(A) pSTAT3 Y705 immunoblot, with laminin A/C control, of nuclear extracts from transduced HaCaT keratinocytes (n = 3). (B) qPCR of RNA from transduced HaCaT keratinocytes for STAT3-regulated genes, with β-actin as control (n = 3). (C) Immunoblot of ΔNp63 and involucrin, with GAPDH as control, of transduced HaCaT keratinocytes cultured in high-calcium (60 μm) media for 3 and 5 days (n = 3). (D–F) Proliferation (n = 3) (D), CFE assay (n = 7) (E), and migration (n = 3) (F) of transduced HaCaT keratinocytes. (G) String analysis demonstrating the interaction of known HPV8 E6 protein binding partners and STAT3. Line colors define interactions as experimentally determined (pink) or from curated database (blue). (H) p300 with GAPDH control immunoblot of WT and HPV8-E2tg, -E6tg and -E7tg mouse keratinocytes (n = 3/genotype). (I) p300, α-tubulin, and DAPI immunofluorescence labeling of transduced HaCaT keratinocytes (n = 3). Scale bar: 40mm. (J) p300, pSTAT3 Y705, and ΔNp63 immunoblot, with GAPDH endogenous control, of HPV8 E6–transduced HaCaT keratinocytes treated with scrambled control and p300 targeting siRNA (n = 3). (K) STAT3 and ΔNp63 immunoblot, with GAPDH control, of HPV8 E6–transduced HaCaT keratinocytes treated with scrambled control and STAT3 targeting siRNA (n = 3). (L) Immunoblot of STAT3 immunoprecipitated nuclear protein from vector and HPV8 E6–transduced HaCaT keratinocytes probed for acetylated STAT3 and total STAT3 (n = 3). (M) qPCR analysis of ΔNp63 primers on STAT3 chromatin immunoprecipitants in HPV8 E6–transduced HaCaT keratinocytes relative to vector (n = 3). Schematic of the 5′-flanking region indicating primers sequences relative to STAT3-RE and ΔNp63 TSS. See also Supplemental Figure 4. Statistical tests included (A, C–F, H, and I) 1-way ANOVA and (B and J–M) 2-tailed Student’s t test. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001.