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流行病学研究和动物实验证明,硒与多种人类癌症的发病率呈负相关,并能抑制实验动物自发性、移植性和化学致癌剂诱发的肿瘤。治疗剂量的硒还能抑制艾氏腹水癌细胞和白血病L_(1210)细胞在小鼠体内扩散,使小鼠的存活期显著延长。上述宏观领域的研究都支持硒具有抗癌作用的假设,但硒的抗癌机制目前尚不清楚。近年来,细胞遗传学、分子遗传学和遗传毒理学等基础学科的飞速发展,为硒的抗癌机制研究提供了理论依据和技术方法。现将该领域的研究进展综述如下。一、硒与程序外DNA 修复(Unschedul-ed DNA Synthesis,UDS)UDS 是细胞非增殖期的一种DNA 修复合成,它能反映DNA 受损伤的程度,并与化学物质的诱癌性有一定的相关。Lo 等(1978)报道,10~(-5)～10~(-3)的亚硒酸钠(Na_2SeO_3可诱导人皮肤纤维母细胞的DNA 断裂、UDS和染色体畸变,与鼠肝S9组分共同温育后该效应显著增强。但硒酸钠(Na_2SeO_4)不
Epidemiological studies and animal experiments show that selenium and a variety of human cancer incidence was negatively correlated, and can inhibit spontaneous, transplanted and chemical carcinogen-induced tumor in experimental animals. Therapeutic doses of selenium can also inhibit Ehrlich ascites cancer cells and leukemia cells in the proliferation of L_ (1210) in mice, so that the survival of mice significantly prolonged. The above macroscopic research supports the hypothesis that selenium has anti-cancer effects, but the anti-cancer mechanism of selenium is not yet clear. In recent years, the rapid development of basic disciplines such as cytogenetics, molecular genetics and genotoxicity has provided a theoretical basis and technical method for the study of anticancer mechanism of selenium. Now the research progress in this area are summarized below. Selenium and Unscheduled DNA Synthesis (UDS) UDS is a DNA repair synthesis of non-proliferative cells that reflects the extent of DNA damage and is associated with the carcinogenicity of chemicals Related. Lo (1978) reported that sodium selenite (Na_2SeO_3) of 10 -5 to 10 -3 could induce DNA cleavage, UDS and chromosome aberration in human skin fibroblasts, The effect was significantly enhanced after incubation, but sodium selenate (Na 2 SeO 4) did not