HPV 5 and 8 E6 Abrogate ATR Activity Resulting in Increased Persistence of UVB Induced DNA Damage
Figure 7
UVB induced p53 response is attenuated in HPV E6 expressing cells.
A. Representative immunoblot showing total p53 and phosphorylated p53 (Ser15 and Ser37) levels in β-HPV E6 expressing HFKs following 10 mJ/cm2 UVB exposure. Nucleolin levels were used as a loading control. B. p53 levels were measured by immunofluorescence following 10 mJ/cm2 UVB exposure in HPV E6 expressing HFKs following 10 mJ/cm2 UVB exposure. Graph shows percentage of cells with p53 levels above background. n≥5, and error bars represent standard errors of the mean. In this experiment, HPV 16 E6 served as a negative control because of its ability to degrade p53. C. Representative immunoblot showing total p53 and acetylated p53 (Lys382) levels in HPV E6 expressing HFK either 24 hours after exposure to 10 mJ/cm2 UVB or mock exposure. D. Following density arrest in G1, HT1080 cells were either exposed to 10 mJ/cm2 UVB or left untreated. This graph shows the difference between the percentage of cells in G1 in UVB exposed cells compared to untreated cells 24 hours after UVB exposure. n≥3. Error bars represent standard errors of the mean. * denotes a statistically significant difference from LXSN cells.