Lysine demethylase 2A expression in cancer-associated fibroblasts promotes breast tumour growth

Background Our previous study demonstrated that lysine demethylase 2A (KDM2A) enhances stemness in breast cancer cells. This demethylase is also highly expressed in cancer-associated fibroblasts (CAFs). However, its clinical significance is unclear. Methods The expression of KDM2A in CAFs was studied using immunohistochemical staining and its association with clinicopathological features and patient's survival was tested. Overexpression and knockdown strategies were used to investigate KDM2A-regulated genes in fibroblasts. Senescent cells were detected by using beta-galactosidase staining. Thein vivotumour-promoting activity of stromal KDM2A was confirmed by animal study. Results Increase of stromal KDM2A is associated with advanced tumour stage and poor clinical outcome in breast cancer patients. Cancer-derived cytokines stimulated KDM2A expression in normal fibroblasts and transformed them into CAFs. Upregulation of KDM2A induced p53-dependent senescence in fibroblasts and enhanced the release of cytokines, which reciprocally promoted cancer cell proliferation. Additionally, KDM2A upregulated programmed death-ligand 1 (PD-L1) expression via transcriptional activation in fibroblasts. Knockdown of KDM2A completely abolished the tumour-promoting activity of CAFs on breast tumour growth in vivo and diminished PD-L1 expression in the stroma of tumour tissues. Conclusions Stromal KDM2A plays an oncogenic role in breast cancer and inhibition of KDM2A reduces fibroblast senescence and suppresses tumour growth.

Automated summary

The study found that increased stromal KDM2A in breast cancer is associated with advanced tumor stage and poor clinical outcome. KDM2A induces p53-dependent senescence and promotes the release of cytokines in fibroblasts, thereby promoting cancer cell proliferation. Inhibition of KDM2A reduces fibroblast senescence and suppresses tumor growth.