Delivery of a STING Agonist Using Lipid Nanoparticles Inhibits Pancreatic Cancer Growth

Area of Science:

• Immunology
• Oncology
• Nanotechnology

Background:

• Pancreatic cancer's tumor microenvironment (TME) is immunosuppressive, hindering anti-tumor immunity.
• Stimulator of interferon genes (STING) agonists can inflame the TME and reduce tumor burden.
• Delivering STING agonists like 2'3' cyclic guanosine monophosphate adenosine monophosphate (cGAMP) intracellularly is challenging due to stability and cell membrane barriers.

Purpose of the Study:

• To develop a novel lipid nanoparticle (LNP) delivery system for 2'3'-cGAMP.
• To evaluate the efficacy of cGAMP-LNP in enhancing anti-tumor immunity within the pancreatic TME.
• To assess the anti-tumor activity of cGAMP-LNP in a preclinical pancreatic cancer model.

Main Methods:

• Encapsulation of 2'3'-cGAMP within a specifically designed lipid nanoparticle (cGAMP-LNP).
• In vitro assessment of nanoparticle cellular uptake, cytosolic release, and cytotoxicity.
• Evaluation of cGAMP-LNP anti-tumor effects in a syngeneic mouse model of pancreatic cancer.

Main Results:

• The LNP formulation significantly enhanced the cellular uptake of 2'3'-cGAMP.
• cGAMP-LNP demonstrated promising anti-tumor activity in the preclinical pancreatic cancer model.
• The lipid platform facilitated efficient cytosolic delivery of the STING agonist.

Conclusions:

• The LNP platform is a viable strategy for delivering exogenous 2'3'-cGAMP or its analogs for cancer therapy.
• This approach holds potential for overcoming delivery challenges associated with STING agonists in pancreatic cancer.
• Further development of LNP-based STING agonists could offer new therapeutic avenues for pancreatic cancer treatment.