배양된 쥐 갑상선세포 성장에 미치는 각종 성장인자들과 TSH 수용체항체간의 상호작용 및 그 기전에 관한 연구

To evaluate the interaction of various growth factors and TSH receptor antibodies (TRAb) on the growth of cultured rat thyroid cells, FRTL-5 cells, and to verify their mechanisms of action, we measured 3H-thymidine incorporation into FRTL-5 cells with various combinations of TSH, Graves' IgG and other growth stimulators (insulin, IGF-I, multiplication stimulation activity, forskolin, dBcAMP and phorbol ester). We evaluated the effects of blocking TRAb and adenosine on the growth factor-stimulated growth of FRTL-5 cells. Insulin, IGF-I and MSA increased 3H-thymidine incorporation into FRTL-5 cells and showed a synergistic effect when incubated simultaneously with TSH or Graves IgG. Forskolin, PGE2, and dBcAMP also increased 3H-thymidine incorporation by themselves and their effects were synergistically potentiated by insulin and IGF-I. Adenosine inhibited both TSH and Graves' IgG induced 3H-thymidine incorporation into FRTL-5 cells. Blocking TRAb inhibited both TSH and Graves' IgG induced 3H-thymidine incorporation, but did not inhibit the effects of insulin, IGF-I, forskolin and dBcAMP on the growth of FRTL-5 cells. Phorbol ester (TPA) did stimulate the growth of FRTL-5 cells by itself and inhibited both TSH and Graves IgG induced 3H-thymidine incorporation into FRTL-5 cells. These results suggest that 1) there might be two or more signal transduction systems for the growth of thyroid cells; TSH and Graves IgG stimulate the growth of thyroid cells through the adenylate cyclase-cAMP system, and IGF-I and other growth facors act through another system, and 2) blocking TRAb may inhibit the growth of thyroid cells by inhibiting TSH-stimulated cAMP generation.