Fig 2: KATP channels drive proliferation in an in vivo mouse model.A Tumour growth curves for mice implanted with HeLa cells stably expressing either a non-targetting (shNTC) or an SUR1-specific shRNA (shSUR1 A). Tumour volume was calculated using the formula V = 0.5*L*W2. Both individual curves for each replicate (left) and curves representing mean values ± SD of five mice per group (right) are displayed. B Tumour growth delay, calculated as the period of time between injection of tumours and growth to a set volume (250 mm3). Bars represent means ± SD of five biological replicates with individual data points displayed. *P < 0.05 (Student’s t test). C Kaplan–Meier survival curve of mice bearing shNTC and shSUR1 A tumours. Indicates that one mice remained alive at the conclusion of the study. **P < 0.01 (log-rank (Mantel–Cox) test).

Fig 3: Schematic demonstrating E7-mediated upregulation of KATP channel expression and activity.HPV E7 upregulates expression of ABCC8, the gene encoding SUR1 which constitutes the regulatory subunit of KATP channels. Increased KATP channel activity contributes towards the activation of MAPK and AP-1 signalling. This, in turn, drives transcription from the viral URR and changes in host gene expression which together stimulate proliferation. Figure created using BioRENDER.com.

Fig 4: KATP channel overexpression is sufficient to stimulate proliferation in the absence of HPV.Growth curve analysis (A), colony formation assay (B) and soft agar assay (C) of C33A cells transfected with plasmids expressing HA-tagged Kir6.2 and/or SUR1. Data shown is means ± SD of three biological replicates with individual data points displayed where appropriate. Ns not significant, *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001 (Student’s t test).

Fig 5: Depletion of SUR1 reduces HPV gene expression in cervical cancer cells.A, B Relative expression of ABCC8 mRNA in (A) HeLa and SiHa cells transfected with a pool of SUR1-specific siRNA (n = 4) and (B) two monoclonal HeLa cell lines stably expressing SUR1-specific shRNAs measured by RT-qPCR. Samples were normalised against U6 mRNA levels. C Relative mean DiBAC4(3) fluorescence levels in HeLa and SiHa cells transfected with SUR1 siRNA. Samples were normalised to scramble controls. D, E Relative expression of E6 and E7 mRNA in (D) HeLa and SiHa cells transfected with SUR1 siRNA (n = 4) and (E) HeLa cell lines stably expressing SUR1-specific shRNAs measured by RT-qPCR. Samples were normalised against U6 mRNA levels. F, G Representative western blots of E6 and E7 expression in (F) HeLa and SiHa cells transfected with SUR1 siRNA and (G) HeLa cell lines stably expressing either a non-targeting (shNTC) or a SUR1-specific shRNA. GAPDH served as a loading control. H Relative firefly luminescence in HeLa and SiHa cells co-transfected with SUR1 siRNA and either a HPV18 or HPV16 URR reporter plasmid respectively (n = 4 for all conditions). Luminescence values were normalised against Renilla luciferase activity and data is displayed relative to scramble controls. Bar graphs represent means ± SD of three biological replicates (unless stated otherwise) with individual data points displayed. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001 (Student’s t test).