Re: new findings...
Interesting:
"We applied some rare and mutually exclusive lineage markers to isolate subsets of luminal-like and basal-like breast cancer cells, which enabled us to do single cell cloning with a reasonable success rate," Petersen says. "We enriched for populations with or without prominent basal-like traits from individual tumors, and from single cell cloning of cell lines and recovered cells with a luminal-like phenotype."
What they discovered was that luminal-like cells without specific basal-like traits were fully capable of initiating tumors in laboratory test mice; in fact, the tumors generated by luminal-like cells were larger than those from basal-like cells. In addition, when tested in an invasion assay, these phenotypically pure luminal-like cells were more invasive than the basal-like cells.
"Our findings demonstrate that basal-like cells, as defined currently, are not a requirement for breast tumor aggressiveness and that within a single tumor there are multiple cells with tumorigenic potential," Bissell says. "This casts doubt on the current hypothesis of hierarchical or differentiative loss of tumorigenicity."
The marker used by the Petersen-Bissell collaboration to isolate the luminal-like cancer cells was milk mucin (MM), one of the glycans, the sugar molecules that are ubiquitous to cell surfaces and central to cellular signaling. Basal-like cancer cells were marked with the protein CD271. The MM glycan was detected by the antibody M18. The CD271 marker was detected by the ME20.4 antibody.
In their investigation, the collaborators found that the ability of the luminal-like breast cancer cells to form large invasive tumors depended on the expression of the glycoprotein gene GCNT1, which in turn is required for the MM glycan to be detected by the M18 antibody. The collaborators believe this finding might be of potential clinical importance for breast cancer as co-author Kuhn, a member of Bissell's research group, explains.
Have to see how this develops. The markers used do seem different from other CSC studies. Whether that's an improvement or confounder is the question.
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