Activity

BET degraders potently induced apoptosis in sensitive NSCLC cells and were accompanied by reduction of Mcl-1 and c-FLIP levels, which are critical for mediating induction of apoptosis and enhancement of TRAIL-induced apoptosis. Accordingly, ZBC260 exerted more potent activity than JQ-1 in vivo against the growth of NSCLC xenografts and patient-derived xenografts. These findings warrant future clinical validation of the efficacy of BET degraders in NSCLC, particularly those with high levels of BRD proteins, especially BRD4. Copyright ©2020, American Association for Cancer Research.Dysregulation of Wnt/β-catenin signaling is frequently observed in human gastric cancer. Elucidation of the tumor immune microenvironment is essential for understanding tumorigenesis and for the development of immunotherapeutic strategies. However, it remains unclear how β-catenin signaling regulates the tumor immune microenvironment in the stomach. EMD638683 Here we identify CCL28 as a direct transcriptional target gene of β-catenin/T cell factor (TCF). Protein levels of β-catenin and CCL28 positively correlated in human gastric adenocarcinoma. Activation of CCL28 by β-catenin recruited Regulatory T (Treg) cells in a transwell migration assay. In a clinically relevant mouse gastric cancer model established by Helicobacter (H.) felis infection and MNU treatment, inhibition of β-catenin/TCF activity by a pharmacological inhibitor iCRT14 suppressed CCL28 expression and Treg cell infiltration in the stomach. Moreover, an anti-CCL28 antibody attenuated Treg cell infiltration and tumor progression in H. felis/MNU mouse models. Diphtheria toxin (DT)-induced Treg cell ablation restrained gastric cancer progression in H. felis/MNU-treated DEREG (Foxp3-DTR) mice, clarifying the tumor-promoting role of Treg cells. Thus, the β-catenin-CCL28-Treg cell axis may serve as an important mechanism for immunosuppression of the stomach tumor microenvironment. Our findings reveal an immunoregulatory role of β-catenin signaling in stomach tumors and highlight the therapeutic potential of CCL28 blockade for the treatment of gastric cancer. Copyright ©2020, American Association for Cancer Research.The recurring association of specific genetic lesions with particular types of cancer is a fascinating, and largely unexplained area of cancer biology. This is particularly true of clear cell renal cell carcinoma (ccRCC) where although key mutations such as loss of VHL is an almost ubiquitous finding, there remains a conspicuous lack of targetable genetic drivers. In this study, we have identified a previously unknown pro-tumorigenic role for the RUNX genes in this disease setting. Analysis of patient tumor biopsies together with loss of function studies in preclinical models established the importance of RUNX1 and RUNX2 in ccRCC. Patients with high RUNX1 (and RUNX2) expression exhibited significantly poorer clinical survival compared to patients with low expression. This was functionally relevant as deletion of RUNX1 in ccRCC cell lines reduced tumor cell growth and viability in vitro and in vivo. Transcriptional profiling of RUNX1-CRISPR-deleted cells revealed a gene signature dominated by extracellular matrix remodelling, notably affecting STMN3, SERPINH1, and EPHRIN signaling. Finally, RUNX1 deletion in a genetic mouse model of kidney cancer improved overall survival and reduced tumor cell proliferation. In summary, these data attest to the validity of targeting a RUNX1-transcriptional program in ccRCC. Copyright ©2020, American Association for Cancer Research.Immunotherapies targeting programmed cell death protein 1 (PD-1) and programmed cell death 1 ligand 1 (PD-L1) immune checkpoints represent a major breakthrough in cancer treatment. PD-1 is an inhibitory receptor expressed on the surface of activated T-cells that dampens T-cell receptor (TCR)/CD28 signaling by engaging with its ligand PD-L1 expressed on cancer cells. Despite the clinical success of PD-1 blockade using monoclonal antibodies, most patients do not respond to the treatment, and the underlying regulatory mechanisms of PD-1 remain incompletely defined. Here we show that PD-1 is extensively N-glycosylated in T cells and the intensities of its specific glycoforms are altered upon TCR activation. Glycosylation was critical for maintaining PD-1 protein stability and cell surface localization. Glycosylation of PD-1, especially at the N58 site, was essential for mediating its interaction with PD-L1. The monoclonal antibody STM418 specifically targeted glycosylated PD-1, exhibiting higher binding affinity to PD-1 than FDA-approved PD-1 antibodies, potently inhibiting PD-L1/PD-1 binding, and enhancing anti-tumor immunity. Together these findings provide novel insights into the functional significance of PD-1 glycosylation and offer a rationale for targeting glycosylated PD-1 as a potential strategy for immunotherapy. Copyright ©2020, American Association for Cancer Research.Immunotherapy is innovating clinical cancer management. Nevertheless, only a small fraction of patients benefit from current immunotherapies. To improve clinical management of cancer immunotherapy, it is critical to develop strategies for response monitoring and prediction. In this study, we describe Inducible T cell Costimulator (ICOS) as a conserved mediator of immune response across multiple therapy strategies. ICOS expression was evaluated by flow cytometry, 89Zr-DFO-ICOS mAb PET/CT imaging was performed on Lewis lung cancer models treated with different immunotherapy strategies, and the change in tumor volume was used as a read-out for therapeutic response. ImmunoPET imaging of ICOS enabled sensitive and specific detection of activated T cells and early benchmarking of immune response. A STING agonist was identified as a promising therapeutic approach in this manner. The STING agonist generated significantly stronger immune responses as measured by ICOS ImmunoPET and delayed tumor growth compared to PD-1 checkpoint blockade. More importantly, ICOS ImmunoPET enabled early and robust prediction of therapeutic response across multiple treatment regimens. This data shows that ICOS is an indicator of T cell-mediated immune response and suggests ICOS ImmunoPET as a promising strategy for monitoring, comparing, and predicting immunotherapy success in cancer. Copyright ©2020, American Association for Cancer Research.