Application of a functional genomics approach to identify differentially expressed genes in human myometrium during pregnancy and labour

The molecular mechanisms regulating uterine relaxation and contraction duri ng pregnancy are poorly understood. In the present study, we used for the f irst time a functional genomics approach applying gene array technology to identify novel candidate genes involved in the regulation of uterine quiesc ence and contractility during pregnancy. The purpose of this approach was t o obtain a molecular snapshot of the expression profile of gene transcripts as a function of the time dependent process regulating myometrial quiescen ce. Using this approach, we found several genes whose expression in human m yometrium was altered with the onset of labour. For example, the expression of insulin-like growth factor (IGF)-II, calgranulin A and B, and G-protein coupled receptor were decreased while the expression of IGF-binding protei ns, Ca2+/CaM binding protein kinase C substrate, and angiotensin converting enzyme were increased in the labouring, compared with non-labouring, pregn ant myometrium. The differentially-expressed genes include several genes wh ose roles in myometrial quiescence are yet to be understood, although they have been reported to regulate vascular smooth muscle tone. Our findings il lustrate the advantage of a functional genomics approach over a single gene analysis in identifying a large number of novel and potentially important genes mediating uterine smooth muscle contractile activity.