Expression of the TNF-α gene on mouse lung carcinoma cells suppresses spontaneous lung metastasis without affecting tumorigenicity
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- Published online on: May 1, 2002 https://doi.org/10.3892/or.9.3.585
- Pages: 585-588
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Abstract
Forced expression of TNF-α in tumor cells has been shown to inhibit their tumor growth in vivo through a number of mechanism such as activation of an immune system and induction of an apoptotic process. We re-examined the anti-tumor effects caused by the TNF-α gene transfer using high-metastatic, murine lung carcinoma A11 cells. Expressed TNF-α molecules remained on cell surface and were not secreted into culture supernatants in vitro. Syngeneic immunocompetent mice developed tumors of TNF-α-expressed A11 cells and the growth of their subcutaneous tumors was not different from that of parent tumors. Spleen of the mice that developed TNF-α-expressed A11 tumors was significantly larger than that of the mice bearing parent tumors, but relative ratios of each cell population were not different. In contrast to subcutaneous tumors, the number of spontaneous lung foci metastasized from the subcutaneous TNF-α-expressed A11 tumors was markedly reduced compared with that from parent tumors. Expressed TNF-α on tumors is released by matrix metalloproteinases from surrounding tissues and anti-tumor effects by TNF-α can be influenced by local environmental conditions.