ヒトnon-glial tumorにおけるinsulin-likegrowth factor I受容体の発現について—Epidermal growth factor受容体との比較検討

EXPRESSION OF INSULIN-LIKE GROWTH FACTOR I (IGF-I) AND EPIDERMAL GROWTH FACTOR (EGF) RECEPTORS IN PRIMARY NON-GLIAL HUMAN BRAIN TUMORS

　抄録　meningiomaを主体としたヒトprimary non-glial brain tumorにおけるinsulin-like growthfactor I （IGF-I）およびepidermal growth factor （EGF）受容体発現の有無について検討した。その結果，検索した全てのmeningiomaおよびhemangioblastomaに高親和性のIGF-IおよびEGF受容体の存在が認あられ，neurinomaおよびmalignant lymphomaにおいてはIGF-I受容体のみ存在し，EGF受容体は測定限界以下であった。また，IGF-IおよびEGFはmeningioma細胞のDNA合成を濃度依存性に促進し，これら両成長因子はmeningioma細胞の増殖に対し互いにsynergisticな作用を持つことが示唆された。以上の結果より，IGF-IはEGFと共にgliomaのみならず，non-glial originの脳腫瘍に対してもその増殖にautocrine又はparacrine peptideとして重要な役割を演じていると考えられた。

The expression of IGF- I and EGF receptors in the primary non-glial brain tumors (8 meningiomas, 2 neurinomas, 1 hemagioblastoma, 2 primary ma-lignant lymphomas) was analyzed by using in vitro quantitative auoradiographic techniques. Specific binding sites for IGF- I were co-localized with those for EGF in the meningiomas and the he-mangioblastoma examined. However, in the neu-rinomas and the malignant lymphomas, only IGF-I binding sites were present. In addition, IGF-I and EGF synergistically increased 3H-thymidineincorporation into DNA synthesis by the primary cultured meningioma cells, in dose-dependent man-ner. These observations can be interpreted to mean that both IGF- I and EGF may exist asautocrine or paracrine peptides involved in the growth not only of glioma but also of non-glial brain tumors.