Kennedy R S, Konok G P, Bounous G, Baruchel S, Lee T D
Department of Surgery, Dalhousie University, Halifax, Nova Scotia, Canada.
Anticancer Res. 1995 Nov-Dec;15(6B):2643-9.
Glutathione (GSH) concentration is high in most tumour cells and this may be an important factor in resistance to chemotherapy. Previous in-vitro and animal experiments have shown a differential response of tumour versus normal cells to various cysteine delivery systems. More specifically, an in-vitro assay showed that at concentrations that induce GSH synthesis in normal human cells, a specially prepared whey protein concentrate, Immunocal, caused GSH depletion and inhibition of proliferation in human breast cancer cells. On the basis of this information five patients with metastatic carcinoma of the breast, one of the pancreas and one of the liver were fed 30 grams of this whey protein concentrate daily for six months. In six patients the blood lymphocyte GSH levels were substantially above normal at the outset, reflecting high tumour GSH levels. Two patients (#1, #3) exhibited signs of tumour regression, normalization of haemoglobin and peripheral lymphocyte counts and a sustained drop of lymphocyte GSH levels towards normal. Two patients (#2, #7) showed stabilisation of the tumour, increased haemoglobin levels. In three patients (#4, #5, #6,) the disease progressed with a trend toward higher lymphocyte GSH levels. These results indicate that whey protein concentrate might deplete tumour cells of GSH and render them more vulnerable to chemotherapy.
大多数肿瘤细胞中的谷胱甘肽（GSH）浓度较高，这可能是化疗耐药的一个重要因素。先前的体外和动物实验表明，肿瘤细胞与正常细胞对各种半胱氨酸递送系统的反应存在差异。更具体地说，一项体外试验表明，在能诱导正常人细胞合成GSH的浓度下，一种特制的乳清蛋白浓缩物Immunocal会导致人乳腺癌细胞内GSH耗竭并抑制其增殖。基于这一信息，对5例转移性乳腺癌患者、1例胰腺癌患者和1例肝癌患者每天喂食30克这种乳清蛋白浓缩物，持续6个月。6例患者一开始血液淋巴细胞中的GSH水平显著高于正常水平，这反映出肿瘤中的GSH水平较高。2例患者（病例1、病例3）出现肿瘤消退迹象，血红蛋白和外周淋巴细胞计数恢复正常，淋巴细胞GSH水平持续下降至正常。2例患者（病例2、病例7）肿瘤病情稳定，血红蛋白水平升高。3例患者（病例4、病例5、病例6）病情进展，淋巴细胞GSH水平呈上升趋势。这些结果表明，乳清蛋白浓缩物可能会耗尽肿瘤细胞中的GSH，使其更容易受到化疗的影响。
