DMBA诱导的肝脏特异性IGF-1基因缺失鼠原发性乳腺癌的组织学特征

Histological Features of Primary Mammary Tumor in LID Mice In- duced by 7, 12-Dimethybenz (a) Anthracene

目的 探讨血清中胰岛素样生长因子-1(IGF-1)水平与乳腺肿瘤发生过程中组织学改变的关系。方法 实验中所用的肝脏特异性IGF-1基因缺失(LID)小鼠，其循环中IGF-1水平仅为正常小鼠(对照组小鼠)的25％。管饲化学致癌剂7，12-二甲基苯蒽(DMBA)诱导产生原发性乳腺癌。结果 对照组肿瘤晚期可见广泛的鳞状上皮化生，而LID鼠肿瘤晚期出现广泛增生，极少出现化生。与对照组相比，鼠乳腺肿瘤的潜伏期均明显延长，LID小鼠可触及的乳腺肿瘤发病率明显下降，其肿瘤的出现也明显延迟。结论 在致癌剂DMBA诱导的乳腺肿瘤模型中，IGF-1水平决定了乳腺肿瘤发生的组织学类型。

Objective To investigate the potential relationship between serum IGF-1 level and histological features of mammary cancer. Methods The liver-specific deficient ( LID) mice, in which IGF-1 levels in the circulation were 25% of control levels, were used. Induction of mammary-tumors was achieved by using the 7, 12-dimethybenz (a) anthracene (DMBA). Results Histo-logically, squamous tumors from LID mice demonstrated extensive hyperplasia but little metaplasia. The latency period of mammary tumor development in LID mice was substantially longer. The incidence of palpable mammary tumors was significantly lower in LID mice (26% in LID mice versus 56% in controls) and the onset of the tumors was delayed (74. 0 +1. 2 days in LID mice versus 59. 5 ± 1. 1 days in controls). Conclusion In the established mammary tumor model, circulating IGF-1 levels is the key in the determination of the histological types of primary mammary tumors.