Pregnenolone promotes immune evasion through blocking endogenous retrovirus expression

Area of Science:

• Oncology
• Immunology
• Endocrinology

Background:

• Steroid hormones significantly influence tumor biology.
• Pregnenolone's role in cancer progression and immune response remains largely unexplored.

Purpose of the Study:

• To investigate the impact of pregnenolone on tumor progression and immunotherapy efficacy.
• To elucidate the molecular mechanisms by which pregnenolone affects tumor immunity.

Main Methods:

• Utilized multiple mouse tumor models.
• Measured pregnenolone levels in maternal mice with mating deficiency.
• Investigated pregnenolone's molecular interactions with Kap1 and Trim39.
• Assessed the effects of pregnenolone antagonism on tumor growth and immunotherapy.

Main Results:

• Pregnenolone promoted tumor progression and decreased immunotherapy sensitivity.
• Elevated pregnenolone levels were observed in maternal mice with mating deficiency.
• Pregnenolone stabilizes Kap1 by inhibiting Trim39-mediated ubiquitination, repressing endogenous retrovirus (ERV) expression and type-I interferon production.
• Pharmacological blockade of pregnenolone suppressed tumor growth and enhanced immunotherapy.

Conclusions:

• Pregnenolone signaling is a critical regulator of tumor immune evasion.
• Mating-associated steroid metabolism is linked to tumor immune regulation.
• Targeting pregnenolone offers a novel therapeutic strategy for enhancing cancer immunotherapy.