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.
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.
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>.