The CD44 <sup>(+)</sup>, CD133 <sup>(+)</sup> cell subpopulations were isolated from human prostate tumors which exhibit stem-like properties showing therapeutic-resistance, capacity of self-renewal, and exact recapitulation of the original tumor <i>in vivo</i>.
These results show that CD44 isoforms are expressed on human prostate tumor cell lines, including the expression of variant isoforms containing the v6 region, and provide a rationale for the further study of this cellular adhesion molecule in prostate cancer.
Immunocytochemistry showed high level expression of CD44 in cells from a high grade prostate tumor, and two androgen-independent, invasive prostatic carcinoma lines, PC-3 and TSU-Pr1.
Both PPC-1 and ALVA-31 cells display tumorigenesis and invasiveness in nude mice, whereas LNCap cells exhibit a less malignant phenotype, suggesting a correlation between CD44 variant (CD44v) expression and aggressive prostate tumor behavior.