Novel p53 Reactivators Show Promise in Treating Gynecologic Cancers with Mutant p53

Strategic Insights -

Recent research from the University of New Mexico has shed light on a novel therapeutic strategy for gynecologic cancers characterized by mutations in the tumor suppressor gene TP53. According to study results, ovarian and endometrial cancers frequently harbor TP53 mutations, resulting in unregulated cell growth and resistance to standard treatments. Researchers propose that converting mutant p53 to a wild-type conformation could greatly improve treatment outcomes.

Key Takeaways:

  • The study found that two purported p53 reactivators, HO-3867 and APR-246, showed promise in inhibiting cell proliferation in gynecologic cancer cell lines.
  • HO-3867 was particularly effective, with IC50 values in the low micromolar range, and was synergistic with the PARP inhibitor olaparib in vitro and in vivo.
  • RNA sequencing data suggest that HO-3867 acts through both p53-independent and p53-dependent pathways, resulting in the inhibition of DNA repair pathways.
  • The development of resistance to PARP inhibitors is a major problem in advanced gynecologic cancers, and the study shows that adding a p53 reactivator like HO-3867 enhances the efficacy of PARP inhibitors in p53-mutant cancer models.
  • The researchers propose that converting mutant p53 to a wild-type conformation and restoring its tumor suppressive functions has the potential to greatly improve treatment outcomes.
  • The study was conducted using cell lines that harbor oncogenic mutations in p53, including high-grade serous ovarian cancer.
  • Jamie L. Padilla, University of New Mexico, led the research with additional authors Lane E. Smith, Angelina Licor, Mara P. Steinkamp, Irina V. Lagutina, Yan Guo, Eric J. Devor, Vernon S. Pankratz, Annahita Sallmyr, Olufunmilola M. Oyebamiji, Jun-Yong Choe, Geneva L. Williams, and Kimberly K. Leslie.

Statistics:

  • Over 90% of ovarian cancers harbor a mutation in the TP53 tumor suppressor gene.
  • The study found that HO-3867 was effective in inhibiting cell proliferation in gynecologic cancer cell lines with IC50 values in the low micromolar range.
  • The study was conducted using five cell lines studied in vitro and in vivo in a xenograft model of high-grade serous ovarian cancer.
  • The development of resistance to PARP inhibitors is a major problem, with a cause of treatment failures in advanced gynecologic cancers.
  • The study was published in Translational Oncology, Volume 61, Issue 102522, in 2025.

Sources:

  • Translational Oncology, 2025;61:102522
  • University of New Mexico
  • Jamie L. Padilla, University of New Mexico
  • NewsRx. Study Data from University of New Mexico Provide New Insights into Gynecologic Cancer (Novel p53 reactivators that are synergistic with olaparib for the treatment of gynecologic cancers with mutant p53). OBGYN & Reproduction Week. September 22, 2025; p 923