铁剥夺在TPA 诱导K562 细胞分化中对细胞 生长分化及EGR1mRNA 表达的影

目的：通过，IPA诱导K562细胞分化过程中干预细胞铁代谢探讨白血病细胞铁与细胞分化的关系及对EGR1mRNA表达的影响。方法：应用体外细胞培养技术通过细胞形态，细胞化学染色观察细胞生长分化情况；用FCM、RT—PCR等技术检细胞周期、细胞表面分化抗原CD33、CD14及EGR1mRNA的表达。结果：在，IPA诱导K562细胞分化过程中铁剥夺可明显抑制K562细胞生长，并可阻止，IPA诱导K562细胞分化，使K562细胞停止在S期。铁剥夺可降低，TPA诱导K562细胞分化过程中EGR1mRNA的表达。讨论：铁剥夺明显抑制K562细胞生长、阻止TPA诱导K562细胞分化，故铁剥夺剂（DFO）可能作为一种辅助抗癌药用于白血病的化疗，但由于它能阻止白血病细胞的分化，故不宜用于白血病的诱导分化治疗。铁剥夺使K562细胞分化过程中E—GR1mRNA表达降低可能参与了阻止TPA诱导K562细胞的分化过程。

K562 Cell Growth and Differentiation and EGR1mRNA Expression were Affected by Iron Deprivation During TPA- Induced K562 Cell Differentiation

Objective: To investigate the relationship between iron and K562 cells differentiation and EGR1mRNA expression by TPA inducing K562 cells differentiation and interfering with iron metabolism. Methods: Morphology(Wright. s staining , NSE staining , iron staining) and flow cytometry were applied to observe the differentiation characteristics of K562 cells, cell- cycle and the differentiation antigen expression of CD33, CD14 on the surface of cells. PT- PCR was applied to assay the EGR1mRNA expression. Results: The rate of K562 cell growth was 8. 67%, 6. 01% and 98. 88% in k562 + TPA group, TPA+ Fe group and TPA- Fe group respectively. The rate of differentiation- inducing of K562 was 4. 5% and 95%, 92. 5%, 11% in the control group and other three experiment groups, respectively. K562 cells with NSE staining showed strong positive in groups of TPA or TPA+ Fe treatment K562 cell, but negative or weak positive in most cells both control group and TPA - Fe treatment K562 cell group. Inhibiting rate of NaF of K562 was 16. 13%, 58. 72%, 61. 93% and 19. 23% in every group respectively. Cell cycle remained at S phase in the control group and TPA- Fe group: the percent of S phase cells was 60. 21% and 60. 99% respectively, but in groups of TPA or TPA+ Fe treatment K562 cell, cell- cycle remained at G0+ G1 phase: the percent of their cells was 51. 7% and 53. 69% respectively . The expression of CD33 on the surface of cells was similarly 0. 99, 0. 93, 0. 92 and 0. 96 in every group respectively. The expression of CD33 on the surface of cell was different: in TPA group and TPA+ Fe group ( 0. 31 and 0. 44 respectively) , in control group and TPAFe group( 0. 05 and 0. 09 respectively) . EGR1mRNA was expressed only in three experiment groups with TPA or TPA+ Fe group or TPA- Fe group: 1. 0173? 0. 0223, 0. 992? 0. 039 and 0. 4993 ? 0. 028 respectively. Our experiment suggested that iron deprivation inhibited cell growth and blocked cell differentiation and decreased EGR1mRNA expression, and cell cycle remained at the Speriod during TPA- inducing K562 cell. Conclusion: K562 cell growth were inhibited and their differentiation were blocked at cell cycle S period, so the agent of iron deprivation could be regarded as a supplementary anticancer drug in chemical therapy of leukemia. EGR1mRNA expression was reduced by iron deprivation during TPA- inducing K562 cell differentiation and could participate in blocking K562 cell differentiation course induced by TPA.