Medicine and Health Sciences Commons^™

Targeting Parp-1 With Metronomic Therapy Modulates Mdsc Suppressive Function And Enhances Anti-Pd-1 Immunotherapy In Colon Cancer, Mohamed A. Ghonim, Salome V. Ibba, Abdelmetalab F. Tarhuni, Youssef Errami, Hanh H. Luu, Matthew J. Dean, Ali H. El-Bahrawy, Dorota Wyczechowska, Ilyes A. Benslimane, Luis Del Valle, Amir A. Al-Khami, Augusto C. Ochoa, A Hamid Boulares

School of Graduate Studies Faculty Publications

BACKGROUND: Poly(ADP-ribose) polymerase (PARP) inhibitors (eg, olaparib) are effective against BRCA-mutated cancers at/near maximum tolerated doses by trapping PARP-1 on damaged chromatin, benefitting only small patient proportions. The benefits of targeting non-DNA repair aspects of PARP with metronomic doses remain unexplored. METHODS: Colon epithelial cells or mouse or human bone marrow (BM)-derived-myeloid-derived suppressor cells (MDSCs) were stimulated to assess the effect of partial PARP-1 inhibition on inflammatory gene expression or immune suppression. Mice treated with azoxymethane/four dextran-sulfate-sodium cycles or mice bred into PARP-1 or treated with olaparib were used to examine the role of PARP-1 in colitis-induced or spontaneous colon …