Figure 4. EMT tumor cells are resistant to chemotherapy.

a, Schema of cyclophosphamide (CTX) treatment in Tri-PyMT orthotopic model. Mice bearing an RFP+ primary tumor were treated with CTX (100mg/kg, once per week, for 4 weeks, as indicated by blue arrows). After two weeks of treatment, PT was removed (black arrow). Lung metastasis growth was permitted for 4 weeks post CTX treatment. Fluorescent imaging of lungs revealed the contribution of GFP+ tumor cells to lung metastases (n=9 mice).

b, Ratio of GFP+ to RFP+ cells in early metastatic lungs (4 weeks post orthotopic injection) of untreated (Cont) and CTX-treated (+CTX) mice as quantified by flow cytometry (n=4, *p<0.05).

c, Apoptosis (as measured by Annexin binding) of RFP+ and GFP+ Tri-PyMT cells treated with CTX (n=2 biological replicates).

d, Flow cytometry scatter plot showing the proportions of RFP+ and GFP+ Tri-PyMT cells prior to intravenous injection. Mice were treated with CTX (100mg/kg per week for 3 weeks, n=5 mice per group).

e, Quantification of flow cytometry data showing the percentage of RFP+ and GFP+ tumor cells (red and green bars, respectively) of total cells in the lung of the Control and CTX treated mice (CTX) (n=5 mice per group, *p<0.05).

f, Quantification of flow cytometry data showing the ratio of GFP+ to RFP+ cells in lungs of Control and CTX-treated mice. Black line represents the starting ratio of GFP+ to RFP+ cells prior to injection as derived from the data in Fig. 4d (*p<0.05).