GSE178177
Targeting KDM4C upregulates the transcriptional activity of Cxcl10 to enhance the efficacy of combining radiotherapy and immunotherapy in lung cancer
The use of checkpoint blockade immunotherapy has revolutionized the field of cancer therapy. Although Immune checkpoint blockade (ICB) can achieve persistent response in several cancers, only 20-40% of patients can benefit from this therapeutic method. Preclinical and clinical evidence show that Radiotherapy (RT) can enhance tumor immunogenicity and improve the effects of immune checkpoint inhibitors. However, the actual outcomes are not satisfactory. Our previous studies revealed that the oncogene, Lysine-specific demethylase 4C (KDM4C) could regulate the radiosensitivity of lung cancer cells in vitro and in vivo. However, the role of KDM4C in antitumor immunity remains inconclusive. To that end, we analyzed the composition of infiltrating immune cells in our mouse tumor model using flow cytometry and found that KDM4C silencing could promote the intratumoral infiltration of CD8+ T cells. Further functional analysis showed that KDM4C silencing could promote proliferation, migration and activation of CD8+ T cells in vivo and in vitro and delay CD8+ T cells exhaustion. Mechanistically, using RNA-seq and Chip-PCR analysis, we determined that KDM4C silencing promotes the binding of H3K36me3 to the Cxcl10 promoter region to increase its transcriptional activity and thus induce CD8+ T cell-mediated antitumor response. Our results suggest that KDM4C-specific inhibitor, SD70 can reprogram the epigenetic state and improve the tumor microenvironment. More importantly, we found that the combined use of SD70, RT, and PD-L1 monoclonal antibodies exhibited the strongest antitumor effects and prolonged the survival time of tumor-bearing mice. Together, our findings suggest that a combination of KDM4C-targeted treatment, radiotherapy, and immune checkpoint blockade is safe and efficient for treating lung cancer. Overall design: Lewis cells treated with DMSO or SD70 for 24 hours were analyzed by RNA-seq.