T S Tzai1, C I Lin, A L Shiau, C L Wu. 1. Department of Urology, National Cheng Kung University, Tainan, Taiwan, Republic of China.
Abstract
INTRODUCTION AND OBJECTIVES: TGF-beta is a potent immunosuppressive cytokine produced by many tumor cells. Secretion of TGF-beta by malignant cells may be a mechanism by which tumor cells escape destruction by tumor-specific T lymphocytes. In this study, we used a TGF-beta producing C3H/He-MBT-2 murine bladder tumor model to investigate the feasibility of antisense oligonucleotide (ODN) gene therapy strategy to block the production of TGF-beta from tumor cells and evaluate its influence on both in vitro tumor growth and in vivo tumor formation. MATERIALS AND METHODS: Using a plasmid, pRUFCD, we constructed a recombinant plasmid pRUFCD/TGF-beta 1(-) containing antisense TGF-beta ODN and then transfected in into MBT-2 cells by electroporation. Three transfectant clones were successfully obtained by their resistance to 5-fluorouracil and cytosine. RESULTS: The secretion of TGF-beta from the three obtained TGF-beta antisense-blocked MBT-2 cell clones, as assessed by ELISA, were all decreased. Moreover, they all exhibited smaller colony size in the in vitro anchorage-independent soft agar colony forming assay. Tumor growths in mice injected with these three clones were all inhibited compared with those injected with parental tumor cells. CONCLUSION: This study demonstrates that after reducing the secretion of TGF-beta 1 on tumor cells by TGF-beta 1 antisense, ODN can inhibit their in vitro growth and in vivo tumor formation suggesting that this approach can be a potentially useful strategy to abolish the adverse immunosuppression effect of TGF-beta 1 producing autologous tumor vaccine and therefore to enhance host antitumor immune response.
INTRODUCTION AND OBJECTIVES:TGF-beta is a potent immunosuppressive cytokine produced by many tumor cells. Secretion of TGF-beta by malignant cells may be a mechanism by which tumor cells escape destruction by tumor-specific T lymphocytes. In this study, we used a TGF-beta producing C3H/He-MBT-2 murinebladder tumor model to investigate the feasibility of antisense oligonucleotide (ODN) gene therapy strategy to block the production of TGF-beta from tumor cells and evaluate its influence on both in vitro tumor growth and in vivo tumor formation. MATERIALS AND METHODS: Using a plasmid, pRUFCD, we constructed a recombinant plasmid pRUFCD/TGF-beta 1(-) containing antisense TGF-betaODN and then transfected in into MBT-2 cells by electroporation. Three transfectant clones were successfully obtained by their resistance to 5-fluorouracil and cytosine. RESULTS: The secretion of TGF-beta from the three obtained TGF-beta antisense-blocked MBT-2 cell clones, as assessed by ELISA, were all decreased. Moreover, they all exhibited smaller colony size in the in vitro anchorage-independent soft agar colony forming assay. Tumor growths in mice injected with these three clones were all inhibited compared with those injected with parental tumor cells. CONCLUSION: This study demonstrates that after reducing the secretion of TGF-beta 1 on tumor cells by TGF-beta 1 antisense, ODN can inhibit their in vitro growth and in vivo tumor formation suggesting that this approach can be a potentially useful strategy to abolish the adverse immunosuppression effect of TGF-beta 1 producing autologous tumor vaccine and therefore to enhance host antitumor immune response.
Authors: Christian Niedworok; Katharina Röck; Inga Kretschmer; Till Freudenberger; Nadine Nagy; Tibor Szarvas; Frank Vom Dorp; Henning Reis; Herbert Rübben; Jens W Fischer Journal: PLoS One Date: 2013-11-06 Impact factor: 3.240