Induction of monocyte antitumor response by human cancer cells transduced with TNF-GFP fusion gene: possible implications for immunotherapy of cancer

• Main Authors: Kazimierz Węglarczyk, Rafał Szatanek, Bożenna Mytar, Jerzy Więckiewicz, Jarosław Baran
• Format: Article
• Language: English
• Published: Via Medica 2011-10-01
• Series: Folia Histochemica et Cytobiologica
• Subjects: fusion gene; monocytes; tumor cells; tumor necrosis factor
• Online Access: http://czasopisma.viamedica.pl/fhc/article/view/9448
• ISSN: 0239-8508; 1897-5631

This study was undertaken to determine how human pancreatic cancer (HPC-4) cells transduced with the TNF-GFP fusion gene (TLG) alter the antitumor response of human monocytes <i>in vitro</i> and whether they could act as an antitumor vaccine. In our model, HPC-4 cells were transduced with retroviral vector harboring TLG gene and designated as HPC-4<sub>TLG</sub>. The TLG protein expression was confirmed by Western blot and flow cytometry analysis. Monocytes were co-cultured with transduced and control HPC-4 cells. The secretion of TNF, IL-10 and IL-12 was measured by ELISA. The cytotoxicity of monocytes against HPC-4 cells was determined by MTT test. The results show that the HPC-4<sub>TLG</sub> cells expressed membrane-bound, intracellular and secretory TLG protein. When cultured with HPC-4<sub>TLG</sub> cells, monocytes released a higher amount of TNF, but IL-10 and IL-12 secretion was inhibited. The pre-exposure of monocytes to HPC-4<sub>TLG</sub>, but not to HPC-4, cells did not decrease TNF nor increase IL-10 production, thus not leading to monocyte deactivation. Also, the antitumor cytotoxicity of monocytes stimulated with HPC-4<sub>TLG</sub> was not downregulated, which occurred when non-transduced HPC-4 cells were used. In conclusion, compared to parental HPC-4 cells, TLG gene transduced HPC-4 cells induced stronger antitumor response of monocytes <i>in vitro</i> and prevented deactivation of monocytes. (<i>Folia Histochemica et Cytobiologica 2011, Vol. 49, No. 3, 512–520</i>)