or LLC-1/FasL/mGM-CSF. After administrating a mixture of LLC-1 cells and different preparations of tumor vaccines to the mice, tumor formation was partially suppressed in mice treated with LLC-1+LLC-1/FasL/pZeoSV and LLC-1+LLC-1/ mGM-CSF. Moreover, tumor formation was completely suppressed in the LLC-1+LLC-1/FasL/ mGM-CSF treated group. Among the mice injected with LLC-1 cells and administrated with the vaccines 3 or 7 days later, delayed tumor growth was observed in those treated with LLC-1/FasL/ mGM-CSF whereas tumor growth was not significantly influenced by the treatment of LLC-1/FasL/pZeoSV. Based on the in vivo experiments, the tumor vaccines LLC-1/FasL/ mGM-CSF and LLC-1/FasL/pZeoSV may induce immunity against LLC-1 while LLC-1/mGM-CSF has only a minor effect. These results indicate that co-transducing FasL and GM-CSF into a tumor vaccine (LLC-1/FasL/mGM-CSF) may produced a more effective synergistic anti-tumor immunity and efficiently suppress lung cancer cells in mice. This strategy may be a feasible and effective alternative for clinical cancer gene therapy.
Titel: |
Combination of Fas ligand and GM-CSF in immunotherapy of lung cancer
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Autor/in / Beteiligte Person: | Ho, Ming-Yi ; 何明怡 |
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Veröffentlichung: | 2004 |
Medientyp: | Hochschulschrift |
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