Blocking the recruitment of naive CD4+ T cells reverses immunosuppression in breast cancer

The humanized mouse: Emerging translational potential

The humanized mouse (HM) has emerged as a valuable animal model in cancer research. Engrafted with components of a human immune system and subsequently implanted with tumor tissue from cell lines or in the form of patient-derived xenografts, the HM provides a unique platform in which the tumor microenvironment (TME) can be evaluated in vivo. This model may also be beneficial in the assessment of potential cancer treatments including immune checkpoint inhibitors. However, to maximize its utility, researchers need to understand the critical factors necessary to ensure that the tumor immune interactions in the HM are representative of those within cancer patients. In most current HM models, the human T cells residing in the HM are educated in a murine thymus, allogeneic to implanted tumor tissue, and/or alloreactive to mouse tissues, making their interaction and reactivity with tumor cells suspect. There are several strategies underway to harmonize the immune-tumor environment in the HM. Once the essential components of the HM-tumor TME interface have been identified and understood, the HM model will permit not only the discovery of effective immunotherapy treatments, but it can be used to predict patient responses to great clinical benefit.

The landscape of immune cell infiltration and its clinical implications of pancreatic ductal adenocarcinoma

The details of the immunological microenvironment and its clinical implications for pancreatic cancer are still unclear. In this study, we obtained data from public databases, such as the Gene Expression Omnibus, the Cancer Genome Atlas Program, the International Cancer Genome Consortium Data Portal, the ArrayExpress Data Warehouse, and the cBioPortal for Cancer Genomics. We used these data to evaluate the pattern of immune cells infiltration in pancreatic ductal adenocarcinoma (PDAC) tissues. We observed that the levels of M0 macrophages and activated dendritic cells in tumor tissues were significantly higher than that in para-tumor tissues. M0 macrophages, gamma delta T cells and naive CD4 T cells were independent predictive factors of a poor outcome for PDAC patients. An immune score determined by M0 macrophages, gamma delta T cells and naive CD4 T cells could predict the survival of patients. The results of this study suggest that the infiltration of immune cells, such as M0 macrophages, may be a possible target for the treatment of PDAC. However, these findings need to be confirmed by additional studies.

The Landscape and Prognosis Potential of the T-Cell Repertoire in Membranous Nephropathy

Membranous nephropathy (MN), a common pathological type of adult nephrotic syndrome, is an antibody-mediated kidney disease. It is widely accepted now that MN is an immune-related disease that involves the whole immune system. In this study, we analyzed the T-cell receptor beta chain (TCRβ) repertoire of the circulating T lymphocytes of MN patients and healthy controls using high-throughput sequencing. We compared multiple aspects of the TCRβ repertoire, including diversity and the Vβ and Jβ genes between MN patients and healthy controls, and we found that the diversities within the VJ cassette combination in the peripheral blood of MN patients were lower than in the healthy controls. We also found the TCRβ repertoire similarity between pre- and post-therapy could reflect the clinical outcome, and two Vβ genes in pre-therapy had the potential to predict the therapeutic effect. These findings indicated the potential of the TCRβ repertoire as non-invasive biomarkers for the prognosis prediction of MN. The characteristics of circulating T-lymphocyte repertoires shed light on MN detection, treatment, and surveillance.

Complement Signals Determine Opposite Effects of B Cells in Chemotherapy-Induced Immunity

Understanding molecular mechanisms that dictate B cell diversity is important for targeting B cells as anti-cancer treatment. Through the single-cell dissection of B cell heterogeneity in longitudinal samples of patients with breast cancer before and after neoadjuvant chemotherapy, we revealed that an ICOSL⁺ B cell subset emerges after chemotherapy. Using three immunocompetent mouse models, we recapitulated the subset switch of human tumor-infiltrating B cells during chemotherapy. By employing B-cell-specific deletion mice, we showed that ICOSL in B cells boosts anti-tumor immunity by enhancing the effector to regulatory T cell ratio. The signature of ICOSL⁺ B cells is imprinted by complement-CR2 signaling, which is triggered by immunogenic cell death. Moreover, we identified that CD55, a complement inhibitory protein, determines the opposite roles of B cells in chemotherapy. Collectively, we demonstrated a critical role of the B cell subset switch in chemotherapy response, which has implications in designing novel anti-cancer therapies. VIDEO ABSTRACT.

Peroxiredoxins and Immune Infiltrations in Colon Adenocarcinoma: Their Negative Correlations and Clinical Significances, an In Silico Analysis

Background: Peroxiredoxins (PRDXs) were reported to be associated with inflammation response in previous studies. In colon adenocarcinoma (COAD), however, their correlations and clinical significance were unclear.

Methods: The RNA-seq data of 452 COAD patients with clinical information was downloaded from The Cancer Genome Atlas (TCGA) and transcripts per million (TPM) normalized. Comparisons of relative expressions of PRDXs between COAD tumor and normal controls were applied. PRDXs dy-regulations in COAD were validated via Oncomine, Human Protein Atlas (HPA) and Gene Expression Omnibus (GEO) repository. Through Tumor Immune Estimation Resource (TIMER), the immune estimation of TCGA-COAD patients was downloaded and the dy-regulated PRDXs were analyzed for their correlations with immune infiltrations in COAD. The TCGA-COAD patients were divided into younger group (age≤65 years) and older group (age>65 years) to investigate the prognostic roles of age, TNM stage, dy-regulated PRDXs and the immune infiltrations in different age groups through Kaplan-Meier survival and Cox regression analyses.

Results: Three of the PRDX members showed their expressional differences both at protein and mRNA level. PRDX2 was consistently up-regulated while PRDX6 down-regulated in COAD. PRDX1 was overexpressed (mRNA) while nuclear absent (protein) in the tumor tissues. PRDX1 overexpression and PRDX6 under-expression were also shown in the stem-like colonospheres from colon cancer cells. Via TIMER, PRDX1, PRDX2, and PRDX6 were found to be negatively correlated with the immune infiltrations in COAD. Both in the younger and older patients, TNM stage had prognostic effects on their overall survival (OS) and recurrence-free survival (RFS). CD4⁺ T cell had independent unfavorable effects on OS of the younger patients while age had similar effects on RFS of the older ones. CD8⁺ T cell was independently prognostic for RFS in the two groups.

Conclusions: Late diagnosis indicated poor prognosis in COAD and dy-regulated PRDXs w might be new markers for its early diagnosis. Age was prognostic and should be considered in the treatments of the older patients. Dy-regulated PRDXs were negatively correlated with immune infiltration levels. CD4⁺ T cell and CD8⁺ T cell infiltrations were prognostic in COAD and their potential as immune targets needed further investigation.

A. R. ENS, Mat Lazim N, Mohamud R, Yean CY, Shueb RH. Technical Considerations in Ex Vivo Human Regulatory T Cell Migration and Suppression Assays

Regulatory T cells (Tregs) are renowned for maintaining homeostasis and self-tolerance through their ability to suppress immune responses. For over two decades, Tregs have been the subject of intensive research. The immunosuppressive and migratory potentials of Tregs have been exploited, especially in the areas of cancer, autoimmunity and vaccine development, and many assay protocols have since been developed. However, variations in assay conditions in different studies, as well as covert experimental factors, pose a great challenge to the reproducibility of results. Here, we focus on human Tregs derived from clinical samples and highlighted caveats that should be heeded when conducting Tregs suppression and migration assays. We particularly delineated how factors such as sample processing, choice of reagents and equipment, optimization and other experimental conditions could introduce bias into the assay, and we subsequently proffer recommendations to enhance reliability and reproducibility of results. It is hoped that prioritizing these factors will reduce the tendencies of generating false and misleading results, and thus, help improve our understanding and interpretation of Tregs functional studies.

