[1140] Stem Cell Marker Expression in Endometrial Carcinoma.

Jordi Tarragona, Maria Santacana, Joan Valls, Esther Oliva, Jose Palacios, Xavier Matias-Guiu. Hospital Universitari Arnau de Vilanova, University of Lleida, IRB Lleida, Spain; Hospital Virgen del Rocio, Sevilla, Spain; Massachusetts General Hospital, Boston

Background: It has been suggested that cancers contain minor populations of neoplastic stem-cells that are capable of tumor initiation. Cancer stem cells (CSC) are postulated to be responsible for resistance to hypoxia and have been associated with resistance to radiation therapy. CD133, CD44, CD59, CD9, Oct-4 and ALDH1 have been suggested as stem cell markers in different malignancies but only CD133 has been proposed as a marker for the stem cell population in endometrial carcinoma (EC). However, the immunohistochemical profile of CSC in EC has not been fully elucidated.
Design: CD133, CD44, CD59, CD9, Oct-4 and ALDH1 expression was assessed in three tissue microarrays (TMA) constructed from 70 paraffin-embedded blocks of normal endometrium (NE) in different phases of the menstrual cycle, 157 primary EC and 16 vaginal post- radiation recurrences. CD133, CD44, CD59, CD9, Oct-4 and ALDH1 expression was correlated with stage, histological type and grade of primary EC, and was also compared between primary EC and post-radiation recurrences.
Results: CD44, CD9 and CD59 immunostaining was higher in the secretory than in the proliferative phase (p=0.0007, p=0.01, p=0.02, respectively). CD44, ALDH1 and CD59 immunostaining was higher in EC compared to NE (p=0.01429, p<0.00001, p<0.00001, respectively). A decreasing trend of CD44 and CD9 expression was observed with higher histologic grade (CD44 p=0.05, CD9 p= 0.015). CD44 (mean=29.11), ALDH1 (mean=7.96), CD59 (mean=56.9) and Oct-4 (mean=11.8) expression was lower in post-radiation recurrences when compared to primary EC (mean=122.86, 63.73, 118.1, 65.98, respectively). There was no significant correlation between CD133, CD44, CD59, CD9, Oct-4 and ALDH1 expression and tumor stage.
Conclusions: Some stem cell markers (CD44, ALDH1 and CD59) show increased expression in EC when compared to NE, suggesting a role in tumor development and progression. Moreover, CD44, CD9, ALDH1, CD59 and Oct-4 might not be good predictors of radiation resistance in EC.
Category: Gynecologic & Obstetrics

Wednesday, March 2, 2011 1:00 PM

Poster Session VI # 174, Wednesday Afternoon

 

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