Fig 1.
Histograms of tumors pO2 at different time points.
Histograms of pO2 [mm Hg] data with Gaussian fit (red). B16F10 tumors oxygenation data are presented in A and B both protocols contained 6 ITPP doses but with different time regiment, A: 5,6,11,12,17 and 18 days post tumor inoculation, B: 5,6,12,13,19,20 days post tumor inoculation. Data from 4T1 tumors are presented in C: 3 ITPP doses were administrated at 8,12 and 16 days post tumor inoculation, D: 4 ITPP doses administrated at 8,9,15,16 days post tumor inoculation. Time points after ITPP/saline injection were categorized in following periods for 4T1 tumors 8–11, 12–16 and >16 days and for B16F10 tumors 5–10, 11–16, 17–20 and >20 days after tumor inoculation. Due to different setup of experiments only one treatment protocol includes information of B16F10 tumor oxygenation before first ITPP/saline dose (see methods). The blue line marks 10 mm Hg. Data were collected from 39 BALB/c mice and 29 C57BL/6J mice.
Fig 2.
pO2 changes during ITPP treatment.
Local pO2 measurements in B16F10 tumors (6 ITPP doses injected at 5,6,11,12,17,18 or 5,6,12,13,19,20 days after tumor inoculation) and 4T1 (ITPP injected at 8,12,16 or 8,9,15,16 days after tumor inoculation). All points represent the mean pO2 level with SD for all EPR measurements performed after 1–6 ITPP doses (depending on the protocol). The time gap between ITPP injections was between 1–6 days. * p<0.05 based on a comparison between saline and ITPP-treated mice after selected conditions (Kruskal-Wallis ANOVA). The same data as presented in Fig 1, collected from 39 BALB/c mice and 29 C57BL/6J mice. Due to the inability to collect data in early time points for one group of B16F10 tumors, two points are missing (before and after 1 dose of ITPP).
Fig 3.
Relative changes of pO2 during ITPP treatment.
(A, B) Change of pO2 level (ΔpO2 tx-tbefore, for each tumor) and (C, D) tumor growth kinetic of 4T1 and B16F10 tumors. Breast cancer tumors were treated with 3 ITPP injections at 8,12, and 16 days after inoculation, whereas melanoma-bearing mice received 6 ITPP injections at 5,6,11,12,17, and 18 days after tumor inoculation. All pO2 data are represented as means with standard errors as a function of number of the ITPP dose (time gaps between doses were from 1–6 days). All 4T1 (A, C) and B16F10 (B, D) tumors were divided into normoxic and hypoxic before treatments. Marked significance only between ITPP and saline treated animals with hypoxic or normoxic tumors, * p≤0.05 (Kruskal-Wallis ANOVA). Additional statistical significance is described in the text. As presented in Fig 1, the same data were collected from 20 BALB/c mice and 18 C57BL/6J mice.
Fig 4.
Blood vessels dynamic during ITPP treatment.
(A) Doppler detected volume of active blood vessels expressed as a percent of tumor volume (PV) in normoxic and hypoxic 4T1 tumors after treatment with three ITPP/Saline doses (number of doses presented on the x-axis), data points represent means ± standard errors. (B) Local pO2 did not correlate with tumor PV, neither for tumors before treatment nor after ITPP/Saline injections. Linear correlation statistics—before treatment: r = -0.09, p = 0.47, r2 = 0.01; after 1st ITPP dose: r = -0.23, p = 0.52, r2 = 0.05; after 1st saline dose: r = -0.44, p = 0.2, r2 = 0.2. Data were collected from 20 BALB/c mice.