Safa A R, Brightwell J R, Tseng M T
J Endocrinol. 1984 Apr;101(1):21-6. doi: 10.1677/joe.0.1010021.
Recent investigations of certain enzymes as markers for predicting the response of breast tumours to hormonal therapy have neglected the possible differential contribution of cell subpopulation(s) within a solid tumour to enzyme activity. In this investigation, lactate dehydrogenase (LDH) and peroxidase activities in density-defined cell subpopulations from autotransplanted 7,12-dimethylbenz[alpha]anthracene-induced mammary tumours were determined. The effects of ovariectomy and subsequent oestrogen administration on the activity of these enzymes were also examined. Five cell subpopulations (cell bands) were routinely obtained from each mammary tumour. The highest LDH activity was found in cell band 4. The highest level of peroxidase activity was found in cell band 5. These two cell bands with high levels of enzyme activity consisted mainly of poorly differentiated cells. After bilateral ovariectomy, a significant (P less than 0.001) decrease in the level of LDH activity in cell bands 3, 4 and 5 was observed. The enzyme activity was reduced to 20, 2.1 and 12% of the preovariectomy levels respectively. Significant (P less than 0.05) decreases between baseline and postovariectomy peroxidase values were evident in each cell band. In the presence of oestradiol-17 beta, significant increases in the LDH activity of band 4 (P less than 0.001) and the peroxidase activity of band 5 (P less than 0.05) were observed. Our data suggest that, given the existence of multiple cell types in hormone-responsive tumour tissue, the actual cell subpopulation(s) responsible for any enzyme response may be a more precise indicator of hormone dependence.
近期，将某些酶作为预测乳腺肿瘤对激素治疗反应的标志物的研究，忽略了实体瘤内细胞亚群对酶活性可能存在的不同贡献。在本研究中，测定了自移植的7,12-二甲基苯并[a]蒽诱导的乳腺肿瘤密度定义的细胞亚群中的乳酸脱氢酶（LDH）和过氧化物酶活性。还研究了卵巢切除术及随后给予雌激素对这些酶活性的影响。每个乳腺肿瘤常规获得五个细胞亚群（细胞带）。在细胞带4中发现LDH活性最高。在细胞带5中发现过氧化物酶活性水平最高。这两个酶活性水平高的细胞带主要由低分化细胞组成。双侧卵巢切除术后，观察到细胞带3、4和5中LDH活性水平显著（P<0.001）下降。酶活性分别降至卵巢切除术前水平的20%、2.1%和12%。每个细胞带中，卵巢切除术前和术后过氧化物酶值之间均有显著（P<0.05）下降。在存在17β-雌二醇的情况下，观察到细胞带4的LDH活性显著增加（P<0.001），细胞带5的过氧化物酶活性显著增加（P<0.05）。我们的数据表明，鉴于激素反应性肿瘤组织中存在多种细胞类型，负责任何酶反应的实际细胞亚群可能是激素依赖性更精确的指标。
