Glucose-driven histone lactylation promotes the immunosuppressive activity of monocyte-derived macrophages in glioblastoma.

Immunosuppressive macrophages restrict anti-cancer immunity in glioblastoma (GBM). Here, we studied the contribution of microglia (MGs) and monocyte-derived macrophages (MDMs) to immunosuppression and mechanisms underlying their regulatory function. MDMs outnumbered MGs at late tumor stages and suppressed T cell activity. Molecular and functional analysis identified a population of glycolytic MDM expressing GLUT1 with potent immunosuppressive activity. GBM-derived factors promoted high glycolysis, lactate, and interleukin-10 (IL-10) production in MDMs. Inhibition of glycolysis or lactate production in MDMs impaired IL-10 expression and T cell suppression. Mechanistically, intracellular lactate-driven histone lactylation promoted IL-10 expression, which was required to suppress T cell activity. GLUT1 expression on MDMs was induced downstream of tumor-derived factors that activated the PERK-ATF4 axis. PERK deletion in MDM abrogated histone lactylation, led to the accumulation of intratumoral T cells and tumor growth delay, and, in combination with immunotherapy, blocked GBM progression. Thus, PERK-driven glucose metabolism promotes MDM immunosuppressive activity via histone lactylation.

CD137+ and regulatory T cells as independent prognostic factors of survival in advanced non-oncogene addicted NSCLC patients treated with immunotherapy as first-line.

BACKGROUND: Immune checkpoint inhibitors (ICIs), administered alone or combined with chemotherapy, are the standard of care in advanced non-oncogene addicted Non-Small Cell Lung Cancer (NSCLC). Despite these treatments' success, most long-term survival benefit is restricted to approximately 20% of patients, highlighting the need to identify novel biomarkers to optimize treatment strategies. In several solid tumors, immune soluble factors, the activatory CD137+ Tcells, and the immunosuppressive cell subsets Tregs and MDSCs (PMN(Lox1+)-MDSC and M-MDSCs) correlated with responses to ICIs and clinical outcomes thus becoming appealing predictive and prognostic factors. This study investigated the role of distinct CD137+ Tcell subsets, Tregs, MDSCs, and immune-soluble factors in NSCLC patients as possible biomarkers. METHODS: The levels of T cells, MDSCs and soluble factors were evaluated in 89 metastatic NSCLC patients who underwent ICIs as first- or second-line treatment. T cell analysis was performed by cytoflurimetry evaluating Tregs and different CD137+ Tcell subsets also combined with CD3+, CD8+, PD1+, and Ki67+ markers. Circulating cytokines and immune checkpoints were also evaluated by Luminex analysis. All these parameters were correlated with several clinical factors (age, sex, smoking status, PS and TPS), response to therapy, PFS , and OS . The analyses were conducted in the overall population and in patients treated with ICIs as first-line (naïve patients). RESULTS: In both groups of patients, high levels of circulating CD137+ and CD137+PD1+ T cells (total, CD4 and CD8) and the soluble factor LAG3 positively correlated with response to therapy. In naïve patients, PMN(Lox1+)-MDSCs negatively correlated with clinical response, and a high percentage of Tregs was associated with favorable survival. Moreover, the balance between Treg/CD137+ Tcells or PMN(Lox1+)-MDSC/CD137+ Tcells was higher in non-responding patients and was associated with poor survival. CD137+ Tcells and Tregs resulted as two positive independent prognostic factors. CONCLUSION: High levels of CD137+, CD137+PD1+ Tcells and sLAG3 could predict the response to ICIs in NSCLC patients independently by previous therapy. Combining the evaluation of CD137+ Tcells and Tregs also as Treg/CD137+ T cells ratio it is possible to identify naive patients with longer survival.

Targeting FGFRs by pemigatinib induces G1 phase cell cycle arrest, cellular stress and upregulation of tumor suppressor microRNAs.

