Systemic GM-CSF Recruits Effector T Cells into the Tumor Microenvironment in Localized Prostate Cancer

Race-Related Differences in Sipuleucel-T Response among Men with Metastatic Castrate-Resistant Prostate Cancer

Sipuleucel-T is an autologous cellular immunotherapy that targets prostatic acid phosphatase (PAP) and is available for treatment of men with asymptomatic or minimally symptomatic metastatic castration-resistant prostate cancer (mCRPC). In this single-arm, two-cohort, multicenter clinical study, potential racial differences in immune responses to sipuleucel-T in men with mCRPC were explored. Patients' blood samples were obtained to assess serum cytokines, humoral responses, and cellular immunity markers before and after treatment. Baseline cumulative product parameters (total nucleated and CD54+ cell counts and CD54 upregulation) were evaluated. IgM titers against the immunogen PA2024, the target antigen PAP, prostate-specific membrane antigen (PSMA) and prostate-specific antigen (PSA) were quantified by ELISA. Cytotoxic T-lymphocyte activity was determined by ELISpots, and cytokine and chemokine concentrations were determined by Luminex.Twenty-nine African American (AA) men and 28 non-African American (non-AA) men with mCRPC received sipuleucel-T. Baseline total nucleated cell count, CD54+ cell count, CD54 expression, and cumulative product parameters were higher in non-AA men. Although PSA baseline levels were higher in AA men, there were no racial differences in IgM antibody and IFNγ ELISpots responses against PA2024, PAP, PSA, and PSMA before and after treatment. Expression of co-stimulatory receptor ICOS on CD4+ and CD8+ T cells, and the levels of Th1 cytokine granulocyte-macrophage colony-stimulating factor and chemokines CCL4 and CCL5, were significantly higher in AA men before and/or after treatment. Despite no difference in the overall survival, PSA changes from baseline were significantly different between the two races. The data suggest that immune correlates in blood differ in AA and non-AA men with mCRPC pre- and post-sipuleucel-T.

SIGNIFICANCE

Our novel findings of higher expression of co-stimulatory receptor ICOS on CD4+ and CD8+ T cells in African American patients with metastatic castrate-resistant prostate cancer (mCRPC) prior and post-sipuleucel-T suggest activation of CD4+ and CD8+ T cells. The data indicate that racial differences observed in these and other immune correlates before and after sipuleucel-T warrant additional investigation to further our understanding of the immune system in African American men and other men with mCRPC.

Recombinant GM-CSF for diseases of GM-CSF insufficiency: Correcting dysfunctional mononuclear phagocyte disorders

Introduction

Endogenous granulocyte-macrophage colony-stimulating factor (GM-CSF), identified by its ability to support differentiation of hematopoietic cells into several types of myeloid cells, is now known to support maturation and maintain the metabolic capacity of mononuclear phagocytes including monocytes, macrophages, and dendritic cells. These cells sense and attack potential pathogens, present antigens to adaptive immune cells, and recruit other immune cells. Recombinant human (rhu) GM-CSF (e.g., sargramostim [glycosylated, yeast-derived rhu GM-CSF]) has immune modulating properties and can restore the normal function of mononuclear phagocytes rendered dysfunctional by deficient or insufficient endogenous GM-CSF.

Methods

We reviewed the emerging biologic and cellular effects of GM-CSF. Experts in clinical disease areas caused by deficient or insufficient endogenous GM-CSF examined the role of GM-CSF in mononuclear phagocyte disorders including autoimmune pulmonary alveolar proteinosis (aPAP), diverse infections (including COVID-19), wound healing, and anti-cancer immune checkpoint inhibitor therapy.

Results

We discuss emerging data for GM-CSF biology including the positive effects on mitochondrial function and cell metabolism, augmentation of phagocytosis and efferocytosis, and immune cell modulation. We further address how giving exogenous rhu GM-CSF may control or treat mononuclear phagocyte dysfunction disorders caused or exacerbated by GM-CSF deficiency or insufficiency. We discuss how rhu GM-CSF may augment the anti-cancer effects of immune checkpoint inhibitor immunotherapy as well as ameliorate immune-related adverse events.

Discussion

We identify research gaps, opportunities, and the concept that rhu GM-CSF, by supporting and restoring the metabolic capacity and function of mononuclear phagocytes, can have significant therapeutic effects. rhu GM-CSF (e.g., sargramostim) might ameliorate multiple diseases of GM-CSF deficiency or insufficiency and address a high unmet medical need.

Dense GM-CSFRα-expressing immune infiltration is allied with longer survival of intrahepatic cholangiocarcinoma patients

Background

Intrahepatic cholangiocarcinoma (iCCA) is a cancer arising from intrahepatic bile duct epithelium. An iCCA incidence is increasing worldwide; however, the outcome of the disease is dismal. The linkage between chronic inflammation and iCCA progression is well established, but the roles of granulocyte-macrophage colony-stimulating factor (GM-CSF) remain unrevealed. Thus, a better understanding of GM-CSF functions in CCA may provide an alternative approach to CCA treatment.

