Torosian M H
Division of Surgical Oncology, University of Pennsylvania School of Medicine, Philadelphia 19104, USA.
J Surg Res. 1995 Aug;59(2):225-8. doi: 10.1006/jsre.1995.1158.
Previous research has documented significant acceleration of tumor growth in animals receiving short-term parenteral nutrition. This study was performed to determine the effect of long-term enteral protein intake on tumor cell cycle kinetics in the tumor-bearing host. Fifty Lewis/Wistar rats with subcutaneous mammary tumor implants (AC-33) were randomized to receive a standard protein diet (22.0% protein; 4.20 kcal/g) or protein-depleted diet (0.03% protein; 4.27 kcal/g). Animals were sacrificed after 7 or 14 days on each diet and tumor cytokinetics determined by flow cytometry. Tumor volume was significantly reduced in animals receiving the protein-depleted versus standard protein diet after 14 days (P < 0.01). No difference was found in tumor cell cycle kinetics (% G0/G1, S, or G2/M populations) or tumor growth fraction (S + G2/M) in animals receiving standard or protein-depleted diet after 7 or 14 days. These results suggest that reduced tumor growth with prolonged protein depletion in this model occurs by either (a) movement of tumor cells from the active cell cycle to the dormant G0 state or (b) uniform increase of cell cycle duration without changing the relative proportion of cells throughout the cell cycle. The potential therapeutic implications of nutrient-induced alterations in tumor growth are discussed.
先前的研究已证明，接受短期肠外营养的动物体内肿瘤生长显著加速。本研究旨在确定长期肠内蛋白质摄入对荷瘤宿主肿瘤细胞周期动力学的影响。将50只皮下植入乳腺肿瘤（AC - 33）的Lewis/Wistar大鼠随机分为两组，分别接受标准蛋白质饮食（蛋白质含量22.0%；4.20千卡/克）或低蛋白饮食（蛋白质含量0.03%；4.27千卡/克）。每组动物在分别食用每种饮食7天或14天后处死，通过流式细胞术测定肿瘤细胞动力学。14天后，接受低蛋白饮食的动物的肿瘤体积相比接受标准蛋白质饮食的动物显著减小（P < 0.01）。在食用标准饮食或低蛋白饮食7天或14天后的动物中，未发现肿瘤细胞周期动力学（G0/G1期、S期或G2/M期细胞百分比）或肿瘤生长分数（S + G2/M）存在差异。这些结果表明，在该模型中，长期蛋白质缺乏导致肿瘤生长减缓，其原因可能是（a）肿瘤细胞从活跃的细胞周期进入静止的G0期，或者（b）细胞周期持续时间均匀增加，而整个细胞周期中细胞的相对比例不变。本文还讨论了营养物质诱导的肿瘤生长改变的潜在治疗意义。
