Up-regulation of inducible nitric oxide synthase and production of nitric oxide by the Swarm rat and human chondrosarcoma.

Abstract

Production of nitric oxide by solid tumors may have important ramifications regarding tumor growth and potential metastasis. This study demonstrated that the chondrosarcoma of the Swarm rat has upregulated mRNA for inducible nitric oxide synthase and produces nitric oxide. These results were confirmed by (a) the presence of a 4.4-kb band of mRNA detected by Northern blot using a probe for inducible nitric oxide synthase, (b) a 133-kDa band of protein that was detected with either a polyclonal or monoclonal antibody to the inducible nitric oxide synthase of the murine macrophage, and (c) the detection of nitrites from the culture medium of freshly cultured, isolated chondrosarcoma cells. This study showed that the expression of inducible nitric oxide synthase and the production of nitric oxide by the tumor can be increased by stimulation with endotoxin lipopolysaccharide and can be inhibited by inducible nitric oxide synthase inhibitors (L-N(g)-monomethyl arginine and aminoguanidine). Immunostaining confirmed the presence of inducible nitric oxide synthase within the tumor cells and appeared to localize the enzyme to the cytoplasm of the cells. A human chondrosarcoma was also shown to have an upregulated inducible nitric oxide synthase by both the detection of mRNA for inducible nitric oxide synthase and the presence of nitrites from the culture medium of the tumor in organ culture. Because the chondrosarcoma of the Swarm rat is a well differentiated solid tumor that rarely metastasizes, nitric oxide may be produced by the tumor to promote local growth by effects on vascular supply.

• Authors: P E Di Cesare, C S Carlson, M Attur, A A Kale, S B Abramson, C Della Valle, G Steiner, A R Amin
• Journal: Journal of orthopaedic research : official publication of the Orthopaedic Research Society (J Orthop Res) Vol. 16 Issue 6 Pg. 667-74 (Nov 1998) ISSN: 0736-0266 [Print] United States
• PMID: 9877390 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Guanidines
• Lipopolysaccharides
• RNA, Messenger
• Nitric Oxide
• NOS2 protein, human
• NOS3 protein, human
• Nitric Oxide Synthase
• Nitric Oxide Synthase Type II
• Nitric Oxide Synthase Type III
• Nos2 protein, rat
• Nos3 protein, rat
• pimagedine

Topics

• Animals
• Bone Neoplasms (enzymology)
• Chondrosarcoma (enzymology)
• Guanidines (pharmacology)
• Humans
• Lipopolysaccharides (pharmacology)
• Male
• Nitric Oxide (biosynthesis)
• Nitric Oxide Synthase (biosynthesis, genetics)
• Nitric Oxide Synthase Type II
• Nitric Oxide Synthase Type III
• RNA, Messenger (analysis)
• Rats
• Rats, Sprague-Dawley
• Up-Regulation