BACKGROUND: Fibroblast growth factor receptor (FGFR) gene family alterations are found in several cancers, indicating their importance as potential therapeutic targets. The FGFR-tyrosine kinase inhibitor (TKI) pemigatinib has been introduced in the treatment of advanced cholangiocarcinoma and more recently for relapsed or refractory myeloid/lymphoid neoplasms with FGFR2 and FGFR1 rearrangements, respectively. Several clinical trials are currently investigating the possible combination of pemigatinib with immunotherapy. In this study, we analyzed the biological and molecular effects of pemigatinib on different cancer cell models (lung, bladder, and gastric), which are currently objective of clinical trial investigations. METHODS: NCI-H1581 lung, KATO III gastric and RT-112 bladder cancer cell lines were evaluated for FGFR expression by qRT-PCR and Western blot. Cell lines were treated with Pem and then characterized for cell proliferation, apoptosis, production of intracellular reactive oxygen species (ROS), and induction of senescence. The expression of microRNAs with tumor suppressor functions was analyzed by qRT-PCR, while modulation of the proteins coded by their target genes was evaluated by Western blot and mRNA. Descriptive statistics was used to analyze the various data and student's t test to compare the analysis of two groups. RESULTS: Pemigatinib exposure triggered distinct signaling pathways and reduced the proliferative ability of all cancer cells, inducing G1 phase cell cycle arrest and strong intracellular stress resulting in ROS production, senescence and apoptosis. Pemigatinib treatment also caused the upregulation of microRNAs (miR-133b, miR-139, miR-186, miR-195) with tumor suppressor functions, along with the downregulation of validated protein targets with oncogenic roles (c-Myc, c-MET, CDK6, EGFR). CONCLUSIONS: These results contribute to clarifying the biological effects and molecular mechanisms mediated by the anti-FGFR TKI pemigatinib in distinct tumor settings and support its exploitation for combined therapies.

Circulating CD137+ T Cell Levels Are Correlated with Response to Pembrolizumab Treatment in Advanced Head and Neck Cancer Patients.

Pembrolizumab, an anti-PD-1 antibody, has been approved as first-line treatment for recurrent or metastatic head and neck squamous cell carcinoma ((R/M) HNSCC). However, only a minority of patients benefit from immunotherapy, which highlights the need to identify novel biomarkers to optimize treatment strategies. CD137+ T cells have been identified as tumour-specific T cells correlated with immunotherapy responses in several solid tumours. In this study, we investigated the role of circulating CD137+ T cells in (R/M) HNSCC patients undergoing pembrolizumab treatment. PBMCs obtained from 40 (R/M) HNSCC patients with a PD-L1 combined positive score (CPS) ≥1 were analysed at baseline via cytofluorimetry for the expression of CD137, and it was found that the percentage of CD3+CD137+ cells is correlated with the clinical benefit rate (CBR), PFS, and OS. The results show that levels of circulating CD137+ T cells are significantly higher in responder patients than in non-responders (p = 0.03). Moreover, patients with CD3+CD137+ percentage ≥1.65% had prolonged OS (p = 0.02) and PFS (p = 0.02). Multivariate analysis, on a combination of biological and clinical parameters, showed that high levels of CD3+CD137+ cells (≥1.65%) and performance status (PS) = 0 are independent prognostic factors of PFS (CD137+ T cells, p = 0.007; PS, p = 0.002) and OS (CD137+ T cells, p = 0.006; PS, p = 0.001). Our results suggest that levels of circulating CD137+ T cells could serve as biomarkers for predicting the response of (R/M) HNSCC patients to pembrolizumab treatment, thus contributing to the success of anti-cancer treatment.

Soluble PD-L1 as a Prognostic Factor for Immunotherapy Treatment in Solid Tumors: Systematic Review and Meta-Analysis.

