Specific Surface Markers Characterize Pancreatic Cancer Stem Cells

Cancer researchers have isolated a highly tumorigenic subpopulation of pancreatic cancer cells that seems to be analogous to the putative stem cells already found in human blood, brain, and breast cancers.

Investigators at the University of Michigan Medical Center (Ann Arbor, USA) implanted human pancreatic cancer cells removed during patient surgery into immuno-compromised mice. Tumors were then excised from the mice, and advanced cell sorting techniques used to isolate those that had three surface protein markers − CD44, CD24, and ESA. Cells from this subpopulation were then transplanted into a new group of immuno-compromised mice.

Results published in the February 1, 2007, issue of Cancer Research revealed that pancreatic cancer cells with the CD44+CD24+ESA+ phenotype (0.2–0.8% of pancreatic cancer cells) had a 100-fold increased tumorigenic potential compared with cancer cells lacking these surface markers. Half the animals injected with as few as 100 CD44+CD24+ESA+ cells formed tumors that were histologically indistinguishable from the human tumors from which they originated.

"The cells we isolated are quite different from 99% of the millions of other cells in a human pancreatic tumor, and we think that, based on some preliminary research, standard treatments like chemotherapy and radiation may not be touching these cells,” said senior author Dr. Diane Simeone, associate professor of surgery at the University of Michigan Medical Center. "If that is why pancreatic cancer is so hard to treat, a new approach might be to design a drug that specifically targets pancreatic cancer stem cells without interfering with normal stem cell function.”




Related Links:
University of Michigan Medical Center