Methods

Differential GM-CSF and GM-CSFRα mRNA expressions in CCA tissues were investigated by Gene Expression Profiling Interactive Analysis (GEPIA) based on The Cancer Genome Atlas (TCGA) database. The protein expressions and localizations of GM-CSF and its cognate receptor (GM-CSFRα) in iCCA patients' tissues were demonstrated by the immunohistochemistry (IHC) techniques. The survival analyses were performed using Kaplan-Meier survival analysis with log-rank test and Cox proportional hazard regression model for multivariate analysis. The GM-CSF productions and GM-CSFRα expressions on CCA cells were assessed by ELISA and flow cytometry. The effects of GM-CSF on CCA cell proliferation and migration were evaluated after recombinant human GM-CSF treatment. The relationship between GM-CSF or GM-CSFRα level and related immune cell infiltration was analyzed using the Tumor Immune Estimation Resource (TIMER).

Results

GEPIA analysis indicated GM-CSF and GM-CSFRα expressions were higher in CCA tissues than in normal counterparts, and high GM-CSFRα was related to the longer disease-free survival of the patients (p < 0.001). IHC analysis revealed that CCA cells differentially expressed GM-CSF, while GM-CSFRα was expressed on cancer-infiltrating immune cells. The patient whose CCA tissue contained high GM-CSF expressed CCA, and moderate to dense GM-CSFRα-expressing immune cell infiltration (ICI) acquired longer overall survival (OS) (p = 0.047), whereas light GM-CSFRα-expressing ICI contributed to an increased hazard ratio (HR) to 1.882 (95% CI [1.077-3.287]; p = 0.026). In non-papillary subtype, an aggressive CCA subtype, patients with light GM-CSFRα-expressing ICI had shorter median OS (181 vs. 351 days; p = 0.002) and the HR was elevated to 2.788 (95% CI [1.299-5.985]; p = 0.009). Additionally, TIMER analysis demonstrated GM-CSFRα expression was positively correlated with neutrophil, dendritic cell, and CD8+ T cell infiltrations, though it was conversely related to M2-macrophage and myeloid-derived suppressor cell infiltration. However, the direct effects of GM-CSF on CCA cell proliferation and migration were not observed in the current study.

Conclusions

Light GM-CSFRα-expressing ICI was an independent poor prognostic factor for iCCA patients. Anti-cancer functions of GM-CSFRα-expressing ICI were suggested. Altogether, the benefits of acquired GM-CSFRα-expressing ICI and GM-CSF for CCA treatment are proposed herein and require elucidation.

IL-2/GM-CSF enhances CXCR3 expression in CAR-T cells via the PI3K/AKT and ERK1/2 pathways

OBJECTIVE

To investigate the effects of cytokines IL-2 and GM-CSF on CXCR3 expression and chemotaxis of CAR-T cells.

BACKGROUND

High lymphocyte infiltration within the tumor is a basic requirement for good results in tumor immunotherapy; C-X-C motif chemokine receptor 3 (CXCR3) is an important factor for the chemotaxis of lymphocytes to tumor tissues. The tumor microenvironment can exhibit diverse cytokine suppression or promote antitumor immunity. Both interleukin (IL)-2 and granulocyte macrophage colony-stimulating factor (GM-CSF) contribute to the regulation of immunosuppression in the tumor microenvironment. However, the effects of IL-2 and GM-CSF on CXCR3 expression on the T cell surface and its mechanisms are not well understood. Here, we explored the effects of polycytokines on CXCR3 expression in chimeric antigen receptor T cells (CAR-T cells) and on HuH-7 in situ hepatocellular carcinoma.

MATERIALS AND METHODS

Peripheral blood mononuclear cells (PBMCs) were isolated, followed by purifying using CD3 immunomagnetic beads. Cells were divided into three groups. After 24h of activation using CD3/CD28 antibody, T cells were transfected using lentiviral vector, pGC-SV40-EGFP-GPC3-CAR. Three culture methods were used to amplify the transfected T cells. Method 'A' was to incubate T cells with CD3/CD28 antibody; method 'B' was with CD3/CD28 antibody and IL-2 at a final concentration of 1000 U/ml; method 'C' was with method B in addition of GM-CSF at a final concentration of 1000 U/ml. The phosphorylation of MAPK and PI3K/AKT was determined by western blot. The chemotaxis effect of CAR-T cells on Huh-7 HCCIA in situ was assayed by immunofluorescence and immunohistochemistry.

RESULTS

The CD3/CD28/IL-2/GM-CSF combination is the most potent for stimulating activated CAR-T cell proliferation and CXCR3 expression in vitro; CD3/CD28/IL-2 induces CAR-T cell expression of CXCR3 through the activation of the PI3K/APK pathway and GM-CSF induces CXCR3 expression in CAR-T cells through the activation of ERK1/2 rather than the p38 MAPK signaling pathway. CAR-GPC3-T cells with high CXCR3 expression showed increased chemotaxis ability to HuH in situ hepatocellular carcinoma, and considerably inhibited the growth of in situ tumors in nude mouse livers.

CONCLUSION

A multi-factorial amplification protocol can effectively improve CXCR3 expression on the surface of activated CAR-T cells in vitro, as well as enhance the chemotaxis ability of CAR-T cells in vivo, which significantly inhibit the growth of liver cancer.

