Expression of Notch1 is upregulated in cervical cancer cell lines. (A) The expression of Notch1 in HeLa, SiHa, C33A, Caski and HT-3 cells was determined by western blot analysis. (B) Relative expression of Notch1 in HeLa, SiHa, C33A, Caski and HT-3 cells was analyzed according to the Notch1/β-actin ratio. β-actin was used as the loading control. The results are expressed as the mean ± standard deviation from three experiments performed in duplicate.