Long-term recovery of irradiated prostate cancer increases cancer stem cells.
Prostate. 2012 Apr 18. Epub 2012 Apr 18. PMID: 22513891
Cancer Stem Cell Section, Laboratory of Cancer Prevention, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland; Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
BACKGROUND: Despite improvements in treatment, prostate cancer (PC) remains the second-leading cause of cancer death in men. Radiotherapy is among the first-line treatments for PC, but a significant number of patients relapse. Recent evidence supports the idea that PC is initiated by a subset of cells, termed cancer stem cells (CSCs). CSCs have also been implicated in radioresistance in various malignancies, but their role in PC has not yet been investigated. METHODS: We compared the relative radiosensitivity of isolated CSCs to the total population of their corresponding cell lines, and examined the relative numbers of CSCs in irradiated cell lines following long-term recovery and in recurrent human PC. RESULTS: Here, we show that while irradiation does not immediately favor increased survival of CSCs, irradiated PC cell lines showed an increase in CSC properties with long-term recovery. These data suggest that, although CSCs are initially damaged by radiation, they possess a greater capacity for recovery and regrowth. CONCLUSIONS: The combination of radiotherapy with a CSC-targeted therapeutic strategy may prevent tumor recurrence. Prostate© 2012 Wiley Periodicals, Inc.