Nakahashi K, Kitahori Y, Konishi N, Ohnishi T, Sugimura M, Hiasa Y
Department of Oral Maxillo-facial Surgery, Nara Medical University, Japan.
Cancer Lett. 1996 Mar 29;101(2):247-55. doi: 10.1016/0304-3835(96)04128-6.
We previously established transplantable rat thyroid carcinoma cell lines in vivo from primary thyroid tumors induced by N-bis-(2-hydroxypropyl)nitrosamine (DHPN). In the present study, an insulin-like growth factor I (IGF-I)-responsive cell line (TRTC-G1-C-A4) in culture was derived from one (well differentiated papillary type) of these carcinoma cell lines G1. TRTC-G1-C-A4 cells were found to exhibit specific saturable binding of IGF-I with a Kd of 1.16 nM at approximately 43.6 fmol/10(5) cells. Inclusion of IGF-I (10 and 50 ng/ml) in the culture medium resulted in a significant increase of [3H]thymidine incorporation and marked cell proliferation. IGF-II (10 ng/ml) and insulin (1 microgram) produced no such effects. The molecular weight of IGF-I receptors on the cell membrane was determined by Western blotting analysis, a single band of binding proteins with a molecular weight of 125 kDa being evident under non-reducing conditions. Reverse transcriptase polymerase chain reaction (RT-PCR) showed that the TRTC-G1-C-A4 cells contained IGF-I receptor mRNA with a sequence corresponding to that determined from rat uterus. These results demonstrate that the IGF-I receptor can be expressed in a thyroid carcinoma with an important contribution to cell growth.
我们之前通过N-双（2-羟丙基）亚硝胺（DHPN）诱导的原发性甲状腺肿瘤在体内建立了可移植的大鼠甲状腺癌细胞系。在本研究中，一种培养中的胰岛素样生长因子I（IGF-I）反应性细胞系（TRTC-G1-C-A4）源自这些癌细胞系G1中的一个（高分化乳头状型）。发现TRTC-G1-C-A4细胞表现出IGF-I的特异性饱和结合，在约43.6 fmol/10(5)细胞时Kd为1.16 nM。在培养基中加入IGF-I（10和50 ng/ml）导致[3H]胸腺嘧啶核苷掺入显著增加和明显的细胞增殖。IGF-II（10 ng/ml）和胰岛素（1微克）未产生此类作用。通过蛋白质印迹分析确定细胞膜上IGF-I受体的分子量，在非还原条件下可见一条分子量为125 kDa的结合蛋白条带。逆转录聚合酶链反应（RT-PCR）显示TRTC-G1-C-A4细胞含有IGF-I受体mRNA，其序列与从大鼠子宫确定的序列相对应。这些结果表明IGF-I受体可在甲状腺癌中表达，对细胞生长有重要作用。