Dendritic Cell Vaccines: A Promising Approach in the Fight against Ovarian Cancer

Simple Summary

With an overall 5-year survival of only 20% for advanced-stage ovarian cancer patients, enduring and effective therapies are a highly unmet clinical need. Current standard-of-care therapies are able to improve progression-free survival; however, patients still relapse. Moreover, immunotherapy has not resulted in clear patient benefits so far. In this situation, dendritic cell vaccines can serve as a potential therapeutic addition against ovarian cancer. In the current review, we provide an overview of the different dendritic cell subsets and the roles they play in ovarian cancer. We focus on the advancements in dendritic cell vaccination against ovarian cancer and highlight the key outcomes and pitfalls associated with currently used strategies. Finally, we address future directions that could be taken to improve the dendritic cell vaccination outcomes in ovarian cancer.

Abstract

Ovarian cancer (OC) is the deadliest gynecological malignancy in developed countries and is the seventh-highest cause of death in women diagnosed with cancer worldwide. Currently, several therapies are in use against OC, including debulking surgery, chemotherapy, as well as targeted therapies. Even though the current standard-of-care therapies improve survival, a vast majority of OC patients relapse. Additionally, immunotherapies have only resulted in meager patient outcomes, potentially owing to the intricate immunosuppressive nexus within the tumor microenvironment. In this scenario, dendritic cell (DC) vaccination could serve as a potential addition to the therapeutic options available against OC. In this review, we provide an overview of current therapies in OC, focusing on immunotherapies. Next, we highlight the potential of using DC vaccines in OC by underscoring the different DC subsets and their functions in OC. Finally, we provide an overview of the advances and pitfalls of current DC vaccine strategies in OC while providing future perspectives that could improve patient outcomes.

Developing New Treatment Options for Castration-Resistant Prostate Cancer and Recurrent Disease

Prostate cancer (PCa) is a major diagnosed cancer among men globally, and about 20% of patients develop metastatic prostate cancer (mPCa) in the initial diagnosis. PCa is a typical androgen-dependent disease; thus, hormonal therapy is commonly used as a standard care for mPCa by inhibiting androgen receptor (AR) activities, or androgen metabolism. Inevitably, almost all PCa will acquire resistance and become castration-resistant PCa (CRPC) that is associated with AR gene mutations or amplification, the presence of AR variants, loss of AR expression toward neuroendocrine phenotype, or other hormonal receptors. Treating CRPC poses a great challenge to clinicians. Research efforts in the last decade have come up with several new anti-androgen agents to prolong overall survival of CRPC patients. In addition, many potential targeting agents have been at the stage of being able to translate many preclinical discoveries into clinical practices. At this juncture, it is important to highlight the emerging strategies including small-molecule inhibitors to AR variants, DNA repair enzymes, cell survival pathway, neuroendocrine differentiation pathway, radiotherapy, CRPC-specific theranostics and immune therapy that are underway or have recently been completed.

Mutant p53 drives an immune cold tumor immune microenvironment in oral squamous cell carcinoma

The critical role of the tumor immune microenvironment (TIME) in determining response to immune checkpoint inhibitor (ICI) therapy underscores the importance of understanding cancer cell-intrinsic mechanisms driving immune-excluded ("cold") TIMEs. One such cold tumor is oral cavity squamous cell carcinoma (OSCC), a tobacco-associated cancer with mutations in the TP53 gene which responds poorly to ICI therapy. Because altered TP53 function promotes tumor progression and plays a potential role in TIME modulation, here we developed a syngeneic OSCC models with defined Trp53 (p53) mutations and characterized their TIMEs and degree of ICI responsiveness. We observed that a carcinogen-induced p53 mutation promoted a cold TIME enriched with immunosuppressive M2 macrophages highly resistant to ICI therapy. p53-mutated cold tumors failed to respond to combination ICI treatment; however, the combination of a programmed cell death protein 1 (PD-1) inhibitor and stimulator of interferon genes (STING) agonist restored responsiveness. These syngeneic OSCC models can be used to gain insights into tumor cell-intrinsic drivers of immune resistance and to develop effective immunotherapeutic approaches for OSCC and other ICI-resistant solid tumors.

EphB4 and ephrinB2 act in opposition in the head and neck tumor microenvironment

Differential outcomes of EphB4-ephrinB2 signaling offers formidable challenge for the development of cancer therapeutics. Here, we interrogate the effects of targeting EphB4 and ephrinB2 in head and neck squamous cell carcinoma (HNSCC) and within its microenvironment using genetically engineered mice, recombinant constructs, pharmacologic agonists and antagonists. We observe that manipulating the EphB4 intracellular domain on cancer cells accelerates tumor growth and angiogenesis. EphB4 cancer cell loss also triggers compensatory upregulation of EphA4 and T regulatory cells (Tregs) influx and their targeting results in reversal of accelerated tumor growth mediated by EphB4 knockdown. EphrinB2 knockout on cancer cells and vasculature, on the other hand, results in maximal tumor reduction and vascular normalization. We report that EphB4 agonism provides no additional anti-tumoral benefit in the absence of ephrinB2. These results identify ephrinB2 as a tumor promoter and its receptor, EphB4, as a tumor suppressor in HNSCC, presenting opportunities for rational drug design.

