Uren J R, Lazarus H
Cancer Treat Rep. 1979 Jun;63(6):1073-9.
The L-cyst(e)ine requirements of normal and malignant cells are reviewed and expanded within the context of establishing whether the measurement of gamma-cystathionase levels constitutes a predictive test for tumor sensitivity to L-cyst(e)ine depletion. The ability of both purified L-cysteine desulfhydrase and gamma-cystathionase to inhibit the growth of the L-cystine-dependent L1210 leukemia in culture is presented, as well as approaches to circumvent the limitations of these enzymes for in vivo therapy. The ability of proparagylglycine to inhibit L-cysteine biosynthesis in vivo is reviewed for its possible use in combination therapy. In addition, the ability of poly D,L-alanine modification of Escherichia coli L-asparaginase to increase the plasma half-life in mice tenfold as well as to decrease the immunogenicity of the enzyme is presented.
在确定γ-胱硫醚酶水平的测量是否构成肿瘤对L-胱氨酸耗竭敏感性的预测性测试的背景下，对正常细胞和恶性细胞的L-胱氨酸需求进行了综述并加以扩展。文中介绍了纯化的L-半胱氨酸脱硫酶和γ-胱硫醚酶抑制培养中依赖L-胱氨酸的L1210白血病生长的能力，以及克服这些酶用于体内治疗的局限性的方法。综述了炔丙基甘氨酸在体内抑制L-半胱氨酸生物合成的能力，探讨其在联合治疗中的潜在用途。此外，还介绍了聚D，L-丙氨酸修饰的大肠杆菌L-天冬酰胺酶在小鼠体内使血浆半衰期延长10倍以及降低该酶免疫原性的能力。