Lactic Acidosis Together with GM-CSF and M-CSF Induces Human Macrophages toward an Inflammatory Protumor Phenotype

In established tumors, tumor-associated macrophages (TAM) orchestrate nonresolving cancer-related inflammation and produce mediators favoring tumor growth, metastasis, and angiogenesis. However, the factors conferring inflammatory and protumor properties on human macrophages remain largely unknown. Most solid tumors have high lactate content. We therefore analyzed the impact of lactate on human monocyte differentiation. We report that prolonged lactic acidosis induces the differentiation of monocytes into macrophages with a phenotype including protumor and inflammatory characteristics. These cells produce tumor growth factors, inflammatory cytokines, and chemokines as well as low amounts of IL10. These effects of lactate require its metabolism and are associated with hypoxia-inducible factor-1α stabilization. The expression of some lactate-induced genes is dependent on autocrine M-CSF consumption. Finally, TAMs with protumor and inflammatory characteristics (VEGF^high CXCL8⁺ IL1β⁺) are found in solid ovarian tumors. These results show that tumor-derived lactate links the protumor features of TAMs with their inflammatory properties. Treatments that reduce tumor glycolysis or tumor-associated acidosis may help combat cancer.

Multiplex profiling of peritoneal metastases from gastric adenocarcinoma identified novel targets and molecular subtypes that predict treatment response

OBJECTIVE

Peritoneal carcinomatosis (PC) occurs frequently in patients with gastric adenocarcinoma (GAC) and confers a poor prognosis. Multiplex profiling of primary GACs has been insightful but the underpinnings of PC's development/progression remain largely unknown. We characterised exome/transcriptome/immune landscapes of PC cells from patients with GAC aiming to identify novel therapeutic targets.

DESIGN

We performed whole-exome sequencing (WES) and whole transcriptome sequencing (RNA-seq) on 44 PC specimens (43 patients with PC) including an integrative analysis of WES, RNA-seq, immune profile, clinical and pathological phenotypes to dissect the molecular pathogenesis, identifying actionable targets and/or biomarkers and comparison with TCGA primary GACs.

RESULTS

We identified distinct alterations in PC versus primary GACs, such as more frequent CDH1 and TAF1 mutations, 6q loss and chr19 gain. Alterations associated with aggressive PC phenotypes emerged with increased mutations in TP53, CDH1, TAF1 and KMT2C, higher level of 'clock-like' mutational signature, increase in whole-genome doublings, chromosomal instability (particularly, copy number losses), reprogrammed microenvironment, enriched cell cycle pathways, MYC activation and impaired immune response. Integrated analysis identified two main molecular subtypes: 'mesenchymal-like' and 'epithelial-like' with discriminating response to chemotherapy (31% vs 71%). Patients with the less responsive 'mesenchymal-like' subtype had high expression of immune checkpoint T-Cell Immunoglobulin And Mucin Domain-Containing Protein 3 (TIM-3), its ligand galectin-9, V-domain Ig suppressor of T cell activation (VISTA) and transforming growth factor-β as potential therapeutic immune targets.

CONCLUSIONS

We have uncovered the unique mutational landscape, copy number alteration and gene expression profile of PC cells and defined PC molecular subtypes, which correlated with PC therapy resistance/response. Novel targets and immune checkpoint proteins have been identified with a potential to be translated into clinics.

siRNA therapeutics for breast cancer: recent efforts in targeting metastasis, drug resistance, and immune evasion

Small interfering RNA (siRNA) has an established and precise mode of action to achieve protein knockdown. With the ability to target any protein, it is very attractive as a potential therapeutic for a plethora of diseases driven by the (over)expression of certain proteins. Utilizing siRNA to understand and treat cancer, a disease largely driven by genetic aberration, is thus actively investigated. However, the main hurdle for the clinical translation of siRNA therapeutics is to achieve effective delivery of siRNA molecules to tumors and the site of action, the cytosol, within cancer cells. Several nanoparticle delivery platforms for siRNA have been developed. In this Review, we describe recent efforts in developing siRNA therapeutics for the treatment of cancer, with particular emphasis on breast cancer. Instead of conventionally targeting proliferation and apoptosis aspects of tumorigenesis, we focus on recent attempts in targeting cancer's metastasis, drug resistance, and immune evasion, which are considered more challenging and less manageable in clinics with current therapeutic molecules. siRNA can target all proteins, including traditionally undruggable proteins, and is thus poised to address these clinical challenges. Evidence also suggests that siRNA can be superior to antibodies or small molecule inhibitors when inhibiting the same druggable pathway. In addition to cancer cells, the role of the tumor microenvironment has been increasingly appreciated. Components in the tumor microenvironment, particularly immune cells, and thus siRNA-based immunotherapy, are under extensive investigation. Lastly, multiple siRNAs with or without additional drugs can be codelivered on the same nanoparticle to the same target site of action, maximizing their potential synergy while limiting off-target toxicity.

Blocking migration of regulatory T cells to leukemic hematopoietic microenvironment delays disease progression in mouse leukemia model

Blocking the migration of regulatory T cells (Tregs) to the tumor microenvironment is a promising strategy for tumor immunotherapy. Treg accumulation in the leukemic hematopoietic microenvironment (LHME) has adverse impacts on patient outcomes. The mechanism and effective methods of disrupting Treg accumulation in the LHME have not been well established. Here, we studied the distribution and characteristics of Tregs in the LHME, investigated the effects of Treg ablation on leukemia progression, explored the mechanisms leading to Treg accumulation, and studied whether blocking Treg migration to the LHME delayed leukemia progression in MLL-AF9-induced mouse acute myeloid leukemia (AML) models using wildtype (WT) and Foxp3^DTR/GFP mice. Increased accumulation of more activated Tregs was detected in the LHME. Inducible Treg ablation prolonged the survival of AML mice by promoting the antileukemic effects of CD8⁺ T cells. Furthermore, both local expansion and migration accounted for Treg accumulation in the LHME. Moreover, blocking the CCL3-CCR1/CCR5 and CXCL12-CXCR4 axes inhibited Treg accumulation in the LHME and delayed leukemia progression. Our findings provide laboratory evidence for a potential leukemia immunotherapy by blocking the migration of Tregs.

