硒对淋巴细胞抗大肠癌作用影响的基础和临床研究

STUDY ON SELENIUM TO ENHANCE T LYMPHOCYTE ANTI-COLONIC CANCER FUNCTION

目的 :探讨硒对淋巴细胞抗大肠癌的作用。方法 :包括实验与临床二部分 ,以半胱氨酸硒作为影响因素、人 T淋巴细胞为效应细胞 ,人结肠癌细胞 (L o Vo细胞株 )为靶细胞 ;采用 MTT比色法、凋亡细胞荧光计数检测凋亡细胞的数量 ;同时检测上清液中 TNF- α(肿瘤坏死因子 α)的含量。然后 ,于 1998年 3月至 1999年 3月 ,将 40例大肠癌患者 ,随机分成对照组和治疗组分别给予一般酵母和酵母硒 (6 0 0 μg/ d)持续两周 ,观察治疗前后血硒水平、T细胞亚群和免疫球蛋白 ,以及细胞因子 αTNF的变化。结果 :半胱氨酸硒在一定的浓度范围内 (0 .5 μg/ m l～ 1.0 μg/ m l)可增强人 T淋巴细胞的抗肿瘤活性(P <0 .0 5 ) ,促进人结肠癌细胞的凋亡 ,且肿瘤细胞的凋亡比例上升 (P <0 .0 5 ) ;T淋巴细胞抗肿瘤作用的增强与上清液中的 TNF- α的增高有关 (P <0 .0 5 )。大肠癌患者经补硒后 ,血硒由 (0 .76± 0 .17) μm ol/ L 上升到 (0 .99± 0 .2 3) μmol/L,P <0 .0 5 ;CD4由 (2 4.0 9± 4.10 ) %上升到 (2 7.95± 4.91) %,CD8由 (2 0 .18± 2 .48) %上升到 (2 3.0 9± 4.47) %,P <0 .0 5 ;血清中 Ig M从 (83.7± 2 3.37) mg上升到 (10 3.6 9± 35 .49) mg,P <0 .0 5。结论 :硒可提高淋巴细胞的抗肿瘤作用 。

Objective:This paper is to study whether selenocysteine could enhance T lymphocyte anti-colonic cancer cell function. Methods: This study includes two parts: the experiment and clinical practice. Selenocysteine was tested as an influencing factor to human T lymphocyte in human colonic tumor cells (LoVo cel: human colonic adenocarcinoma) as a target cell. MTT and acridine orange for quantitative measurement were used. TNFa was also measured. 40 patients wiht colorectal carcinoma were randomly divided into two groups, therapeutic group and control group. Subjects were assigned to a 2-weeks trial with either 600ug Se/day (as selenium enruiched yeast) or pure yeast as a placebo. The changes of serum selenium levels, T lymphocyte subsets, immunoglobin, and cytokine TNFα in serum were examined before and after the experiment. Results: MTT and acridine orange dying showed that selenium enhanced T lymphocyte anti-tumor function of and induced LoVo cells to apoptosis within the proper levels (0.5-1.0g/L). Enhancement of T lymphocyte anti-tumor function is related to TNFα (P=0.01), and not to SOD and MDA (P>0.05). Serum Se level (0.81±0.10 μmol/L), T lymphocyte subsets, were lower in colorectal cancer patient than normal, but improved significantly after Se supplementation in therapeutic group (P<0.05), and was significant different from control group (P<0.05). Conclusoin: Administration selenocysteine can enhance T lymphocyte anti-colonic cancer function, and improve the immunity of patients with colorectal cancer.