BSI-201, also known as iniparib, can interact with the zinc finger domain of poly(ADP-ribose) polymerase 1 (PARP1) in vitro, but fails to inhibit the enzyme (Patel et al.). The nitroso metabolite of BSI-201 is highly reactive and forms non-specific covalent interactions with many cysteine-containing proteins (Liu et al.). BSI-201 has demonstrated anti-proliferative effects in triple-negative breast cancer cells (Chuang et al.; Yin et al.), and early studies indicated that it may be useful in treating early-stage triple-negative and BRCA1/2 mutation-associated breast cancer (O’Shaughnessy et al. 2009); however, its efficacy was later found to be insignificant (O’Shaughnessy et al. 2014).


REPROGRAMMING
· When used in combination with other small molecules, enables derivation of extended pluripotent stem (EPS) cells from both humans and mice (Yang et al.).

CANCER RESEARCH
· Inhibits the growth of a subset of triple-negative breast cancer cells (Myc/MDA-231), in combination with cisplatin (Chuang et al.; Yin et al.).