Effects of Nimotuzumab on the response of KYSE30 ESCC xenografts to RT. (a) Representative KYSE30 cell xenografts in RT treatment and RT + Nimotuzumab treatment groups. p-EGFR and IGFBP-3 expressions of KYSE30 cell xenograft tumors were examined by IHC. p-EGFR was positively stained in the majority of RT-treated KYSE30 cells of xenograft, while most cells had negative expression of IGFBP-3. In RT + Nimotuzumab-treated KYSE30 cell xenograft tumor, most tumor cells showed negative expression of pEGFR, while the majority of cells was positively stained with IGFBP-3 (100×). (b) KYSE30 cells were injected subcutaneously in athymic nude mice. Treatment was initiated when tumors in each group (N = 6) achieved an average volume of approximately 170–200 mm3. The mice were randomized into three groups: control, radiation alone (8Gy × 1), and Nimotuzumab (a single dose of 1.0 mg per mouse) combined with radiation. Tumor volume was determined at the indicated time points thereafter.