Figure 4. PMIP significantly inhibits tumor growth and recurrence in vivo.

a) MDA-MB-231 cells in Matrigel were injected into the mammary fat pad of scid mice, and daily peptide treatment (50µg/g body weight of hPMIP or PTD4) began when tumors reached 100mm³ (hPMIP and PTD4 n=8 mice) and primary tumor growth was assessed (*, p=0.028, ANOVA). Tumor burden represents the average volume (v= a² × b/₂) of all tumors at the stage indicated. b) After the end of treatment, the amount of time the tumors took to progress to 1000mm³ was measured (**, p=0.03, ANOVA). c) After resection, mice were observed for tumor regrowth at the primary site or secondary mammary glands (hPMIP n=7 mice and PTD4 n=8 mice). d) MDA-MB-231 cells in Matrigel were injected into the mammary fat pad of scid mice, and daily peptide treatment (50µg/g of hPMIP or PTD4) began when tumors reached 500mm³ (hPMIP n=6 mice and PTD4 n=4 mice) and primary tumor growth was assessed. e) Following 21 days of treatment the tumors were resected immediately and tumor regrowth at the primary site and spread to secondary mammary glands was monitored (hPMIP n=4 mice and PTD4 n=4 mice). Error bars represent standard error.