Elevated Gene Expression in Tubal Pregnancy and Its Relation to Ectopic Implantation

Background: Establishment of viable pregnancy requires em-bryo implantation and placentation. Ectopic pregnancy (EP) oc-cur outside of the uterine cavity with around 98% implanting in the fallopian tube. Among the effective genes involved in the receptive endometrium and appropriate implantation procedure FGF2, CSF1, HBEGF, MUC1 and VEGF-A are of considerable importance. This study aims to investigate mRNA expression of above mentioned genes in fallopian tubes (ampulla) and endo-metrium of women who had EP compared with fallopian tubes and endometrium of pseudo-pregnant women.Materials and Methods: This case-control study consisted of ampulla and endometrium of EP patients who underwent sal-pingectomy (n=5) and five women overtaken pseudo-pregnant fallopian tubes and endometrial tissue that underwent hysterec-tomy. Prior to tubal sampling, each control woman received an injection of human chorionic gonadotropin (HCG) to produce a state of pseudo-pregnancy. All samples collected in window of implantation phase. Ampulla sections are separated slightly away from trophoblastic implantation site. Fallopian tubes and endometrial tissue from both groups were procured, and after the RNA extraction and cDNA synthesis, mRNA expressions were analyses in endometrial tissue and ampulla region of the fallopian tube by qRT-PCR. Data were analyzed by SPSS 21 software, and P ≤0.05 was considered as significant.Results: Our results showed altered expressions of these genes in endometrial tissue and ampulla region in both groups. The expression of MUC1, HBEGF, and FGF2 genes in endometrial and ampulla was significantly higher in the case group than control (P ≤0.05). The expression of VEGFA and CSF genes was significantly higher in the endometrium of the EP whereas was significantly higher in ampulla of the control group com-pare to patients (P ≤0.05).Conclusion: Different expression of selected genes in the WOI of endometrium and ampulla of tubal pregnancy might have a role in the pathogenesis of ectopic embryo implantation, espe-cially due to critical function of these in appropriate implanta-tion process. This data suggests a fallopian tube probably pre-disposing implantation and non-receptive endometrium in EP.

Keywords:

Tubal Pregnancy , Gene Expression , Heparin-binding EGF-like growth factor , Colony Stimulating Factor 1 , Fallopian Tube