Veneziani B M, Villone G, Romano R, Di Carlo A, Garbi C, Tramontano D
Dipartimento di Medicina Sperimentale, Università degli Studi di Reggio, Calabria, Catanzaro, Italy.
J Cell Biol. 1990 Dec;111(6 Pt 1):2703-11. doi: 10.1083/jcb.111.6.2703.
Thyroid stimulating hormone (TSH) and insulin-like growth factors type 1 (IGF-I) regulate the proliferation and differentiation of cultured thyroid cells but not of cultured liver cells. We have examined the influence of TSH and IGF-I on the metabolic functions and proliferation of somatic hybrids obtained by fusing rat thyroid cells (FRTL5) with rat liver cells (BRL). While IGF-I is able to stimulate the proliferation of the hybrid cells (TxL) TSH fails to induce their growth. However, the hybrid TxL cells have surface TSH receptors with normal ligand characteristics. The addition of TSH to TxL cells led to typical enhancement of cAMP production and depolymerization of actin filaments. Yet, TSH failed to stimulate iodine uptake in the hybrid cells. Interestingly, iodine inhibited TxL proliferation induced by IGF-I but not by serum. It is concluded that the hybrid TxL cells inherited from the parental thyroid cells several important differentiated traits including mitogenic pathways induced and used by IGF-I, functional TSH receptors, and sensitivity to the inhibitory action of iodine.
促甲状腺激素（TSH）和胰岛素样生长因子1（IGF-I）可调节培养的甲状腺细胞的增殖和分化，但对培养的肝细胞无此作用。我们研究了TSH和IGF-I对大鼠甲状腺细胞（FRTL5）与大鼠肝细胞（BRL）融合获得的体细胞杂种的代谢功能和增殖的影响。虽然IGF-I能够刺激杂种细胞（TxL）的增殖，但TSH不能诱导其生长。然而，杂种TxL细胞具有具有正常配体特性的表面TSH受体。向TxL细胞中添加TSH导致cAMP产生的典型增强和肌动蛋白丝的解聚。然而，TSH未能刺激杂种细胞摄取碘。有趣的是，碘抑制了由IGF-I诱导的TxL增殖，但不抑制由血清诱导的增殖。结论是，杂种TxL细胞从亲代甲状腺细胞继承了几个重要的分化特征，包括IGF-I诱导和使用的促有丝分裂途径、功能性TSH受体以及对碘抑制作用的敏感性。
