[Action of granulocyte-colony stimulating factor and cisplatin on two models of human digestive, esophageal and colonic, cancers].

A combined therapy using a colony-stimulating factor and a chemotherapeutic agent has been designed, in vitro and in vivo, on digestive tumor cells to assess the effects of these agents administered alone or in combination, on the cells' or the tumor's growth rate. A recombinant human granulocyte colony-stimulating factor (rh G-CSF) and Cisplatin (CDDP) has been administered at various concentrations in vitro on oesophageal (ECYO) or on colonic (COLO 205) cell lines and in vivo on oesophagal tumor transplanted in Nude mice. In vitro, the oesophagal model is sensitive to G-CSF. The administration of G-CSF induces a stimulation of the cell proliferation. The DNA synthesis is stimulated or inhibited by low or high concentrations of G-CSF without any dose-response relationship. CDDP inhibits the DNA synthesis in ECYO cells. The association of the two agents leads to an activation of the DNA synthesis but only for some concentrations. On the contrary, the colonic model treated or not by CDDP is not sensitive to G-CSF. In vivo, G-CSF does not allow any inhibition or activation of oesophagal tumor's growth rate. CDDP alone is also inefficient. When G-CSF is administered before CDDP, there is no effect on the tumors. On the contrary, when G-CSF is administered with or after the chemotherapeutic agent, there is a significant inhibition of the tumor's growth rate.