Dysplasia of Human Prostate CD133hi Sub-Population in NOD-SCIDS Is Blocked by c-myc Anti-Sense

BACKGROUND. The CD133(hi) sub-population of prostate epithelial cells has been demonstrated to possess tumor-initiating capacity consistent with that of the cancer stem cell theory. However, the involvement of oncogenes such as c-myc has not been fully elucidated in the CD133(hi) sub-population. METHODS. We have isolated primary prostate cell strains (1BC-10a) and immortalized them by transfection with hTERT. The in vitro and in vivo tumorigenic capacity of isolated CD133(hi) and CD133(lo) cells was evaluated with respect to c-myc expression using specific sense and antisense oligonucleotides. RESULTS. Freshly immortalized cells consisted of < 3.3% CD133(hi)/CD24(hi) sub-population (SP). Prostaspheres generated from single CD133(hi) cells in the presence of EGF consisted of similar to 10% CD133(hi) SPs in 12-21 day cultures. A single Prostasphere generated from single CD133(hi) cells (6-10 cell stage at day 6 injected i.t) produced dysplastic lesions in NOD-SCID mice (n = 4/5). Treatment of Prostaspheres from CD133(hi) SPs in vitro with c-myc or cyclin D1 anti-sense oligonucleotides totally blocked colony forming ability and growth. Furthermore, treatment of fully formed, 6-day Prostaspheres for 48 hr with c-myc anti-sense significantly reduced c-myc expression and their ability to generate lesions in NOD-SCIDs (n = 10 Prostaspheres injected i.t./mouse). CONCLUSIONS. These data demonstrate for the first time that a single CD133(hi) cell is competent to generate Prostaspheres in vitro and that CD133(hi) Prostaspheres require c-myc to grow and form dysplastic lesions in vivo. Prostate 69: 689-698, 2009. (C) 2009 Wiley-Liss, Inc.