CD44 EXPRESSION IN BENIGN AND NEOPLASTIC HUMAN PROSTATES

Background: CD44, a major cell surface receptor for hyaluronic acid, i s a family of ubiquitous cell surface glycoproteins. Altered levels of CD44 expression, seen in many epithelial neoplasms, have prognostic i mplications. Expression of standard and variant isoforms of CD44 was a ssessed in normal and neoplastic human prostate tissue and culture cel ls to evaluate as a marker for malignant transformation. Methods and R esults: Expression of CD44s, CD44R, v5, v6, v7/8 and v10 was assessed in prostate tissue (benign and malignant) and cell lines (DU-145, PC-3 , LNCaP, p69) and primary cultures of normal prostates and adenocarcin oma cells obtained from prostatectomies using reverse transcriptor pol ymerase chain reaction, Western blotting, and immunofluorescence. No C D44 expression was seen in LNCaP cells. p69, DU-145, and PC-3 cells ex pressed CD44s and CD44R. p69 cells demonstrated a 1000-bp-long form of CD44 mRNA, unique to this normal cell line. Both normal and neoplasti c prostatic tissue demonstrated CD44s on Western blotting. Conclusions : In agreement with previous studies, prostatic adenocarcinoma cells, except LNCaP, expressed CD44s. Different patterns of CD44 expression w ere seen in benign and neoplastic prostate. Benign prostate exhibited higher v5 protein levels, whereas neoplastic prostates demonstrated hi gher CD44s expression. CD44s expression was identified in all neoplast ic prostates as compared with only 50% of the benign prostates. No sig nificant difference in expression of the other variants assessed (v6, v7, v7/8, and v10) was observed in the benign and neoplastic prostates .