Clinical Implications of Tumor-Infiltrating Immune Cells in Breast Cancer

The immune infiltration of tumors is closely related to clinical outcomes. The composition of tumor-infiltrating immune cells (TIICs) can serve as biomarkers for predicting response to treatment and survival in different patient subgroups in terms of chemotherapy and immunotherapy. This study is focused on investigating the clinical implications of TIICs in breast cancer patients. We performed several in silico analyses of gene expression profiles in 2976 nonmetastatic tumor samples. CIBERSORT was used to estimate the proportion of 22 immune cell types to analyze their correlation with overall survival (OS) and disease-free survival (DFS) in different breast cancer subtypes and stages. Our results showed that a higher fraction of plasma cells in estrogen receptor (ER)-positive breast cancer patients indicated an increase in DFS (hazard ratio [HR]=0.66, 95% confidence interval [CI] 0.54~0.82, p<0.01), while a decreased OS was correlated with a greater number of M0 macrophages (HR=2.02, 95% CI 1.27~3.30, p=0.01) and regulatory T cells (HR=1.90, 95% CI 1.20~3.02, p=0.02). In ER-negative or progesterone receptor (PR)-negative subtypes or in a combined subtype, the increase in activated memory CD4⁺ T cells was correlated with increased DFS (HR=0.46, 95% CI 0.33~0.63, p<0.01). In all breast cancer patients, a higher proportion of M0 macrophages indicated a decreased DFS (HR=1.67, 95% CI 1.22~2.27, p<0.01), while increased OS was associated with relatively larger fractions of resting memory CD4⁺ T cells (HR=0.70, 95% CI 0.55~0.90, p=0.02) and γδ T cells (HR=0.66, 95% CI 0.51~0.85, p<0.01). Therefore, this study revealed that the composition of TIICs is different in patients with various subtypes of breast cancer and is directly related to prognosis, suggesting that TIICs are important participants in tumor progression and may, potentially be used for future diagnosis and treatment.

Regulatory T Cells Tailored with pH-Responsive Liposomes Shape an Immuno-Antitumor Milieu against Tumors

Cell-based delivery platforms have received great interest in recent years and have been indicated as a promising strategy for cancer immunotherapy. Despite their wide applications in the clinical and preclinical stages, their concomitant viability and efficacy remain major issues. Herein, a strategy for harnessing regulatory T (Treg) cells is developed as an actively targeting drug-delivery system to transport drug-loaded liposomes to the desired tumor sites via conjugating liposomes on the surface of Treg cells. Under the guidance of tumor-oriented chemokines, liposome-anchored Treg cells can be leveraged to migrate and infiltrate the acidic tumor microenvironment, where pH-sensitive liposomes release the loaded cargos [comprising interleukin-2, programmed cell death ligand 1 antibody (PD-L1), and imiquimod], provoke dramatic dendritic cell maturation, block the PD-1/PD-L1 immune-checkpoint, elevate the frequency of infiltrating CD8⁺ effector T cells, and collectively contribute to potent inhibition of in situ and metastatic tumors. Here, the findings suggest a potential approach that offers a simple, robust, and safe insight into the tuning of Treg cells as an encouraging vector for augmenting cancer immunotherapy.

Connecting blood and intratumoral Treg cell activity in predicting future relapse in breast cancer

Regulatory T (T_reg) cells play a major role in the development of an immunosuppressive tumor microenvironment. The origin of intratumoral T_reg cells and their relationship with peripheral blood T_reg cells remain unclear. T_reg cells consist of at least three functionally distinct subpopulations. Here we show that peripheral blood CD45RA^-FOXP3^hi T_reg cells (T_reg II cells) are phenotypically closest to intratumoral T_reg cells, including in their expression of CCR8. Analyses of T cell antigen receptor repertoires further support the hypothesis that intratumoral T_reg cells may originate primarily from peripheral blood T_reg II cells. Moreover, the signaling responsiveness of peripheral blood T_reg II cells to immunosuppressive, T helper type 1 (T_H1) and T helper type 2 (T_H2) cytokines reflects intratumoral immunosuppressive potential, and predicts future relapse in two independent cohorts of patients with breast cancer. Together, our findings give important insights into the relationship between peripheral blood T_reg cells and intratumoral T_reg cells, and highlight cytokine signaling responsiveness as a key determinant of intratumoral immunosuppressive potential and clinical outcome.

Potential applications of nanoparticles for tumor microenvironment remodeling to ameliorate cancer immunotherapy

In recent years, researchers have made significant innovations in the field of tumor immunotherapy based on the knowledge of biology, oncology, and immunology. Tumor immunotherapy involves the use of immune checkpoint inhibitors and CAR (chimeric antigen receptor)-T cell therapy. As compared with conventional chemotherapy, immunotherapy is a potential approach to induce a more powerful immune response against tumor in the patient suffering from the advanced stage malignancy. Regardless of the developments made, a large number of clinical studies have confirmed that a substantial number of cancer patients still demonstrate non-responsiveness to immunotherapy, mainly due to the immunomodulating interactions of tumor cells with the immunosuppressive tumor microenvironment (iTME). It leads to immune tolerance of tumors and influences the efficacy of immunotherapy. This immune failure could be attributed to a complex immunosuppressive network comprising stromal and inflammatory cells, vessel system, ECM (extracellular matrix) and the cytokines released in tumor microenvironment (TME). The antitumor immune activity can be enhanced at different stages of tumor development by selective suppression of inhibitory pathways in the TME. This specific task can be achieved by using nano-sized drug delivery tools which are specific in their action and biocompatible in nature. Several recent studies have described the use of nanoparticles for iTME remodeling through the specific elimination of immunosuppressive cells, obstructing immune checkpoints, promotion of inflammatory cytokines, and amending the regulatory cells of the immune system. The efficacy of current immunotherapy can be improved by nanoparticle-mediated remodeling of iTME.

The Complex Interaction between the Tumor Micro-Environment and Immune Checkpoints in Breast Cancer

The progression of breast cancer and its association with clinical outcome and treatment remain largely unexplored. Accumulating data has highlighted the interaction between cells of the immune system and the tumor microenvironment in cancer progression, and although studies have identified multiple facets of cancer progression within the development of the tumor microenvironment (TME) and its constituents, there is lack of research into the associations between breast cancer subtype and staging. Current literature has provided insight into the cells and pathways associated with breast cancer progression through expression analysis. However, there is lack of co-expression studies between immune pathways and cells of the TME that form pro-tumorigenic relationships contributing to immune-evasion. We focus on the immune checkpoint and TME elements that influence cancer progression, particularly studies in molecular subtypes of breast cancer.

Tumor-infiltrating CD4+ and CD8+ lymphocytes and macrophages are associated with prognostic factors in triple-negative canine mammary complex type carcinoma

This study aimed to evaluate the association of CD3⁺, CD4⁺, and CD8⁺ T cells and tumor-infiltrating macrophages (TIMs) with the clinical parameters of female dogs harboring mammary gland tumors. Thirty female dogs affected with mammary carcinomas were used, and all tumors were histologically classified as complex carcinoma and were triple-negative phenotype determined by immunohistochemistry. Freshly frozen sections were used to determine CD3⁺, CD4⁺ and CD8⁺ T cells by immunohistochemistry, and TIMs were determined by immunofluorescence assays. Ten out of the 30 dogs showed lymph node metastasis at diagnosis. Fifteen dogs had a tumor of grade I (15/30), nine (9/30) had a tumor of grade II and six (6/30) had a tumor of grade III. The mean overall survival was 680.5 days (± 200.4). Dogs with sentinel lymph node positivity (10/30) (P = .0035) and dogs that developed metastasis (P = .0001) showed a shorter survival time. In addition, dogs with a high level of inflammatory infiltrate in tumor tissues presented a shorter survival time (P = .0001) than that of other dogs. Dogs with tumors containing higher numbers of CD3+ T cells (P = .001), CD4+ T cells (P = .001), or TIM cells (P < .0001) showed a shorter survival time than that of other dogs. Our results suggested that characteristics of immune cell infiltrates, including CD3⁺ T cells, CD4⁺ T cells, and TIMs, can be used as potential prognostic indicators for predicting clinical outcomes in dogs with mammary gland tumors, particularly tumors with a complex histological subtype and triple-negative phenotype.

