KAI_1在原发性肝癌组织中的表达水平及调控机制的初探

The expression levels of KAI_1/CD82 mRNA in hepatocellular carcinoma and investigation the regulative mechanism

目的 初探KAI1/CD82在原发性肝细胞癌组织中的表达水平及可能涉及的机制。方法 采用多重逆转录聚合酶链反应 ,对 8例原发性肝细胞癌组织和 4例肝血管瘤正常组织中KAI1/CD82mRNA表达水平进行半定量检测 ,并对肝癌细胞株用Bel 74 0 2和SMMC 772 1在肿瘤促进剂佛波醇肉桂酸乙酸酯 (PMA)和去甲基化试剂 5 氮脱氧胞苷作用下KAI1/CD82表达水平及可能涉及的机制进行了初步探讨。结果 肝癌癌组织中KAI1/CD82mRNA表达水平(0 .70± 0 .13)较癌旁组织 (1.4 7± 0 .18)和肝血管瘤的正常肝组织中KAI1/CD82mRNA表达水平 (1.5 3± 0 .0 3)呈显著降低 (P <0 .0 5 ) ,后两者之间则不存在明显差异。去甲基化试剂 5 氮脱氧胞苷使Bel 74 0 2中KAI1/CD82mRNA表达有一定增高 ,但对SMMC 772 1中KAI1/CD82mRNA表达水平无明显作用。PMA对Bel 74 0 2和SMMC 772 1中KAI1/CD82mRNA表达具有一定的调节作用。结论 原发性肝细胞癌组织KAI1/CD82表达明显降低 ,可能是癌细胞转移的一个标志 ,这种表达降低可能涉及到基因甲基化等多种复杂调控的机制。

Objective KAI 1/CD82, a member o TM4SF(Transmembrane 4 Superfamily),has important biological roles such as regulatiog cell adhesion and cell migration. The ratios of KAI 1/CD82mRNA to β actin cDNA in the same tissue was used as the expression level of KAI 1/CD82 mRNA in hepatocellular carcinoma and normal hepatic tissues,studies on the regulative mechanism.Methods KAI 1 mRNA of 8 cases with hepatocellular carcinoma and normal hepatic tissues were detected using duplex reverse transcription polymerase chain reaction (duplex RT PCR)method as compared with product of β actin.KAI 1/CD82mRNA and β actin mRNA were reversed transcription in one tube, so that the condition of reverse transcription polymerase chain reaction between KAI 1 and β-actin genes were same. Bel 7402 and SMMC 7721 of human hepatocellular carcinoma celllines were cultured after being demethylated by 5 aza deoxycytidine. The condition is 37℃ ,5%CO 2 saturation humidity,nonbacterium.The expression levels rations of KAI 1/β actin,mRNA by duplex reverse transcription polymerase chain rection were detected,used the instrument of light density scanning.Results The product of KAI 1 was 484 bp and the one of β actin was 370 bp.Under the condition of being sure that the extracted total RNA was pure, the results as follows ,the average expression levels of KAI 1/CD82 mRNA in depatocellular carcinoma (0.70±0.13)were significant lower than that in normal hepatic tissues (1.53±0.03) and that in paracancer tissues(1.47±0.18)P<0.05.After being demethylated by 5 aza deoxycytidine, the expression level of KAI 1/CD82 mRNA in Bel-7402 cell increased,but couldn't detect significant change in SMMC 7721cell.Conclusion These results indicated that decreased KAI 1/CD82 in hepatocellular carcinoma might be a marker for hepatocellular carcinoma cell migration and that several regulatory mechanisms including gene demethylation might be involved in KAI 1/CD82 expression. The decreasing of the expression levels of KAI 1/CD82 mRNA affected by many factors and maybe demethylate gene.The mechanisms are different on various type cells.