CYCLIC BCL-2 GENE-EXPRESSION IN HUMAN UTERINE ENDOMETRIUM DURING MENSTRUAL-CYCLE

To investigate an apoptotic role for bcl-2 in menses, we studied bcl-2 protein production throughout the cycle. Bcl-2 protein was observed i n endometrial glandular, stromal and myometrial smooth-muscle cells. G landular cells expressed bcl-2 at proliferative through early secretor y phases but not at late secretory through menstrual phases. This cycl ic expression of bcl-2 gene was similar to that of oestrogen and proge sterone receptors. Thus bcl-2 expression in glandular cells may be reg ulated by ovarian hormones. The disappearance of bcl-2 expression in g landular cells at late secretory phase was consistent with the appeara nce of apoptotic cells in the same phase.