• 作者： 楊倍昌; 陳榮富; 邱仲慶; 張文昌; 林銘德; 林秀娟
• 作者服務機構： 成功大學醫學院微免研究所; 奇美醫院神經外科; 成功大學醫學院藥理科; 成功大學醫學院生化科; 成功大學醫學院小兒科
• 中文摘要： 為探討人類惡性神經膠質瘤細胞生理功能改變之情形，本研究以胰島素之訊號傳遞反應為對象。結果發現胰島素會降低人類惡性神經膠質瘤鈿胞serine/threonine蛋白質磷酸化反應；但是在體外培養之正常神經膠質細胞，胰島素則有增強蛋白質磷酸化反應之作用。此種蛋白質磷酸化反應之改變僅見於神經膠質瘤細胞，而腦膜瘤及許旺氏瘤細胞則無此反應。此外，當我們測定細胞中之Protein Kinase C (PKC)酵素活性時，發現於胰島素存在之狀況下，其中一株惡性神經膠質瘤細胞之PKC酵素活性總量有明顯的增加；我們並利用PKC亞型抗體，證實增加活性的為PKCα,β,δ,ε及γ亞型。但是神經膠質瘤細胞質內之PKC-γ及細胞膜上之PKC-ε個別之活性則受到抑制。本研究證實人類惡性神經膠質瘤細胞對於胰島素之訊號傳遞反應與正常神經膠質細胞不同。
• 英文摘要： Modulation of protein phosphorylation activities by insulin was investigated in glioma and normal glialcells. Insulin suppressed the in vitro protein phosphorylation of glioma cells in a dose-dependent mannerwhile it stimulated that of meningiomas, neurilemmomas and glial cells. Although gliomas and glial cellscontained different species of tyrosyl phosphoproteins before treatment, they expressed similar kinds oftyrosyl phosphoproteins in response to insulin. Insulin increased the activities of casein kinase II and totalprotein kinase C (PKC) in glioma and normal glial cells. The membrane-bound PKC activity in U373-MGcells was elevated by insulin. The PKC isozymes, including subtypesα,β,δ,εandγ, were detected in gliomas,but few were found in glial cells. Insulin down regulated the cytosolic PKC-γ and the membrane-boundPKC-εproteins in gliomas. These results indicate that an altered insulin signaling pathway exists in humangliomas, which might involve differential regulation of PKC isozymes.
• 中文關鍵字： glioma; insulin; protein phosphorylation; protein kinase C.
• 英文關鍵字： --