Identification of differences in gene expression in primary cell cultures of human endometrial epithelial cells and trophoblast cells following their interaction

Background: The interaction between epithelial cells of endometrium and trophoblast cells during implantation is presumed to be accompanied by a change in gene expression in the cell types involved. The objective of this study was to identify such differentially expressed genes. Methods: The interaction between the cell types was simulated in vitro by growing primary cell cultures of human endometrial epithelial cells and trophoblast cells together (co-culture) and separately (control cultures). Gene expression in the cell cultures was compared using the Differential Display method and confirmed using a modified Northern Blot method. Results: Twelve transcripts were identified as being differentially expressed following the interaction between trophoblast and endometrial cells. Some of these sequences show homology to known human genes while other sequences are coding for potential novel genes: (1) one sequence was homologous to the to Homer 1 gene, (2) one identical to the mRNA for XP-G factor, (3) one similar to a hypothetical protein, (4) transcripts showing homologies to a mRNA coding for a cellular proapoptotic protein, and (5) sequences homologous to regions on human chromosomes 5 and 16. Besides, some differentially expressed transcripts have sequences, which could be translated into ribosomal proteins or possibly code for novel proteins. Conclusion: These sequences may be important to the course of events following the interaction between endometrial epithelial and trophoblast cells and responsible for implantation.