Project description:Sephin1 is the selective inhibitor of Protein Phosphatase 1 Regulatory Subunit 15A (PPP1R15A), which is an important factor in the integrated stress response (ISR) of mammalian cells. Sephin1 can promote ISR by inhibiting the dephosphorylation of eIF2α, and preventing neurodegenerative disease occurrence in mice. However, we found that Sephin1 plays a protumorigenic role in mouse tumor models by suppressing the antitumor immune activities, which was highly relevant to the function of PPP1R15A. To fully understand the mechanism of Sephin1 to the antitumor immunity, we designed this experiment to explore the function of PPP1R15A and Sephin1 in the single-cell expression level. To understand effect of injection of Sephin1 to the immune cells in blood and tumor microenvironment in mice, we injected Sephin1 to mice intraperitoneally, and then subcutaneously inoculated with B16F1 cells. Blood before/after the tumor development and tumor tissues were collected and immune cells were isolated for single-cell sequencing and bioinformatics analysis afterwards. We found that in C57BL/6 mice, Sephin1 treatment could lead to higher levels of ISR activity and lower levels of antitumor immune activities. Specifically, Sephin1 treatment caused reductions in several tumor-killing immune cell populations, including CD8+ T cells, NK cells and NKT cells. The expression levels of cytotoxicity-related genes in lymphocytes were altered upon Sephin1 treatment. Additionally, TCR repertoire analysis demonstrated that the clonal expansion of tumor-specific T cells was inhibited by Sephin1, resulting in a compromised antitumor immune response. A special TCR+ macrophage subtype was identified to be significantly depleted upon Sephin1 treatment, implying that this type of macrophage plays a key antitumor role in the tumor microenvironment. The effects of Sephin1 were also verified in in vitro experiments and studies of other tumor cell lines. Taken together, these data suggest that inhibiting PPP1R15A promotes tumorigenesis by inducing adverse immune suppression. PPP1R15A has the potential to be an effective target for tumor therapy. Besides, a macrophage subtype, the TCR+ macrophages, played an important role in the anti-tumor immunity and can also be significantly inhibited by Sephin1.
Project description:Acupuncture has been considered as an available complement therapy against various malignancy cancer by regulating immunity. However, it is not clear whether acupuncture influences the antitumor immune efficacy of PD-1 inhibitor. This study evaluates the efficacy of acupuncture combined with PD-1 inhibitor on the antitumor immune response against breast cancer and revealed the potential molecular mechanisms based on RNA-Seq transcriptome analysis. The results depicted that acupuncture combined with PD-1 inhibitor significantly hindered tumor development by inducing tumor cell apoptosis and inhibiting tumor growth, angiogenesis and metastasis. RNA-Seq analysis indicated that the different expression genes upon acupuncture intervention mainly enriched in immune response, T cell activation and cytokine interaction etc. items containing immune cell-related CD genes (CD5, CD4 and CD8 etc.). Acupuncture stimulation enhanced CD5 expression that had a positive correlation with overall survival of breast cancer patients. The improved immunity including the enhancement of CD5+ dendritic cell, CD4+ and CD8+ T cell content as well as various cytokine (IL-2, IL-6, TNF-α, IFN-γ) secretion in serum was found upon acupuncture combination with PD-1 inhibitor treatment. Taken together, present work reveals that acupuncture intervention promotes the antitumor immune response of PD-1 inhibitor, providing a prospective therapy for ICI therapy against breast cancer.
Project description:Verteporfin (VP) inhibts colon cancer growth in vivo and in cell lines by inducing high molecular weight oligomerization of proteins. The antitumor effect of VP is independent of its YAP inhibitor activity. Tumor hypoxia contributes partly to antitumor effect of VP by impairing clearance of VP-induced high molecular weight aggregates.
