title: An enzyme-linked immunosorbent poly(ADP-ribose) polymerase biomarker assay for clinical trials of PARP inhibitors.
abstract: Many established cancer therapies involve DNA-damaging chemotherapy or radiotherapy. The DNA repair capacity of the tumor represents a common mechanism used by cancer cells to survive DNA-damaging therapy. Poly(ADP-ribose) polymerase (PARP) is a nuclear enzyme that is activated by DNA damage and has critical roles in DNA repair. Inhibition of PARP potentiates the activity of DNA-damaging agents such as temozolomide, topoisomerase inhibitors and radiation in both in vitro and in vivo preclinical models. Recently, several PARP inhibitors have entered clinical trials either as single agents or in combination with DNA-damaging chemotherapy. Because PARP inhibitors are not cytotoxic, a biomarker assay is useful to guide the selection of an optimal biological dose. We set out to develop an assay that enables us to detect 50% PAR reduction in human tumors with 80% power in a single-plate assay while assuring no more than a 10% false-positive rate. We have developed and optimized an enzyme-linked immunosorbent assay (ELISA) to measure PARP activity that meets the above-mentioned criterion. This robust assay is able to detect PAR levels of 30-2000 pg/ml in both tumor and peripheral blood monocyte samples. In a B16F10 mouse syngeneic tumor model, PARP inhibitor ABT-888 potentiates the effect of temozolomide in suppressing tumor growth, and PARP activity is greatly reduced by ABT-888 at efficacious doses. In summary, the ELISA assay described here is suitable for biomarker studies in clinical trials of PARP inhibitors.
authors.affiliation: Cancer Research, GPRD, Abbott Laboratories, 100 Abbott Park Road, Abbott Park, IL 60064, USA. xuesong.liu@abbott.com
authors.forename: Xuesong
authors.initials: X
authors.lastname: Liu
authors.forename: Joann
authors.initials: J
authors.lastname: Palma
authors.forename: Robert
authors.initials: R
authors.lastname: Kinders
authors.forename: Yan
authors.initials: Y
authors.lastname: Shi
authors.forename: Cherrie
authors.initials: C
authors.lastname: Donawho
authors.forename: Paul A
authors.initials: PA
authors.lastname: Ellis
authors.forename: Luis E
authors.initials: LE
authors.lastname: Rodriguez
authors.forename: Milagros
authors.initials: M
authors.lastname: Colon-Lopez
authors.forename: Mary
authors.initials: M
authors.lastname: Saltarelli
authors.forename: David
authors.initials: D
authors.lastname: LeBlond
authors.forename: C Thomas
authors.initials: CT
authors.lastname: Lin
authors.forename: David J
authors.initials: DJ
authors.lastname: Frost
authors.forename: Yan
authors.initials: Y
authors.lastname: Luo
authors.forename: Vincent L
authors.initials: VL
authors.lastname: Giranda
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001562:Benzimidazoles / Q000737:chemistry / Q000494:pharmacology*; D015415:Biomarkers / Q000032:analysis; D002986:Clinical Trials as Topic; D003606:Dacarbazine / Q000031:analogs & derivatives / Q000494:pharmacology; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D006801:Humans; D008546:Melanoma, Experimental / Q000201:enzymology; D051379:Mice; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D011065:Poly(ADP-ribose) Polymerases / Q000032:analysis* / Q000378:metabolism; D000077204:Temozolomide
chemical_list: D000970:Antineoplastic Agents; D001562:Benzimidazoles; D015415:Biomarkers; D004791:Enzyme Inhibitors; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; C521013:veliparib; D003606:Dacarbazine; D011065:Poly(ADP-ribose) Polymerases; D000077204:Temozolomide