{
  "id": 1790171,
  "title": "How chronic environmental stress drives immune dysfunction in cold tumors",
  "url": "https://urgent.news/2026/08/18/how-chronic-environmental-stress-drives-immune-dysfunction-in-cold",
  "topic": "health",
  "section": "Health & Medicine",
  "published": "2026-08-18T20:20:12.000Z",
  "source": {
    "name": "Medical Xpress",
    "slug": "medical-xpress",
    "url": "https://medicalxpress.com/news/2026-08-chronic-environmental-stress-immune-dysfunction.html"
  },
  "original_language": "en",
  "account": "Chronic environmental and metabolic stress plays a significant role in impairing immune function, particularly in cold tumors such as ovarian, breast, and prostate cancers. These tumors are able to evade immune attack and respond poorly to immunotherapies. Researchers from Pusan National University, led by Professor Yuseok Moon, have investigated how long-term environmental and dietary stress reprograms natural killer (NK) cells, the frontline defenders against cancer. Using epithelial ovarian cancer as a model, the team found that persistent activation of the aryl hydrocarbon receptor (AhR) drives NK-cell maladaptation. The GDF15–IDO1–kynurenine–AhR signaling axis sustains NK-cell activation and gradually transforms them from an active tumor-killing state into an exhausted, maladaptive state. Chemoresistant tumor cells produce high levels of GDF15, which activates AhR through increased IDO1 activity and kynurenine production. As NK cells become exhausted, their cancer-killing ability declines, leading to immune escape and reduced responsiveness to immunotherapy. Blocking AhR signaling restores NK-cell function, suggesting that targeting the GDF15–AhR axis could be a promising therapeutic approach. The study also highlights the importance of environmental factors in shaping cancer immunity and provides a potential biomarker for identifying patients who may be less likely to respond to immunotherapy.",
  "summary": "Immunotherapy has transformed cancer treatment, yet many tumors remain stubbornly resistant to its effects. Among the most challenging are \"cold tumors,\" including ovarian, breast and prostate cancers, which evade immune attack and respond poorly to existing immunotherapies.",
  "key_points": [
    "Chronic environmental and metabolic stress impairs immune function in cold tumors.",
    "Aryl hydrocarbon receptor (AhR) reprograms natural killer (NK) cells in ovarian cancer.",
    "GDF15–AhR signaling axis sustains NK-cell exhaustion, reducing immunotherapy response."
  ],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}