Figure 1. Cathepsin to cystatin C ratio influences patient-to-patient variability in cancer cell invasion.

(A) Monocytes isolated from five patients among the first set were stimulated with M-CSF for 14 days to differentiate them into macrophages. On day 14, differentiated macrophages were plated onto a transwell coated with Matrigel with or without MCF-7 breast cancer cells, and allowed to transmigrate through to the other side. After 24 hours, number of invaded breast cancer cells were counted and invasion index was calculated by dividing the number of MCF-7 cells that invaded through the Matrigel and transwell when co-cultured with MDMs by the number of MCF-7 cells that invaded in the absence of MCF-7 cells. (B) Conditioned media was collected from days 14-15 and loaded for cathepsin zymography to measure secreted cathepsin activity which was quantified through densitometry. Zymogram gels and blots are cropped for space in the figure (C) The amount of cystatin C in conditioned media was measured using Western blotting with densitometry shown in the graph below.