Following up tumor-specific regulatory T cells in cancer patients

CCL19/CCR7 drives regulatory T cell migration and indicates poor prognosis in gastric cancer

BACKGROUND

Gastric cancer is associated with significant morbidity and mortality in the world. Blocking programmed cell death protein 1 pathway have been approved for the treatment of a variety of tumors and have achieved remarkable clinical therapeutic effects. However, immune checkpoint inhibitors failed to achieve satisfactory results in gastric cancer. There is a need to identify novel immunotherapy targets in gastric cancer.

METHODS

We analysed the correlation between Treg cells and CD8 + T cells in gastric cancer samples. We studied the relationship between chemokines and Treg cells or CD8 + T cells in gastric cancer. We compared CCL19/CCR7 expression in gastric cancer patients in TCGA database. We performed transwell experiments to determine the influence of CCL19 on Treg cells and CD8 + T cells migratory capacity. We conducted survival analysis of CCL19 and CCR7 in gastric cancer database.

RESULTS

Treg cells show positive correlation with CD8 + T cells in gastric cancer. Treg cell expression was significantly upregulated in tumor tissues. Patients with high FOXP3 expression had worse overall survival than those with low FOXP3 expression. CCL19 had strong correlation with FOXP3 and weak correlation with CD8A. CCL19 had strong impact on the migratory capacity of Treg cells but weak impact on the migratory capacity of CD8 + T cells. Both CCL19 and CCR7 expression were significantly upregulated in gastric cancer tissues. Survival analysis demonstrated that both CCL19 and CCR7 indicate poor prognosis in gastric cancer.

CONCLUSIONS

CCL19/CCR7 may be a potential novel therapeutic target in gastric cancer.

Updated Neoadjuvant Treatment Landscape for Early Triple Negative Breast Cancer: Immunotherapy, Potential Predictive Biomarkers, and Novel Agents

Simple Summary

In recent years, several agents have been tested in randomized clinical trials in addition to anthracycline and taxane-based neoadjuvant chemotherapy (NACT) in early-stage triple-negative breast cancer (TNBC) to improve pathological complete response rate and, ultimately, survival outcome. Platinum agents, immune checkpoint inhibitors (ICIs), and PARP-inhibitors are the most extensively studied, while established predictors of their efficacy are lacking. Based on the biological features of TNBC, the purpose of this review is to provide an overview of the role of platinum agents, immunotherapy, and novel target therapies in the neoadjuvant setting. Moreover, based on safety issues and financial costs, we provide an overview of potential biomarkers associated with increased likelihood of benefit from the addition of platinum, ICIs, and novel target therapies to NACT.

Abstract

Triple-negative breast cancer (TNBC) is characterized by the absence of hormone receptor and HER2 expression, and therefore a lack of therapeutic targets. Anthracyclines and taxane-based neoadjuvant chemotherapy have historically been the cornerstone of treatment of early TNBC. However, genomic and transcriptomic analyses have suggested that TNBCs include various subtypes, characterized by peculiar genomic drivers and potential therapeutic targets. Therefore, several efforts have been made to expand the therapeutic landscape of early TNBC, leading to the introduction of platinum and immunomodulatory agents into the neoadjuvant setting. This review provides a comprehensive overview of the currently available evidence regarding platinum agents and immune-checkpoint-inhibitors for the neoadjuvant treatment of TNBC, as well as the novel target therapies that are currently being evaluated in this setting. Taking into account the economic issues and the side effects of the expanding therapeutic options, we focus on the potential efficacy biomarkers of the emerging therapies, in order to select the best therapeutic strategy for each specific patient.

Resolving the difference between left-sided and right-sided colorectal cancer by single-cell sequencing

Colorectal cancers (CRCs) exhibit differences in incidence, pathogenesis, molecular pathways, and outcome depending on the location of the tumor. The transcriptomes of 27,927 single human CRC cells from 3 left-sided and 3 right-sided CRC patients were profiled by single-cell RNA-Seq (scRNA-Seq). Right-sided CRC harbors a significant proportion of exhausted CD8⁺ T cells of a highly migratory nature. One cluster of cells from left-sided CRC exhibiting states preceding exhaustion and a high ratio of preexhausted/exhausted T cells were favorable prognostic markers. Notably, we identified a potentially novel RBP4⁺NTS⁺ subpopulation of cancer cells that exclusively expands in left-sided CRC. Tregs from left-sided CRC showed higher levels of immunotherapy-related genes than those from right-sided CRC, indicating that left-sided CRC may have increased responsiveness to immunotherapy. Antibody-dependent cellular phagocytosis (ADCP) and antibody-dependent cellular cytotoxicity (ADCC) induced by M2-like macrophages were more pronounced in left-sided CRC and correlated with a good prognosis in CRC.

