A study published in Cancer Cell International finds that an exposure of ultra-high concentration of gaseous nitric oxide followed by the surgical removal of the primary tumor 14 days later induces a strong and potent anti-tumor response.
Here we present a novel treatment paradigm involving in-situ tumor ablation with UHCgNO. Treating tumors in-situ with UHCgNO showed significant secondary anti-tumor effects in vivo, with mice rejecting a second tumor inoculation. Additionally, UHCgNO treatment resulted in an enhanced immune profile within the tumor microenvironment and systemically.
Study overview: CT26 cells were inoculated subcutaneously on the right flank of 8–10 weeks old male Balb/c mice at a concentration of 5.0 × 10CT26 cells in 100 µL HBSS. Treatment was initiated once tumors reached an average volume of ~ 50 mm. Mice were evaluated for tumor volume using a digital caliper up to 14 days post-gNO treatment, and tumors were surgically removed. Seven days later , mice were inoculated with challenge tumor cells on the contralateral flank.
$${\text{Tumor Volume }}=\frac{\pi }{6} \times \left[ {{\text{Diameter 1}} \times {\text{ Diameter 2}} \times {\text{ Diameter 3}}} \right]$$Fourteen days after NO treatment of CT26 tumor-bearing mice, all remaining tumors were excised. The tumor of one mouse in the 20,000 ppm NO group was excised 10 days post-treatment due to tumor size. This mouse was excluded from the average primary CT26 tumor volume graph but included in challenge assay graphs.
Hydration status: normal—0, skin tents when pinched quickly recovers—1, skin tents when pinched slowly recovers—2, skin remains tented severe dehydration -3.Natural Behavior: normal, i.e., active—0, less mobile and alert—1, isolated—2, restless/shivering/very still—3Body weight: not different from controls—0, weight loss of 0–10%—1, weight loss of 10–20%, weight loss over 20% -3.