Glucocorticoid and Estrogen Receptors Have Elevated Activity in Human Endometrial and Ovarian Tumors as Compared to the Adjacent Normal Tissues and Recognize Sequence Elements of the H‐ras Proto‐oncogene

We examined the level of receptor binding in H‐ras elements, using nuclear extracts derived from human endometrial and ovarian lesions and from adjacent normal tissue in gel retardation assays. We found increased binding of the glucocorticoid receptor (GR) to the H‐ras GR element in more than 90% of endometrial tumors and in all ovarian tumors tested, as compared to the corresponding adjacent normal tissue. Additionally, we found elevated binding of the estrogen receptor (ER) in H‐ras ER element in all pairs of ovarian tumor/normal tissue tested, whereas in ER‐negative control breast tumor/normal tissue pairs, no differences in ER DNA‐binding levels were observed. These results suggest that steroid hormone receptor binding could directly activate the H‐ras oncogenic potency in human endometrial and ovarian lesions, providing additional evidence for the role of H‐ras expression in hormonally responsive human cancers.