EXPRESSION OF COMPONENT DESMOSOMAL PROTEINS IN UTERINE ENDOMETRIAL CARCINOMA AND THEIR RELATION TO CELLULAR-DIFFERENTIATION

BACKGROUND. While the assessment of the malignancy of neoplasms is bas ed on morphologic studies of cells and tissues, use of objective molec ular markers is leading to a better understanding and more biologicall y meaningful classification of neoplasms. In recent years, changes in the expression of cell adhesion molecules, especially E-cadherin, cate nin, and adenomatous polyposis coli (APC), in carcinomas have attracte d the attention of researchers. However, little is known about desmoso mes in the uterine endometrium or in endometrial carcinomas. In this s tudy, we semiquantified the desmosomal components desmoplakin I and II and desmoglein, in tissue sections using confocal laser scanning micr oscopy (LSM), and examined their relationship to the pathological type , the occurrence of lymph node metastases, and the extent of myometria l invasion. METHOD, Frozen sections of 31 specimens of normal endometr ium, 5 specimens of atypical hyperplasia, and 41 specimens of endometr ial carcinoma were stained by the immunofluorescence method using anti desmoplakin I and II and antidesmoglein, and these markers were then s emiquantified in tissue sections by LSM. RESULTS, The expression and l ocation of desmoplakin I and II and desmoglein were similar, and their expression decreased with loss of differentiation. The expression was lower in cases of lymph node metastasis than in negative cases and wa s lower in the cases with > one-half myometrial invasion than in cases with < one-half myometrial invasion. CONCLUSIONS. Reduction of desmop lakin I and II and desmoglein expression may play an important role in the invasiveness and metastatic activity of human endometrial carcino ma. They can therefore be used as differentiation markers for endometr ial carcinoma. (C) 1996 American Cancer Society.