Fig. 5: Loss of sGC signalling sensitizes CDX17P to cisplatin/etoposide in vivo.

a Schematic of our strategy to study chemotherapy responses in vivo. b IHC for GUCY1B1 expression (brown stain) of CDX17P sgNTA and sgB1-2 tumours to demonstrate maintenance of reduced GUCY1B1 expression after in vivo passage. Scale bar set to 50 μm and equivalent throughout panels. Whole tumours were analysed and representative areas are shown. c Individual tumour volumes of vehicle-treated mice implanted with CDX17P sgNTA or CDX17P sgB1-2 cells. Data are from five animals per experimental arm. d Mice implanted with CDX17P sgNTA or CDX17P sgB1-2 cells were treated with a combination of 5 mg/kg cisplatin and 8 mg/kg etoposide or vehicle treated. Data from five animals per experimental arm and represented as mean ± SEM. e Kaplan–Meier survival curve comparing vehicle and cisplatin/etoposide-treated mice until the tumour reaches 4× initial tumour volume (ITV). P values from two-sided log-rank test, chi square = 8.221, d.f. = 1. f IHC of CDX17P sgNTA and sgB1-2 tumours for GUCY1B1 (brown stain). Scale bar set to 50 μm and equivalent throughout panels. Whole tumours were analysed and representative areas are shown. Two representative replicates of CDX17P sgNTA and sgB1-2 tumours are shown. g Western blot for GUCY1B1 and VASP on tumour lysates derived from two replicates per experimental arm. (−): Vehicle-arm, (C/E): cisplatin/etoposide-arm, lanes 9-12: non-randomized mice. VASP served as a loading control. h Quantification of GUCY1B1 expression (RVI) of g, normalized to VASP expression. Six replicates for sgNTA and sgB1-2 cohorts were analysed (n = 6), data are represented as mean ± SD. P values from two-sided unpaired Student’s t-test. t = 3.367, d.f. = 10. i Mice implanted with CDX17P were treated with a combination of cisplatin/etoposide, l-NMMA, cisplatin/etoposide + l-NMMA or vehicle treated. Data are from three to five animals per experimental arm and represented as mean ± SEM. j Kaplan–Meier survival curve comparing percent event-free survival of mice until the tumour volume reaches 4× initial tumour volume (ITV). P values from two-sided log-rank test, chi square = 3.875, d.f. = 1. See also Supplementary Fig. 5.