EphB2在先天性肛门直肠畸形直肠末端表达的研究

Expression of EphB2 in congenital anorectal malformation

目的研究酪氨酸蛋白激酶受体——EphB2在先天性肛门直肠畸形直肠末端组织中的mRNA表达和蛋白表达的水平，探讨EphB2与先天性肛门直肠畸形发生的关系。方法RT-PCR方法和Western蛋白印迹方法，检测31例不同类型先天性肛门直肠畸形直肠后壁末端、5例后天瘘及8例正常直肠后壁末端EphB2在蛋白水平和mRNA水平的表达情况，应用单因素方差分析比较正常组和畸形组、不同类型的畸形组之间EphB2表达水平的差异。结果①先天性肛门直肠畸形末端肠壁EphB2基因mRNA相对表达量明显低于正常对照组（0．99±0．11，P=0．00）。不同类型的畸形组之间，高位组（0．43±0．07）和中位组（0．47±0．10）之间差异无统计学意义（P=0．33），但二者明显低于低位组（0．64±0．06，P=0．00）。后天瘘组（0．97±0．09）与正常对照组比较差异没有统计学意义（P=0．63）；②Western蛋白印迹结果显示，先天性肛门直肠畸形高位组（0．21±0．05）、中位组（0．24±0．04）和低位组蛋白表达水平均明显低于后天瘘组（0．51±0．05）和正常对照组（0．52±0．03，P=0．00）。不同类型的畸形之间，高位组和中位组之间无明显差异（P=0．11），但二者明显低于低位组（P〈0．01）。后天瘘组与正常对照组比较差异没有统计学意义（P=0．67）。结论EphB2在先天性肛门直肠畸形直肠末端低表达。EphB2的表达和肛门直肠畸形的发生有关，EphB2在先天性肛门直肠畸形的发生中可能具有重要作用。

Objective To investigate the expression of EphB2 in the terminal rectum with congenital anorectal malformation（CAM）, and to explore the relationship between the expression of EpnB2 and the development of CAM. Methods Specimens were obtained from 44 patients including 31 patients with CAM, 5 patients with infective rectovestibular fistula and 8 normal controls. Expression of EphB2 gene and protein were detected by RT-PCR and Western-blot respectively. One-way ANOVA was used to statistically analyze the differences of EphB2 expression between the normal and malformation groups. Results The EphB2 mRNA expression in normal rectum was significantly higher than that in malformations（0. 99±0.11, P = 0. 00）. There was no significant difference of expression of EphB2 between high（0.43±0. 07） and intermediate（0.47±0. 10） CAM（P= 0. 33）. However, the expression of EphB2 mRNA in high and intermediate CAM were significant lower than that in low group（0.64±0. 06,P = 0. 00）. Moreover, there was no significant difference of EphB2 mRNA expression between the infective rectovestibular fistula（0. 97± 0.09） and the control group（P = 0. 63）. The expression of EphB2 protein in high, intermediate and low CAM had a marked decrease compared with that in controls （0. 21±0. 05, 0.24 ± 0. 04 and 0. 30±0. 04 vs 0. 52 ±0. 03, P = 0.00）. There was no significant difference of EphB2 protein expression between high and intermediate CAM detected by Western-blot （P = 0. 33）. However, the levels of EphB2 protein in high and intermediate CAM were significant lower than those in low group （P = 0. 00）. There was no significant difference of EphB2 protein level between the infective rectovestibular fistula and the control group（P = 0. 67）. Conclusions Both mRNA and protein levels of EphB2 in CAM are decreased. EphB2 may play an important role in the development of CAM.