Iniparib (160003-66-7) was originally thought to be a PARP1 inhibitor but this is controversial.1,2?Inhibits ionizing radiation-induced single-stranded DNA break repair in lymphoid cell lines?in vivo.3?Inhibits growth of certain breast cancer cell lines?in vitro. Iniparib non-selectively modifies cysteine-containing proteins in tumor cells.4
Poly(ADP-ribose) polymerase (PARP) is a critical DNA repair enzyme involved in DNA single-strand break repair via the base excision repair pathway. PARP1 is activated by DNA damage. Inhibiting its activity has been linked to synthetic lethality and loss of either of the breast cancer susceptibility genes, BRCA1 and BRCA2. BSI-201 is an irreversible, noncompetitive inhibitor of PARP1 that disrupts binding between PARP1 and DNA by interacting with the DNA binding domain. It produces rapid apoptosis in various cancer cell lines with IC50 values ranging from 40-128 μM and is not toxic in Syrian hamsters at doses as high as 200 mg/kg. In phase II clinical studies, BSI-201, in combination with carboplatin and gemcitabine, has produced promising results in "triple-negative" breast cancers, increasing median overall survival from 7.7 months to 12.3 months.
Iniparib (BSI-201) is an antineoplastic originally thought to be a poly(ADP-ribose) polymerase-1 (PARP-1) inhibitor. Recent studies indicate Iniparib is not a PARP-1 inhibitor, and its mechanism of action is currently unknown.
Iniparib is an irreversible PARP1 inhibitor. Studies show that potential therapeutic agent for the treatment of cancer, including triple-negative breast cancer.
ChEBI: 4-iodo-3-nitrobenzamide is a carbonyl compound and an organohalogen compound.
1) Sinha?et al. (2014),?Downfall of iniparib: a PARP inhibitor that doesn’t inhibit PARP after all; J. Natl. Cancer Inst.,?106?447
2) Mateo?et al.?(2013),?Appraising iniparib, the PARP inhibitor that never was –what must we learn?;?Nat. Rev. Clin. Oncol.,?10?688
3) Ma?et al. (2012),?Differential effects of poly(ADP-ribose) polymerase inhibition on DNA break repair in human cells are revealed with Epstein-Barr virus; Proc. Natl. Acad. Sci. USA,?109?6590
4) Liu?et al. (2012),?Iniparib nonselectively modifies cysteine-containing proteins in tumor cells and is not a bona fide PARP inhibitor; Clin. Cancer Res.,?18?510
