Shaver J K, Tezelman S, Siperstein A E, Duh Q Y, Clark O H
Department of Surgery, Mount Zion Medical Center, University of California, San Francisco 94115.
Surgery. 1993 Dec;114(6):1064-9.
Thyroid-stimulating hormone (TSH) stimulates thyroid growth through two signal transduction pathways: the G protein-adenylate cyclase system and the G protein-phospholipase C (PLC) system. The adenylate cyclase system has been studied extensively, but there is little information available concerning PLC activity in thyroid neoplasms.
Human thyroid membranes were incubated for 30 minutes at 37 degrees C in the presence or absence of bovine TSH (300 mU/ml). PLC activity was assayed by liberation of inositol phosphates from the enzymatic hydrolysis of tritiated phosphatidylinositol bisphosphate. Fifty-six tissues were assayed (normal, 23; multinodular goiter, 5; follicular adenoma, 9; and differentiated thyroid cancer, 19 [9 low risk and 10 high risk]).
TSH significantly increased PLC activity in normal, benign, and most malignant thyroid neoplasms. Although there were no differences in basal or TSH-stimulated PLC activity between the groups of normal thyroid, multinodular goiter, follicular adenoma, or the cancers, one half of the high-risk cancers had an aberrant PLC response.
This is the first demonstration that TSH stimulates PLC activity in normal and neoplastic human thyroid tissue. Aberrant TSH-stimulated PLC activity was present in half of the aggressive thyroid neoplasms.
促甲状腺激素（TSH）通过两条信号转导途径刺激甲状腺生长：G蛋白-腺苷酸环化酶系统和G蛋白-磷脂酶C（PLC）系统。腺苷酸环化酶系统已得到广泛研究，但关于甲状腺肿瘤中PLC活性的信息却很少。
将人甲状腺膜在有或无牛TSH（300 mU/ml）存在的情况下于37℃孵育30分钟。通过从氚标记的磷脂酰肌醇二磷酸的酶促水解中释放肌醇磷酸来测定PLC活性。共检测了56个组织（正常组织23个；多结节性甲状腺肿5个；滤泡性腺瘤9个；分化型甲状腺癌19个[低风险9个，高风险10个]）。
TSH显著增加正常、良性及大多数恶性甲状腺肿瘤中的PLC活性。尽管正常甲状腺、多结节性甲状腺肿、滤泡性腺瘤或癌症组之间的基础或TSH刺激的PLC活性没有差异，但一半的高风险癌症存在异常的PLC反应。
这是首次证明TSH可刺激正常和肿瘤性人甲状腺组织中的PLC活性。一半侵袭性甲状腺肿瘤存在异常的TSH刺激的PLC活性。
