Adenosine receptor A2b confers ovarian cancer survival and PARP inhibitor resistance through IL-6-STAT3 signalling.

Ovarian cancer is the deadliest gynecologic cancer worldwide, and the therapeutic options are limited. PARP inhibitor (PARPi) represents an effective therapeutic strategy and has been approved for maintenance therapy. However, the intrinsic or acquired resistance to PARPi becomes a big challenge. To investigate the mechanisms for PARPi resistance, we analysed public databases and established Olaparib-resistant ovarian cancer cells for exploration. Our results showed that the inflammatory pathway and adenosine receptor A2b (Adora2b/A ) expression were significantly increased in Olaparib-resistant cells. A was highly expressed in recurrent ovarian tumours and negatively correlated with the clinical outcomes in cancer patients. Olaparib treatment enhanced A expression through NF-κB activation. The elevated A contributed to Olaparib resistance by sensing adenosine signal and promoting tumour cell survival, growth and migration via IL-6-STAT3 signalling. Therefore, inhibition of A -IL-6-STAT3 axis could overcome Olaparib resistance and synergize with Olaparib to reduce cancer cell growth and lead to cell death. Our findings reveal a critical role of A signalling in mediating PARPi resistance independent of DNA damage repair, providing insights into developing novel therapies in ovarian cancers.