# Glucocorticoid Receptor Activation Reprograms NK Cells to Drive AREG‐Mediated Immunosuppression: A Pan‐Cancer Role for AREG

## TL;DR

Natural killer cells in tumors produce less anti-cancer signals and more tumor-promoting amphiregulin due to glucocorticoid receptor activation, offering a new therapeutic target.

## Contribution

Identifies a novel GR–AREG axis in tumor-associated NK cells that drives immunosuppression and is a potential therapeutic target.

## Key findings

- Glucocorticoid receptor activation in NK cells increases amphiregulin production, linked to tumor progression.
- Genetic or pharmacological inhibition of GR blocks glucocorticoid-induced AREG in NK cells.
- Adoptive transfer of AREG-deficient NK cells suppresses tumor growth in mice.

## Abstract

Natural killer (NK) cells are potent mediators of anti‐tumor immunity, yet their functions are frequently subverted by tumor microenvironment‐driven immunosuppression. Here, it dissects the molecular mechanisms underlying NK cell dysfunction in cutaneous malignancies and identifies a paradoxical cytokine shift in tumor‐associated NK cells–reduced production of IFN‐γ and TNF‐α alongside elevated amphiregulin (AREG), an EGFR ligand linked to tumor progression. Single‐cell transcriptomic analysis indicates that this reprogramming correlates with elevated glucocorticoid receptor (GR/NR3C1) pathway activity in tumor‐infiltrating NK cells. Functional validation demonstrated that glucocorticoids specifically induce AREG production in NK cells, with tumor‐associated prostaglandin E2 (PGE2) augmenting this response. Genetic ablation or pharmacological inhibition of NR3C1 abolished glucocorticoid‐driven AREG induction. Moreover, primary GR activation established persistent chromatin accessibility at the AREG locus, sensitizing NK cells to enhanced AREG production upon secondary glucocorticoid exposure. Functionally, AREG counteracts NK cell‐mediated tumor apoptosis, while the adoptive transfer of AREG‐deficient human NK cells significantly suppressed melanoma, cutaneous squamous cell carcinoma (cSCC), and hepatocellular carcinoma growth in NCG mice. These findings establish the GR‐AREG axis as a multi‐layered therapeutic target for restoring NK cell anti‐tumor function.

Natural killer cells, central to anti‐tumor defense, undergo unexpected reprogramming within the tumor microenvironment. Instead of producing IFN‐γ and TNF‐α, they elevate amphiregulin, a tumor‐promoting factor. This shift is linked to glucocorticoid receptor activity and prostaglandin signaling. The findings reveal a surprising GR–AREG axis that undermines tumor immunity and emerges as a promising therapeutic target.