Low Density Lipoprotein Receptor-Related Protein (LRP-1) Expression in Endometrial Carcinomas
Ll Catasus, M Cuatrecasas, A Gallardo, C Pons, J Munoz, V Llorente-Cortes, J Prat. Hospital de la Santa Creu i Sant Pau. Autonomous University of Barcelona, Barcelona, Spain
Background: Low density lipoprotein receptor-related protein (LRP-1) is a multifunctional cell surface receptor with a wide variety of ligands that modulate key processes in cancer regulation. Little is known about LRP-1 activity in endometrial carcinomas.
Design: LRP-1 expression was analyzed in 110 endometrial carcinomas (85 endometrioid endometrial carcinomas [EEC], 13 non-endometrioid endometrial carcinomas [NEEC], and 12 mixed EEC-NEEC). mRNA analysis was performed by real time PCR and protein expression was evaluated on tissue arrays by immunohistochemistry. Results of LRP-1 expression were compared with various genetic alterations including MI, PTEN, PIK3CA, p53, K-RAS, CTNNB1 alterations, with the clinicopathologic parameters, and patients follow-up.
Results: LRP-1 immunostaining was detected in 27% (30/110) of cases. Histologic type and grade varied significantly according to the expression of LRP-1 (P=0.001 and P=0.000, respectively); LRP-1 immunoreaction was more frequent in NEECs (61.5%) and mixed carcinomas (50%) than in pure EECs (19%). Strong immunostaining was more commonly found in grade 3 (48%) than in grade 2 (12%) or grade 1 (11%) carcinomas. Almost all tumors with LRP-1 expression had deep myometrial invasion but the association did not reach statistical significance (P=0.081). There was correlation between LRP-1 mRNA expression and immunohistochemical staining. mRNA expression was stronger in NEECs and mixed tumors than in EECs and normal tissues. p53 alterations (strong immunoexpression or mutation) were more frequently found in carcinomas with LRP-1 expression than in carcinomas lacking it.
Conclusions: Expression of LRP-1 in NEECs is stronger than in EECs and could contribute to the adverse prognosis of the former tumors.
Wednesday, March 11, 2009 1:00 PM
Poster Session VI # 149, Wednesday Afternoon