Transcription Factor-Mediated Reprogramming of Cancer-Associated Fibroblasts Reveals Targetable Vulnerabilities in...

Area of Science:

• Oncology
• Immunotherapy
• Cell Biology

Background:

• Cancer-associated fibroblasts (CAFs) create an immunosuppressive tumor microenvironment, hindering effective cancer therapies like chimeric antigen receptor (CAR) T cell therapy.
• CAFs contribute to immune exclusion and resistance to treatments in solid tumors.

Purpose of the Study:

• To develop a novel strategy for reprogramming CAFs into normal fibroblasts (NFs) to overcome tumor-induced immune suppression.
• To investigate the potential of transcription factor (TF)-guided fibroblast reprogramming to enhance CAR T cell therapy.

Main Methods:

• Developed a TF-based reprogramming strategy using Vitamin D receptor (VDR), Peroxisome Proliferator-Activated Receptor gamma (PPARγ), and p53.
• Utilized lentiviral expression to reprogram prostate-derived CAFs (pCAFs) into VDR-reprogrammed NFs (VDR-rpNFs).
• Evaluated reprogramming efficacy through in vitro 3D co-cultures and in vivo models, assessing CAF markers, metabolic activity, cytokine production, tumor architecture, T cell infiltration, and necrosis.

Main Results:

• VDR-rpNFs exhibited reduced CAF markers and suppressed immunosuppressive factors (TGF-β, IL6), alongside increased metabolic activity (ATP).
• Reprogrammed fibroblasts disrupted tumor architecture, significantly enhancing CAR T cell infiltration into tumors.
• Both VDR-rpNFs and reprogrammed NFs using PPARγ and p53 demonstrated similar beneficial reprogramming effects.

Conclusions:

• Transcription factor-guided reprogramming is a promising approach to reverse CAF phenotype and remodel the tumor microenvironment.
• This strategy holds potential for improving the efficacy of CAR T cell therapy and other immune cell therapies in solid tumors.
• Targeting fibroblasts offers a new avenue to overcome therapeutic resistance driven by the tumor microenvironment.