Abstract
CTLA-4 immune checkpoint blockade is clinically effective in a subset of patients with metastatic melanoma. We identify a subcluster of MAGE-A cancer-germline antigens, located within a narrow 75 kb region of chromosome Xq28, that predicts resistance uniquely to blockade of CTLA-4, but not PD-1. We validate this gene expression signature in an independent anti-CTLA-4-treated cohort and show its specificity to the CTLA-4 pathway with two independent anti-PD-1-treated cohorts. Autophagy, a process critical for optimal anti-cancer immunity, has previously been shown to be suppressed by the MAGE-TRIM28 ubiquitin ligase in vitro. We now show that the expression of the key autophagosome component LC3B and other activators of autophagy are negatively associated with MAGE-A protein levels in human melanomas, including samples from patients with resistance to CTLA-4 blockade. Our findings implicate autophagy suppression in resistance to CTLA-4 blockade in melanoma, suggesting exploitation of autophagy induction for potential therapeutic synergy with CTLA-4 inhibitors. Increased expression of a subcluster of MAGE-A cancer-germline antigens predicts resistance specific to CTLA-4, but not PD-1, blockade, and its association with autophagy suppression implicates the role of autophagy in regulating primary resistance to anti-CTLA-4 therapy in melanoma patients.
Original language | English (US) |
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Pages (from-to) | 624-633.e8 |
Journal | Cell |
Volume | 173 |
Issue number | 3 |
DOIs | |
State | Published - Apr 19 2018 |
Externally published | Yes |
Keywords
- CTLA-4
- MAGE-A
- PD-1
- autophagy
- cancer-germline antigen
- checkpoint blockade
- immunogenomics
- immunotherapy
- ipilimumab
- melanoma
ASJC Scopus subject areas
- General Biochemistry, Genetics and Molecular Biology