Glutathione-dependent degradation of SMARCA2/4 for targeted lung cancer therapy with improved selectivity

Area of Science:

• Oncology
• Molecular Biology
• Drug Discovery

Background:

• SMARCA2 and SMARCA4 are key components of the SWI/SNF chromatin remodeling complex.
• Targeting SMARCA2/4 presents a promising strategy for cancer therapy, particularly using Proteolysis-Targeting Chimeras (PROTACs).
• Off-tissue toxicity of current therapeutic strategies remains a significant challenge.

Purpose of the Study:

• To develop a glutathione (GSH)-inducible PROTAC precursor targeting SMARCA2/4.
• To achieve selective anti-lung cancer activity with minimal cytotoxicity to normal cells.
• To evaluate the efficacy and safety of the optimized PROTAC precursor in vitro and in vivo.

Main Methods:

• Optimization of a SMARCA2/4-based PROTAC precursor.
• In vitro and in vivo testing for cytotoxicity and anti-tumor activity.
• Assessment of GSH-responsiveness and targeted protein degradation via the proteasome pathway.
• Xenograft model studies to evaluate in vivo efficacy and safety.

Main Results:

• The optimized PROTAC precursor demonstrated selective anti-cancer activity against lung cancer cells.
• The precursor showed negligible cytotoxicity towards normal cells in both in vitro and in vivo models.
• Selective degradation of SMARCA2/4 in lung tumors induced DNA damage and apoptosis, inhibiting proliferation.
• No significant adverse events were observed in normal tissues.

Conclusions:

• The GSH-responsive PROTAC precursor effectively targets and degrades SMARCA2/4 in lung cancer cells.
• This approach offers a promising strategy for lung cancer therapy with enhanced safety.
• The study highlights the potential of targeted protein degradation using GSH-responsive PROTACs.