The cGAS-STING pathway is a master regulator of OCT4 expression in persistent sarcoma cells and enhances cellular immunotherapy with NK and CIK lymphocytes

Advanced sarcomas have a poor prognosis and limited therapeutic options. Disease recurrence is caused by persistent cells that survive drug treatments. The alkylating agent trabectedin, when combined with the poly (ADP-ribose) polymerase 1 (PARP1) inhibitor olaparib, exhibits variable antitumor effects in advanced sarcomas. In this study, we demonstrate that the expression of the transcription factor OCT4 is upregulated in persistent cells that survive treatment with trabectedin and olaparib, through the cGAS-STING-IRF3-IFN beta pathway. This route also leads to the upregulation of natural killer (NK) and cytokine-induced killer (CIK) lymphocyte activating ligands. These molecular events enhance the antitumor efficacy of immunotherapy with NK and CIK cells, targeting both the bulk population and residual drug-tolerant cells. In conclusion, the activation of the cGAS-STING pathway has a double-edged effect, enriching the OCT4+ persistent cell population while increasing the expression of NK/CIK ligands. The addition of olaparib to trabectedin potentiates the cGAS-STING pathway activation and the upregulation of NKG2DLs, while simultaneously counteracting the OCT4 overexpression. Therefore, sequential treatment with trabectedin and olaparib followed by NK/CIK immunotherapy represents a promising strategy against advanced sarcomas and warrants further investigation.