Project description:In contrast to the ubiquitous expression profile of PTEN, PTENα is predominantly expressed in brain. To study the biological function of PTENα in brain, we employed LCMV to induce murine viral encephalitis model. Through single cell RNA sequencing, we revealed the immunological function of PTENα during viral infection in the brain.
Project description:we report that USP9X and FBXW11 selectively regulate the stability of PTENα/β but not PTEN proteins by deubiqitination and ubiquitination respectively. USP9X promotes and FBXW11 suppresses tumorigenesis mediated by PTENα/β. In contrast to the current paradigm for PTEN as a tumor suppressor, PTENα/β promote tumorigenesis of cancer cells in a phosphatase-independent manner. Mechanistically, PTENα/β localized in the nucleus regulate expressions of tumor-promoting genes such as NOTCH3 in the similar way as the H3K4 presenter WDR5. Further, PTENα/β but not PTEN directly interact with WDR5 to promote trimethylation of H3K4 and maintain a tumor-promoting signature.
Project description:To explore the binding sites of PTENα on viral or host RNAs, we performed HyperTRIBE assay of HEK293T cells overexpressing ADAR1-CD, PTENα-N(WT)-ADAR1-CD, or PTENα-N(6R/D)-ADAR1-CD fusion protein under VSV-GFP (green fluorescent protein-expressing vesicular stomatitis virus) infection.
Project description:As a tumor suppressor, PTEN is frequently mutated in human cancers and PTEN mutants promote tumor progression and metastasis. PTEN mutations have been implicated in immune regulation, but the underlying mechanism is largely unknown. We report that PTENα, the isoform of PTEN, remains active in cancer bearing stop-gained PTEN mutations. Through counteraction of CD8+ T cell-mediated cytotoxicity, presence of PTENα leads to T cell dysfunction and accelerates immune-resistant cancer progression. Clinical analysis further uncovers that PTENα-active mutations suppress host immune responses and result in poor prognosis in cancer as relative to PTENα-inactive mutations. Furthermore, germline deletion of Ptenα in mice increases cell susceptibility to immune attack through augmenting stress granule formation and limiting synthesis of peroxidases, leading to massive oxidative cell death and severe inflammatory damage. We propose that PTENα protects tumor from T cell killing and thus PTENα is a potential target in antitumor immunotherapy.
Project description:we report that USP9X and FBXW11 selectively regulate the stability of PTENα/β but not PTEN proteins by deubiqitination and ubiquitination respectively. USP9X promotes and FBXW11 suppresses tumorigenesis mediated by PTENα/β. In contrast to the current paradigm for PTEN as a tumor suppressor, PTENα/β promote tumorigenesis of cancer cells in a phosphatase-independent manner. Mechanistically, PTENα/β localized in the nucleus regulate expressions of tumor-promoting genes such as NOTCH3 in the similar way as the H3K4 presenter WDR5. Further, PTENα/β but not PTEN directly interact with WDR5 to promote trimethylation of H3K4 and maintain a tumor-promoting signature.
Project description:To determine whether PTENα directly binds to viral RNA, we performed Cross-Linking and Immunoprecipitation (CLIP) sequencing of HEK293T cells transfected with vector encoding PTENα under VSV (vesicular stomatitis virus) infection
Project description:As a tumor suppressor, PTEN is frequently mutated in human cancers and PTEN mutants promote tumor progression and metastasis. PTEN mutations have been implicated in immune regulation, but the underlying mechanism is largely unknown. We report that PTENα, the isoform of PTEN, remains active in cancer bearing stop-gained PTEN mutations. Through counteraction of CD8+ T cell-mediated cytotoxicity, presence of PTENα leads to T cell dysfunction and accelerates immune-resistant cancer progression. Clinical analysis further uncovers that PTENα-active mutations suppress host immune responses and result in poor prognosis in cancer as relative to PTENα-inactive mutations. Furthermore, germline deletion of Ptenα in mice increases cell susceptibility to immune attack through augmenting stress granule formation and limiting synthesis of peroxidases, leading to massive oxidative cell death and severe inflammatory damage. We propose that PTENα protects tumor from T cell killing and thus PTENα is a potential target in antitumor immunotherapy.
Project description:To explore the effect of Ptenα on antiviral immunity pathway, we conducted RNA transcriptome profiling of wild-type and Ptenα-/- MEFs (mouse embryonic fibroblast cells) in response to VSV (vesicular stomatitis virus)
