HOMEOBOX GENES DLX4 AND HB24 ARE EXPRESSED IN REGIONS OF EPITHELIAL-MESENCHYMAL CELL-INTERACTION IN THE ADULT HUMAN ENDOMETRIUM

The adult human endometrium rapidly cycles through stages of cell prol iferation, differentiation and degeneration. Inappropriate endometrial cell differentiation is a contributing factor in diseases such as end ometrial carcinoma and endometriosis. We have identified two homeobox genes that may play a role in the control of endometrial cell differen tiation and development. In-situ mRNA hybridization experiments were u sed to show differential expression of DLX4 at different phases of the endometrial cycle. Higher levels of DLX4 expression were observed in proliferative phase endometrial epithelium compared with secretory pha se endometrial epithelium. The HB24 homeobox gene was shown to be expr essed in both the proliferative and secretory phase endometrial epithe lium. We predict that DLX4 and HB24 will be required for the transcrip tional control of genes important for endometrial cell differentiation . Furthermore, we propose that DLX4 and HB24 are part of a conserved c ombinatorial code of homeobox genes that are required for controlling epithelial-mesenchymal cell interactions in the endometrium.