IL-33 drives the antitumour effects of dendritic cells via upregulating CYLD expression in pulmonary adenocarcinoma

Lung adenocarcinoma is one of the leading causes of cancer-related death worldwide. Low expression of Interleukin-33 (IL-33) was reported to be associated with the progression of pulmonary adenocarcinoma. However, the IL-33-mediated immunoregulation in pulmonary adenocarcinoma remains unclear. In this study, we found that IL-33 treatment evidently repressed tumour growth, induced CD4⁺ T cells infiltration and IL-17 expression in pulmonary adenocarcinoma. Notably, IL-33 treatment increased the number of Dendritic Cells (DCs) in pulmonary adenocarcinoma. More importantly, IL-33 induced maturation and regulated the function of DCs by increasing expression of DCs mature markers (CD40 and CD80, CD86) DCs-function-related gene including antigen presentation genes (HLA-DMA, HLA-DMB and CD74) and cytokines (IL-1β, IL-6 and TNF). Mechanistic studies demonstrated that IL-33 treatment induced DCs maturation by upregulating CYLD expression in DCs. In addition, CYLD played an important role in DCs-induced T cell proliferation and IL-17 secretion. In conclusion, our study demonstrated that IL-33 mediated immunoregulation in pulmonary adenocarcinoma by improving DC-induced T cell proliferation by upregulating CYLD expression.

Smoking history influences the prognostic value of peripheral naïve CD4+ T cells in advanced non-small cell lung cancer

Background

Considering the effect of smoking on tumor immunity, we attempted to investigate the impact of smoking history on the prognostic value of circulating naïve and memory CD4+ and CD8+ T cells in advanced non-small cell lung cancer (NSCLC) treated with chemo(radio)therapy.

Methods

Of 196 histologically confirmed advanced NSCLC, 98 eligible ones were enrolled. Naïve and memory CD4+ and CD8+ T cells from peripheral blood were measured by flow cytometry. Kaplan-Meier curves helped estimate patients' survival. The uni- and multivariate Cox proportional hazards regression model was employed in the assessment of the prognostic value of factors.

Results

Multivariate survival analyses showed that peripheral naïve CD4+ T cells independently predicted favorable overall survival (OS) in ever smokers with advanced NSCLC (P = 0.007), but unfavorable OS in never smokers with the same ailment (P = 0.012). Ever smokers presented a different distribution of naïve and memory T cells: low expression levels of naïve CD4+ T (P = 0.005), naïve CD8+ T (P = 0.031), CD4+ naïve/memory ratio (P = 0.020), and CD8+ naïve/memory ratio (P = 0.019), and high distributions of memory CD4 + T (P = 0.004), memory CD8 + T (P = 0.034), and naïve CD8/CD4 ratio (P = 0.020), when compared to never smokers.

Conclusions

We revealed the impact of cigarette-smoking on peripheral naïve CD4+ T cells' prognostic value in advanced NSCLC patients. These results could help in refining personalized treatment for advanced NSCLC patients.

Blocking Triggering Receptor Expressed on Myeloid Cells-1-Positive Tumor-Associated Macrophages Induced by Hypoxia Reverses Immunosuppression and Anti-Programmed Cell Death Ligand 1 Resistance in Liver Cancer

Tumor-associated macrophages (TAMs) are recognized as antitumor suppressors, but how TAMs behave in the hypoxic environment of hepatocellular carcinoma (HCC) remains unclear. Here, we demonstrated that hypoxia inducible factor 1α induced increased expression of triggering receptor expressed on myeloid cells-1 (TREM-1) in TAMs, resulting in immunosuppression. Specifically, TREM-1-positive (TREM-1⁺ ) TAMs abundant at advanced stages of HCC progression indirectly impaired the cytotoxic functions of CD8⁺ T cells and induced CD8⁺ T-cells apoptosis. Biological and functional assays showed that TREM-1⁺ TAMs had higher expression of programmed cell death ligand 1 (PD-L1) under hypoxic environment. However, TREM-1⁺ TAMs could abrogate spontaneous and PD-L1-blockade-mediated antitumor effects in vivo, suggesting that TREM-1⁺ TAM-induced immunosuppression was dependent on a pathway separate from PD-L1/programmed cell death 1 axis. Moreover, TREM-1⁺ TAM-associated regulatory T cells (Tregs) were crucial for HCC resistance to anti-PD-L1 therapy. Mechanistically, TREM-1⁺ TAMs elevated chemokine (C-C motif) ligand 20 expression through the extracellular signal-regulated kinase/NF-κβ pathway in response to hypoxia and tumor metabolites leading to CCR6⁺ Foxp3⁺ Treg accumulation. Blocking the TREM-1 pathway could significantly inhibit tumor progression, reduce CCR6⁺ Foxp3⁺ Treg recruitment, and improve the therapeutic efficacy of PD-L1 blockade. Thus, these data demonstrated that CCR6⁺ Foxp3⁺ Treg recruitment was crucial for TREM-1⁺ TAM-mediated anti-PD-L1 resistance and immunosuppression in hypoxic tumor environment. Conclusion: This study highlighted that the hypoxic environment initiated the onset of tumor immunosuppression through TREM-1⁺ TAMs attracting CCR6⁺ Foxp3⁺ Tregs, and TREM-1⁺ TAMs endowed HCC with anti-PD-L1 therapy resistance.

Immune Checkpoint Inhibition Overcomes ADCP-Induced Immunosuppression by Macrophages

Antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) critically contribute to the efficacy of anti-tumor therapeutic antibodies. We report here an unexpected finding that macrophages after ADCP inhibit NK cell-mediated ADCC and T cell-mediated cytotoxicity in breast cancers and lymphomas. Mechanistically, AIM2 is recruited to the phagosomes by FcγR signaling following ADCP and activated by sensing the phagocytosed tumor DNAs through the disrupted phagosomal membrane, which subsequently upregulates PD-L1 and IDO and causes immunosuppression. Combined treatment with anti-HER2 antibody and inhibitors of PD-L1 and IDO enhances anti-tumor immunity and anti-HER2 therapeutic efficacy in mouse models. Furthermore, neoadjuvant trastuzumab therapy significantly upregulates PD-L1 and IDO in the tumor-associated macrophages (TAMs) of HER2⁺ breast cancer patients, correlating with poor trastuzumab response. Collectively, our findings unveil a deleterious role of ADCP macrophages in cancer immunosuppression and suggest that therapeutic antibody plus immune checkpoint blockade may provide synergistic effects in cancer treatment.

