The role of prokineticins in recurrent implantation failure.

The aim of the present study was to investigate the expression patterns of prokineticins (PROK) and prokineticin receptors (PROKR) in the endometrium of women with recurrent implantation failure (RIF). Fifteen (15) women with RIF and 15 fertile controls were enrolled in this study. Endometrial samples were taken from study participants with an endometrial biopsy cannula during the implantation window. Real time polymerase chain reaction and immunohistochemistry were used to determine PROK/PROKR mRNA expression and protein localization, respectively. PROK1 mRNA levels were 6.09 times higher compared to endometrial samples obtained from women with RIF than in samples obtained from fertile controls, whereas PROKR1 mRNA levels were 2.46 times lower in endometrial samples obtained from women with RIF than in samples from fertile controls. In addition, decreased PROKR1 was supported by immunohistochemistry analysis at protein level. There was no statistically significant difference between women with RIF and fertile controls regarding PROK2 and PROKR2 levels. Altered expression of the PROK1/PROKR1 system could be one of the numerous abnormalities in the endometrium of women with RIF.