[Immunotherapy for Lung Cancer: Mechanisms of Resistance and Response Strategy]

Inhibition of immune checkpoints is at the forefront of immunotherapy for lung cancer. However, a high percentage of lung cancer patients do not respond to these immunotherpy or their responses are transient, indicating the existence of immune resistance. Emerging evidence suggested that the interactions between cancer cells and immune system were continuous and dynamic. Here, we review how a range of cancer-cell-autonomous characteristics, tumor-microenvironment factors, and host-related influences account for heterogenous responses. Furthermore, with the identification of new targets of immunotherapy and development of immune-based combination therapy, we elucidate the methods might useful to overcome resistance.

Identification of Immune-Related Prognostic Genes and LncRNAs Biomarkers Associated With Osteosarcoma Microenvironment

Osteosarcoma (OS) is the most common malignancy of the bone that occurs majorly in young people and adolescents. Although the survival of OS patients markedly improved by complete surgical resection and chemotherapy, the outcome is still poor in patients with recurrent and/or metastasized OS. Thus, identifying prognostic biomarkers that reflect the biological heterogeneity of OS could lead to better interventions for OS patients. Increasing studies have indicated the association between immune-related genes (IRGs) and cancer prognosis. In the present study, based on the data concerning OS obtained from TARGET (Therapeutically Applicable Research to Generate Effective Treatments) database, we constructed a classifier containing 12 immune-related (IR) long non-coding RNAs (lncRNAs) and 3 IRGs for predicting the prognosis of OS by using the least absolute shrinkage and selection operation Cox regression. Besides, based on the risk score calculated by the classifier, the samples were divided into high- and low-risk groups. We further investigated the tumor microenvironment of the OS samples by ESTIMATE and CIBERSORT algorithms between the two groups. Finally, we identified three small molecular drugs with potential therapeutic value for OS patients with high-risk score. Our results suggest that the IRGs and IR-lncRNAs–based classifier could be used as a reliable prognostic predictor for OS survival.

Comprehensive Analysis of Tumor-Infiltrating Immune Cells and Relevant Therapeutic Strategy in Esophageal Cancer

A growing body of evidence has indicated that behaviors of cancers are defined by not only intrinsic activities of tumor cells but also tumor-infiltrating immune cells (TIICs) in the tumor microenvironment. However, it still lacks a well-structured and comprehensive analysis of TIICs and its therapeutic value in esophageal cancer (EC). The proportions of 22 TIICs were evaluated between 150 normal tissues and 141 tumor tissues of EC by the CIBERSORT algorithm. Besides, correlation analyses between proportions of TIICs and clinicopathological characters, including age, gender, histologic grade, tumor location, histologic type, LRP1B mutation, TP53 mutation, tumor stage, lymph node stage, and TNM stage, were conducted. We constructed a risk score model to improve prognostic capacity with 5 TIICs by least absolute shrinkage and selection operator (lasso) regression analysis. The risk score = −1.86∗plasma + 2.56∗T cell follicular helper − 1.37∗monocytes − 3.64∗activated dendritic cells − 2.24∗resting mast cells (immune cells in the risk model mean the proportions of immune cell infiltration in EC). Patients in the high-risk group had significantly worse overall survival than these in the low-risk group (HR: 2.146, 95% CI: 1.243-3.705, p = 0.0061). Finally, we identified Semustine and Sirolimus as two candidate compounds for the treatment of EC based on CMap analysis. In conclusion, the proportions of TIICs may be important to the progression, prognosis, and treatment of EC.

Neoadjuvant therapy for triple-negative breast cancer: potential predictive biomarkers of activity and efficacy of platinum chemotherapy, PARP- and immune-checkpoint-inhibitors

INTRODUCTION

Despite recent advances in the molecular characterization of triple-negative breast cancer (TNBC), the standard treatment for early-stage TNBC is represented by the historically used anthracycline and taxane-based chemotherapy. In this modern era of precision medicine, several new therapeutic strategies and novel agents have been investigated in the neoadjuvant setting of TNBC, in order to individualize treatment.

