Fig. 6
CDC6 knockdown sensitized CNE2-R tumor xenografts to IR-induced tumor regression. The CNE2-shCDC6 (a) or CNE2-R-shCDC6 (c) cells were used to generate xenografts in immune-deficient nude mice. The tumor xenografts were palpable within 2 weeks. Tumor xenografts of similar size then were treated with or without tetracycline to induce CDC6 knockdown. The CNE2-R-shRNA control and CNE2-shCDC6 xenografts were treated with or without X-ray radiation once on day 12. The tumor volumes were measured every 2 days until 32 days in CNE2-shCDC6 xenografts and every 4 days until 48 days in CNE2-R-shCDC6 xenografts. b Tumors of CNE2-shRNA control and CNE2-shCDC6 without IR were harvested on day 22, and tumors of CNE2-shRNA control and CNE2-shCDC6 with IR were harvested on day 32. d Tumors of CNE2-R-shRNA control and CNE2-R-shCDC6 without IR were harvested on day 32, and tumors of CNE2-R-shRNA control and CNE2-R-shCDC6 with IR were harvested on day 48. e The protein was extracted from the harvested tumors, and the protein levels of CDC6 and p16 were tested by western blot. f Cell apoptosis was detected in the tumor xenografts by TUNEL assay. *P < 0.05, ** P < 0.01, *** P < 0.001
