Fig. 2

Emerging strategies to overcome PARP inhibitor resistance. a Inhibition of DNA damage checkpoint proteins such as ATM, ATR, CHK1 or WEE1 induces synthetic lethality with PARP inhibitor. b Blocking POLQ mediated MMEJ repair sensitizes tumor to PARP inhibition. c PARPi enhances expression of PD-L1 on cell surface by inhibiting GS3Kβ and activating cGAS-STING pathway. Combination of PD-1/PD-L1 blockade and PARPi may be the potential approaches to increase the anti-tumor activity of PARPi