Kubota Y, Nakada T, Sasagawa I, Yanai H, Itoh K
Department of Urology, Yamagata University School of Medicine, Japan.
Cancer. 1998 Jan 1;82(1):176-9.
Although malignant pheochromocytoma is a life-threatening illness, there is no excretory profile that is predictive of malignancy. Reliable prediction of malignant behavior on the basis of histopathology is also notoriously difficult. Although DNA ploidy can be a helpful indicator, aneuploidy per se is not considered to be a specific marker of malignancy. Mutations in p53 have been reported to occur frequently in cases of benign pheochromocytoma. Thus, molecular analysis of this protein is not a useful diagnostic tool. The authors analyzed telomerase activity in benign and malignant pheochromocytomas and assessed its utility as a prognostic marker.
Telomerase activity was estimated in 16 benign pheochromocytomas, 3 malignant pheochromocytomas, and 16 normal adrenal medullae by the fluorescence-based telomeric repeat amplification protocol. The telomerase activities of each group of samples were compared.
No telomerase activity was detected in any of the normal adrenal medullae or the benign pheochromocytomas. By contrast, all of the three malignant pheochromocytomas had elevated telomerase activity. The telomerase activity in each tumor was determined to be 87.6 units, 71.2 units, and 180.3 units, respectively.
The expression of telomerase activity in pheochromocytoma clearly suggests the malignant behavior of the component cells. Analysis of telomerase activity appears to be a powerful tool for the diagnosis of malignant pheochromocytoma.
尽管恶性嗜铬细胞瘤是一种危及生命的疾病，但尚无排泄特征可预测其恶性程度。基于组织病理学对恶性行为进行可靠预测也极为困难。虽然DNA倍性可能是一个有用的指标，但非整倍体本身并不被认为是恶性的特异性标志物。据报道，p53突变在良性嗜铬细胞瘤病例中经常出现。因此，对该蛋白进行分子分析并非有用的诊断工具。作者分析了良性和恶性嗜铬细胞瘤中的端粒酶活性，并评估其作为预后标志物的效用。
采用基于荧光的端粒重复序列扩增法，对16例良性嗜铬细胞瘤、3例恶性嗜铬细胞瘤和16例正常肾上腺髓质的端粒酶活性进行评估。比较每组样本的端粒酶活性。
在任何正常肾上腺髓质或良性嗜铬细胞瘤中均未检测到端粒酶活性。相比之下，所有3例恶性嗜铬细胞瘤的端粒酶活性均升高。每个肿瘤中的端粒酶活性分别测定为87.6单位、71.2单位和180.3单位。
嗜铬细胞瘤中端粒酶活性的表达清楚地表明了组成细胞的恶性行为。端粒酶活性分析似乎是诊断恶性嗜铬细胞瘤的有力工具。