AREAS COVERED

This review provides a comprehensive overview of the currently available evidence regarding the activity and efficacy of platinum agents, PARP- and immune-checkpoint-inhibitors for the neoadjuvant treatment of TNBC, highlighting the available data on potential predictive biomarkers of response or resistance to such treatments.

EXPERT OPINION

The genomic and immune landscape of TNBC has encouraged the exploration of drugs that interfere with the DNA repair mechanism and that modulate immune response. Overall, these drugs seem to improve the pCR rate in TNBC, despite preliminary and heterogeneous results. Taking into account the economic issues and the side effects of these drugs, it is crucial to further explore the potential predictive role of BRCA mutational status and homologous recombination deficiency score, for platinum agents and PARP-inhibitors, and tumor infiltrating lymphocytes and other immune biomarkers for checkpoint inhibitors, respectively.

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.

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

The origin of tumor-infiltrating Tregs, critical mediators of tumor immunosuppression, is unclear. Here, we show that tumor-infiltrating naive CD4⁺ T cells and Tregs in human breast cancer have overlapping TCR repertoires, while hardly overlap with circulating Tregs, suggesting that intratumoral Tregs mainly develop from naive T cells in situ rather than from recruited Tregs. Furthermore, the abundance of naive CD4⁺ T cells and Tregs is closely correlated, both indicating poor prognosis for breast cancer patients. Naive CD4⁺ T cells adhere to tumor slices in proportion to the abundance of CCL18-producing macrophages. Moreover, adoptively transferred human naive CD4⁺ T cells infiltrate human breast cancer orthotopic xenografts in a CCL18-dependent manner. In human breast cancer xenografts in humanized mice, blocking the recruitment of naive CD4⁺ T cells into tumor by knocking down the expression of PITPNM3, a CCL18 receptor, significantly reduces intratumoral Tregs and inhibits tumor progression. These findings suggest that breast tumor-infiltrating Tregs arise from chemotaxis of circulating naive CD4⁺ T cells that differentiate into Tregs in situ. Inhibiting naive CD4⁺ T cell recruitment into tumors by interfering with PITPNM3 recognition of CCL18 may be an attractive strategy for anticancer immunotherapy.

Cytokine patterns in cancer patients: A review of the correlation between interleukin 6 and prognosis

OBJECTIVE

In tumor patients, IL-6 appears to be one component of a consistent cancer-associated cytokine network resulting in both a systemic immune stimulation and a microenvironment of cancer-induced immune suppression that ultimately protects the cancer cells. IL-6 has been associated with prognosis in cancer patients, but so far a systemical analysis has not been carried out.

METHODS

The present meta-analysis studies the relation between IL-6 serum levels and the prognosis of cancer patients in the available clinical literature of 100 articles published between 1993 and 2013 comprising 11,583 patients.

RESULTS

The IL-6 serum level was described as significantly correlating with survival in 82/101 series comprising 85.6% of patients (9917/11,583) with 23 different cancer types. A total of 64 studies dichotomized patient cohorts according to various cut-off IL-6 serum levels: in 59/64 of these series corresponding to 94.5% of the reported patients (7694/8142) significant correlations between IL-6 serum level and survival were seen. The median survival of cancer patients had been determined above various cut-off levels of serum IL-6 in 24 dichotomized studies (26 cohorts). There was a highly significant inverse correlation between median survival of the cohorts with IL-6 serum level above cut-off (1272 patients) and their corresponding IL-6 cut-off values (Spearman R -0,48 p= < 0.001) following a linear regression when both parameters were log-transformed (p < 0.001). A significant correlation between increasing serum IL-6 and tumor stage or metastases was described in 39/44 studies and 91% of published patients (4221/4636) where clinical parameters had been specified.

CONCLUSIONS

Closely associated with the patient's clinical condition and independent of the cancer histology, the increased IL-6 serum level uniformly appears to correlate with survival as paraneoplastic condition in later cancer stages independent of the cancer type. Modifications of this paraneoplastic immune reaction may offer new therapeutic options in cancer.

