Activation of CD8+ T Cells Contributes to Antitumor Effects of CDK4/6 Inhibitors plus MEK Inhibitors.
Cancer Immunol Res
; 8(9): 1114-1121, 2020 09.
Article
em En
| MEDLINE
| ID: mdl-32661093
ABSTRACT
Concurrent MEK and CDK4/6 inhibition shows promise in clinical trials for patients with advanced-stage mutant BRAF/NRAS solid tumors. The effects of CDK4/6 inhibitor (CDK4/6i) in combination with BRAF/MEK-targeting agents on the tumor immune microenvironment are unclear, especially in melanoma, for which immune checkpoint inhibitors are effective in approximately 50% of patients. Here, we show that patients progressing on CDK4/6i/MEK pathway inhibitor combinations exhibit T-cell exclusion. We found that MEK and CDK4/6 targeting was more effective at delaying regrowth of mutant BRAF melanoma in immunocompetent versus immune-deficient mice. Although MEK inhibitor (MEKi) treatment increased tumor immunogenicity and intratumoral recruitment of CD8+ T cells, the main effect of CDK4/6i alone and in combination with MEKi was increased expression of CD137L, a T-cell costimulatory molecule on immune cells. Depletion of CD8+ T cells or blockade of the CD137 ligand-receptor interaction reduced time to regrowth of melanomas in the context of treatment with CDK4/6i plus MEKi treatment in vivo Together, our data outline an antitumor immune-based mechanism and show the efficacy of targeting both the MEK pathway and CDK4/6.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Acrilonitrila
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Linfócitos T CD8-Positivos
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Quinase 4 Dependente de Ciclina
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Quinase 6 Dependente de Ciclina
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Compostos de Anilina
Limite:
Animals
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Humans
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Male
Idioma:
En
Revista:
Cancer Immunol Res
Ano de publicação:
2020
Tipo de documento:
Article