Table 3.

Frequency of tumor-initiating cells in mammary gland lesions from PyMT; Gata-3+/+ or PyMT; Gata-3+/nlslacZ micea

No. of cells injected per mammary fat padNo. of tumorsb
PyMT; Gata-3+/+PyMT; Gata-3+/nlslacZ
101/120/12
400/61/6
1606/128/12
6407/1010/10
2,56011/1212/12
10,2405/56/6
    Tumor-initiating frequency (95% confidence interval)1/556 (1/972–1/318)1/156 (1/275–1/89)
    P value0.001
  • a Limiting dilution analysis of the tumor-initiating frequency of unsorted mammary gland cells isolated from PyMT; Gata-3+/+ or PyMT; Gata-3+/nlslacZ mice at 5 to 6 weeks of age. Cells were injected into the cleared mammary fat pads of 3-week-old syngeneic FVB/N recipients and fat pads collected 10 weeks posttransplantation. Data are shown for two independent experiments.

  • b Shown as number of outgrowths per number of injected fat pads.