Figure 1.

Liver is an extramedullary reservoir for leukemia stem cells (LSCs).

A-B, BM and liver leukemic burden (A) and LSC percentage (B) in leukemia mice at day 12 post leukemic transplantation (n=4).

C, Liver and bone were harvested at indicated time points post leukemic transplantation. Leukemic burden, LSC percentage, leukemia cell number and LSC cell number were determined (per whole liver or per femur + tibia). Hematoxylin and eosin (H&E) staining of liver sections from leukemic mice were shown on the top. For 10X, scale bar represents 100 μm; for 20X, scale bar represents 50 μm.

D, LSC frequency in BM and liver leukemia cells accessed by limiting dilution assays.

E-F, BM and liver leukemic burden (E) and leukemia progenitor percentage (F) in FDN mice at day 24 post leukemic transplantation (n=8).

G, Mice were injected with cells that contain ~50% leukemia cells (GFP+/YFP+ cells) (20 million cells/mouse). BM and liver leukemia cell percentage were examined 16 h after injection (n=6).

H-I, Leukemic mice were treated with chemotherapy consisting of 5-day treatment of Ara-C (100 mg/kg, i.p.) and 3-day treatment of doxorubicin (3 mg/kg, i.p., first 3 days). BM and liver leukemic burden, leukemia cell number, fold change of leukemia cell number (H) and LSC percentage (I) were examined after chemotherapy (n=4).

Error bars denote mean ± SD. *p<0.05, **p<0.005, ***p<0.0005, ****p<0.00005.