Dual Targeting of CX3CR1 and PARP in Models of High-Grade Serous Ovarian Carcinoma

Background/objectives: Clinical use of poly(ADP-ribose) polymerase inhibitors (PARPis) against metastatic high-grade serous ovarian carcinoma (HGSOC) is limited to cases with deficient a homologous recombination (HR). Our objective was to determine whether the impairment of the fractalkine receptor (CX₃CR1) could sensitize HR-proficient cases to PARPis.

Methods: The efficacy of a dual drug combination, including AZD8797, an inhibitor of CX₃CR1, and several PARPis was examined using cell lines and xenograft models.

Results: The effectiveness of PARPis and AZD8797 drug combinations ranged from additive to strongly synergistic. Olaparib was synergistic with AZD8797 in OVCAR-4, Caov-3, and OHSAHO. Niraparib and AZD8797 produced synergy in OVCAR-4 and ES2. Rucaparib and AZD8797 were strongly synergistic in Caov-3 and OVSAHO. Veliparib was strongly synergistic with AZD8797 in OVCAR-4 and Caov-3. Notably, a combination of veliparib and AZD8797 produced a strong synergistic effect in a xenograft model.

Conclusions: While the exact mechanisms determining the nature of the PARPis and AZD8797 interaction remain to be uncovered, our data indicate that, in a subset of models, selected PARPis strongly synergize with the inhibition of CX₃CR1, suggesting a potential therapeutic opportunity.

combination treatment; fractalkine receptor; high-grade serous ovarian cancer; poly(ADP)-ribose inhibitor.