title: Inducible NO synthase inhibits the growth of free tumor cells, but enhances the growth of solid tumors.
abstract: To elucidate the role of nitric oxide (NO) in tumor cell growth in vivo, dynamic aspects of the growth of Ehrlich ascites tumor cells (EATCs) were studied in wild-type (WT) mice and in an inducible strain of NO synthase (iNOS)-deficient (iNOS(-/-)) mice. Kinetic analysis showed that the rate of free tumor cell growth in the peritoneal cavity was significantly higher in the iNOS(-/-) mice than in the WT mice. In contrast, EATCs inoculated subcutaneously rapidly grew and formed a solid tumor in WT mice, but failed to grow in iNOS(-/-) mice. These results clearly indicate that NO generated by iNOS predominantly inhibits the growth of tumor cells in their free form, but enhances the growth of solid tumors.
authors.affiliation: Department of Biochemistry, Osaka City University Medical School, 1-4-3 Asahimachi, Abeno-ku, Osaka 545-8585, Japan. nishikawa@med.osaka-cu.ac.jp
authors.forename: Manabu
authors.initials: M
authors.lastname: Nishikawa
authors.forename: Baojun
authors.initials: B
authors.lastname: Chang
authors.forename: Masayasu
authors.initials: M
authors.lastname: Inoue
mesh_terms: D000818:Animals; D002286:Carcinoma, Ehrlich Tumor / Q000473:pathology*; D002455:Cell Division / Q000502:physiology*; D053938:DNA Fragmentation; D007700:Kinetics; D051379:Mice; D018345:Mice, Knockout; D052247:Nitric Oxide Synthase Type II / Q000172:deficiency* / Q000235:genetics* / Q000378:metabolism; D010534:Peritoneal Neoplasms / Q000473:pathology*
chemical_list: D052247:Nitric Oxide Synthase Type II