SDF-1/CXCR4轴对人绒毛膜癌细胞侵袭、迁移能力的影响及意义

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

目的 研究SDF-1/CXCR4轴对人绒毛膜癌细胞株JAR细胞侵袭、迁移能力的影响及AMD3100对CXCR4的阻断作用,同时研究对下游PI3K/AKT信号通路的影响作用,进而探讨SDF-1/CXCR4轴在子痫前期发病中的作用机制.方法 将JAR细胞分为4组：AMD3100处理组（100 ng/ml）、SDF-1处理组（50 ng/ml）、SDF-1＋AMD3100混合组（100 ng/ml AMD3100孵育2 h后再加入50 ng/ml SDF-1）、空白对照组.RT-PCR检测SDF-1和AMD3100处理后JAR细胞中CXCR4 mRNA表达水平的变化;Western blot 检测CXCR4及下游p-AKT蛋白的表达水平.采用MTT增殖试验,在0 h、24 h、48 h、72 h时间点分别检测不同浓度的SDF-1（10、30、50、100 ng/ml）对JAR细胞增殖能力的促进作用;Transwell侵袭试验、划痕试验分别检测不同处理因素条件下4组JAR细胞侵袭和迁移能力的变化情况.结果 （1）RT-PCR结果显示：SDF-1处理组JAR细胞中CXCR4 mRNA的表达（1.839＆#177;0.083）明显高于空白对照组（1.372＆#177;0.086）、AMD3100处理组（0.694＆#177;0.045）、SDF-1＋AMD3100混合组（0.703＆#177;0.093）,差异有统计学意义（F=30.67,P〈0.05）;与空白对照组比较,AMD3100处理组JAR细胞中CXCR4 mRNA的表达显著降低,差异有统计学意义（P〈0.01）.（2）Western blot结果显示SDF-1处理组JAR细胞中CXCR4及p-AKT蛋白表达水平明显高于空白对照组、AMD3100处理组、SDF-1＋AMD3100混合组;与空白对照组比较,AMD3100处理组JAR细胞中CXCR4及p-AKT蛋白表达水平显著降低.（3）MTT结果显示：与10、30、100 ng/ml浓度的SDF-1处理组相比,50 ng/ml SDF-1对JAR细胞的促增殖作用最强;且在48 h时,促增殖效应最大,与调零组及空白对照组比较差异均有统计学意义（P〈0.05）.（4）Transwell侵袭试验显示：SDF-1组侵袭细胞数（70.49 ＆#177; 2.42）明显多于空白对照组（54.36＆#177;2.26）、AMD3100处理组（21.68＆#177;8.31）、SDF-1＋AMD3100混合组（28.18＆#177;4.61）,差异有统计学意义（F=116.26,P〈0.01）;与空白对照组比较,AMD3100处理组侵袭细胞数显著减少,差异有统计学意义（P〈0.05）.（5）划痕试验结果显示,24 h之后,SDF-1组相对迁移距离（1.162＆#177;0.034）明显高于空白对照组（0.823＆#177;0.101）、AMD3100处理组（0.160＆#177;0.047）、SDF-1＋AMD3100混合组（0.183＆#177;0.064）,差异有统计学意义（F=30.500,P〈0.05）;与空白对照组比较,AMD3100处理组相对迁移距离显著减少,差异有统计学意义（P〈0.01）.结论SDF-1可增强人绒毛膜癌细胞株JAR的侵袭、迁移能力,但能被AMD3100阻断,因此推测在子痫前期发病过程中SDF-1/CXCR4轴可能受到抑制,并引起下游PI3K/AKT信号通路活化异常,进而引起滋养细胞的增殖异常、侵袭迁移不足,导致胎盘形成异常.

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＆#177;0.083） as compared with that in the blank control group （1.372＆#177;0.086）,AMD3100 group （0.694＆#177;0.045） or SDF-1＋AM3100 mixed group （0.703＆#177;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＆#177;2.42） was more than that in the blank control group （54.36＆#177;2.26）,AMD3100 group （21.68＆#177;8.31）,or SDF-1＋AMD3100 mixed group （28.18＆#177;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＆#177;0.034） as compared with that in the blank control group （0.823＆#177;0.101）,AMD3100 group （0.160＆#177;0.047）,or SDF-1＋AMD3100 mixed group （0.183＆#177;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.