Cancer associated fibroblasts have phenotypic and functional characteristics similar to the fibrocytes that represent a novel MDSC subset

Circulating fibrocytes were reported to represent a novel myeloid-derived suppressor cell (MDSC) subset and they were also proposed to be involved in the tumor immune escape. This novel fibrocyte subset had a surface phenotype resembling non-monocytic MDSCs (CD14^-CD11c^hiCD123^-) and exhibited immunomodulatory roles. Most effector functions of fibrocytes (circulating fibroblast-progenitors) are accomplished as tissue fibroblasts, likewise in the tumor microenvironment. Therefore, fibroblasts at tumor tissues should be evaluated whether they display similar molecular/gene expression patterns and functional roles to the blood-borne fibrocytes. A chemically induced rat breast carcinogenesis model was utilized to obtain cancer associated fibroblasts (CAFs). CAFs and normal tissue fibroblasts (NFs) were isolated from cancerous and healthy breast tissues, respectively, using a previously described enzymatic protocol. Both CAFs and NFs were analyzed for cell surface phenotypes by flow cytometry and for gene expression profiles by gene set enrichment analysis (GSEA). PBMCs were cocultured with either NFs or CAFs and proliferations of PBMCs were assessed by CFSE assays. Morphological analyses were performed by immunocytochemistry stainings with vimentin. CAFs were spindle shaped cells unlike their blood-borne counterparts. They did not express CD80 and their MHC-II expression was lower than NFs. Although CAFs expressed the myeloid marker CD11b/c, its expression was lower than that on the circulating fibrocytes. CAFs did not express granulocytic/neutrophilic markers and they seemed to have developed in an environment containing T_HELPER2-like cytokines. They also showed immunosuppressive effects similar to their blood-borne counterparts. In summary, CAFs showed similar phenotypic and functional characteristics to the circulating fibrocytes that were reported to represent a unique MDSC subset.

Trial Watch: Radioimmunotherapy for oncological indications

During the past two decades, it has become increasingly clear that the antineoplastic effects of radiation therapy do not simply reflect the ability of X-, β- and γ-rays to damage transformed cells and directly cause their permanent proliferative arrest or demise, but also involve cancer cell-extrinsic mechanisms. Indeed, among other activities, radiotherapy has been shown to favor the establishment of tumor-specific immune responses that operate systemically, underpinning the so-called 'out-of-field' or 'abscopal' effect. Thus, ionizing rays appear to elicit immunogenic cell death, a functionally peculiar variant of apoptosis associated with the emission of a particularly immunostimulatory combination of damage-associated molecular patterns. In line with this notion, radiation therapy fosters, and thus exacerbates, the antineoplastic effects of various treatment modalities, including surgery, chemotherapy and various immunotherapeutic agents. Here, we summarize recent advances in the use of ionizing rays as a means to induce or potentiate therapeutically relevant anticancer immune responses. In addition, we present clinical trials initiated during the past 12 months to test the actual benefit of radioimmunotherapy in cancer patients.

Consensus guidelines for the detection of immunogenic cell death

Apoptotic cells have long been considered as intrinsically tolerogenic or unable to elicit immune responses specific for dead cell-associated antigens. However, multiple stimuli can trigger a functionally peculiar type of apoptotic demise that does not go unnoticed by the adaptive arm of the immune system, which we named "immunogenic cell death" (ICD). ICD is preceded or accompanied by the emission of a series of immunostimulatory damage-associated molecular patterns (DAMPs) in a precise spatiotemporal configuration. Several anticancer agents that have been successfully employed in the clinic for decades, including various chemotherapeutics and radiotherapy, can elicit ICD. Moreover, defects in the components that underlie the capacity of the immune system to perceive cell death as immunogenic negatively influence disease outcome among cancer patients treated with ICD inducers. Thus, ICD has profound clinical and therapeutic implications. Unfortunately, the gold-standard approach to detect ICD relies on vaccination experiments involving immunocompetent murine models and syngeneic cancer cells, an approach that is incompatible with large screening campaigns. Here, we outline strategies conceived to detect surrogate markers of ICD in vitro and to screen large chemical libraries for putative ICD inducers, based on a high-content, high-throughput platform that we recently developed. Such a platform allows for the detection of multiple DAMPs, like cell surface-exposed calreticulin, extracellular ATP and high mobility group box 1 (HMGB1), and/or the processes that underlie their emission, such as endoplasmic reticulum stress, autophagy and necrotic plasma membrane permeabilization. We surmise that this technology will facilitate the development of next-generation anticancer regimens, which kill malignant cells and simultaneously convert them into a cancer-specific therapeutic vaccine.

