Different Basic Fibroblast Growth Factor and Fibroblast Growth Factor-Antisense Expression in Eutopic Endometrial Stromal Cells Derived from Women with and without Endometriosis

In all species studied, the basic fibroblast growth factor (bFGF) gene is transcribed into multiple mRNAs, one of which is an antisense RNA (1B FGF-AS) probably involved in regulating the stability of the sense transcript. In this study we investigated whether the regulatory mechanisms of bFGF expression might be altered in endometrial stromal cells derived from women with endometriosis, bFGF and 1B FGF-AS mRNA levels were quantified in primary cultures of eutopic endometrial stromal cells derived from 29 women without endometriosis and 24 patients affected by the disease. When the data were analyzed according to the phase of the menstrual cycle, endometrial stromal cells derived from patients in the late proliferative phase showed significantly higher bFGF mRNA values and significantly lower 1B FGF-AS mRNA levels compared with control samples. Furthermore, the mean bFGF/1B FGF-AS mRNA ratio was significantly higher in endometrial stromal cells derived from patients compared with that in controls (mean ± SEM, 2.31 ± 0,55 and 0.77 ± 0.14, respectively; P = 0.009). Moreover, for bFGF expression the differences existing at the mRNA level were maintained at the protein level. These findings support the hypothesis that 1B FGF-AS mRNA could regulate the expression of the sense transcript and suggest that in endometrial cells derived from patients, the presence of higher bFGF levels could improve their ability to proliferate at the ectopic site.