Kokura Satoshi, Yoshida Norimasa, Ishikawa Takeshi, Higashihara Hiroshi, Sakamoto Naoyuki, Takagi Tomohisa, Uchiyama Kazuhiko, Naito Yuji, Mazda Osam, Okanoue Takeshi, Yoshikawa Toshikazu
Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan.
Cancer Lett. 2005 Feb 10;218(2):171-9. doi: 10.1016/j.canlet.2004.07.026.
The transcription factor NF-kappa B is constitutively activated in many human cancers, and induces the expression of multiple proteins including antiapoptotic proteins. Recent papers indicate that NF-kappa B activation is inhibited by interleukin (IL)-10. In this study, we investigated the effect of IL-10 plasmid DNA on colon cancer in mice. In vitro study: Colon 26 murine colon adenocarcinoma cells were either treated or untreated with IL-10 for 60 min. The cells were subsequently stimulated with TNF-alpha. In vivo study: to induce a high level of IL-10 in plasma, we transferred the naked plasmid vectors encoding the mouse IL-10 gene into the liver via the intravenous route. To establish tumors, we injected Colon 26 cells into BALB/c mice subcutaneously. In vitro study: a 24-h incubation with TNF-alpha did not affect cell viabilities; however, pretreatment with IL-10 significantly enhanced the level of apoptosis induced by TNF-alpha. Pretreating Colon 26 cells with IL-10 significantly attenuated the TNF-alpha-induced NF-kappa B activation. In vivo study: IL-10 plasmid controlled the growth of subcutaneous tumors. In subcutaneous tumor, NF-kappa B was activated in response to tumor growth. IL-10 plasmid markedly inhibited this activation of NF-kappa B in subcutaneous tumor. IL-10 plasmid induced cancer cell apoptosis linked to the down-regulation of antiapoptotic proteins, and the activation of caspase-3. These results demonstrate that IL-10 plasmid may constitute a new strategy for treating cancer growth.
