The expression of growth hormone and insulin-like growth factor I recepter mRNAs in brai]tumors and tumor proliferation

生长激素(GH)和胰岛素样生长因子-I(IGF-I)受体mRNAs在脑肿瘤中的表达与肿瘤增殖的关系，目前尚未阐明GH-R和IGF-I受体在人脑肿瘤中的表达与肿瘤增殖的关系。应用逆转录-聚合酶链式反应(RT-PCR)和免疫组织化学技术检测了22例星形细胞瘤和20例脑膜瘤组织中这些受体的表达。星形细胞瘤22例，其中低级别11例，高级别1例。RT-PCR检测GH-R在95%的脑膜瘤和86.4%的星形细胞瘤中表达。80%的脑膜瘤和91.0%的星形细胞瘤表达IGF-I-R mRNA。GH-R和IGF-I-R在星形细胞瘤中的表达不仅在高级别星形细胞瘤中表达，在低级别星形细胞瘤中也有表达。统计学分析表明，这些基因的表达与组织学分级无明显关系。在冰冻组织免疫组织化学研究中，IGF-I-R广泛分布于脑膜瘤细胞和星形细胞瘤细胞的胞浆中。另一方面，使用石蜡包埋组织的肿瘤细胞不能检测到IGF-I-R。这些结果证实了人脑星形细胞瘤和脑膜瘤中存在IGF-I-R和GH-R。这些受体可能在肿瘤细胞的增殖和生长中起作用，可能不仅是IGF-I-R，而且GH本身也可能是星形细胞肿瘤和脑膜瘤的生长促进因子之一。

The expression of growth hormone(GH) and insulin-like growth factor I(IGF-I) receptor mRNAs in brain tumors, and tumor proliferation.The relationship between the expression of GH receptor (GH-R) and IGF-I receptor (IGF-I R)mRNAs, and tumor proliferation has not been elucidated in human brain tumors. We investigated the expression of these receptors in 22 cases of astrocytic tumor and 20 cases of meningioma using not only reverse transcription-PCR(RT-PCR) but also immunohistochemical technique. In 22 case of astrocytic tumor, 11 cases were low grade astrocytoma and the rest were high grade one. Using RT-PCR,GH-R mRNA was found in 95% of meningiomas and in 86.4% of astrocytic trumors. IGF-I-R mRNA was found in 80% of meningiomas and in 91.0% of astrocytic tumors. GH-R and IGF-I-R mRNA in astrocytic tumors were expressed not only in high grade astrocytomas but also in low grade astrocytomas. Statistically, there were no significant relationship between the expression of these mRNAs and histological grade. In immunohistochemical study using frozen tissue, the distribution of IGF-I-R was diffusely recognized in the cytoplasm of meningioma cells and astrocytic tumor cells. On the other hand, IGF-I-R could not be detected in the tumor cells using paraffin embedded tissue. These results demonstrated the existence of IGF-I-R and GH-R in human astrocytic tumors and meningiomas. These receptors may play a role in the tumor cell proliferation and growth, and it is possible that not only IGF-I-R but also GH itself are one of growth accelerating factors in astrocytic tumors and meningiomas.We are now investigating the distribution of GH-R and IGF-I-R mRNAs in brain tumors using in site hybridization technique.