In a study reported in Cancer Gene Therapy, Xu and colleagues found that the addition of pigment epithelium-derived factor (PEDF) to radiation improved tumor response in a mouse model of lung cancer.
Lewis lung cancer allografts in nude mice were treated with radiation, PEDF, and PEDF plus radiation. Significant inhibition of tumor growth was found when radiation was administered during a vascular normalization window between days 3 and 7 after the start of PEDF. PEDF treatment resulted in a significant reduction in the thickness of the basement membrane and a significant increase in pericyte coverage. The tumor hypoxic fraction decreased between days 3 and 7 after PEDF treatment, suggesting improved intratumoral oxygenation.
The investigators concluded: “Taken together, our results show that PEDF improved the effects of radiation therapy on [Lewis lung cancer] allografts by inducing a vascular normalization window from the 3rd to the 7th day after PEDF treatment. Our findings provide a basis for treating lung cancer with the combination of PEDF and radiation.” ■
Xu Z, et al: Cancer Gene Ther. January 16, 2015 (early release online).