Effects of endothelial nitric oxide synthase gene expression on the tumor biology of human oral carcinoma SCC-25 cells.
Stable transfection of endothelial nitric oxide synthase (eNOS) cDNA in human oral carcinoma SCC-25 cells was performed. Two eNOS-expressing clones were isolated, and both were shown to have increased eNOS expression as assayed by Northern and Western analyses. Furthermore, a nitrite assay indicated that nitric oxide production in eNOS-transfected cells was increased. The growth rate and plating efficiency of eNOS-transfected cells in vitro were lower than that of the wild-type parental or vector control-transfected cells as assayed by growth curves, [3H]thymidine incorporation, and standard plating efficiency assays in L-arginine-rich medium. However, when these cancer cells were inoculated into nude mice, tumor size of eNOS-transfected cells was smaller during the first 25 days but increased later as compared to tumor size of parental and vector control-transfected cells. It is not clear whether the later increase in tumor size was due to an increase in SCC-25 cancer cell proliferation, normal stromal cell proliferation, or both. These results show significant effects of overexpression of eNOS on tumor growth in vitro and in vivo.
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Radiation Research Laboratory, The University of Iowa, Iowa City 52242, USA.
Oberley
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Oberley
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D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D002417:Cattle; D002455:Cell Division; D002462:Cell Membrane / Q000201:enzymology; D003593:Cytoplasm / Q000201:enzymology; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009062:Mouth Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D009569:Nitric Oxide / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000032:analysis / Q000235:genetics*; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D009573:Nitrites / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis; D012334:RNA, Neoplasm / Q000032:analysis; D014162:Transfection; D014407:Tumor Cells, Cultured
D009573:Nitrites; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D009569:Nitric Oxide; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C496315:Nos3 protein, mouse