Otsuki Toshifumi
- kawaokashinpei3
- 1 日前
- 読了時間: 1分
Selected journal : Nature Metabolism
Extracellular CD44 lactylation impairs CD8+ T cell function in KRAS-mutant colorectal cancer
What is the main question of the paper?
What drives immune evasion in KRAS-mutant colorectal cancer?
How did the anthor address the question?
■Step1
TRIP6 is high in KRAS-WT tumors, where it blocks the glycolytic enzyme ENO2 (via KDM1A/H3K9 methylation). More TRIP6 meant more CD8⁺ T cells in the tumor.
■Step2
In KRAS-mutant cells, ERK signaling phosphorylates TRIP6, disabling that brake. ENO2 rises, glycolysis speeds up, lactate builds up. The lactate then chemically modifies CD44 on CD8⁺ T cells (lactylation), which blocks CD44 from binding hyaluronan and weakens AKT signaling — so the T cells stop killing well.
■Step3
Knockout and knock-in mice at each step (Trip6, Eno2, phospho-dead TRIP6, lactylation- resistant CD44) confirmed the chain. A peptide blocking TRIP6 phosphorylation reversed it all — T cells came back, and combined with anti-PD-1, tumor control improved further.
What is the strength of the paper?
It's a full mechanistic bridge from oncogene to a druggable peptide — mutation → kinase → epigenetics → metabolite → a new T cell surface modification → immune suppression — each step proven with its own mouse model, and the therapeutic peptide boosts existing checkpoint blockade rather than replacing it.
Comment
This paper describes a novel mechanism by which KRAS-mutant colorectal cancer suppresses CD8⁺ T-cell function through extracellular CD44 lactylation. I think this is a well- designed study with a clear mechanistic story. The comprehensive mechanistic experiments and genetically engineered mouse models make the conclusions highly convincing.
Comment by Du Yilin
