白血病细胞TGFβ1及其受体基因表达与白血病患者血清TGFβ …

目的：研究转化生长因子β（ＴＧＦβ１）对白血病细胞增殖抑制作用的机制及急性白血病患者血清ＴＧＦβ１变化及意义。方法：应用逆转录－聚合酶链反应方法检测白血病细胞的细胞因子及其受体基因表达；应用白血病细胞集落试验测定ＴＧＦβ１对ＨＬ－６０、ＤＡＭＩ、Ｋ５６２细胞增殖作用；应用ＥＬＩＳＡ方法测定３３例急性白血病患者血清ＴＧＦβ１水平。结果：ＴＧＦβ１对ＨＬ－６０、Ｋ５６２、ＤＡＭＩ细胞增殖具有明显的抑制

Study on gene expression of TGF beta 1 and its receptor in leukemia cells and the serum TGF beta 1 level in the patients with acute leukemia]

OBJECTIVE: To investigate the mechanism by which TGF beta 1 inhibits the growth of leukemic cells and the significance of serum TGF beta 1 level in acute leukemia(AL) patients. METHODS: RT-PCR was used to detect gene expression of cytokines including IL-1, IL-3, IL-6, TGF beta 1 and their receptors (R) in leukemic and normal cells. Leukemic colony assay was carried out to determine the effect of TGF beta 1 on the growth of leukemic cells and the serum TGF beta 1 level in 33 AL patients were measured by ELISA. RESULTS: TGF beta 1 was found to significantly inhibit the proliferation of leukemia cells of HL-60, K562 and DAMI cell lines. Furthermore, a variety of leukemia cell lines including HEL, HL-60, K562, U937, DAMI, MEG-01, HUT78 and CA were found to express mRNAs for TGF beta 1 and its receptor. In addition, TGF beta 1 was found to be able to evidently down-regulate the expression of mRNAs for IL-6, IL-6R, IL-3, GM-CSFR in DAMI cells and, interestingly, up-regulate TGF beta 1 gene expression in the cells per se before the cells showed DNA fragmentation, a molecular hallmark for cell apoptosis. It was shown that serum TGF beta 1 levels were significantly decreased in leukemic patients, restored to normal in the patients achieved complete remission, and tended to decrease again in the recurrent patients. CONCLUSION: 1. TGF beta 1 may act as an inhibitory autocrine factor in the proliferation of leukemia cells; 2. the mechanism by which TGF beta 1 inhibits the growth of leukemia cells involves its down-regulating expression of positive cytokines and receptors and up-regulating TGF beta 1 expression in leukemia cells per se; 3. serum TGF beta 1 is a valuable parameter in monitoring the prognosis of leukemia and weakened control of TGF beta 1 on leukemia cells may play an important role in the pathogenesis of AL.