Brightwell J, Tseng M T
Cancer Res. 1982 Nov;42(11):4562-6.
Peroxidase has been investigated as a potential marker protein for the prediction of response to hormonal therapy in tumors of steroid-sensitive tissues, but the cellular origin of the enzyme has been questioned. To localize the observed peroxidase activity, in this study cell subpopulations were isolated from mammary tumors induced by 7,12-dimethylbenz(a)anthracene and from mammary tissue of virgin and lactating female rats. Cells from each of the four cell bands, regularly obtained by isopyknic velocity sedimentation after mechanical and enzymatic dispersion of these tissues, were assayed biochemically and histochemically for peroxidase activity. In addition, cells from each subpopulation were examined at both the light and electron microscopic levels. Elevated enzyme levels were observed in each of the cell subpopulations of 7,12-dimethylbenz(a)anthracene-induced tumors when these were compared with tissue in either of the physiological states assayed. In each tissue type, the levels of peroxidase increased from the lighter cell bands to the heavier cell bands. Light and electron microscopic examination revealed the highest proportion of epithelial cells in the lighter bands and an increase in granulocytes and fibroblasts in the heavier bands, suggesting a nonepithelial contribution. Histochemical examination of intact tissue revealed most peroxidase activity in the stromal compartment with limited activity in parenchymal cells.
过氧化物酶已被作为一种潜在的标记蛋白进行研究，用于预测类固醇敏感组织肿瘤对激素治疗的反应，但该酶的细胞来源一直存在疑问。为了定位观察到的过氧化物酶活性，在本研究中，从7,12 - 二甲基苯并(a)蒽诱导的乳腺肿瘤以及未生育和哺乳期雌性大鼠的乳腺组织中分离细胞亚群。通过对这些组织进行机械和酶分散后，通过等密度速度沉降定期获得的四个细胞带中的细胞，进行了过氧化物酶活性的生化和组织化学测定。此外，对每个亚群的细胞进行了光镜和电镜检查。与所检测的任何一种生理状态下的组织相比，在7,12 - 二甲基苯并(a)蒽诱导的肿瘤的每个细胞亚群中都观察到酶水平升高。在每种组织类型中，过氧化物酶水平从较轻的细胞带向较重的细胞带增加。光镜和电镜检查显示，较轻的细胞带中上皮细胞比例最高，较重的细胞带中粒细胞和成纤维细胞增加，提示非上皮细胞的贡献。完整组织的组织化学检查显示，大部分过氧化物酶活性存在于间质区室，实质细胞中的活性有限。
