Eprenetapopt (APR-246)

APR-246 (PRIMA-1MET) is the first clinical-stage compound that reactivates mutant p53 and induces apoptosis. APR-246 is a prodrug that is converted to the active compound methylene quinuclidinone (MQ), a Michael acceptor that binds to cysteine residues in mutant p53 and restores its wild-type conformation.  It not only reactivates p53 but also decreases intracellular glutathione levels in a dose-dependent manner. APR-246 can trigger apoptosis in a p53-independent manner by inducing ROS and endoplasmic reticulum (ER) stress and by inhibiting thioredoxin reductase 1 (TrxR1). It was also reported that APR-246 induces cell death in myeloma cells independently of p53 status by impairing the GSH/ROS balance^[1]. PRIMA-1Met/APR-246 efficiently inhibited the growth of the SCLC cell lines expressing mutant p53 in vitro and induced apoptosis, associated with increased fraction of cells with fragmented DNA, caspase-3 activation, PARP cleavage, Bax and Noxa upregulation and Bcl-2 downregulation in the cells^[2].

APR-246 showed a good safety profile in a Phase I/II clinical dose-finding study on hematological malignancies and prostate cancer and both clinical and p53-dependent biological responses were observed. In animal studies, APR-246 is well tolerated. Single treatment with APR-246 inhibits tumor growth by 21% in mice bearing the aggressively growing A2780-CP20 tumor xenografts^[1].

• Cell lines

  OVCAR-3 cells

• Concentrations

  40 μM

• Incubation Time

  20 h

• Method

  OVCAR-3 cells were plated at a density of 75 000 cells per well in 3 ml of medium in 12-well plates. After staining, the samples were analyzed by LSRII flow cytometer. 

• Animal Models

  CD-1 Nu/Nu mice

• Dosages

  400 mg/kg/day

• Administration

  i.v.