ヒト悪性脳腫瘍における脂質分析

LIPID COMPOSITION OF HUMAN MALIGNANT BRAIN TUMORS

　抄録　細胞悪性化に伴う糖脂質の変化については，細胞接触や分化増殖に伴う変化，胎児性抗原との異同との関連において研究されてきた。脳組織は本来脂質に富む組織であり，腫瘍化に伴う脂質組成の変化が予想されるが，その変化を観察した報告は少い。今回我々は悪性脳腫瘍20例（glioma 12例，転移性脳腫瘍7例，malignant meningioma 1例）につき，cholesterol,lipid-bound phosphorus, cerebroside, sulfa-tide, gangliosideを定量し，正常脳組織と脳腫瘍の脂質組成の相違，gliomaと転移性脳腫瘍の脂質組成の相違，glioma悪性度と脂質組成の相関について検討した。gangliosideをはじめ，cerebroside, sulfatideについても，転移性脳腫瘍，gliomaそれぞれに特徴的な変化がみられた。特にgangliosideについては，転移性脳腫瘍ではGM₃含有率の増加が，またgliomaではGM₃，GD₃含有率の増加が認められた。またmalignant gliomaではlow grade gliomaに比べ，GM₃，GD₃含有率の増加が著明であった。これらの結果に基づき，脳腫瘍における脂質組成変化の意味を検討するとともに，脂質研究の臨床応用への可能性について併せて検討を加えた。

Abstract Malignant transformation is characterized by the uncontrolled proliferation of cells. And changes in the composition of glycolipids, cell surface component which may be involved in regulation of cell growth, were often observed in the malig-nant transformation. In this study, cholesterol, lipid-bound phosphorus, cerebroside, sulfatide and ganglioside were quantitated in the tissue of 20 human malignant brain tumors (malignant glioma, 8; low grade glioma, 4; metastatic tumor, 7; malignant meningioma, 1).

As compared with normal brain, all tumor tissue contained lower cholesterol, sialic acid, cereboside and sulfatide. Metastatic brain tumor or glioma showed characteristic patterns in the content of ganglioside, cerebroside and sulfatide respective-ly. The ganglioside patterns of metastatic tumor or glioma contained a greater proportion of struc-tually simpler gangliosides than normal brain. And in metastatic tumor, GM₃ was a major ganglioside. On the contrary, glioma had increased proportion of GM₃ and GD₃ gangliosides. High grade glioma such as Grade 3-4 contained higher proportion of GM₃ and GD₃, whereas low grade glioma (Grade 1-2) contained less proportion of GM₃ and GD₃.