Abstract |
Chromosomal region 9p21 containing tumor suppressors CDKN2A/B and methylthioadenosine phosphorylase (MTAP) is one of the most frequent genetic deletions in cancer. 9p21 loss is correlated with reduced tumor-infiltrating lymphocytes (TILs) and resistance to immune checkpoint inhibitor (ICI) therapy. Previously thought to be caused by CDKN2A/B loss, we now show that it is loss of MTAP that leads to poor outcomes on ICI therapy and reduced TIL density. MTAP loss causes accumulation of methylthioadenosine ( MTA) both intracellularly and extracellularly and profoundly impairs T cell function via the inhibition of protein arginine methyltransferase 5 (PRMT5) and by adenosine receptor agonism. Administration of MTA-depleting enzymes reverses this immunosuppressive effect, increasing TILs and drastically impairing tumor growth and importantly, synergizes well with ICI therapy. As several studies have shown ICI resistance in 9p21/MTAP null/low patients, we propose that MTA degrading therapeutics may have substantial therapeutic benefit in these patients by enhancing ICI effectiveness.
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Authors | Donjeta Gjuka, Elio Adib, Kendra Garrison, Jianfeng Chen, Yuxue Zhang, Wenjiao Li, Daniel Boutz, Candice Lamb, Yuri Tanno, Amin Nassar, Talal El Zarif, Neil Kale, Mehrdad Rakaee, Tarek H Mouhieddine, Sarah Abou Alaiwi, Alexander Gusev, Thomas Rogers, Jianjun Gao, George Georgiou, David J Kwiatkowski, Everett Stone |
Journal | Cancer cell
(Cancer Cell)
Vol. 41
Issue 10
Pg. 1774-1787.e9
(10 09 2023)
ISSN: 1878-3686 [Electronic] United States |
PMID | 37774699
(Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't)
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Copyright | Copyright © 2023 Elsevier Inc. All rights reserved. |
Chemical References |
- 5'-methylthioadenosine phosphorylase
- Purine-Nucleoside Phosphorylase
- PRMT5 protein, human
- Protein-Arginine N-Methyltransferases
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Topics |
- Humans
- T-Lymphocytes
(metabolism)
- Neoplasms
(drug therapy, genetics)
- Purine-Nucleoside Phosphorylase
(genetics)
- Immunotherapy
- Protein-Arginine N-Methyltransferases
(genetics)
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