A Functional GM-CSF Receptor on Dendritic Cells Is Required for Efficient Protective Anti-Tumor Immunity

Dendritic cells (DC) play a major role during the priming phase of anti-tumor immunization, as they are required for an efficient tumor-associated antigens presentation. At least one dendritic cell-based therapy has already been successfully approved by regulators for clinical application in prostate cancer patients. Moreover, DC development is dependent on the granulocyte macrophage colony stimulating factor (GM-CSF), a cytokine that has been successfully used as a potent inducer of anti-tumoral immunity. To better understand the relation between DC and GM-CSF in anti-tumor immunity, we studied the DC function in mice lacking the cytokine receptor common subunit beta (βc-/-) for GM-CSF, IL-3 and IL-5 and immunized with irradiated tumor cells. Such immunization induces a protective, specific tumor immunization in wild-type mice, while βc-/- mice failed to mount an immune response. Upon in vitro stimulation, DC from βc-/- mice (DCβc-/-) are unable to undergo a full maturation level. In vivo experiments show that they lack the ability to prevent tumor growth, in contrast to DCWT. Moreover, matured DCWT rescued immunization in βc-/- mice. DC maturation is dependent on a functional pathway involving GM-CSF signaling through a biologically functional receptor. These findings may contribute to new strategies for efficient anti-tumor immunotherapies.

Sargramostim and immune checkpoint inhibitors: combinatorial therapeutic studies in metastatic melanoma

The use of immune checkpoint inhibitors in patients with metastatic melanoma generates clinical benefit, including improved survival. Yet disease resistance and immune-related adverse events persist as unmet needs. Sargramostim, a yeast-derived recombinant human GM-CSF, has shown clinical activity against diverse solid tumors, including metastatic melanoma. Here we review the use of sargramostim for treatment of advanced melanoma. Potential sargramostim applications in melanoma draw on the unique ability of GM-CSF to link innate and adaptive immune responses. We review preclinical and translational data describing the mechanism of action of sargramostim and synergy with immune checkpoint inhibitors to enhance efficacy and reduce treatment-related toxicity.

Cross-platform comparison of immune-related gene expression to assess intratumor immune responses following cancer immunotherapy

Neoadjuvant immunotherapy can induce immune responses within the tumor microenvironment. Gene expression can be used to assess responses with limited amounts of conventionally-fixed patient-derived samples. We aim to assess the cross-platform concordance of immune-related gene expression data. We performed comparisons across three panels in two platforms: Nanostring nCounter® PanCancer Immune Profiling Panel (nS), HTG EdgeSeq Oncology Biomarker Panel (HTG OBP) and Precision Immuno-Oncology Panel (HTG PIP). All tissue samples of 14 neoadjuvant GM-CSF treated, 14 neoadjuvant Provenge treated, and 12 untreated prostate cancer patients were radical prostatectomy (RP) tissues, while 6 prostatitis patients and 6 non-prostatitis subjects were biopsies. For all 52 patients, more than 90% of the common genes were significantly correlated (p < 0.05) and more than 76% of the common genes were highly correlated (r > 0.5) between any two panels. Co-inertia analysis also demonstrated high overall dataset structure similarity (correlation>0.84). Although both dimensionality reduction visualization analysis and unsupervised hierarchical cluster analysis for highly correlated common genes (r > 0.9) suggested a high-level of consistency across the panels, there were subsets of genes that were differentially expressed across the panels. In addition, while the effect size of the differential testing for neoadjuvant treated vs. untreated localized prostate cancer patients across the panels were significantly correlated, some genes were only differentially expressed in the HTG panels. Finally, the HTG PIP panel had the best classification performance among the 3 panels. These differences detected may be a result of the different panels or platforms due to their technical setting and focus. Thus, researchers should be aware of those potential differences when deciding which platform and panel to use.

High intratumoral CD8+ T-cell infiltration is associated with improved survival in prostate cancer patients undergoing radical prostatectomy

BACKGROUND

A high density of CD8⁺ tumor infiltrating lymphocytes (TILs) is associated with improved survival in multiple cancers, but its prognostic role in prostate cancer remains controversial. The aim of our study was to evaluate the prognostic value of CD8⁺ TILs in prostate cancer patients undergoing radical prostatectomy (RP). We hypothesized that elevated density of CD8⁺ TILs in the RP specimen would correlate with improved clinical outcomes. This information may be helpful for future immunotherapy clinical trial design and treatment selection.

METHODS

Tumor microarrays constructed from 230 patients with localized prostate cancers who underwent RP from 2006 to 2012 at Roswell Park Comprehensive Cancer Center were analyzed retrospectively using immunohistochemistry. CD8⁺ cell density was evaluated using a computerized scoring system. The cohorts were separated by CD8⁺ TIL density at the 25th percentile (i.e., low <quartile 1 and high ≥quartile 1). The quartile 1 threshold was chosen through a "minimal p value approach" based on overall survival with correction of significance to adjust for multiple testing. Clinical outcomes were compared in the high versus low CD8⁺ TIL density groups.

