Objective: To evaluate the mechanism of action of recombinant human tumor necrosis factor (TNF)-binding protein-1 by assessing differential expression of messenger RNA (mRNA) for cytokines, matrix metalloproteinases, and growth and adhesion factors in baboons.
Design: Analysis of gene expression in a prospective randomized study.
Setting: University Fertility Center.
Animal(s): In the in vivo study, 14 baboons were randomly and subcutaneously (SC) treated with either phosphate-buffered saline (PBS), GnRH antagonist, or recombinant human TNF-binding protein-1 at the time of induction. In the ex vivo study, 4 baboons were treated by menstrual endometrium that had been incubated randomly with either PBS or recombinant human TNF-binding protein-1 before intrapelvic injection.
Intervention(s): In the in vivo study, analysis of 11 endometrial and 10 endometriosis biopsies included either PBS (n = 5), GnRH antagonist (n = 8), or recombinant human TNF-binding protein-1 (n = 8). In the ex vivo study, 2 endometrial and 4 endometriosis biopsies were analyzed from 4 baboons.
Main outcome measure(s): The mRNA expression of TNF-alpha, IL-8, IL-6, transforming growth factor-beta (TGF-beta), vascular endothelial growth factor, intercellular adhesion molecule-1, matrix metalloproteinase-1, and regulated on activation, normal T-cell expressed and secreted were investigated using real-time reverse transcriptase-polymer chain reaction (PCR).
Result(s): TGF-beta mRNA expression was decreased in endometriotic lesions from baboons treated with recombinant human TNF-binding protein-1 when compared with the placebo group.
Conclusion(s): Except TGF-beta, mRNA expression of inflammatory cytokines and adhesion/growth factors is not affected in endometrial and endometriosis biopsies from baboons after induction of endometriosis combined with either systemic injection of recombinant human TNF-binding or GnRH antagonist or ex vivo treatment with recombinant human TNF-binding protein-1. Further studies are needed to elucidate the mode of action on how inhibition of TNF-alpha activity prevents the development of endometriosis.