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ABSTRACT: Background & aims
Advanced colorectal carcinoma (CRC) is characterized by a high frequency of primary immune evasion and refractoriness to immunotherapy. Given the importance of interferon (IFN)-γ in CRC immunosurveillance, we investigated whether and how acquired IFN-γ resistance in tumor cells would promote tumor growth, and whether IFN-γ sensitivity could be restored.Methods
Spontaneous and colitis-associated CRC development was induced in mice with a specific IFN-γ pathway inhibition in intestinal epithelial cells. The influence of IFN-γ pathway gene status and expression on survival was assessed in patients with CRC. The mechanisms underlying IFN-γ resistance were investigated in CRC cell lines.Results
The conditional knockout of the IFN-γ receptor in intestinal epithelial cells enhanced spontaneous and colitis-associated colon tumorigenesis in mice, and the loss of IFN-γ receptor α (IFNγRα) expression by tumor cells predicted poor prognosis in patients with CRC. IFNγRα expression was repressed in human CRC cells through changes in N-glycosylation, which decreased protein stability via proteasome-dependent degradation, inhibiting IFNγR-signaling. Downregulation of the bisecting N-acetylglucosaminyltransferase III (MGAT3) expression was associated with IFN-γ resistance in all IFN-γ-resistant cells, and highly correlated with low IFNγRα expression in CRC tissues. Both ectopic and pharmacological reconstitution of MGAT3 expression with all-trans retinoic acid increased bisecting N-glycosylation, as well as IFNγRα protein stability and signaling.Conclusions
Together, our results demonstrated that tumor-associated changes in N-glycosylation destabilize IFNγRα, causing IFN-γ resistance in CRC. IFN-γ sensitivity could be reestablished through the increase in MGAT3 expression, notably via all-trans retinoic acid treatment, providing new prospects for the treatment of immune-resistant CRC.
SUBMITTER: Krug J
PROVIDER: S-EPMC10009756 | biostudies-literature | 2023 Mar
REPOSITORIES: biostudies-literature
Krug Julia J Rodrian Gabriele G Petter Katja K Yang Hai H Khoziainova Svetlana S Guo Wei W Bénard Alan A Merkel Susanne S Gellert Susan S Maschauer Simone S Spermann Monika M Waldner Maximilian M Bailey Peter P Pilarsky Christian C Liebl Andrea A Tripal Philipp P Christoph Jan J Naschberger Elisabeth E Croner Roland R Schellerer Vera S VS Becker Christoph C Hartmann Arndt A Tüting Thomas T Prante Olaf O Grützmann Robert R Grivennikov Sergei I SI Stürzl Michael M Britzen-Laurent Nathalie N
Gastroenterology 20221117 3
<h4>Background & aims</h4>Advanced colorectal carcinoma (CRC) is characterized by a high frequency of primary immune evasion and refractoriness to immunotherapy. Given the importance of interferon (IFN)-γ in CRC immunosurveillance, we investigated whether and how acquired IFN-γ resistance in tumor cells would promote tumor growth, and whether IFN-γ sensitivity could be restored.<h4>Methods</h4>Spontaneous and colitis-associated CRC development was induced in mice with a specific IFN-γ pathway in ...[more]