Fig. 1.

Exogenous recombinant human IL-6, IL-8 and TGFβ1 induce reactivation of dormant breast cancer colonies but do not promote growth of growing colonies. a Cytokines induce regrowth of dormant colonies. One thousand MCF-7 cells were incubated in fibronectin-coated wells with FGF-2 for 6 days, followed by addition of recombinant human IL-6, IL-8 and TGFβ1 on day 6 and incubation for an additional 6 days, as described. Cells were stained with 0.1% crystal violet and growing and dormant colonies were counted on day 6 and 12. b Cytokines do not promote the growth of growing colonies. MCF-7 cells were incubated in fibronectin-coated wells with FGF-2 or recombinant human IL-6, IL-8 or TGFβ1, as described. Cells were stained with 0.1% crystal violet and growing and dormant colonies were counted on day 6. c Time lapse photography demonstrating regrowth potential of dormant clones. Photographs demonstrate growth expansion or degradation of both dormant and growing colonies. MCF cells were incubated on fibronectin-coated plates without and with FGF-2 for six days, followed by an additional 6 day incubation with fresh DMEM/10% FCS without or with rhIL-6, IL-8 and TGFβ1, as described. Time-lapse microscopic images of the same individual colonies in the same fields were obtained once daily for these six days. Size markers are 200 μM