黏附分子CD44表达对白血病细胞黏附、迁移及浸润的影响

The influence of CD44 on the adhesive, migratory and infiltrative abilities of leukemia cells

目的探讨黏附分子CD44表达对白血病细胞黏附、迁移、浸润的影响。方法选择对数生长期的白血病细胞株SHI-1、THP-1、NB4、K562细胞，采用逆转录一聚合酶链反应（RT—PCR）和Westernblot法检测各种白血病细胞株CD44mRNA和蛋白的相对表达水平，并将各株白血病细胞分为对照组（加入同种同型IgG）和实验组（加入CD44单抗），然后观察白血病细胞与人静脉内皮细胞系ECV304细胞的黏附率；用包被ECV304细胞的Transwell小室培养法观察细胞迁移率；用包被人工基质膜Matrigel的Transwell小室培养法观察白血病细胞穿过人工基质膜的浸润能力。结果SHI．1、THP-1、NB4细胞均表达CD44mRNA和蛋白，而K562细胞CD44mRNA和蛋白表达量少甚至不表达；SHI-1、THP-1、NB4细胞CD44mRNA的相对表达水平分别为0．0731±0．0072、0．0827±0．0151、0．1473-t-O．0365，与K562细胞（0．0002±0．0000）相比，差异均有统计学意义（P值均〈0．01）。黏附实验结果显示：实验组SHI-1、THP-1、NB4细胞黏附率均较对照组下降（分别为72．78％、64．09％、57．42％），而实验组K562细胞黏附率为106．16％。迁移实验结果显示：对照组SHI-1、THP-1、NB4细胞迁移率分别为55％、29％、25％，实验组细胞迁移率下降（分别为32％、18％、12％），而两组中K562细胞无明显变化（均为2％）。浸润实验显示：对照组SHI-1、THP-1、NB4细胞穿过Matrigel的细胞率分别为24％、15％、13％，实验组均有所下降（分别为12％、8％、4％），而两组中K562细胞不能穿过。结论CD44抗原可能通过改变细胞的黏附、迁移及浸润能力，参与白血病细胞的髓外浸润过程。

Objective To investigate the expression of CD44 in leukemia cell lines and its role in adhesion, migration and infiltration of leukemia cells. Methods The expression levels of CD44 in four leuke- mia cell lines SHI-1, THP-1, NB4 and K562 were assayed by reverse transcription-polymerase chain reaction （RT-PCR） and Western blot when they were in logarithmic phase. And these cell lines were divided into con- trol group （ treated with same species and isotype IgG） and experimental group （ treated with anti-CD44 mono- clonal antibody）. The assays of cell-cell adhesion to endothelial cells line ECV304, migration through the ar- tificial matrix membrane and infiltration through the Matrigel were performed. Results The relative expres- sion ratios of CD44 to GAPDH in SHI-1, THP-1, NB4 cells were 0. 0731 ± 0. 0072, 0. 0827 ± 0. 0151 and 0. 1473 ±0. 0365, respectively,which were significantly higher than that in K562 cells （0. 0002 ± 0. 0000, P 〈0.01 ）. Cell-cell adhesion assay showed that the adhesion rates of SHI-1, THP-1 and NB4 cells in the ex- perimental group decreased to 72.78%, 64.09% and 57.42%, respectively, and were lower than those of the control groups, while that of K562 cells in the experimental group was 106.16%. Migration assay showed that the transmembrane rates of SHI-1 ,THP-1 and NtM cells were 55%, 29% and 25% in the control group, respectively, and decreased to 32% , 18% and 12% in the experimental group, respectively, while those of K562 cells in both control group and experimental group remained 2%. The infiltration rates of SHI-1, THP- 1 and NB4 cells decreased from 24%, 15% and 13% in the control group to 12%, 8% and4% in the experimental group, respectively, while K562 cells in both groups could not pass through the Ma- trigel. Conclusion CD44 antigen might play an important role in the adhesion, migration and infiltration of leukemia cells and be involved in the extra-medullary infiltration of leukemia cells.