Jean François Jeannin

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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)
From an established cell culture line obtained from a chemically-induced rat colon carcinoma, two sublines have been selected and isolated according to their susceptibility to trypsin-mediated detachment from plastic surfaces. Subline TR, the most resistant to the detaching effect of trypsin, gave progressive tumors in most of the syngeneic rats in which it(More)
Nitric oxide (NO) is generated by a family of isoenzymes named nitric oxide synthases (NOS) which includes a cytokine-inducible form, NOSII. NO is a free radical known to inhibit cell proliferation, to induce apoptosis, and to be a mediator of macrophage cytostatic and cytotoxic effects. We investigated NOS in 40 human breast carcinomas and 8 benign breast(More)
Imbalanced proliferation and apoptosis is important in tumor progression. Endothelin (ET)-1, a 21-amino-acid peptide with vasoconstricting and mitogenic activities, has been shown to be involved in the regulation of apoptosis. Progressive and regressive rat colon (PROb and REGb cells) carcinoma cell lines express the components of the ET-1 system(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)
Tumor neovascularization is considered to be a critical step in the development of a malignant tumor. Endothelin (ET)-1 is a powerful vasoconstrictor and mitogenic peptide that is produced by many cancer cell lines. The cellular distribution of the ET components was evaluated in human colon tumors and compared to normal colon. There was more of the ET(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)
A wide variety of cells usefully but sometimes destructively produce nitric oxide via inducible nitric oxide synthase (iNOS). Data obtained by gel shift analysis and reporter assays have linked murine iNOS gene induction by cytokines and bacterial products with the binding of a number of proteins to a proximal promoter, as well as to a distal enhancer of(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)