RESULTS

One hundred and forty-nine (65%) patients had high risk diseases (Gleason >7 or pT3/4). The median follow-up time was 8.4 years. High CD8⁺ TIL density was associated with improved 5-year overall survival (98% vs. 91%, p = .01) and prostate cancer-specific survival (99% vs. 95%, p = .04) compared with patients with low CD8⁺ TIL density. There was a trend toward higher 5-year biochemical recurrence-free survival and metastasis-free survival in the cohort of patients with high CD8⁺ TIL density (52% vs. 38% and 86% vs. 73%, respectively), although the difference did not reach statistical significance (p = .18 and p = .05, respectively). In a multivariate analysis high CD8⁺ TIL density was an independent favorable prognostic factor for overall survival (hazards ratio = 0.38; 95% confidence interval: 0.17-0.87; p = .02). In contrast to the prognostic value of CD8⁺ TIL density, the CD8⁺ cell density in the matched normal prostate tissue was not associated with any clinical outcomes.

CONCLUSION

Intratumoral CD8⁺ T-cell infiltration in the RP specimen is independently associated with improved survival after RP in this high-risk prostate cancer cohort. Pre-RP immunomodulation that promotes intratumoral CD8⁺ cytotoxic T-cell infiltration may be beneficial for this population.

Synergistic Therapeutic Effects of Probiotic Lactobacillus casei TD-2 Consumption on GM-CSF-Induced Immune Responses in a Murine Model of Cervical Cancer

We perceive the potential of combined immunotherapy for the synergistic treatment of human papillomavirus (HPV)-associated tumors. So, the tumor inhibiting effects of combination of L. casei TD2a and GM-CSF on the TC-1 growth were evaluated In Vivo using lymphocyte proliferation, lymphocyte cytotoxicity, splenocyte, and tumor cytokine assays. The results showed that tumor inhibition in transplanted mice in the GM-CSF combined with probiotic L. casei group was significantly higher than that observed in the other groups excluding GM-CSF group whose tumor inhibition effect was considerable. The findings also indicated that the combined group could generate tumor-specific cytolytic and splenocyte proliferative responses. The levels of IFN-γ, IL-4, and IL-12 after treating with GM-CSF combined with probiotic L. casei were significantly higher than those of other groups. The intratumoral Tumor Necrosis Factor Related Apoptosis-Inducing Ligand (TRAIL) was also significantly increased in the combined group. Tumor analysis further showed that the combined group decreased the accumulation of IL-10 in the tumor microenvironment of treated mice. Furthermore, tumor volume analysis demonstrated that combination group and even GM-CSF suppress tumor growth. Our findings showed that the combination of GM-CSF and probiotic results in improved tumor suppression against HPV-associated tumors and stimulates enhancement of specific antitumor immune responses.

Selective inhibition of mTORC1 in tumor vessels increases antitumor immunity

A tumor blood vessel is a key regulator of tissue perfusion, immune cell trafficking, cancer metastasis, and therapeutic responsiveness. mTORC1 is a signaling node downstream of multiple angiogenic factors in the endothelium. However, mTORC1 inhibitors have limited efficacy in most solid tumors, in part due to inhibition of immune function at high doses used in oncology patients and compensatory PI3K signaling triggered by mTORC1 inhibition in tumor cells. Here we show that low-dose RAD001/everolimus, an mTORC1 inhibitor, selectively targets mTORC1 signaling in endothelial cells (ECs) without affecting tumor cells or immune cells, resulting in tumor vessel normalization and increased antitumor immunity. Notably, this phenotype was recapitulated upon targeted inducible gene ablation of the mTORC1 component Raptor in tumor ECs (RaptorECKO). Tumors grown in RaptorECKO mice displayed a robust increase in tumor-infiltrating lymphocytes due to GM-CSF-mediated activation of CD103+ dendritic cells and displayed decreased tumor growth and metastasis. GM-CSF neutralization restored tumor growth and metastasis, as did T cell depletion. Importantly, analyses of human tumor data sets support our animal studies. Collectively, these findings demonstrate that endothelial mTORC1 is an actionable target for tumor vessel normalization, which could be leveraged to enhance antitumor immune therapies.

Genomic analysis of the prognostic value of colony-stimulating factors (CSFs) and colony-stimulating factor receptors (CSFRs) across 24 solid cancer types

Background

The prognostic roles of granulocyte-/granulocyte-macrophage colony-stimulating factor (G-/GM-CSF) and its receptors (CSFRs) from the genomic perspective remain controversial. The aim of our study was to evaluate their prognostic value in multiple cancer types by analyzing omics data.

Methods

The omics data of G-/GM-CSF and receptors were obtained from the cBioportal database. Cutoff values were determined by X-tile. Overall survival (OS) was assessed by Kaplan–Meier curves. Differentially expressed genes (DEGs) and common regulated genes were analyzed using R software and Venny 2.1.0, while enrichment pathway analyses were performed by Metascape.

Results

A comprehensive mRNA analysis was performed in 8,565 patients across 24 cancer types. The combination subgroup of CSF2 and its receptors with high expression and favorable prognosis was associated with the activation of immune-related pathways, while the subgroup with unfavorable prognosis was associated with the activation of inflammatory and cellular pathways. As for the combination subgroup of CSF3 and its receptor, the high expression and poor prognosis subgroup was accompanied by the activation of inflammation and signaling transduction pathways.

Conclusions

The prognostic value of CSFs and CSFRs are cancer-type dependent. Therefore, personalized risk stratification based on CSF and CSFR pathway should be considered for cancer patients.

