PROBLEM: To investigate the relationship between the histologic phase and the quantitative expression of epidermal growth factor receptor (EGFR) mRNA in the endometrium of normal and leiomyomatous uteri.
METHODS: To test this relationship, endometrium was collected at hysterectomy from 38 women with a history of regular cycles. Total RNA (20 μg) was isolated and analyzed by Northern blot using a human EGFR-specific 32P labeled cDNA probe. The hybridization signals were quantified by densitometry, standardized, and reported in densitometry signal units. Separate portions of the same endometrial specimens were simultaneously prepared for histologic evaluation. The differences between menstrual phases were evaluated by Student's t-test.
RESULTS: EGFR mRNA was expressed in all endometrial tissues tested. Levels were higher in the midproliferative phase than in all other phases for both myomatous and nonmyomatous uteri (P <.05). Myomatous uteri showed lower expression than nonmyomatous uteri in the early and late proliferative phase (P <.05). Age did not appear to alter endometrial EGFR mRNA expression.
CONCLUSION: This data suggest that endometrial EGFR mRNA expression varies in association with the histologic changes of the normal menstrual cycle, and may be associated with the presence of leiomyomata uteri.