The molecular basis for sonographic cervical shortening at term: identification of differentially expressed genes and the epithelial-mesenchymal transition as a function of cervical length.

OBJECTIVE: The purpose of this study was to determine whether cervical shortening of a ripe cervix at term is associated with changes in the cervical transcriptome.

STUDY DESIGN: Sonographically measured cervical lengths and biopsy specimens were obtained from 19 women at term who were not in labor with a ripe cervix. Affymetrix HG-U133 Plus 2.0 arrays (Affymetrix Inc, Santa Clara, CA) were used. Gene expression was analyzed as a function of cervical length. Gene Ontology, pathway analyses, quantitative real-time reverse transcription-polymerase chain reaction, and immunohistochemistry were performed.

RESULTS: Cervical length shortening was associated with differential expression of 687 genes. Fifty-four biologic processes, 22 molecular functions, and 9 pathways were enriched. Quantitative real-time reverse transcription-polymerase chain reaction analysis confirmed differential expression of 13 genes. Bone morphogenetic protein-7, claudin-1, integrin beta-6, and endometrial progesterone-induced protein messenger RNA, and protein expressions were down-regulated with cervical shortening.

CONCLUSION: Sonographic cervical shortening in patients at term who are not in labor with a ripe cervix is associated with changes in the uterine cervix transcriptome. The epithelial-mesenchymal transition may participate in the mechanism of cervical shortening at term.