Extended Data Fig. 9: Additional data on the mapping and functional characterization of interacting domains in PCSK9 and MHC I, and on the association of PCSK9 expression with the prognosis of TCGA cohorts.
From: Inhibition of PCSK9 potentiates immune checkpoint therapy for cancer
a, Domain structure of mouse PCSK9. Catalytic, catalytic domain; CRD; C-terminal domain; Pro, propeptide; SP, signal peptide. b, Immunoprecipitation/western blot analysis of the interaction between full-length FLAG-labelled H2-K1 and full-length or partially deleted mouse HA-labelled PCSK9. Plasmids encoding the two genes were transfected into 293T cells in pairs, and lysates from transduced cells were immunoprecipitated with an anti-HA antibody and probed with an anti-FLAG antibody by western blot analysis. The analyses were repeated twice with biologically independent samples with similar results. c, Immunoprecipitation/western blot analysis of the interaction between full-length HA-labelled mouse PCSK9 and full-length or partially deleted FLAG-labelled H2-K1 (amino acids 66–202) (α1–α2 domains). The analyses were repeated twice with biologically independent samples, with similar results. d, Immunoprecipitation/western blot analysis of the interaction of HA-labelled mouse PCSK9 with full-length H2-K1 or H2-K1 with more limited deletions (amino acids 66–100, α1 domain; or amino acids 68–70). The analyses were repeated twice with biologically independent samples, with similar results. e, f, Tumour growth rates (e) and Kaplan–Meier survival curves (f) for mice inoculated with PCSK9KO B16F10 tumour cells, with re-expressed wild-type or partially (ΔM2) deleted PCSK9. n = 5 tumours per group. Error bars show means ± s.e.m.; P-values were determined by two-way ANOVA (e) and log-rank test (f). g, h, Tumour growth rates (g) and Kaplan–Meier survival curve (h) for mice inoculated with H2-K1KO or H2-K1/PCSK9 double-knockout (DKO) B16F10 tumour cells re-expressed with wild-type or partially deleted (Δ68–70) H2-K1. n = 5 tumours per group. Error bars show means ± s.e.m.; P-values were determined by two-way ANOVA (g) and log-rank test (h). i, Higher levels of PCSK9 expression correlate with worse survival in nine cohorts of patients with cancer, including liver hepatocellular carcinoma (LIHC), pancreatic adenocarcinoma (PAAD), skin cutaneous melanoma (SKCM), uveal melanoma (UVM), bladder urothelial carcinoma (BLCA), lung adenocarcinoma (LUAD), kidney renal clear cell carcinoma (KIRC), kidney renal papillary cell carcinoma (KIRP) and ovarian carcinoma (OV). P-values were calculated by log-rank test. Data are from TCGA data sets.
