Figure 5.

Effect of combination of pan IR700 and tra IR700 mediated PIT on SW780 xenografts. Combination treatment of pan IR700 and tra IR700 has stronger anti-tumor effects than single agents. Athymic Nu/Nu female mice of 5 weeks age were injected on the right thigh with 3 million/100 µl SW780 cells resuspended in 50% Matrigel in PBS. After 7 days, the tumors are about 50–100 mm³ in volume. The mice were randomized to groups of 10–11 animals/cohort and injected intravenously with 100 µg/100 µl of pan IR700, tra IR700 or pan IR700 + tra IR700 or 100 µl of vehicle (1x PBS). About 24 hours post injection, each mouse was restrained with 3% isoflurane and irradiated with (A) 100 J/cm² of NIR light. Tumors were measured with external calipers twice a week for the next 28 days. Tumor volumes were measured by formula: (length) × (breadth)² × 0.5. Data is represented as mean ± SEM (*P = 0.0335: pan IR700 + tra IR700 with NIR light vs. pan IR700 with NIR light; P = 0.068: pan IR700 + tra IR700 with NIR light vs. tra IR700 light; Mann-Whitney U test). (B) Tumor measurements of individual mice in each cohort treated with 100 J/cm² of NIR light. There are about 10–11 mice in each cohort except in the combination PIT group of pan IR700 + tra IR700 where 4 out of 11 mice died following the NIR light treatment due to unrelated complications.