Polypeptides synthesized and released by human endometriosis differ from those of the uterine endometrium in cell and tissue explant culture

OBJECTIVE: To identify and compare the pattern of polypeptide synthesis and release of endometriosis with that of the normal endometrium in culture. DESIGN: Endometriosis and endometrial biopsy specimens were obtained from women presenting for a variety of diagnostic and therapeutic examinations. Specimens were cultured as isolated epithelial and stromal cells and tissue explants with L-[35S]methionine. De novo synthesized proteins were identified by two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis, fluorography, and Western blot analysis. RESULTS: Five major deviations in protein synthesis and secretion were noted when comparing endometriotic and endometrial culture media. Endometriosis synthesized and secreted two proteins of stromal cell origin that were not produced by normal endometrium: endometriosis protein group I (M(r) 40,000 to 55,000; pI 4.0 to 5.2) and endometriosis protein group II (M(r) 30,000 to 32,000; pI 7.0 to 9.0). Conversely, endometriosis lacked the ability to secrete or asynchronously secreted three groups of secretory phase endometrial proteins in culture: endometrial protein group I (M(r) 25,000 to 27,000; pI 4.5 to 5.5) and endometrial protein group II (M(r) 68,000 to 72,000; pI 3.0 to 3.2) were endometrial epithelial cell products whereas endometrial protein group III (M(r) 70,000; pI 5.7) was of endometrial stromal cell origin. CONCLUSIONS: Unique characteristics in endometriosis protein synthesis and secretion as compared with the endometrium indicate biochemical dissimilarities between these tissues, which may be used to develop diagnostic markers and gain insight into the etiology and/or pathophysiology of the disease.