Figure 1

Oct4/Nanog overexpression enhances cancer stem-like property and resistance ability in 97 L cell line. (A, B) MHCC97L cells were infected with lentiviral vectors encoding cDNA of Oct4 and Nanog (97 L-ON) or a control empty vector (97 L-Ctrl). 97 L-ON cells were analyzed by Western blot and real-time RT-PCR for Oct4 and Nanog expression (*P < 0.05, **P < 0.01). (C) Cell proliferation of 97 L-ON and 97 L-Ctrol cells by CCK-8 assay analysis (*P < 0.05). Proliferation is significant promoted in 97 L cell lines after overexpression of Oct4 and Nanog genes. (D) 97 L-ON cells and 97 L-Ctrl cells were subjected to sphere formation assay. The sphere formation was photographed (left) and quantified (right). Colony formation of 97 L-ON cells was increased significantly in comparison with 97 L-Ctrol cells (68 ± 19 vs. 202 ± 38, P = 0.002). (E) The mRNA expression of stem cell markers (CD133, CD44, ALDH1, BMi-1, ABCG2, MDR1) between 97 L-ON cells and 97 L-Ctrol cells was analyzed by real-time RT-PCR, *P < 0.05, **P < 0.01, ***P < 0.001 (F) 97 L-ON cells formed the self-renewing spheroid bodies (left). The spheroid body formation rate of 97 L-ON cells was higher than that of 97 L-Ctrol cells (right, 18 ± 3 vs. 4 ± 1, P = 0.01). (G) 97 L-ON cells were treated with cisplatin (0.1, 0.25, 0.5, 1.0, 2.5, 5, 10 μmol/L) for 48 h. Cell survival was determined by CCK-8 assay (*P < 0.05).