Immunohistochemical Study of Heat Shock Protein(HSP) and Estrogen Receptor(ER) in the Normal Endometrium and in Adenocarcinoma of the Endometrium

ABSTRACT

Heat shock protein(HSP), first found in the MCF-7 human breast tumor cell line is one of the estrogen-regulated proteins and its synthesis is stimulated by estradiol. In this study, immunohistochemical staining was done for estrogen receptor(ER) and HSP on formalin-fixed, paraffin-embedded tissue sections in twelve normal cyclic and twenty carcinomatous endometria. 1) During the proliferative and early secretary phases, the nuclei of surface and glandular epithelial cells and stromal cells had moderate to strong staining for ER, whereas during the mid and late secretary phases, the glandular epithelial and stromal cells had weak staining for ER. The surface epithelial cells had positive staining of variable intensity. 2) From the early proliferative to mid secretary phases, the glandular and surface epithelial cells showed a positive reaction of variable intensity for HSP. In the late secretary phase, the glandular and surface epithelial cells showed a weak positive or a negative reaction for HSP. During the menstrual cycle, the stromal cells remained negative for HSP. 3) In adenocarcinomas of the endometrium, 8 of 11 (72.7%) well differentiated carcinomas were positive for both ER and HSP, while only 3 of 9(33.3%) moderately and poorly differentiated carcinomas were positive for ER and HSP. In conclusion, ER and estrogen-regulated heat shock protein(HSP) were closely related in normal and carcinomatous endometria and the reactivity was decreased according to poor differentiation.