Fluctuations in the Immunoexpression of DNA

DNA fragmentation factors 40 and 45 (DFF40 and DFF45) and B-cell lymphoma 2 (Bcl-2) 16 expression were evaluated in the normal human endometrium and myometrium. DFF40, DFF45, 17 and Bcl-2 expression was assessed via immunohistochemistry in the proliferative, secretory, and 18 atrophic endometrium and myometrium collected postmenopausally and premenopausally during 19 the proliferative and secretory phases of the menstrual cycle. The endometrium showed 20 significantly higher DFF40 and DFF45 expression than that in the uterine myometrium; compared 21 to the stroma, endometrial glands showed the highest expression in preand postmenopausal 22 specimens. Glandular expression of DFF45 was dependent on the menstrual cycle, reaching its 23 highest level in the secretory endometrium. The glandular expression of DFF40 and DFF45 was 24 significantly lower in postmenopausal specimens than that in premenopausal tissue. No cycle25 dependent changes were reported for stromal or myometrial DFF40 or DFF45 expression. 26 Compared to the endometrial stroma and myometrium, Bcl-2 showed the highest expression in the 27 glandular proliferative endometrium and the lowest expression in the stromal secretory 28 endometrium and myometrium during the secretory phase of the cycle. DFF45 and Bcl-2 showed 29 menstrual cycle-dependent expression, which was limited to the glandular layer of the 30 endometrium. 31