Figure 7.

Stromal L929 fibroblasts and NIH-3T3 fibroblasts, respectively induced radio-resistance of breast and prostate tumors. MPR31.4 prostate (A–D) and Py8119 breast (E–H) cancer cells alone or together with NIH-3T3 embryonic (A,B,E,F) L929 skin (C,D,G,H), or fibroblasts [ratio of (1+1)] were subcutaneously co-implanted onto the hint leg of C57BL/6 mice. When tumor volumes of 100 mm3 were reached, one group received a single radiation dose of 10 Gy to the tumor. The tumor volume was determined at indicated time points (left diagram). Data were represented as mean ± SEM from 2 to 3 independent experiments (in total 10-27 mice). Tumor growth and respective tumor growth delay were determined as time (days) until the 4–6-fold volume was reached (right diagram). ^*p < 0.05, ^***p < 0.001, ^****p < 0.0001 by one-way ANOVA followed by Tukey's test.