Blocking the Programmed Cell Death Protein 1 (PD-1)/programmed death ligand-1 (PD-L1) axis has demonstrated great efficacy in cancer immunotherapy treatment and remains the central modality of immune targeting. To support the rational and tailored use of these drugs, it is important to identify reliable biomarkers related to survival. The role of the soluble form of the PD-L1 (sPD-L1) as a prognostic biomarker related to survival in solid cancer patients treated with immunotherapy has not yet been consistently evaluated. A systematic literature search of original articles in PubMed, MEDLINE and Scopus was conducted. Studies reporting hazard ratios (HRs) with a 95% confidence interval (CI) or Kaplan−Meier curves or individual patient data for overall survival (OS) or progression-free survival (PFS) associated with baseline levels of sPD-L1 in cancer patients undergoing immunotherapy treatment were considered eligible. Twelve studies involving 1076 patients and different tumor types treated with immunotherapy were included in the analysis. High blood levels of sPD-L1 correlated with poorer OS and PFS in cancer patients treated with immunotherapy (HR = 1.49, 95%CI: 1.15, 1.93, p < 0.01, I2 = 77% for OS; HR = 1.59, 95%CI: 1.20, 2.12, p < 0.01, I2 = 82% for PFS). A subgroup analysis highlighted that high levels of sPD-L1 were associated with worse survival in patients affected by NSCLC (HR = 1.81 95%CI: 1.09−3.00, p = 0.02, I2 = 83% for OS; HR = 2.18, 95%CI: 1.27−3.76, p < 0.01, I2 = 88% for PFS). An HR > 1 indicated that patients with low levels of sPD-L1 have the highest rates of OS/PFS. In this meta-analysis, we clarified the role of sPD-L1 in different solid cancers treated exclusively with Immune checkpoint inhibitors (ICIs). sPD-L1 could represent a non-invasive biomarker that is easily dosable in the blood of patients. The pooled data from the selected studies showed that a high circulating concentration of sPD-L1 in cancer patients correlates with worse survival, suggesting that it may be a helpful prognostic biomarker for the selection of cancer patients before immunotherapy, thus improving the efficacy of ICIs and avoiding unnecessary treatment.

Glycan-Lectin Interactions as Novel Immunosuppression Drivers in Glioblastoma.

Despite diagnostic and therapeutic improvements, glioblastoma (GB) remains one of the most threatening brain tumor in adults, underlining the urgent need of new therapeutic targets. Lectins are glycan-binding proteins that regulate several biological processes through the recognition of specific sugar motifs. Lectins and their ligands are found on immune cells, endothelial cells and, also, tumor cells, pointing out a strong correlation among immunity, tumor microenvironment and vascularization. In GB, altered glycans and lectins contribute to tumor progression and immune evasion, shaping the tumor-immune landscape promoting immunosuppressive cell subsets, such as myeloid-derived suppressor cells (MDSCs) and M2-macrophages, and affecting immunoeffector populations, such as CD8+ T cells and dendritic cells (DCs). Here, we discuss the latest knowledge on the immune cells, immune related lectin receptors (C-type lectins, Siglecs, galectins) and changes in glycosylation that are involved in immunosuppressive mechanisms in GB, highlighting their interest as possible novel therapeutical targets.

Immunogenic Cell Death and Immunomodulatory Effects of Cabozantinib.

Cabozantinib (XL-184) is a multitarget tyrosine kinase inhibitor (TKI) targeting receptor tyrosine kinases (RTKs) involved in oncogenesis and angiogenesis. It is currently the standard therapy for medullary thyroid cancer (MTC), metastatic renal cell carcinoma (mRCC), and hepatocellular carcinoma (HCC). Combination of Cabozantinib with immunotherapy is now a standard treatment in metastatic renal cancer, and its efficacy is being tested in ongoing clinical trial in prostate cancer patients. Here, we report that Cabozantinib may exert an immunostimulatory role by inducing immunogenic stress of prostate cancer cells and directly modulating dendritic cells (DCs). Cabozantinib treatment arrested the cell cycle and triggered immunogenic cell death (ICD) in prostate cancer cells in vitro. Cabozantinib had a direct effect on DCs by the down-modulation of ß-catenin and change in migratory and costimulatory phenotype of the DCs. These results may suggest possible immunomodulatory effects induced by Cabozantinib that could be exploited to optimize patient-tailored immunotherapeutic treatments.