Abstract
Cancer immunoresistance and immune escape may play important roles in tumor progression and pose obstacles for immunotherapy. Expression of the immunosuppressive protein B7 homolog 1 (B7-H1), also known as programmed death ligand-1 (PD-L1), is increased in many pathological conditions, including cancer. Here we show that expression of the gene encoding B7-H1 increases post transcriptionally in human glioma after loss of phosphatase and tensin homolog (PTEN) and activation of the phosphatidylinositol-3-OH kinase (PI(3)K) pathway. Tumor specimens from individuals with glioblastoma multiforme (GBM) had levels of B7-H1 protein that correlated with PTEN loss, and tumor-specific T cells lysed human glioma targets expressing wild-type PTEN more effectively than those expressing mutant PTEN. These data identify a previously unrecognized mechanism linking loss of the tumor suppressor PTEN with immunoresistance, mediated in part by B7-H1.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Analysis of Variance
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Antibodies, Monoclonal / pharmacology
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Antigens, CD / genetics*
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Antigens, CD / immunology
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Antigens, CD / metabolism
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B7-H1 Antigen
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Blotting, Western
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Caspase 6 / metabolism
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Cell Line, Tumor
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Cell Survival / drug effects
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Enzyme Activation / drug effects
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Flow Cytometry
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Glioblastoma / genetics
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Glioblastoma / metabolism
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Glioblastoma / pathology
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Glioma / genetics
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Glioma / metabolism
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Glioma / pathology*
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Humans
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Mutation
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PTEN Phosphohydrolase / genetics*
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PTEN Phosphohydrolase / metabolism
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Protein Kinases / metabolism
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Proto-Oncogene Proteins c-akt / antagonists & inhibitors
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Proto-Oncogene Proteins c-akt / metabolism
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RNA Interference
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Reverse Transcriptase Polymerase Chain Reaction
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Ribosomal Protein S6 Kinases / genetics
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Ribosomal Protein S6 Kinases / metabolism
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Signal Transduction / drug effects
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TOR Serine-Threonine Kinases
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Transfection
Substances
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Antibodies, Monoclonal
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Antigens, CD
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B7-H1 Antigen
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CD274 protein, human
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Protein Kinases
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MTOR protein, human
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Proto-Oncogene Proteins c-akt
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Ribosomal Protein S6 Kinases
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TOR Serine-Threonine Kinases
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PTEN Phosphohydrolase
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PTEN protein, human
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Caspase 6