Study of glutamine dependency for cell growth in pediatric cancer cells

我们研究了谷氨酰胺剥夺对人类神经母细胞瘤中谷氨酰胺运输活性的影响。我们使用人类神经母细胞瘤细胞系（SK-N-SH）进行研究。在含有两种不同谷氨酰胺浓度（DMEM+ 10% FBS+ 2mm谷氨酰胺（对照）和DMEM+ 10% FBS（谷氨酰胺剥夺））的培养基中测定体外细胞生长情况。在剥夺谷氨酰胺后0、8、16和24 h测定质膜谷氨酰胺转运，并测定其动力学特性（Km和Vmax）。数据（均数SD）采用Student's t检验进行分析和比较。谷氨酰胺运输发生在高亲和力Na^+依赖载体（系统ASC）。细胞生长速率依赖于谷氨酰胺浓度。在谷氨酰胺剥夺后8、16和24小时，谷氨酰胺运输活性显著降低。动力学研究表明，谷氨酰胺剥夺降低了最大转运速度（Vmax）（对照组为13713 * 803 pmol/mg蛋白/mm；谷氨酰胺剥夺为9553* 646，p< 0.01），但不影响转运亲和度（Km）。谷氨酰胺缺失的人神经母细胞瘤中谷氨酰胺转运活性降低的机制是减少系统ASC谷氨酰胺转运蛋白的数量。这可能会减少谷氨酰胺的可用性，从而影响谷氨酰胺缺乏细胞的细胞生长。

We examined the effects of glutamine deprivation on glutamine transport activity in human neuroblastoma. We used a human neuroblastoma cell line (SK-N-SH) for the study. In vitro cell growth was measured in medium containing two different glutamine concentrations (DMEM+1O%FBS+2 mM Glutamine (Control) and DMIEM+1O%FBS (Glutamine deprivation)). Plasma membrane glutamine transport was measured at 0, 8, 16 and 24 hours after glutamine deprivation and its kinetic characteristics (Km and Vmax) were determined. Data (mean SD) were analyzed and compaired with Student's t-test.Glutamine transport occurred by the high affinity Na^+-dependent carrier (System ASC). CeLl growth rates were dependent on glutamine concentrations. Glutamine transport activity was significantly decreased at 8, 16, and 24 hours after glutamine deprivation. Kinetic studies demonstrated that glutamine deprivation decreased maximum transport velocity (Vmax) (Control, 13713 * 803 pmol/mg protein/mm ; Glutamine deprivation, 9553* 646, p< 0.01) without affecting transport affinity (Km).Glutamine transport activity was decreased in glutamine-deprived human neuroblastoma by the mechanism of decreasing the number of System ASC glutamine transporter. This may diminish glutamine availability and thereby influence cell growth in glutamine-deprived cells.