Side Population Is Enriched in Tumorigenic, Stem-Like Cancer Cells, whereas ABCG2+ and ABCG2− Cancer Cells Are Similarly Tumorigenic

Recently, several human cancers including leukemia and breast and brain tumors were found to contain stem-like cancer cells called cancer stem cells (CSC). Most of these CSCs were identified using markers that identify putative normal stem cells. In some cases, stem-like cancer cells were identified using the flow cytometry-based side population technique. In this study, we first show that approximately 30% of cultured human cancer cells and xenograft tumors examined ( approximately 30 in total) possess a detectable side population. Purified side population cells from two cell lines (U373 glioma and MCF7 breast cancer) and a xenograft prostate tumor (LAPC-9) are more tumorigenic than the corresponding non-side…

• UD
  U.S. Department of Defense
• PC
  Prostate Cancer Foundation
• NI
  National Institutes of Health

  Awards: 105961, ES07784, CA16672, P30 CA16672
• NI
  National Institute of Environmental Health Sciences

  Award: ES07784
• DP
  DOD Prostate Cancer Research Program