Transcriptional Activity and Stability of CD39+CD103+CD8+ T Cells in Human High-Grade Endometrial Cancer

Tumor-infiltrating CD8+ T cells (TIL) are of the utmost importance in anti-tumor immunity. CD103 defines tumor-resident memory T cells (TRM cells) associated with improved survival and response to immune checkpoint blockade (ICB) across human tumors. Co-expression of CD39 and CD103 marks tumor-specific TRM with enhanced cytolytic potential, suggesting that CD39+CD103+ TRM could be a suitable biomarker for immunotherapy. However, little is known about the transcriptional activity of TRM cells in situ. We analyzed CD39+CD103+ TRM cells sorted from human high-grade endometrial cancers (n = 3) using mRNA sequencing. Cells remained untreated or were incubated with PMA/ionomycin (activation), actinomycin D (a platinum-like chemotherapeutic that inhibits transcription), or a combination of the two. Resting CD39+CD103+ TRM cells were transcriptionally active and expressed a characteristic TRM signature. Activated CD39+CD103+ TRM cells differentially expressed PLEK, TWNK, and FOS, and cytokine genes IFNG, TNF, IL2, CSF2 (GM-CSF), and IL21. Findings were confirmed using qPCR and cytokine production was validated by flow cytometry of cytotoxic TIL. We studied transcript stability and found that PMA-responsive genes and mitochondrial genes were particularly stable. In conclusion, CD39+CD103+ TRM cells are transcriptionally active TRM cells with a polyfunctional, reactivation-responsive repertoire. Secondly, we hypothesize that differential regulation of transcript stability potentiates rapid responses upon TRM reactivation in tumors.

Dendritic Cells in Anticancer Vaccination: Rationale for Ex Vivo Loading or In Vivo Targeting

Dendritic cells (DCs) have shown great potential as a component or target in the landscape of cancer immunotherapy. Different in vivo and ex vivo strategies of DC vaccine generation with different outcomes have been proposed. Numerous clinical trials have demonstrated their efficacy and safety in cancer patients. However, there is no consensus regarding which DC-based vaccine generation method is preferable. A problem of result comparison between trials in which different DC-loading or -targeting approaches have been applied remains. The employment of different DC generation and maturation methods, antigens and administration routes from trial to trial also limits the objective comparison of DC vaccines. In the present review, we discuss different methods of DC vaccine generation. We conclude that standardized trial designs, treatment settings and outcome assessment criteria will help to determine which DC vaccine generation approach should be applied in certain cancer cases. This will result in a reduction in alternatives in the selection of preferable DC-based vaccine tactics in patient. Moreover, it has become clear that the application of a DC vaccine alone is not sufficient and combination immunotherapy with recent advances, such as immune checkpoint inhibitors, should be employed to achieve a better clinical response and outcome.

Heme-Derived Metabolic Signals Dictate Immune Responses

Heme is one of the most abundant molecules in the body acting as the functional core of hemoglobin/myoglobin involved in the O₂/CO₂ carrying in the blood and tissues, redox enzymes and cytochromes in mitochondria. However, free heme is toxic and therefore its removal is a significant priority for the host. Heme is a well-established danger-associated molecular pattern (DAMP), which binds to toll-like receptor 4 (TLR4) to induce immune responses. Heme-derived metabolites including the bile pigments, biliverdin (BV) and bilirubin (BR), were first identified as toxic drivers of neonatal jaundice in 1800 but have only recently been appreciated as endogenous drivers of multiple signaling pathways involved in protection from oxidative stress and regulators of immune responses. The tissue concentration of heme, BV and BR is tightly controlled. Heme oxygenase-1 (HO-1, encoded by HMOX1) produces BV by heme degradation, while biliverdin reductase-A (BLVR-A) generates BR by the subsequent conversion of BV. BLVR-A is a fascinating protein that possesses a classical protein kinase domain, which is activated in response to BV binding to its enzymatic site and initiates the downstream mitogen-activated protein kinases (MAPK) and phosphatidylinositol 3-kinase (PI3K) pathways. This links BLVR-A activity to cell growth and survival pathways. BLVR-A also contains a bZip DNA binding domain and a nuclear export sequence (NES) and acts as a transcription factor to regulate the expression of immune modulatory genes. Here we will discuss the role of heme-related immune response and the potential for targeting the heme system for therapies directed toward hepatitis and cancer.

Immune Heterogeneity Between Primary Tumors and Corresponding Metastatic Lesions and Response to Platinum Therapy in Primary Ovarian Cancer

CD3⁺ and CD8⁺ lymphocytes are well known prognostic markers in primary ovarian cancer. In contrast, the predictive value of the immune infiltrate concerning treatment response and the involvement of immune heterogeneity between primary and metastatic lesions are poorly understood. In this study, the immune infiltrate of 49 primary tumors and 38 corresponding lesions in the omentum (n = 23) and the peritoneum (n = 15) was immunohistochemically analyzed and correlated with clinicopathological factors and platinum-sensitivity. Immune heterogeneity was observed between paired primary and metastatic lesions for all immune cell phenotypes. The stromal immune infiltrate was higher in the omental lesions than in the primary tumors, which was reflected by CD45 (p=0.007), CD3 (p=0.005), CD8 (p=0.012), and PD-1 (programmed cell-death protein 1) (p=0.013). A higher stromal infiltrate of both CD45⁺ and CD3⁺ cells in the omental lesions was associated with the detection of lymph node metastasis (CD45, p=0.018; CD3, p=0.037). Platinum-sensitive ovarian cancers revealed a higher intratumoral CD8⁺ infiltrate in the peritoneal lesions compared to the primary tumors (p=0.045). In contrast, higher counts of stromal PD-1⁺ cells in the peritoneal lesions have been associated with reduced platinum-sensitivity (p=0.045). Immune heterogeneity was associated with platinum response and might represent a selection marker for personalized therapy.

