To investigate the treatment effects of chemoradiotherapy on Oct-4 siRNA-treated LC-CD133 + , LC-CD133 + was first transfected by lentivector combined with green fluorescent protein gene (GFP), and then in vivo GFP imaging and histological study were used to monitor the tumor-growth effect. We first injected 10 4 LC-CD133 + -GFP cells into the subcutaneous sites of nude mice with different treatment protocols. The tumor volumes were significantly decreased in Oct-4 siRNA-treated LC-CD133 + when exposed to IR alone, cisplatin alone, or IR combined with cisplatin (p,0.01; Fig. 7A ). To further evaluate the capabilities of tumor invasion and metastasis of LC-CD133 + treated by different regimens, we injected 10 4 LC-CD133 + -GFP cells from each treatment groups into the tail vein of SCID mice. The results of in vivo GFP imaging showed that the tumor foci of lung and metastatic lesions in the Oct-4-siRNA-treated LC-CD133 + groups were significantly lower than those of the LC-CD133 + without Oct-4-siRNA-treated groups (p,0.01; Fig. 7B ). In addition, to investigate the treatment effects of Oct-4 expression in LC-CD133 + in vivo, we injected the seven groups with different regimens individually into the tail vein of SCID mice for xenotransplanted tumorigenicity analysis (Fig. 7C ). Immunohistochemistry (IHC) showed that the expression levels of Oct-4 in the lung tumors of LC-CD133 + -injected SCID mice were highly expressed in comparison with the other treated-groups (Fig. 7C) . Oct-4-IHC levels were significantly decreased in Oct-4 siRNAtreated LC-CD133 + when exposed to IR alone, cisplatin alone, or IR combined with cisplatin (p,0.01; Fig. 7C ). Moreover, using combined chemoradiotherapy with the treatment of Oct-4 siRNA, the mean survival rate of the LC-CD133 + group was significantly prolonged compared with the control or other treated groups (p,0.05; Fig. 7D ). This in vivo study also confirmed that the treatment effect of chemoradiotherapy for the LC-CD133 + group can be improved by the treatment of Oct-4 siRNA.