Peripheral memory and naïve T cells in non-small cell lung cancer patients with lung metastases undergoing stereotactic body radiotherapy: predictors of early tumor response

Background

Further analysis of phase I trial of the KEYNOTE-001 has shown that previous radiotherapy improves the outcomes of patients with advanced non-small cell lung cancer (NSCLC) who received pembrolizumab treatment, possibly explained by the radiation-induced specific anti-cancer immunity with a memory effect. In this study, we aimed to investigate the peripheral memory and naïve T cells as predictors of early response in lung metastases post-stereotactic body radiotherapy (SBRT).

Methods

Sixty-six lung metastases patients with NSCLC who received SBRT were enrolled in this study. Analyses of peripheral memory CD4+ T, memory CD8+ T, naive CD4+ T, and naive CD8+ T in NSCLC patients were performed by flow cytometry. Evaluations of the link between immune cells and early radiation response a month after SBRT were carried out via logistic regression analyses.

Results

Higher levels of memory CD4+ T, memory CD8+ T, and lower levels of naïve CD4+ T, CD4+ naïve/memory ratio, and CD8+ naïve/memory ratio were shown in responders compared with non-responders (all P < 0.05). Logistic regression analyses of univariate and multivariate revealed that peripheral memory CD4+ T (OR: 0.14, 95% CI 0.04–0.50, P = 0.003; OR: 0.17, 95% CI 0.05–0.66, P = 0.010), memory CD8+ T (OR: 0.11, 95% CI 0.01–0.87, P = 0.037; OR: 0.11, 95% CI 0.01–0.97, P = 0.047), naïve CD4+ T (OR: 16.25, 95% CI 3.17–83.13, P = 0.001; OR: 12.67, 95% CI 2.26–71.18, P = 0.004) and CD4+ naïve/memory ratio (OR: 11.27, 95% CI 2.67–47.58, P = 0.001; OR: 8.50, 95% CI 1.90–38.14, P = 0.005) were independent predictors for tumor response to SBRT in the lung metastases of NSCLC patients.

Conclusions

The tumor response of lung metastases a month after SBRT independently correlated with peripheral memory CD4+ T, memory CD8+ T, naïve CD4+ T, and CD4+ naïve/memory ratio. These findings could be helpful in incorporating additional treatments to improve clinical outcomes in the case of poor responders.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0839-5) contains supplementary material, which is available to authorized users.

Discovery of CCL18 antagonist blocking breast cancer metastasis

Our previous studies have proved that CCL18 is the most secreted chemokine in breast cancer microenvironment by tumor associated macrophages (TAMs). CCL18 promotes breast cancer invasiveness by binding to its cognate receptor PITPNM3 and activating the downstream signaling pathways. The high level of CCL18 in serum or tumor stroma is associated with tumor metastasis and poor patients overall survival. In this study, we identify an effective small molecular compound (SMC) to antagonize the effect of CCL18. We screen more than 1000 SMCs from Sun Yat-sen University SMC library and select 15 top scored SMCs by using computer-aided virtual screening based on the structure of CCL18. Then in vitro cell migration assay narrows down the selected 15 SMCs to the most effective SMC-21598. We find 10 µM SMC-21598 significantly inhibits CCL18-induced breast cancer cells adherence, invasiveness, and migration. Our further surface plasmon resonance (SPR), fluorescence spectroscopy and isothermal titration calorimetry (ITC) assays reveal that SMC-21598 binds tightly to CCL18, which blocks the binding of CCL18 with its receptor PITPNM3. The in vivo animal experiments show that SMC-21598 doesn't significantly affect xenografts growth, but inhibits lung metastasis. Our study provides a potential lead compound to antagonize CCL18 function. It would be of great significance to develop SMC drugs to ameliorate breast cancer metastasis and prolong patients' survival.

Atypical Chemokine Receptor 3 (ACKR3): A Comprehensive Overview of its Expression and Potential Roles in the Immune System

Atypical chemokine receptor 3 (ACKR3), previously known as C-X-C chemokine receptor type 7 (CXCR7), has emerged as a key player in several biologic processes, particularly during development. Its CXCL11 and CXCL12 scavenging activity and atypical signaling properties, together with a new array of other nonchemokine ligands, have established ACKR3 as a main regulator of physiologic processes at steady state and during inflammation. Here, we present a comprehensive review of ACKR3 expression in mammalian tissues in search of a possible connection with the receptor function. Besides the reported roles of ACKR3 during development, we discuss the potential contribution of ACKR3 to the function of the immune system, focusing on the myeloid lineage.

Tumor-Contacted Neutrophils Promote Metastasis by a CD90-TIMP-1 Juxtacrine-Paracrine Loop

PURPOSE

The different prognostic values of tumor-infiltrating neutrophils (TIN) in different tissue compartments are unknown. In this study, we investigated their different prognostic roles and the underlying mechanism.Experimental Design: We evaluated CD66b⁺ neutrophils in primary tumors from 341 patients with breast cancer from Sun Yat-sen Memorial Hospital by IHC. The association between stromal and parenchymal neutrophil counts and clinical outcomes was assessed in a training set (170 samples), validated in an internal validation set (171 samples), and further confirmed in an external validation set (105 samples). In addition, we isolated TINs from clinical samples and screened the cytokine profile by antibody microarray. The interaction between neutrophils and tumor cells was investigated in transwell and 3D Matrigel coculture systems. The therapeutic potential of indicated cytokines was evaluated in tumor-bearing immunocompetent mice.

RESULTS

We observed that the neutrophils in tumor parenchyma, rather than those in stroma, were an independent poor prognostic factor in the training [HR = 5.00, 95% confidence interval (CI): 2.88-8.68, P < 0.001], internal validation (HR = 3.56, 95% CI: 2.07-6.14, P < 0.001), and external validation set (HR = 5.07, 95% CI: 2.27-11.33, P < 0.001). The mechanistic study revealed that neutrophils induced breast cancer epithelial-mesenchymal transition (EMT) via tissue inhibitor of matrix metalloprotease (TIMP-1). Reciprocally, breast cancer cells undergoing EMT enhanced neutrophils' TIMP-1 secretion by CD90 in a cell-contact manner. In vivo, TIMP-1 neutralization or CD90 blockade significantly reduced metastasis. More importantly, TIMP-1 and CD90 were positively correlated in breast cancer (r ² = 0.6079; P < 0.001) and associated with poor prognosis of patients.

CONCLUSIONS

Our findings unravel a location-dictated interaction between tumor cells and neutrophils and provide a rationale for new antimetastasis treatments.

Lactate modulates CD4+ T-cell polarization and induces an immunosuppressive environment, which sustains prostate carcinoma progression via TLR8/miR21 axis

Leukocyte infiltration plays an active role in controlling tumor development. In the early stages of carcinogenesis, T cells counteract tumor growth. However, in advanced stages, cancer cells and infiltrating stromal components interfere with the immune control and instruct immune cells to support, rather than counteract, tumor malignancy, via cell-cell contact or soluble mediators. In particular, metabolites are emerging as active players in driving immunosuppression. Here we demonstrate that in a prostate cancer model lactate released by glycolytic cancer-associated fibroblasts (CAFs) acts on CD4⁺ T cells, shaping T-cell polarization. In particular, CAFs exposure (i) reduces the percentage of the antitumoral Th1 subset, inducing a lactate-dependent, SIRT1-mediated deacetylation/degradation of T-bet transcription factor; (ii) increases T_reg cells, driving naive T cells polarization, through a lactate-based NF-kB activation and FoxP3 expression. In turn, this metabolic-based CAF-immunomodulated environment exerts a pro-invasive effect on prostate cancer cells, by activating a previously unexplored miR21/TLR8 axis that sustains cancer malignancy.

