[783] Increased Lef1 Expression in Metastatic Prostate Cancer

H Huang, Y Li, J Melamed, P Lee, A de las Morenas. Boston University School of Medicine, Boston, MA; New York University School of Medicine, New York, NY

Background: The identification of reliable biomarkers of prognosis in prostate cancer is a crucial issue to optimize the rational use of treatment modalities. Recent studies indicated that lymphoid enhancer-binding factor 1 (Lef1) regulated the expression of androgen receptor which played an important role in enhancing the growth and invasion abilities of the prostate cancer cells. In this study, we assessed Lef1 expression in human metastatic prostate cancer and its role in prostate cancer invasion.
Design: Immunohistochemical expression of Lef1 was examined in 20 cases of benign prostatic tissue, 56 cases of primary androgen-dependent prostate cancer and 10 cases of metastatic prostate cancer. The percentage of cells stained (0-100%) was recorded. Statistic analysis was performed using Fisher Exact Test. The invasion ability of LNCaP cells overexpressing Lef1 was determined by Matrigel invasion assays.
Results: No Lef1 expression was identified in all benign prostatic specimens except for some scattered nuclear staining in the basal cells in certain cases. Lef1 was expressed in 9 of 56 (16%) cases of primary androgen-dependent prostate cancer with percentage of positive tumor cells ranging from 20% to 60%. Lef1 was expressed in 5 of 10 (50%) cases of metastatic prostate cancer with percentage of positive tumor cells ranging up to 60%. The differences of Lef1 expression between metastatic prostate cancer and primary androgen-dependent prostate cancer, and between metastatic prostate cancer and benign prostatic tissue were statistically significant (p=0.0289). In parallel to its increased expression in metastatic cancer, Lef1 also increased LNCaP cell invasion up to 2.5 folds in Matrigel invasion assays.
Conclusions: Our data demonstrate for the first time that increased Lef1 expression is associated with metastatic prostate cancer and that Lef1 may be used as a potential biomarker for metastatic and advanced prostate carcinomas.
Category: Genitourinary (including renal tumors)

Monday, March 9, 2009 9:30 AM

Poster Session I Stowell-Orbison/Autopsy Award # 124, Monday Morning