Savini I, D'Angelo I, Annicchiarico-Petruzzelli M, Bellincampi L, Melino G, Avigliano L
Department of Experimental Medicine and Biochemical Sciences, University Tor Vergata, Rome, Italy.
Anticancer Res. 1998 Mar-Apr;18(2A):819-22.
The present study investigated the ability of two neuroblastoma cell lines (SK-N-SH, with one copy of N-myc, and SK-N-BE(2), with over 150 copies of N-myc) to recycle ascorbate by quantifying semidehydroascorbate reductase and dehydroascorbate reductase activities. Both cell lines expressed dehydroascorbate activity (SK-N-SH 28.4 +/- 9.8, SK-N-BE(2) 21.7 +/- 5.2 nmol/min/mg protein). Intracellular semidehydroascorbate activity was present only in SK-N-BE(2) cells (4.7 +/- 1.2 nmol/min/mg protein). Extracellular ascorbate was regenerated by semidehydroascorbate membrane activity, the activity of SK-N-BE(2) being twice that of SK-N-SH cells. The present data may explain the ability of the tumor to progress or regress through mechanisms involving both myc oncogene and apoptosis.
本研究通过定量半脱氢抗坏血酸还原酶和脱氢抗坏血酸还原酶的活性，研究了两种神经母细胞瘤细胞系（SK-N-SH，有一个N-myc拷贝；SK-N-BE(2)，有超过150个N-myc拷贝）循环利用抗坏血酸的能力。两种细胞系均表现出脱氢抗坏血酸活性（SK-N-SH为28.4±9.8，SK-N-BE(2)为21.7±5.2 nmol/分钟/毫克蛋白）。细胞内半脱氢抗坏血酸活性仅存在于SK-N-BE(2)细胞中（4.7±1.2 nmol/分钟/毫克蛋白）。细胞外抗坏血酸通过半脱氢抗坏血酸膜活性得以再生，SK-N-BE(2)的活性是SK-N-SH细胞的两倍。目前的数据可能解释了肿瘤通过涉及myc癌基因和凋亡的机制进展或消退的能力。
