KMT9 reprograms the tumour immune microenvironment in prostate cancer [scRNA-Seq]

Loss of the tumour suppressor PTEN, encoded by one of the most frequently deleted genes in human prostate cancer, is associated with a highly immunosuppressive tumour microenvironment (TME). In consequence, immunotherapies targeting prostate cancer typically show low clinical efficacy.

The immunosuppressive TME state is mediated in part by various cytokines and chemokines resulting in infiltration of heterogeneously differentiated myeloid cells including polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs). Here we show that the methyltransferase KMT9 regulates expression of immunosuppressive proteins such as PD-L1 and myeloid-attracting CXCR2 ligands in prostate tumours of Pten/Trp53 knockout (KO) mice.