Engineering Nanoparticles for Targeted Remodeling of the Tumor Microenvironment to Improve Cancer Immunotherapy

Owing to the fast-paced growth and cross-infiltration of oncology, immunology and molecular biology, tumor immunotherapy technology represented by immune checkpoint blockade and chimeric antigen receptor (CAR) T cell therapy has lately made remarkable advancements. In comparison with traditional chemotherapy, immunotherapy has the potential to elicit a stronger sustained antitumor immune response in those patients who have advanced malignant malignancies. In spite of the advancements made, a significant number of clinical research works have validated that an extensive proportion of cancer patients still manifest insensitivity to immunotherapy, primarily because of the immunomodulatory interactions between tumor cells and the immunosuppressive tumor microenvironment (TME), together mediating the immune tolerance of tumors and accordingly impacting the positive response to immunotherapy. The intricate immunosuppressive networks formed by stromal cells, inflammatory cells, vasculature, extracellular matrix (ECM), and their secreted cytokines in the TME, play a pivotal role in tumor immune escape. Specific blocking of inhibition pathways in the TME is expected to effectively prevent immune escape and tolerance of tumor cells in addition to their metastasis, accordingly improving the antitumor immune response at various phases of tumor growth. Emerging nanoscale targeted drug carriers truly suit this specific requirement due to their specificity, biocompatibility, and convenience of production. This review emphasizes recent attempts to remodel the tumor immune microenvironment using novel nanoparticles, which include specifically eliminating immunosuppressive cells, reprogramming immune regulatory cells, promoting inflammatory cytokines and blocking immune checkpoints. Targeted remodeling of the immunosuppressive TME using well-designed and fabricated nanoparticles provides a promising strategy for improving the effectiveness of current immunotherapy and is greatly significant.

Programmed death ligand-1 is associated with tumor infiltrating lymphocytes and poorer survival in urothelial cell carcinoma of the bladder

Drugs blocking programmed death ligand‐1 (PD‐L1) have shown unprecedented activity in metastatic and unresectable bladder cancer. The purpose of the present study was to investigate the expression, clinical significance and association of PD‐L1 with tumor‐infiltrating lymphocytes (TIL) in resectable urothelial cell carcinoma of the bladder (UCB). In this retrospective study, 248 UCB patients who received radical cystectomy or transurethral resection were examined. Immunohistochemistry was used to evaluate PD‐L1 expression and stromal CD8⁺TIL, Th1 orientation T cell (T‐bet⁺) and PD‐1⁺TIL densities within the intratumoral regions and associated stromal regions. Of the 248 specimens, 23% showed PD‐L1 expression in tumor cells and 55% in tumor‐infiltrating immune cells. CD8⁺TIL, T‐bet⁺TIL and PD‐1⁺TIL were distributed throughout the tumor tissues and were more frequently distributed in stromal regions than in intratumoral regions. PD‐L1⁺ tumor cells and PD‐L1⁺ immune cells were positively associated with aggressive clinical features (all P < .05). Both PD‐L1⁺ tumor cells and PD‐L1⁺ immune cells were associated with poorer recurrence‐free and overall survival (all P < .05). Multivariate analysis showed that PD‐L1⁺ immune cells were an independent prognostic factor for overall (P = .001) and recurrence‐free survival (P = .024). Notably, high stromal CD8⁺TIL and PD‐1⁺TIL density were associated with poorer overall survival (P = .031 and P = .001, respectively). In the stroma, CD8⁺TIL density has strong positive association with PD‐L1⁺ immune cells and PD‐1⁺TIL density (all P < .0001). These results suggested that an exhausted immune state occurred in the tumor stroma in UCB. Further clinical development of immune‐checkpoint inhibitors may be effective for resectable patients with UCB.

The Sweet Surrender: How Myeloid Cell Metabolic Plasticity Shapes the Tumor Microenvironment

Immune cells are one of the most versatile cell types, as they can tailor their metabolic activity according to their required function. In response to diverse environmental cues, immune cells undergo metabolic reprogramming to support their differentiation, proliferation and pro-inflammatory effector functions. To meet a dramatic surge in energetic demand, immune cells rewire their metabolism to utilize aerobic glycolysis. This preferential use of glycolysis even under aerobic conditions is well established in tumor cells, and is known as the "Warburg effect." Tumor cells avidly use glucose for aerobic glycolysis, thereby creating a nutrient-starved microenvironment, outcompeting T cells for glucose, and directly inhibiting T-cell anti-tumoral effector function. Given that both immune and tumor cells use similar modes of metabolism in the tumor stroma, it is imperative to identify a therapeutic window in which immune-cell and tumor-cell glycolysis can be specifically targeted. In this review, we focus on the Warburg metabolism as well as other metabolic pathways of myeloid cells, which comprise a notable niche in the tumor environment and promote the growth and metastasis of malignant tumors. We examine how differential immune-cell activation triggers metabolic fate, and detail how this forbidding microenvironment succeeds in shutting down the vigorous anti-tumoral response. Finally, we highlight emerging therapeutic concepts that aim to target immune-cell metabolism. Improving our understanding of immunometabolism and immune-cell commitment to specific metabolic fates will help identify alternative therapeutic approaches to battle this intractable disease.

Circulating CD8+ T-cell repertoires reveal the biological characteristics of tumors and clinical responses to chemotherapy in breast cancer patients

PURPOSE

CD8+ T cells are primarily cytotoxic cells that provide immunological protection against malignant cells. Considerable evidence suggests that the T-cell repertoire is closely associated with the host immune response and the development of cancer. In this study, we explored the characteristics of the circulating CD8+ T-cell repertoire and their potential value in predicting the clinical response of breast cancer patients to chemotherapy.

EXPERIMENTAL DESIGN

We applied a high-throughput TCR β-chain sequencing method to characterize the CD8+ T-cell repertoire of the peripheral blood from 26 breast cancer patients. In addition, changes in the circulating CD8+ T-cell repertoire during chemotherapy were analyzed.

RESULTS

We found that the HEC ratios of the CD8+ T-cell repertoires from HER2+ breast cancer patients were significantly higher than those of HER2- patients, suggesting that the HER2 protein is released into circulation where it is targeted by CD8+ T cells. Several Vβ and CDR3 motifs preferentially used in HER2+ patients were identified. Besides, we found that the circulating CD8+ T-cell repertoires evolved during chemotherapy and correlated with patient clinical responses to chemotherapy. Increased CD8+ T-cell repertoire heterogeneity during chemotherapy was associated with a better clinical response.

CONCLUSIONS

Although functional studies of clonally expanded CD8+ T-cell populations are clearly required, our results suggest that the circulating CD8+ T-cell repertoire reflects the characteristics of the tumor-associated biomolecules released into the blood and correlates with the clinical responses of the patients to chemotherapy which might assist in making treatment decisions.

Tumor-associated macrophages in breast cancer: Innocent bystander or important player?

