NAC treatment increases metastatic burden in an EO771 experimental metastasis model.

<p><b>A)</b> Schematic of NAC treatment regimen for 4T1.2 primary-resection model. BALB/C mice were orthotopically injected with 4T1.2 breast tumor cells on day 0, and the primary tumor surgically resected at a volume of 35 mm³ (∼day 10). NAC was administered at 40 mM in the drinking water 7 days post-resection (green line) until metastatic endstage. <b>B)</b> Kaplan-Meier survival curve of mice treated as in A (n = 6 all groups; p = 0.57). p values calculated using Log-rank (Mantel-Cox) Test. <b>C)</b> Schematic of NAC treatment regimen for experimental metastasis model. NAC (40 mM) was administered in the drinking water from day -7 (red line) prior to EO771 tumor cell injection. Mice were intravenously injected with EO771 tumor cells through the tail vein on day 0, and lungs analyzed for metastatic burden at day 14. <b>D)</b> Representative histology images (H&E stained) of lungs from C, with metastatic foci indicated by black arrows. Scale bar represents 100 µm. <b>E)</b> Average number of metastatic foci per lung (average determined from 4 whole lung sections per mouse) from D (n = 9 per group). Mean ± SEM; *p<0.05; Student’s t-Test. <b>F)</b> Absolute frequency and percentage of mice with an average of between 0–5, 6–14, 15–50 and >50 metastatic foci per lung section from E.