STING activation reprograms the microenvironment to sensitize NF1-related malignant peripheral nerve sheath tumors...

Area of Science:

• Oncology
• Immunology
• Genetics

Background:

• Neurofibromatosis type 1 (NF1) involves NF1 gene mutations, leading to RAS hyperactivation and neoplasms like malignant peripheral nerve sheath tumors (MPNSTs).
• MPNSTs are aggressive, difficult to treat with current therapies, and are the primary cause of mortality in NF1 patients.
• Immune checkpoint blockade (ICB) shows promise for undruggable cancers but requires an inflamed tumor microenvironment, which MPNSTs typically lack.

Purpose of the Study:

• To investigate if activating stimulator of IFN genes (STING) signaling can convert MPNSTs into T cell-inflamed "hot" tumors.
• To evaluate the efficacy of combining STING activation with ICB as a potential treatment for MPNSTs.

Main Methods:

• Utilized mouse genetic and human xenograft MPNST models.
• Administered a STING agonist in combination with immune checkpoint blockade (ICB).

Main Results:

• STING activation successfully converted MPNSTs from "cold" to "hot" tumors, increasing T cell infiltration.
• Combination therapy of STING agonist and ICB significantly delayed tumor growth in both mouse genetic and human xenograft models.
• The observed tumor growth delay was associated with increased apoptotic cell death within the tumors.

Conclusions:

• Activating STING signaling is a viable strategy to enhance the immunogenicity of MPNSTs.
• Combining STING agonists with ICB represents a promising therapeutic approach for treating MPNSTs in NF1 patients.
• This strategy offers a potential new treatment regimen for MPNSTs, addressing their current resistance to standard therapies.