Project description:Anaplastic thyroid carcinoma (ATC) is one of the most aggressive malignancy and accounts for the majority of thyroid cancer-related deaths. Despite intensive research, there remains no effective treatment for patients with ATC. Here, we identify THZ1, a covalent inhibitor of cyclin-dependent kinase 7 (CDK7), as a potent anti-ATC compound by high-throughput chemical screening. ATC cells, but not papillary thyroid cancer (PTC) cells, are exceptionally sensitive to CDK7 inhibition. Analyzing both gene expression profiles and super enhancer (SE) features reveals that the SE-mediated oncogenic transcriptional amplification renders the vulnerability of ATC cells to THZ1 treatment. Combining this integrative analysis with functional assays discovers a number of novel cancer genes of ATC, including PPP1R15A, SMG9 and KLF2. Inhibition of PPP1R15A with Guanabenz (GBZ) or Sephin1 greatly suppresses ATC growth. Significantly, the expression level of PPP1R15A is correlated with CDK7 expression in ATC tissue samples. Elevated expression of PPP1R15A and CDK7 are both associated with poor clinical prognosis in ATC patients. Importantly, GBZ or THZ1 treatment sensitizes ATC cells to conventional chemotherapy. Taken together, these findings demonstrate transcriptional addiction in ATC pathobiology and identify CDK7 and PPP1R15A as potential biomarkers and therapeutic targets for ATC.
Project description:Anaplastic thyroid carcinoma (ATC) is one of the most aggressive malignancy and accounts for the majority of thyroid cancer-related deaths. Despite intensive research, there remains no effective treatment for patients with ATC. Here, we identify THZ1, a covalent inhibitor of cyclin-dependent kinase 7 (CDK7), as a potent anti-ATC compound by high-throughput chemical screening. ATC cells, but not papillary thyroid cancer (PTC) cells, are exceptionally sensitive to CDK7 inhibition. Analyzing both gene expression profiles and super enhancer (SE) features reveals that the SE-mediated oncogenic transcriptional amplification renders the vulnerability of ATC cells to THZ1 treatment. Combining this integrative analysis with functional assays discovers a number of novel cancer genes of ATC, including PPP1R15A, SMG9 and KLF2. Inhibition of PPP1R15A with Guanabenz (GBZ) or Sephin1 greatly suppresses ATC growth. Significantly, the expression level of PPP1R15A is correlated with CDK7 expression in ATC tissue samples. Elevated expression of PPP1R15A and CDK7 are both associated with poor clinical prognosis in ATC patients. Importantly, GBZ or THZ1 treatment sensitizes ATC cells to conventional chemotherapy. Taken together, these findings demonstrate transcriptional addiction in ATC pathobiology and identify CDK7 and PPP1R15A as potential biomarkers and therapeutic targets for ATC.
Project description:Anaplastic thyroid carcinoma (ATC) is one of the most aggressive malignancy and accounts for the majority of thyroid cancer-related deaths. Despite intensive research, there remains no effective treatment for patients with ATC. Here, we identify THZ1, a covalent inhibitor of cyclin-dependent kinase 7 (CDK7), as a potent anti-ATC compound by high-throughput chemical screening. ATC cells, but not papillary thyroid cancer (PTC) cells, are exceptionally sensitive to CDK7 inhibition. Analyzing both gene expression profiles and super enhancer (SE) features reveals that the SE-mediated oncogenic transcriptional amplification renders the vulnerability of ATC cells to THZ1 treatment. Combining this integrative analysis with functional assays discovers a number of novel cancer genes of ATC, including PPP1R15A, SMG9 and KLF2. Inhibition of PPP1R15A with Guanabenz (GBZ) or Sephin1 greatly suppresses ATC growth. Significantly, the expression level of PPP1R15A is correlated with CDK7 expression in ATC tissue samples. Elevated expression of PPP1R15A and CDK7 are both associated with poor clinical prognosis in ATC patients. Importantly, GBZ or THZ1 treatment sensitizes ATC cells to conventional chemotherapy. Taken together, these findings demonstrate transcriptional addiction in ATC pathobiology and identify CDK7 and PPP1R15A as potential biomarkers and therapeutic targets for ATC.
