Miyamoto T, Hayashi M, Takeuchi A, Okamoto T, Kawashima S, Takii T, Hayashi H, Onozaki K
Department of Hygienic Chemistry, Faculty of Pharmaceutical Sciences, Nagoya City University.
J Biochem. 1996 Oct;120(4):725-30. doi: 10.1093/oxfordjournals.jbchem.a021471.
We have previously reported the purification from human erythrocyte extracts of a novel growth-promoting factor with a wide target cell spectrum. The factor has been identified as catalase. As cell extracts from a variety of tumor cell types exhibited both growth-promoting and catalase activities, the relationship between the two activities was examined using cell extracts from three different cell types, human myeloid cells (U937), human melanoma cells (A375-C6), and human B cells (Daudi). The growth-promoting and catalase activities were well correlated in these cell extracts. The antibody against human catalase absorbed not only catalase activity, but also the growth-promoting activity of extracts from these cell types. Treatment of the cell extracts from these cells with an irreversible catalase inhibitor, aminotriazole, abolished both the catalase and growth-promoting activities. In contrast, glutathione peroxidase (GSH-Px) activity was neither absorbed with the anti-catalase antibody, nor inhibited by aminotriazole. In addition, GSH-Px exhibited growth-promoting activity only in the presence of glutathione (GSH). These results, in conjunction with the effect of aminotriazole on the growth-promoting activity of catalase, suggest that catalase is the major growth-promoting molecule in the cell extracts, and H2O2-decomposing activity is important. Northern blot analysis revealed that these cells contained authentic catalase mRNA, and the mRNA level was compatible with the catalase and growth-promoting activities in the cell extracts. These results suggest that the growth-promoting activity in the tumor cell extracts is due to catalase.
我们之前报道过从人红细胞提取物中纯化出一种具有广泛靶细胞谱的新型生长促进因子。该因子已被鉴定为过氧化氢酶。由于多种肿瘤细胞类型的细胞提取物都表现出促生长和过氧化氢酶活性，因此使用来自三种不同细胞类型的细胞提取物，即人髓细胞（U937）、人黑色素瘤细胞（A375-C6）和人B细胞（Daudi），来研究这两种活性之间的关系。在这些细胞提取物中，促生长活性和过氧化氢酶活性具有良好的相关性。抗人过氧化氢酶抗体不仅能吸附过氧化氢酶活性，还能吸附这些细胞类型提取物的促生长活性。用不可逆的过氧化氢酶抑制剂氨基三唑处理这些细胞的提取物，会同时消除过氧化氢酶活性和促生长活性。相比之下，谷胱甘肽过氧化物酶（GSH-Px）活性既不被抗过氧化氢酶抗体吸附，也不被氨基三唑抑制。此外，GSH-Px仅在存在谷胱甘肽（GSH）时才表现出促生长活性。这些结果，结合氨基三唑对过氧化氢酶促生长活性的影响，表明过氧化氢酶是细胞提取物中主要的促生长分子，并且H2O2分解活性很重要。Northern印迹分析显示这些细胞含有真实的过氧化氢酶mRNA，并且mRNA水平与细胞提取物中的过氧化氢酶活性和促生长活性相符。这些结果表明肿瘤细胞提取物中的促生长活性是由过氧化氢酶引起的。
