视黄酸对BEL-7402细胞酶活性及基因表达的影响

Effect of Retinoic Acid on Ezyme Activity and Gene Expression of BEL 7402

人肝癌ＢＥＬ－７４０２细胞分别以５μｍｏｌ／Ｌ、２０μｍｏｌ／Ｌ和５０μｍｏｌ／Ｌ的视黄酸（ＲＡ）处理后，细胞生长明显受抑，平均细胞群体倍增时间延长，并呈ＲＡ浓度及处理时间依赖性关系．经２０μｍｏｌ／ＬＲＡ处理的细胞中，ｒ－谷氨酰转肽酶（ｒ－ＧＴ）活性自给药后第２天即持续下降，至第６天降至４４．５％，而酪氨酸－α－酮戊二酸转氨酶（ＴＡＴ）活性则持续增高，至第６天较对照组高近１倍．经２０μｍｏｌ／ＬＲＡ处理５ｄ后，ＲＮＡ斑点杂交分析表明ｐ５３基因转录加强，而Ｎ－ｒａｓ基因表达下降，提示该两基因的表达变化可能在ＢＥＬ－７４０２细胞的生长抑制及逆转过程中起重要作用，有关机制尚待深入研究．

The growth of human hepatocarcinoma cell line BEL 7402 was obviously inhibited when the cell line was treated with 5,20 and 50 μmol/L retinoic acid (RA)respectively.The inhibition of cell growth depended on the concentration and treatment time of RA.Comparing with control,the activity of r glutamyltransptidase(r GT)of BEL 7402 greatly decreased during 20 μmol/L RA treatment,and decreased to 44.5% activity of control at sixth day.On the contrary,the activity of tyrosin α ketoglutarate transaminase (TAT) in RA treated cells continuously increased and was near one fold higher than the control at sixth day.The results of RNA dot blot showed that the transcription of p 53 gene increased,but the expression of N ras gene decreased during five day's treatement with 20 μmol/L RA.These results suggested that the different expression patterns of the two genes may play an important role in the growth inhbition of BEL 7402 treaed with RA.However,the more detail studies may be needed in future.