Research for Growth Factor Receptors in Human Tumor Tissues

1)脑肿瘤：胰岛素样生长因子-I受体广泛分布于大鼠脑内调节行为、中枢血压和垂体激素的区域。结合IGF-I在大脑中的表达，我们考虑了IGF-I在中枢神经系统中扮演神经递质和/或神经调节剂的可能性。在脑膜瘤、胶质母细胞瘤和间变性室管膜瘤组织切片中均可见大量的IGF-I和EGF受体，而正常脑组织中仅有少量的IGF-I和EGF受体。在髓母细胞瘤中也观察到IGF-I受体，而不是EGF受体。在肿瘤细胞培养中，两种生长因子都以剂量依赖的方式刺激DNA的合成。2)肺肿瘤：我们发现IGF-I受体存在于鳞状细胞癌、腺癌、小细胞癌和大细胞癌中。IGF-I受体在鳞癌和小细胞癌中呈高表达，而在腺癌中呈低表达。3)肾上腺肿瘤：IGF-I受体和EGF受体均位于肾上腺皮质，而肾上腺髓质中仅有IGF-I受体。但在肾上腺肿瘤中未见IGF-I受体的表达。EGF受体在肾上腺皮质癌中的表达频率(98.4%)明显高于肾上腺皮质腺瘤(43.5%)和嗜铬细胞瘤(57.1%)。我们认为EGF受体的表达与肾上腺皮质癌的生长和/或转移潜能有关。

Receptors of insulin-like growth factor I (IGF-I) and epidermal growth factor (EGF) were analyzed in normal and tumor tissues.1) Brain tumors: Receptors of IGF-I were widely localized in the rat brain areas regulating the behavior, central blood pressure and pituitary hormone. Taken together with the expression of IGF-I mRNA in the brain, the possibility that IGF-I plays the role of a neurotransmitter and/or neuromodulator in the central nervous system is considered. High number of IGF-I and EGF receptors were homogeneously present in tissue sections drived from meningioma, glioblastoma and anaplastic ependymoma, whereas these receptors were faintly present in normal cortex. IGF-I receptors, but not EGF receptors, were also observed in medulloblastoma. Both growth factors stimulated the synthesis of DNA in a dose-dependent manner in the culture of tumor cells. These observations can be interpreted to mean that both IGF-I and EGF may be involved in the growth modulation of brain tumors.2) Lung tumors: We found that IGF-I receptors were present on squamous cell carcinoma, adenocarcinoma, small cell carcinoma and large cell carcinoma. High number of IGF-I receptors were present in cases of squamous cell carcinoma and small cell carcinoma, while cases of adenocarcinoma showed low number. High number of IGF-I receptors, without immunoreactivity, were observed in cases of small cell carcinoma.3) Adrenal tumors: Both IGF-I and EGF receptors were located in the adrenal cortex, while the adrenal medulla contained only IGF-I receptors. However, we could not find the expression of IGF-I receptors in the adrenal tumors. The frequency of EGF receptors expression in the adrenocortical carcinomas (98.4%) was significantly higher than in the adrenocortical adenomas (43.5%) and pheochromocytomas (57.1%). We conclude that the expression of EGF receptors is associated with tumor growth and/or metastatic potential in adrenocortical carcinomas.