Loss of p53 dictates Wnt-dependent systemic inflammation in breast cancer

ABSTRACT: Cancer-associated inflammatory processes in the tumour microenvironment, as well as systemically, are strongly linked with poor disease outcome in cancer patients. For most human solid tumour types, high systemic neutrophil-to-lymphocyte ratios (NLR) are associated with increased metastasis and poor overall survival and recent experimental studies have demonstrated a causal relationship between neutrophils and metastasis formation. However, to date, the cancer cell-intrinsic mechanisms dictating the substantial heterogeneity in systemic neutrophilic inflammation between tumour-bearing hosts are largely unresolved. Using a panel of 16 distinct genetically engineered mouse models (GEMMs) for breast cancer, we demonstrate that tumour cell-intrinsic loss of p53 changes the phenotype and function of macrophages in the microenvironment, leading to activation of a systemic inflammatory cascade that drives neutrophil expansion. Mechanistically, p53 loss in cancer cells induces secretion of Wnt ligands that act in a paracrine fashion to stimulate IL-1b production from tumour-associated macrophages. Intratumoural IL-1β production stimulates an inflammatory cascade leading to the systemic accumulation of neutrophils. Pharmacological and genetic blockade of cancer cell-derived Wnt secretion reverses IL-1β expression by macrophages and subsequent systemic neutrophilic inflammation. Collectively, using pre-clinical mouse models for breast cancer, we demonstrate a novel mechanistic link between loss of p53 in cancer cells, Wnt ligand secretion and systemic immune activation. This illustrates the importance of cancer cell-intrinsic genetic aberrations in dictating cancer-associated inflammation. These insights set the stage for personalized immune intervention strategies for cancer patients.

ORGANISM(S): Mus musculus

PROVIDER: GSE112665 | GEO | 2019/05/20

REPOSITORIES: GEO