Supplementary granulocyte macrophage colony-stimulating factor to chemotherapy and programmed death-ligand 1 blockade decreases local recurrence after surgery in bladder cancer

Despite advances and refinements in surgery and perioperative chemotherapy, there are still unmet medical needs with respect to radical cystectomy for muscle‐invasive bladder cancer (MIBC). We investigated the potential benefit of supplementary granulocyte macrophage colony‐stimulating factor (GM‐CSF) to chemoimmunotherapy with programmed cell death protein‐1 (PD‐1)/programmed death‐ligand 1 (PD‐L1) axis blockade and standard neoadjuvant chemotherapy in bladder cancer. We inoculated 2 × 10⁵MBT2 cells s.c. in C3H mice to create a syngeneic animal model of local recurrence (LR). When the tumor diameter reached 12 mm, the mice were allocated randomly as follows: (i) non‐treated control (vehicle only); (ii) anti‐mPD‐L1 monotherapy; (iii) mGM‐CSF monotherapy; (iv) anti‐mPD‐L1 plus mGM‐CSF; (v) gemcitabine and cisplatin (GC); (vi) GC plus anti‐mPD‐L1; (vii) GC plus mGM‐CSF; and (viii) GC plus anti‐mPD‐L1 plus mGM‐CSF. After completing 2‐week neoadjuvant therapy, tumors were resected for resection margin evaluation and immunohistochemical staining and blood was collected for flow cytometry and ELISA. Operative wounds were sutured, and the operative site was monitored to detect LR. Addition of anti‐mPD‐L1 and mGM‐CSF to neoadjuvant GC chemotherapy enhanced the antitumor effect and reduced positive resection margins (50% vs 12.5%). Combination of GC, anti‐mPD‐L1, and mGM‐CSF resulted in longer LR‐free survival and cancer‐specific survival compared to those in other groups. These effects involved an immunotherapy‐related decrease in oncological properties such as tumor invasion capacity and epithelial‐mesenchymal transition. mGM‐CSF significantly decreased the accumulation of myeloid‐derived suppressor cells in both the blood and tumor microenvironment and blood interleukin‐6 levels. Supplementary GM‐CSF to neoadjuvant GC plus PD‐L1 blockade could decrease LR after radical surgery by immune modulation in the blood and tumor microenvironment.

Evaluation of pro‑ and anti‑tumor effects induced by three colony‑stimulating factors, G‑CSF, GM‑CSF and M‑CSF, in bladder cancer cells: Is G‑CSF a friend of bladder cancer cells?

Cytotoxic chemotherapy is the standard treatment for patients with advanced bladder cancer. However, this treatment can cause transient and prolonged neutropenia, which can result in fatal infection. Three recombinant human colony‑stimulating factors (CSFs), granulocyte CSF (G‑CSF), granulocyte‑macrophage CSF (GM‑CSF), and macrophage CSF (M‑CSF), are currently available to reduce the duration and degree of neutropenia. The present study investigated the pro‑ and anti‑tumor effects of these three CSFs and the changes in molecular profiles. Xenograft tumors in athymic mice were generated by subcutaneously inoculating the human bladder cancer cell lines MGH‑U3 and UM‑UC‑3. A total of 2 weeks after cell inoculation, mice were randomly divided into four groups (control, G‑CSF, GM‑CSF and M‑CSF) and treated thrice a week for 2 weeks. Tumor growth during monitoring and tumor weight at the time of euthanization were significantly higher in mice treated with G‑CSF and lower in mice treated with GM‑CSF compared with the control mice. Tumors were examined by immunostaining with antibodies against proteins associated tumor proliferation (Ki‑67), angiogenesis [CD31 and vascular endothelial growth factor (VEGF)], anti‑immunity (CD204) and epithelial‑mesenchymal transition (EMT; E‑cadherin). Immunohistochemical staining revealed that tumor proliferation, angiogenesis, recruitment of M2 macrophages and EMT were promoted by G‑CSF, whereas lymphangiogenesis and recruitment of M2 macrophages were inhibited by GM‑CSF. Treatment‑associated changes in serum pro‑ and anti‑tumoral cytokines and chemokines were evaluated by enzyme‑linked immunosorbent assay (ELISA)‑based arrays. In the ELISA for serum, the levels of cytokines associated with angiogenesis (interleukin‑6 and VEGF), and EMT (transforming growth factor‑β1 and ‑β2) were elevated in mice treated with G‑CSF. Treatment with GM‑CSF and M‑CSF also affected the level of these cytokines characteristically. The current results indicate that administration of exogenous G‑CSF to patients with bladder cancer promotes tumor growth through promotion of cell proliferation, angiogenesis, recruitment of M2 macrophages and enhancement of EMT through the modulation of the tumor microenvironment.

