Oct-4 expression maintained stem cell properties in prostate cancer-derived CD133+ MDR1+ cells

Purpose: CD133⁺ (prominin-1), a 5-transmembrane glycoprotein, has recently been considered an important marker that represents the subset population of cancer stem-like cells. The purpose of the present study is to isolate cancerous stem-like cells from normal healthy volunteers and prostate cancer patients (CD133⁺ ) which also express MDR1 and to ascertain the influence of Oct-4 on 'stem-ness' and differentiation of these CD133⁺ cells towards epithelium.
Methods: CD133⁺ cells were isolated using magnetic beads from normal healthy volunteers and prostate cancer patients (NV-CD133⁺ and PC-CD133⁺ ). The isolated cells were analyzed using flow cytometry and Western blot technique for CD133⁺ , MDR1 and Oct-4. CD133MDR1cells were cultured in presence and absence of antihuman Oct-4 blocking antibody.
Results: PC-CD133⁺ cells displayed higher Oct-4 expression with the ability to self-renew and may represent a reservoir with differentiation potential for generating prostate cancer cells. Furthermore, PC CD133⁺ cells highly co-expressed the multiple drug-resistant marker MDR1. The treatment with Oct-4 blocking antibody can specifically block the capability of PC-CD133cells to differentiate into prostate epithelial cells bearing CD57.
Conclusion: PC-CD133⁺ cells displayed a higher Oct-4 expression with the ability to self-renew and may represent a reservoir with differentiation potentials for progression of prostate cancer. The MDR1 expression of PC-CD133⁺ cells in vitro and in vivo is partially due to preferential activation of Oct-4 gene expression.

Keywords
Prostate cancer, Cancer stem-like cells, Oct-4, CD133, Multi-drug resistance1 (MDR1)