Fig. 1.

Intrinsic sensitivity to activated CPA, anti-tumor activity, and immune cell recruitment/activation in metronomic CPA-treated B16-F10 and LLC tumors. a, Sensitivity of LLC and B16F10 tumor cell lines to 4-hydroperoxy-CPA in cell culture, determined using a 4-day growth inhibition assay. EC50, effective concentration for 50 % growth inhibition. EC50 for 4-hydroperoxy-CPA-treated GL261 cells, 0.15 μM (data not shown). b, In vivo tumor growth profiles for LLC and B16F10 tumors in response to treatment with 140 mg/kg CPA on treatment days 0, 6, and 12 (arrows along X-axis). c, qPCR analysis of the indicated immune markers in CPA-treated and untreated LLC and B16F10 tumors (shown in b) implanted s.c. in B6 mice. Data in a is representative of n = 5 culture wells per data point, data in b is based on mean ± SE for n = 10–14 tumors per group, and data in c based on n = 4–5 tumors per group. *, p < 0.05 by two-tailed t-test