Figure 7.

Treatment with inactivated arazyme had protective effects in a 4T1 breast adenocarcinoma preclinical model and requires a competent immune system. (A) Female BALB/c mice (five per group) were inoculated into the mammary fat pad with 10⁴ viable 4T1 murine mammary adenocarcinoma cells. Starting on the 1st day after tumor cell inoculation, heat-inactivated arazyme (1 mg/Kg) or PBS (Control) was inoculated intraperitoneally every other day for 4 weeks. The average ± SD of primary tumor volumes are shown. (B) NSG mice (n = 5) were challenged and treated as described in (A) and primary tumor volumes were measured. (C) Survival plot of BALB/c mice depicted in (A). (D) Primary tumor weights, collected on day 30 from BALB/c mice depicted in (A). (E) Metastatic lung nodules of animals were counted 30 d after tumor cell inoculation, using an inverted microscope. Representative images of each group are shown. (F) Lungs from BALB/c mice were collected after 30 d and tissue sections were stained with hematoxylin/eosin (HE) to show metastasis development, and immunostained with monoclonal anti-CD25 or anti-Foxp3 antibodies. Tissues were visualized microscopically, ×200 magnification. Black bars = 100 μm. T, tumor areas; arrows, immunostained areas. *p < 0.05 and **p < 0.01, analyzed using the unpaired Student's t test (in A, B, D, and E) and the Log-Rank test (in C).