Discovery of a potent PARP1 PROTAC as a chemosensitizer for the treatment of colorectal cancer

Eur J Med Chem. 2025 Jan 15:282:117062. doi: 10.1016/j.ejmech.2024.117062. Epub 2024 Nov 17.

Abstract

Given the vulnerability of colorectal cancer (CRC) patients could not obtain a sustained benefit from chemotherapy, combination therapy is frequently employed as a treatment strategy. Targeting PARP1 blockade exhibit specific toxicity towards tumor cells with BRCA1 or BRCA2 mutations through synthetic lethality. This study focuses on developing a series of potent PROTACs targeting PARP1 in order to enhance the sensitivity of CRC cells with BRCA1 or BRCA2 mutations to chemotherapy. Compound C6, obtained based on precise structural optimization of the linker, has been shown to effectively degrade PARP1 with a DC50 value of 58.14 nM. Furthermore, C6 significantly increased the cytotoxic efficacy of SN-38, an active metabolite of Irinotecan, in BRCA-mutated CRC cells, achieving a favorable combination index (CI) of 0.487. In conclusion, this research underscores the potential benefits of employing a combination therapy that utilizes PAPRP1 degrader C6 alongside Irinotecan for CRC patients harboring BRCA mutations in CRC.

Keywords: Chemosensitizer; Chemotherapy; Colorectal cancer; PARP1; PROTAC.

MeSH terms

  • Antineoplastic Agents* / chemical synthesis
  • Antineoplastic Agents* / chemistry
  • Antineoplastic Agents* / pharmacology
  • BRCA1 Protein / metabolism
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Colorectal Neoplasms* / drug therapy
  • Colorectal Neoplasms* / pathology
  • Dose-Response Relationship, Drug
  • Drug Discovery*
  • Drug Screening Assays, Antitumor
  • Humans
  • Irinotecan / chemistry
  • Irinotecan / pharmacology
  • Molecular Structure
  • Poly (ADP-Ribose) Polymerase-1* / antagonists & inhibitors
  • Poly (ADP-Ribose) Polymerase-1* / metabolism
  • Poly(ADP-ribose) Polymerase Inhibitors / chemical synthesis
  • Poly(ADP-ribose) Polymerase Inhibitors / chemistry
  • Poly(ADP-ribose) Polymerase Inhibitors / pharmacology
  • Proteolysis Targeting Chimera* / chemical synthesis
  • Proteolysis Targeting Chimera* / chemistry
  • Proteolysis Targeting Chimera* / pharmacology
  • Structure-Activity Relationship

Substances

  • Antineoplastic Agents
  • BRCA1 Protein
  • Irinotecan
  • PARP1 protein, human
  • Poly (ADP-Ribose) Polymerase-1
  • Poly(ADP-ribose) Polymerase Inhibitors
  • Proteolysis Targeting Chimera