Philippe Lagadec

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The mechanisms of immunosuppression induced by colon cancer in rats were investigated at the systemic and tumor levels. During tumor growth (after i.p. injection of rat colon adenocarcinoma cells in syngeneic BD IX rats), Con A-induced proliferation of splenic mononuclear cells decreased and nitric oxide (NO) production by splenic macrophages increased(More)
The activity of the inducible nitric oxide synthase enzyme (iNOS) is tightly controlled, partly at the transcriptional level. We find NF-kappa B/Rel activation (p50-p50 and p50-p65) in RAW 264.7 macrophages after lipopolysaccharide treatment and binding to both NF-kappa B sites in the mouse iNOS promoter. To delineate the importance of NF-kappa B/Rel in(More)
Colon carcinoma is one of the most frequent causes of cancer death in industrialized countries. The patients generally die of the metastases. In a colon cancer rat model, the authors have shown that lipopolysaccharides from Escherichia coli induced the regression of carcinomatosis and cured 20%-30% of the rats. Some synthetic derivatives of lipid A, which(More)
In a previous work, a cell line (DHD/K12) was established from a colon adenocarcinoma induced in a BDIX rat by 1,2-dimethylhydrazine. From this line, two cloned sublines, PROb and REGb, were then isolated. When subcutaneously inoculated into syngeneic rats, PROb cells yield progressive tumors, whereas REGb cells yield tumors which regress. In this study, in(More)
In a model of colon cancer in syngeneic rats, a new immunomodulator, OM 163, induced the complete disappearance of peritoneal carcinomatosis (nodules measuring 1-5 mm) in 41 out of 82 rats. Those results were confirmed in a survival experiment in which 3 out of 10 treated rats died free of tumour 10, 18 and 28 months after the tumour cell injection while(More)
Transforming growth factor-beta1 (TGF-beta1) has been shown to down-regulate NO synthesis in a variety of normal cells. In the present study, we investigated the influence of TGF-beta1 upon NO production in tumor cells and its consequences for tumor development. During the growth of PROb colon carcinoma cells intraperitoneally injected in syngeneic BDIX(More)
The cloned DHD/K12/TSb line obtained from a chemically-induced rat colon carcinoma, presents tumors which always regress when injected subcutaneously to the syngeneic animal. This study reports that an intraperitoneal injection of the DHD/K12/TSb cells induces a progressive carcinomatosis in a high proportion of the syngeneic rats. This result underlines(More)
Peritoneal carcinomatosis, a common spreading of human colon carcinoma, can be obtained by intraperitoneal injection of colon tumor cells in rats. When BDIX rats are injected with 10(6) syngeneic tumor cells, isolated and cloned from a chemically induced colon carcinoma, they die within 2-3 months with solid peritoneal tumors and hemorrhagic ascites.(More)
The correlation between the activation of macrophages by lipopolysaccharides (LPS) from four different bacterial species and their antitumor effect in a rat model of colon cancer was investigated. The efficacy of LPS from Neisseria meningitidis (Nm), Salmonella minnesota (Sm), Escherichia coli (Ec) and Bordetella pertussis (Bp) was evaluated as the smallest(More)
Lentinan has been tested in a model of colon cancer in rats. Peritoneal carcinomatoses were induced in BDIX rats by i.p. injections of syngeneic cells isolated from a colon carcinoma, and established in a permanent cell line. The treatment consisted of five i.p. injections, 2 days apart, of 2 mg lentinan/kg at a concentration of 200 micrograms/ml. This was(More)