Project description:An innovative multikinase inhibitor (H89)-based antitumor immunotherapy in colorectal cancer (CRC) is presented. The study was designed to evaluate the effect of H89 on colon tumor growth and carcinogenesis through in vivo analyses. Syngeneic mouse models of CRC cancer in BALB/c mice and chemically colon tumorigenesis, reveals that H89 delays colon oncogenesis, related to a preventive effect, and prevents tumor growth, underlying an antitumor effect respectively. Using immunodeficient and monoclonal antibody-specific immunosuppression, we identified immune cell populations involved in the preventive (NK-cell dependent) and antitumor activity of H89 (T-cell dependent). Flow cytometry analysis showed that the antitumor effect of H89 was correlated with an increase in the tumor microenvironment of CD4+ Th1 cells and CD8+ cytotoxic T cells and a decrease of CD4+ Treg cells infiltration. Furthermore, qRT-PCR revealed that H89 can promote naïve CD4+ T cells differentiation into Th1, decreases Treg differentiation and increases ex vivo CD8+ T cell-mediated killing of cancer cells. An RNAseq profiling experiment showed that H89 induces an overexpression of genes involved in antitumor immune response, such as IL-15RA, whose inhibition counteracts the antitumor effect of H89. In conclusion, our findings identify H89 as a potential strategy for the prevention and treatment of CRC.
Project description:Phosphatidylinositol-3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway activation contributes to mantle cell lymphoma (MCL) pathogenesis and drug resistance. However, the use of mTOR inhibitors as single agents have shown limited clinical efficacy in relation with drug activation of feedback loops. Selective PI3K inhibition or dual PI3K/mTOR catalytic inhibition are different therapeutic approaches developed to achieve effective pathway blockage. Here, we evaluated the antitumor activity of a mTOR inhibitor, a pan-PI3K inhibitor and a dual PI3K/mTOR inhibitor in primary MCL cells. We found that dual PI3K/mTOR inhibitor modulated angiogenesis, tumor invasiveness and cytokine signaling compared to a mTOR inhibitor and a pan-PI3K inhibitor in MCL. We used microarrays to compare the effect of these three compounds in MCL and identified distinct classes of down-regulated genes modulated by each compound. Global RNA expression in primary cells from two MCL patients treated with a mTOR inhibitor, a pan-PI3K inhibitor and a dual PI3K/mTOR inhibitor for 8 hours
Project description:Type I interferons (IFN-I) and IFN- foster antitumor immunity by facilitating T cell responses. Paradoxically, IFNs may promote T cell exhaustion by activating immune checkpoints. The downstream regulators of these responses are incompletely understood. Herein, we describe how Interferon Regulatory Factor 1 (IRF1) orchestrates these opposing effects of IFNs. IRF1 expression in tumors blocked Toll-like receptor and IFN-I-dependent host antitumor immunity by preventing IFN stimulated gene (ISG) programs and effector programs in dendritic cells and T cells. In contrast, expression of IRF1 in the host, but not IRF3 or IFN-, was also required for antitumor immunity to wildtype and Irf1-/- tumors. Mechanistically, tumor cell IRF1 regulated major histocompatibility class I expression and bound uniquely or together with STAT1 at many ISGs, contributing to expression of immunosuppressive but not immunostimulatory ISGs. Overexpression of PD-L1 in Irf1-/- tumors only partially restored tumor growth, suggesting that the negative effects of tumor IRF1 on antitumor immunity are multifactorial. Thus, we identify tumor cell IRF1 expression as a previously unrecognized selective inhibitor of host IFN-I dependent antitumor immunity, while host IRF1 and IFN-I are critical drivers of antitumor immune responses.