Tumor-associated macrophages (TAMs) are important tumor-promoting cells in the breast tumor microenvironment. Preclinically TAMs stimulate breast tumor progression, including tumor cell growth, invasion and metastasis. TAMs also induce resistance to multiple types of treatment in breast cancer models. The underlying mechanisms include: induction and maintenance of tumor-promoting phenotype in TAMs, inhibition of CD8+ T cell function, degradation of extracellular matrix, stimulation of angiogenesis and inhibition of phagocytosis. Several studies reported that high TAM infiltration of breast tumors is correlated with a worse patient prognosis. Based on these findings, macrophage-targeted treatment strategies have been developed and are currently being evaluated in clinical breast cancer trials. These strategies include: inhibition of macrophage recruitment, repolarization of TAMs to an antitumor phenotype, and enhancement of macrophage-mediated tumor cell killing or phagocytosis. This review summarizes the functional aspects of TAMs and the rationale and current evidence for TAMs as a therapeutic target in breast cancer.

AUTOIMMUNE RETINOPATHY IN A PATIENT WITH A MISSENSE MUTATION IN PITPNM3

PURPOSE

To describe a patient with a PITPNM3 missense mutation who developed late-onset autoimmune retinopathy.

METHODS

Case report.

RESULTS

An 85-year-old man presented with decreased vision, nyctalopia, and photoaversion after an uncomplicated cataract surgery. Multimodal retinal imaging revealed a scalloped pattern of atrophy and a ring of hyperautofluorescence in the perifoveal area on fundus autofluorescence. Spectral domain optical coherence tomography demonstrated loss of the ellipsoid band, along with outer retinal atrophy, sparing the fovea in both eyes. Full field electroretinogram revealed extinguished rod response and severely attenuated cone response. Antiretinal antibodies to 20-kDa and 125-kDa proteins were detected. Whole-exome sequencing revealed a heterozygous variant, c.2579T>C, p.(Ile860Thr) in PITPNM3, predicted to be severely damaging and deleterious to the protein structure and function. Over the course of 3 months, the patient experienced a rapid progression. Neoplastic workup was negative and he was started on immunosuppressive therapy for a presumed diagnosis of nonparaneoplastic autoimmune retinopathy.

CONCLUSION

To the authors' knowledge, this is the first report of autoimmune retinopathy in a patient with PITPNM3 mutation. PITPNM3 has been previously shown to affect regulatory T cell function.

LNMAT1 promotes lymphatic metastasis of bladder cancer via CCL2 dependent macrophage recruitment

Tumor-associated macrophages (TAMs) are the most abundant inflammatory infiltrates in the tumor microenvironment and contribute to lymph node (LN) metastasis. However, the precise mechanisms of TAMs-induced LN metastasis remain largely unknown. Herein, we identify a long noncoding RNA, termed Lymph Node Metastasis Associated Transcript 1 (LNMAT1), which is upregulated in LN-positive bladder cancer and associated with LN metastasis and prognosis. Through gain and loss of function approaches, we find that LNMAT1 promotes bladder cancer-associated lymphangiogenesis and lymphatic metastasis. Mechanistically, LNMAT1 epigenetically activates CCL2 expression by recruiting hnRNPL to CCL2 promoter, which leads to increased H3K4 tri-methylation that ensures hnRNPL binding and enhances transcription. Furthermore, LNMAT1-induced upregulation of CCL2 recruits macrophages into the tumor, which promotes lymphatic metastasis via VEGF-C excretion. These findings provide a plausible mechanism for LNMAT1-modulated tumor microenvironment in lymphatic metastasis and suggest that LNMAT1 may represent a potential therapeutic target for clinical intervention in LN-metastatic bladder cancer.

NKILA lncRNA promotes tumor immune evasion by sensitizing T cells to activation-induced cell death

Activation-induced cell death (AICD) of T lymphocytes can be exploited by cancers to escape immunological destruction. We demonstrated that tumor-specific cytotoxic T lymphocytes (CTLs) and type 1 helper T (T_H1) cells, rather than type 2 helper T cells and regulatory T cells, were sensitive to AICD in breast and lung cancer microenvironments. NKILA, an NF-κB-interacting long noncoding RNA (lncRNA), regulates T cell sensitivity to AICD by inhibiting NF-κB activity. Mechanistically, calcium influx in stimulated T cells via T cell-receptor signaling activates calmodulin, thereby removing deacetylase from the NKILA promoter and enhancing STAT1-mediated transcription. Administering CTLs with NKILA knockdown effectively inhibited growth of breast cancer patient-derived xenografts in mice by increasing CTL infiltration. Clinically, NKILA overexpression in tumor-specific CTLs and T_H1 cells correlated with their apoptosis and shorter patient survival. Our findings underscore the importance of lncRNAs in determining tumor-mediated T cell AICD and suggest that engineering lncRNAs in adoptively transferred T cells might provide a novel antitumor immunotherapy.

EGF-induced nuclear localization of SHCBP1 activates β-catenin signaling and promotes cancer progression

Aberrant activation of EGFR represents a common event in non-small cell lung carcinoma (NSCLC) and activates various downstream signaling pathways. While EGFR activation of β-catenin signaling was previously reported, the mediating mechanism remains unclear. Our current study found that EGFR activation in NSCLC cells releases SHC-binging protein 1 (SHCBP1) from SHC adaptor protein 1 (SHC1), which subsequently translocates into the nucleus and directly promotes the transactivating activity of β-catenin, consequently resulting in development of NSCLC cell stemness and malignant progression. Furthermore, SHCBP1 promotes β-catenin activity through enhancing the CBP/β-catenin interaction, and most interestingly, a candidate drug that blocks the CBP/β-catenin binding effectively abrogates the aforementioned biological effects of SHCBP1. Clinically, SHCBP1 level in NSCLC tumors was found to inversely correlate with patient survival. Together, our study establishes a novel convergence between EGFR and β-catenin pathways and highlights a potential significance of SHCBP1 as a prognostic biomarker and a therapeutic target.

Distinct Changes of BTLA and HVEM Expressions in Circulating CD4+ and CD8+ T Cells in Hepatocellular Carcinoma Patients

BTLA/HVEM (B and T lymphocyte attenuator/herpes virus entry mediator) pathways play a critical role in T cell suppression in tumor. However, its dynamic changes in different T cell subsets in peripheral blood and their clinical significance are largely unclear in cancer patients. In the current study, we showed distinct changes of BTLA and HVEM expressions on peripheral blood CD4⁺ and CD8⁺ T cells in patients with hepatocellular carcinoma (HCC); BTLA expression were significantly upregulated on circulating CD4⁺ but not CD8⁺ T cells. In sharp contrast, the levels of HVEM expression were significantly downregulated on circulating CD8⁺ but not CD4⁺ T cells. A strong positive correlation between BTLA expression on circulating CD4⁺ T cells and BTLA expression on autologous CD8⁺ counterparts was observed in healthy donors but absent in HCC patients. More importantly, we found that blockade of the BTLA/HVEM pathway increased IFN-γ production in both circulating CD4⁺ and CD8⁺ T cells. Collectively, our data suggested that the BTLA/HVEM pathway contributes to peripheral T cell suppression in HCC patients, and BTLA/HVEM may serve as attractive targets for HCC immunotherapy.

