Tissue expression and serum levels of periostin during pregnancy: a new biomarker of embryo-endometrial cross talk at implantation.

OBJECTIVE: The molecular aspects involved in human implantation include many elements that were first discovered due to their role in cancer cell metastasis. Periostin, a cell adhesion protein that allows the maintenance of cancer stem cells, may influence implantation. The objective of this experimental case-control study was to investigate tissue and serum expression of periostin during pregnancy, and evaluate the potential role of periostin in endometrial receptivity and embryo implantation. STUDY DESIGN: Forty-five subjects were included in the final analysis: 15 women who had experienced spontaneous pregnancy loss were enrolled as cases, and 30 healthy pregnant women awaiting voluntary pregnancy termination were enrolled as controls. For both cases and controls, trophoblastic and decidual tissues were collected at 12 weeks of gestation. Periostin expression in decidual and trophoblastic tissues was evaluated by immunohistochemical staining and reverse transcription polymerase chain reaction in cases and controls, and periostin serum levels was analyzed by Western blotting assays in cases, controls and non-pregnant female volunteers. RESULTS: Periostin mRNA and protein levels were higher in decidual and trophoblastic tissues from women undergoing voluntary pregnancy termination compared with women who had experienced spontaneous pregnancy loss. This finding was also reflected at serum level. CONCLUSIONS: Periostin may be a serum marker of good endometrial receptivity and embryo quality, and predictive of pregnancy evolution.

Negative transcriptional regulation of the human periostin gene by YingYang-1 transcription factor.

Periostin (POSTN), an osteoblast-specific secreted protein known to be associated with cell adhesion activity for bone formation and development by the epithelial cell-derived tumors, leads to a significant enhancement in angiogenesis and tumorigenesis. At present, little is known about the mechanisms underlying its transcriptional control either in physiological or neoplastic conditions. In this study we demonstrate that the ability of the human POSTN promoter to drive transcription mostly depends on the activity of YingYang-1 (YY1) zinc finger transcription factor. YY1, whose regulatory role in biology includes, besides transcriptional control, also chromatin remodeling, DNA damage repair and tumorigenesis, acts as a strong negative modulator of the POSTN expression. We retain that the identification of the functional role of YY1 in the transcriptional control of the human POSTN gene adds new insights in the studies focused on gene expression in normal and transformed cells.