Inflammatory Cytokine Signaling during Development of Pancreatic and Prostate Cancers

Inflammation is essential for many diseases including cancer. Activation and recruitment of immune cells during inflammation result in a cytokine- and chemokine-enriched cell environment, which affects cancer development. Since each type of cancer has its unique tumor environment, effects of cytokines from different sources such as tumor-infiltrating immune cells, stromal cells, endothelial cells, and cancer cells on cancer development can be quite complex. In this review, how immune cells contribute to tumorigenesis of pancreatic and prostate cancers through their secreted cytokines is discussed. In addition, the cytokine signaling that tumor cells of pancreatic and prostate cancers utilize to benefit their own survival is delineated.

Beyond the androgen receptor II: New approaches to understanding and treating metastatic prostate cancer; Report from the 2017 Coffey-Holden Prostate Cancer Academy Meeting

INTRODUCTION

The 2017 Coffey-Holden Prostate Cancer Academy (CHPCA) Meeting, "Beyond the Androgen Receptor II: New Approaches to Understanding and Treating Metastatic Prostate Cancer," was held in Carlsbad, California from June 14-17, 2017.

METHODS

The CHPCA is an annual scientific conference hosted by the Prostate Cancer Foundation (PCF) that is uniquely designed to produce extensive and constructive discussions on the most urgent and impactful topics concerning research into the biology and treatment of metastatic prostate cancer. The 2017 CHPCA Meeting was the 5th meeting in this annual series and was attended by 71 investigators focused on prostate cancer and a variety of other fields including breast and ovarian cancer.

RESULTS

The discussions at the meeting were concentrated on topics areas including: mechanisms and therapeutic approaches for molecular subclasses of castrate resistant prostate cancer (CRPC), the epigenetic landscape of prostate cancer, the role of DNA repair gene mutations, advancing the use of germline genetics in clinical practice, radionuclides for imaging and therapy, advances in molecular imaging, and therapeutic strategies for successful use of immunotherapy in advanced prostate cancer.

DISCUSSION

This article reviews the presentations and discussions from the 2017 CHPCA Meeting in order to disseminate this knowledge and accelerate new biological understandings and advances in the treatment of patients with metastatic prostate cancer.

Use of real-time cellular analysis and Plackett-Burman design to develop the serum-free media for PC-3 prostate cancer cells

In this study, we developed a rapid strategy to screen a serum-free medium for culturing the anchorage-dependent PC-3 prostate cancer cells, which was going to be prepared in large scale to generate GM-CSF/TNFα-surface-modified whole cell prostate cancer vaccine. Automated real-time cellular analysis as a rapid and non-invasive technology was used to monitor the growth of PC-3 cells in 16-well plates. At the same time, Plackett-Burman design was employed to identify the most influential formulation by integrating relevant information statistically. The effects of the 16 selected factors were evaluated during exponential cell growth and three medium constituents (EGF, FGF and linoleic acid) were identified to have significant effects on the cell growth. Subsequently, the response surface methodology with central composite design was applied to determine the interactions among the three factors so that these factors were optimized to improve cell growth. Finally, the prediction of the best combination was made under the maximal response to optimize cell growth by Design-Expert software 7.0. A total of 20 experiments were conducted to construct a quadratic model and a second-order polynomial equation. With the optimized combination validated by the stability test of serial passaging PC-3 cells, the serum-free medium had similar cell density and cell viability to the original serum medium. In summary, this high-throughput scheme minimized the screening time and may thus provide a new platform to efficiently develop the serum-free media for adherent cells.

Analytic and Dynamic Secretory Profile of Patient-Derived Cytokine-Induced Killer Cells

Adoptive immunotherapy with Cytokine Induced Killer (CIK) cells has shown antitumor activity against several kinds of cancers in preclinical models and clinical trials. CIK cells are a subset of ex vivo expanded T lymphocytes with T-NK phenotype and MHC-unrestricted antitumor activity. Literature provides scanty information on cytokines, chemokines and growth factors secreted by CIK cells. Therefore, we investigated the secretory profile of CIK cells generated from tumor patients. The secretome analysis was performed at specific time points (day 1, day 14 and day 21) of CIK cells expansion. Mature CIK cells (day 21) produce a great variety of interleukins and secreted proteins that can be divided into 3 groups based on their secretion quantity: high (IL-13, RANTES, MIP-1α and 1β), medium (IL-1Ra, IL-5, IL-8, IL-10, IL-17, IP-10, INF-γ, VEGF and GMCSF) and low (IL-1β, IL-4, IL-6, IL-7, IL-9, IL-12, IL-15, Eotaxin, PDGF-bb, FGF basic, G-CSF and MCP-1) secreted. Moreover, comparing PBMC (day 1) and mature CIK cells (day 14 and 21) secretome, we observed that IL-5, IL-10, IL-13, GM-CSF, VEGF resulted greatly up-regulated, while IL-1β, IL-6, IL-8, IL-15, IL-17, eotaxin, MCP-1, and RANTES were down-regulated. We also performed a gene expression profile analysis of patient-derived CIK cells showing that mRNA for the different cytokines and secreted proteins were modulated during PBMC to CIK differentiation. We highlighted previously unknown secretory properties and provided for the first time a comprehensive molecular characterization of CIK cells. Our findings provide rationale to explore the functional implications and possible therapeutic modulation of CIK secretome.