NOTCH1 collaborated with innate immune to regulate genomic instability caused by epigenetic enzyme deletion in cold tumor

NOTCH1 was unfavorable to tumor immunoinfiltration in cold tumors. Targeting NOTCH1 for effective immunotherapy has been a challenge. Single cell data analysis found NOTCH1 signaling was gradually activated as lung inflammatory disease progressed. We found that NOTCH1 was highly expressed in proliferating airway epithelial cells of Lung squamous cell carcinoma (LUSC) tumor tissues. Database data analysis found NOTCH1 had adverse effects on tumor innate immunity and immune cell infiltration in LUSC. The function of NOTCH1 was related to protein alkylation, which may caused by KDM4A and SETD2. By constructing KDM4A and SETD2 gene knockout cell lines to simulate different genomic instability cell lines. The knockdown therapy of NOTCH1 was further studied in the above cell lines. IRF3-p and IFNB1 was significantly elevated in KDM4A and NOTCH1 double-knocked down cell lines, which also with the higher DNA damage and the cell apoptosis. However, the opposite trend was seen in SETD2 and NOTCH1 double-knocked down cells, which proliferated was more faster. Metabolomics tests showed NOTCH1 affected folate metabolism and nucleotide synthesis. Nucleotide synthesis rate-limiting enzyme was significantly increased in KDM4A and NOTCH1 double-knocked down cell lines. Mechanically, NOTCH1 knockdown caused significant up-regulation of TBK1-p protein. NOTCH1 acted synergistically with TBK1 which depended cGAS/STING signal and ATM-p to regulate nucleotide synthesis rate-limiting enzymes. The overactived cGAS/STING signal and nucleotide synthesis rate-limiting enzymes leaded cells to apoptosis.