Loading
Life sciences · Journal article
Science Advances · October 2, 2026
No summary has been generated for this record yet. What follows is drawn from its source metadata only.
Journal article.
No findings were extractable from the material analysed.
Safety was not reported in the material analysed. Check the source before drawing any conclusion about harm.
The source did not state who this applies to in practice.
Graded across the dimensions that decide whether you should act, each from what the source actually supports. There is no single score, and where a dimension was not assessed it says so.
This record has not been graded across any dimension yet. Treat the label above as provisional and read the source.
What is missing. This record has no bottom line, key findings, reported figures, evidence dimensions. That is a gap in the analysis, not a judgement about the study.
Triple-negative breast cancer (TNBC) develops in hypoxic, nutrient-limited tumors enriched with macrophages and cell death. We show that metabolically distinct TNBCs differentially exploit macrophage-derived nutrients, influencing tumor growth and therapeutic response. Prolonged hypoxia reprogrammed mouse and human macrophages, enabling them to release metabolites that rescued the growth of select TNBC cell lines during glutamine deprivation or glutamine metabolism inhibition. Hypoxic macrophages reduced glutamine consumption, increased arginine utilization, and secreted higher levels of ornithine, an intermediate of arginine metabolism. Exogenous ornithine, but not arginine, restored the growth of responsive TNBC cells. Mechanistically, TNBC cells diverted ornithine into proline biosynthesis, supporting oxidative pentose phosphate pathway activity. In vivo, depletion of tumor-associated myeloid cells reduced tumor growth and impaired proline synthesis in glutaminase inhibitor–resistant TNBC. These findings identify hypoxia-driven metabolic cross-talk between macrophages and TNBC cells, revealing ornithine-dependent proline metabolism as a mechanism by which macrophages sustain tumor growth under nutrient stress and contribute to resistance to glutamine-targeted therapies.