Liu R, Oberley T D, Oberley L W
Radiation Research Laboratory, The University of Iowa, Iowa City 52242, USA.
Cell Growth Differ. 1998 Mar;9(3):239-46.
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.
将内皮型一氧化氮合酶（eNOS）cDNA稳定转染至人口腔癌SCC - 25细胞中。分离出两个表达eNOS的克隆，通过Northern和Western分析检测发现二者的eNOS表达均增加。此外，亚硝酸盐检测表明，转染eNOS的细胞中一氧化氮生成增加。通过生长曲线、[³H]胸苷掺入以及在富含L - 精氨酸的培养基中进行的标准接种效率测定分析，发现转染eNOS的细胞在体外的生长速率和接种效率低于野生型亲代细胞或载体对照转染细胞。然而，当将这些癌细胞接种到裸鼠体内时，与亲代细胞和载体对照转染细胞的肿瘤大小相比，转染eNOS的细胞在最初25天内肿瘤尺寸较小，但之后增大。目前尚不清楚肿瘤尺寸后期的增加是由于SCC - 25癌细胞增殖增加、正常基质细胞增殖增加，还是两者共同作用。这些结果表明，eNOS过表达对体外和体内肿瘤生长具有显著影响。