Epstein-Barr virus infection induces an increase of T regulatory type 1 cells in Hodgkin lymphoma patients

Epstein-Barr Virus (EBV) is present in the neoplastic cells of around 20-30% of patients with Hodgkin Lymphoma (HL). Although, an immunosuppressive environment is currently described in HL patients, little is known concerning the regulatory mechanism induced by EBV proteins expression in tumour cells. This study aimed to investigate an association between regulatory Type 1 cells (Tr1) and EBV tissue positivity in HL patients. Transcriptomic analysis of both EBV-positive and EBV-negative tumours showed that EBV infection increased gene expression of Tr1-related markers (ITGA2, ITGB2, LAG3) and associated-immunosuppressive cytokines (IL10). This up-regulation was associated with an over-expression of several chemokine markers known to attract T-helper type 2 (Th2) and regulatory T cells thus contributing to immune suppression. This Tr1 cells recruitment in EBV-positive HL was confirmed by immunohistochemical analysis of frozen nodes biopsies and by flow cytometric analysis of peripheral blood mononuclear cells of EBV-positive patients. Additionally, we showed that IL10 production was significantly enhanced in tumours and blood of EBV-positive HL patients. Our results propose a new model in which EBV can recruit Tr1 cells to the nodes' microenvironment, suggesting that the expression of EBV proteins in tumour cells could enable the escape of EBV-infected tumour cells from the virus-specific CTL response.

Opportunistic Autoimmune Disorders Potentiated by Immune-Checkpoint Inhibitors Anti-CTLA-4 and Anti-PD-1

To improve the efficacy of immunotherapy for cancer and autoimmune diseases, recent ongoing and completed clinical trials have focused on specific targets to redirect the immune network toward eradicating a variety of tumors and ameliorating the self-destructive process. In a previous review, both systemic immunomodulators and monoclonal antibodies (mAbs), anti-CTLA-4, and anti-CD52, were discussed regarding therapeutics and autoimmune sequelae, as well as predisposing factors known to exacerbate immune-related adverse events (irAEs). This review will focus on immune-checkpoint inhibitors, and the data from most clinical trials involve blockade with anti-CTLA-4 such as ipilimumab. However, despite the mild to severe irAEs observed with ipilimumab in ~60% of patients, overall survival (OS) averaged ~22-25% at 3-5 years. To boost OS, other mAbs targeting programed death-1 and its ligand are undergoing clinical trials as monotherapy or dual therapy with anti-CTLA-4. Therapeutic combinations may generate different spectrum of opportunistic autoimmune disorders. To simulate clinical scenarios, we have applied regulatory T cell perturbation to murine models combined to examine the balance between thyroid autoimmunity and tumor-specific immunity.

Trial Watch: Chemotherapy with immunogenic cell death inducers

Accumulating evidence suggests that the clinical efficacy of selected anticancer drugs, including conventional chemotherapeutics as well as targeted anticancer agents, originates (at least in part) from their ability to elicit a novel or reinstate a pre-existing tumor-specific immune response. One of the mechanisms whereby chemotherapy can stimulate the immune system to recognize and destroy malignant cells is commonly known as immunogenic cell death (ICD). Cancer cells succumbing to ICD are de facto converted into an anticancer vaccine and as such elicit an adaptive immune response. Several common chemotherapeutics share the ability of triggering ICD, as demonstrated in vaccination experiments relying on immunocompetent mice and syngeneic cancer cells. A large number of ongoing clinical trials involve such ICD inducers, often (but not always) as they are part of the gold standard therapeutic approach against specific neoplasms. In this Trial Watch, we summarize the latest advances on the use of cyclophosphamide, doxorubicin, epirubicin, oxaliplatin, and mitoxantrone in cancer patients, discussing high-impact studies that have been published during the last 13 months as well as clinical trials that have been initiated in the same period to assess the antineoplastic profile of these immunogenic drugs as off-label therapeutic interventions.