Identification of a sodium pump Na+/K+ ATPase α1-targeted peptide for PET imaging of breast cancer

The sodium pump Na⁺/K⁺ ATPase a1 subunit(NKA a1), an attractive cancer-related biomarker and therapeutic target, is closely related to the development and progression of several cancers including breast cancer. Currently, a NKA a1 inhibitor, UNBS1450, has already evidenced its great therapeutic potential in personalized cancer treatment. The ability of non-invasive imaging of NKA a1 expression would be useful for selecting cancer patients who may benefit from this drug. Here, we identified an S3 peptide that is specifically homed to breast cancer by phage display. All data of in vitro and in vivo experiments suggested the excellent targeting character of the S3 peptide. As the binding activity of the S3 phage was positively correlated to the level of NKA α1 expression in various breast cancer cells, NKA α1 was validated as the primary target of the S3 peptide. Based on immunohistochemistry staining result of 107 breast cancer patients, NKA α1 was verified to be a novel tracking marker and a prognostic predictor for breast cancer. Importantly, we proposed and validated an S3 peptide-based radiotracer ¹⁸F-ALF-NOTA-S3 for PET (Positron Emission Tomography) imaging of breast cancer and other NKA α1-overexpressing cancers, including hepatocellular carcinoma and non-small cell lung cancer, in mouse models. Our findings demonstrated the potential application of ¹⁸F-ALF-NOTA-S3 for visualization of NKA α1-positive lesions, which provide a new approach to character tumor phenotypic imaging.

Cyclooxygenase and lipoxygenase gene expression in the inflammogenesis of breast cancer

We examined the expression of major inflammatory genes, cyclooxygenase-1 and 2 (COX1, COX2) and arachidonate 5-lipoxygenase (ALOX5) in 1090 tumor samples of invasive breast cancer from The Cancer Genome Atlas (TCGA). Mean cyclooxygenase expression (COX1 + COX2) ranked in the upper 99th percentile of all 20,531 genes and surprisingly, the mean expression of COX1 was more than tenfold higher than COX2. Highly significant correlations were observed between COX2 with eight tumor-promoting genes (EGR2, IL6, RGS2, B3GNT5, SGK1, SLC2A3, SFRP1 and ETS2) and between ALOX5 and ten tumor promoter genes (CD33, MYOF1, NLRP1, GAB3, CD4, IFR8, CYTH4, BTK, FGR, CD37). Expression of CYP19A1 (aromatase) was significantly correlated with COX2, but only in tumors positive for ER, PR and HER2. Tumor-promoting genes correlated with the expression of COX1, COX2, and ALOX5 are known to effectively increase mitogenesis, mutagenesis, angiogenesis, cell survival, immunosuppression and metastasis in the pathogenesis of breast cancer.

A serum microRNA signature predicts trastuzumab benefit in HER2-positive metastatic breast cancer patients

Trastuzumab is a standard treatment for HER2-positive (HER2⁺) breast cancer, but some patients are refractory to the therapy. MicroRNAs (miRNAs) have been used to predict therapeutic effects for various cancers, but whether miRNAs can serve as biomarkers for HER2⁺ metastatic breast cancer (MBC) patients remains unclear. Using miRNA microarray, we identify 13 differentially expressed miRNAs in the serum of HER2⁺ MBC patients with distinct response to trastuzumab, and four miRNAs are selected to construct a signature to predict survival using LASSO model. Further, our data show that miR-940 is mainly released from the tumor cells and miR-451a, miR-16-5p and miR-17-3p are mainly from the immune cells. All these four miRNAs directly target signaling molecules that play crucial roles in regulating trastuzumab resistance. In summary, we develop a serum-based miRNA signature that potentially predicts the therapeutic benefit of trastuzumab for HER2⁺ MBC patients and warrants future validation in prospective clinical trials.

Resistance to therapy is a significant issue for patients with metastatic breast cancer (MBC). Here the authors analyze total miRNA from serum samples of 386 MBC patients before treatment with a follow up of 31 months and define a four miRNA signature that predicts the therapeutic benefit of trastuzumab.

CCL18 - Beyond chemotaxis

The chemokine CCL18 is constitutively expressed in human lung and serum, and is further elevated during pathologic conditions such as allergy, fibrosis and cancer, suggesting that it may participate in both homeostatic and inflammatory processes. Under steady state conditions, CCL18 has chemotactic activity, albeit modest, toward naïve T cells and as such, may be involved in the initiation of the adaptive response. Its chemotactic effect on inflammatory cells is ambiguous as it attracts both regulatory and inflammatory immune cells. CCL18 can also modulate tissue inflammation by inhibiting cell recruitment through binding to glycosaminoglycans with high affinity, thereby displacing other chemokines bound to the endothelial surface. CCL18 induces regulatory phenotype and function of immune cells through direct activation and plays a major role in fibrotic processes, particularly in the lung. Finally, CCL18 is involved in cancer cell activation and migration and also participates in immune tolerance toward cancer. Its high constitutive expression levels and its further up-regulation in many diseases, together with its moderate chemoattractant properties support the fact that this chemokine has activities beyond cell recruitment.

In-vitro effect of pembrolizumab on different T regulatory cell subsets

Programmed death-1 (PD-1) and interactions with PD-ligand 1 (PD-L1) play critical roles in the tumour evasion of immune responses through different mechanisms, including inhibition of effector T cell proliferation, reducing cytotoxic activity, induction of apoptosis in tumour-infiltrating T cells and regulatory T cell (T_reg ) expansion. Effective blockade of immune checkpoints can therefore potentially eliminate these detrimental effects. The aim of this study was to investigate the effect of anti-PD-1 antibody, pembrolizumab, on various T_reg subpopulations. Peripheral blood mononuclear cells (PBMC) from healthy donors (HD) and primary breast cancer patients (PBC) were treated in vitro with pembrolizumab, which effectively reduced PD-1 expression in both cohorts. We found that PD-1 was expressed mainly on CD4⁺ CD25⁺ T cells and pembrolizumab had a greater effect on PD-1 expression in CD4⁺ CD25^- T cells, compared to CD4⁺ CD25⁺ cells. In addition, pembrolizumab did not affect the expression levels of T_reg -related markers, including cytotoxic T lymphocyte antigen-4 (CTLA-4), CD15s, latency-associated peptide (LAP) and Ki-67. Moreover, we report that CD15s is expressed mainly on forkhead box P3 (FoxP3)^- Helios⁺ T_reg in HD, but it is expressed on FoxP3⁺ Helios^- T_reg subset in addition to FoxP3^- Helios⁺ T_reg in PBC. Pembrolizumab did not affect the levels of FoxP3^+/- Helios^+/- T_reg subsets in both cohorts. Taken together, our study suggests that pembrolizumab does not affect T_reg or change their phenotype or function but rather blocks signalling via the PD-1/PD-L1 axis in activated T cells.

Tumor Associated Macrophages as Therapeutic Targets for Breast Cancer

Tumor-associated macrophages (TAMs) are the most abundant inflammatory infiltrates in the tumor stroma. TAMs promote tumor growth by suppressing immunocompetent cells, including neovascularization and supporting cancer stem cells. In the chapter, we discuss recent efforts in reprogramming or inhibiting tumor-protecting properties of TAMs, and developing potential strategies to increase the efficacy of breast cancer treatment.