Expression of survivin and Bcl-2 in the normal human endometrium

Survivin is a novel inhibitor of apoptosis. It has been reported that survi vin is expressed during fetal development and in cancer tissues, but its ex pression has not been reported in adult tissues. We investigated the expres sion of survivin in the endometria of women with regular menstrual cycles u sing reverse transcription-polymerase chain reaction (RT-PCR) and immunohis tochemistry, and compared these findings with Bcl-2, an apoptosis inhibitor . Survivin mRNA was detected by RT-PCR in all samples (nine of nine) of end ometrium during the secretory phase, but in only four out of seven samples from endometrium during the proliferative phase, and in none of the atrophi c endometrium. Immunohistochemistry demonstrated a survivin protein express ion that was strongest in the nuclei of glandular epithelial cells during t he late secretory phase. In the proliferative phase, glandular epithelial c ells were not stained for survivin. The cyclic changes of survivin and Bcl- 2 showed an inverse relationship, with Bcl-2 expression being strongest in the proliferative phase and survivin expression being strongest in the secr etory phase. The up-regulation of survivin expression may be due to the con current rise in progesterone concentrations during the normal menstrual cyc le. Moreover, survivin could play an important role independent of Bcl-2 in physiological homeostasis in the normal endometrium.