Role of SDF-1/CXCR4 axis in the invasion and migration of human choriocarcinoma cells and its significance in preeclampsia

Abstract

Objective To investigate the effects of stromal cell-derived factor 1 (SDF-1) and an CXC chemokine receptor 4 (CXCR4) antagonist (AMD3100) on the invasion and migration capabilities of the huaman choriocarcinoma cell line JAR for further elucidating the role of SDF-1/CXCR4 axis in the pathogenesis of preeclampsia. Methods JAR cells were divided into four groups: SDF-1 group (treated with 50 ng/ml of SDF-1), SDF-1+ AM3100 mixed group (first treated with 100 ng/ml of AMD3100 for 2 hours and then treated with 50 ng/ml of SDF-1), AMD3100 group (treated with 100 ng/ml of AMD3100) and blank control group (without any treatment). RT-PCR was performed to detect the expression of CXCR4 at mRNA level in JAR cells. Western blot assay was used to measure the expression of CXCR4 and p-AKT at protein level. MTT assay was used to analyze the effects of different concentrations of SDF-1 (10, 30, 50 and 100 ng/ml) on the proliferation of JAR cells at different time points (0, 24, 48, 72 h). Transwell invasion assay and wound-healing assay were used to test the changes in invasion and migration capabilities of JAR cells after different treatments. Results (1) Results of the RT-PCR showed that the expression of CXCR4 at mRNA level in JAR cells was increased in the SDF-1 group (1.839±0.083) as compared with that in the blank control group (1.372±0.086), AMD3100 group (0.694±0.045) or SDF-1+ AM3100 mixed group (0.703±0.093). Moreover, the differences between the SDF-1 group and the other three groups were statistically significant (F=30.67, P<0.05). Compared with the blank control group, the expression of CXCR4 at mRNA level in JAR cells was decreased in the AMD3100 group (P<0.01). (2) Results of the Western blot assay showed that the expression of CXCR4 and p-AKT at protein level in JAR cells were enhanced in the SDF-1 group as compared with that in the blank control group, AMD3100 group or SDF-1+ AM3100 mixed group. Compared with the blank control group, the expression of CXCR4 and p-AKT at protein level in JAR cells were inhibited in the AMD3100 group. (3) Results of the MTT assay showed that SDF-1, especially at the concentration of 50 ng/ml, could enhance the proliferation of JAR cells (P<0.05) and its best effect on proliferation was seen at 48 h. (4) Results of the Transwell invasion assay showed that the number of transmembrane cells in the SDF-1 group (70.49±2.42) was more than that in the blank control group (54.36±2.26), AMD3100 group (21.68±8.31), or SDF-1+ AMD3100 mixed group (28.18±4.61). The differences between the SDF-1 group and the other three groups were statistically significant (F=116.26, P<0.01). Compared with the blank control group, the number of transmembrane cells was reduced in the AMD3100 group (P<0.05). (5) Results of the wound-healing assay showed that the relative migration distance was increased in the SDF-1 group (1.162±0.034) as compared with that in the blank control group (0.823±0.101), AMD3100 group (0.160±0.047), or SDF-1+ AMD3100 mixed group (0.183±0.064). The differences between the SDF-1 group and the other three groups were statistically significant (F=30.500, P<0.05). Compared with the blank control group, the relative migration distance was decreased in the AMD3100 group (P<0.01). Conclusion The invasion and migration of huaman choriocarcinoma JAR cells can be enhanced by SDF-1, but inhibited by AMD3100. This study indicates that the blocked biological axis of SDF-1/CXCR4 may play an important role in the pathogenesis of preeclampsia through inducing abnormal activation of PI3K/AKT pathway, which results in inhibited invasion and migration of trophoblast cells and placenta abnormality. Key words: SDF-1/CXCR4 axis; Invasion; Migration; PI3K/AKT pathway; Trophoblast cell; Preeclampsia