Immune aspects of the breast tumor microenvironment

Major Differences in Lymphocyte Subpopulations Between Cerebrospinal Fluid and Peripheral Blood in Non-Hodgkin Lymphoma Without Leptomeningeal Involvement: Flow Cytometry Evidence of a Cerebral Lymphatic System

Cerebrospinal fluid (CSF) flow cytometry has a crucial role in the diagnosis of leptomeningeal disease in onco-hematology. This report describes the flow cytometry characterization of 138 CSF samples from patients affected by non-Hodgkin lymphoma, negative for disease infiltration. The aim was to focus on the CSF non-neoplastic population, to compare the cellular composition of the CSF with paired peripheral blood samples and to document the feasibility of flow cytometry in hypocellular samples. Despite the extremely low cell count (1 cell/µl, range 1.0-35) the study was successfully conducted in 95% of the samples. T lymphocytes were the most abundant subset in CSF (77%; range 20-100%) with a predominance of CD4-positive over CD8-positive T cells (CD4/CD8 ratio = 2) together with a minority of monocytes (15%; range 0-70%). No B cells were identified in 90% of samples. Of relevance, a normal, non-clonal B-cell population was documented in 5/7 (71%) patients with primary central nervous system lymphoma at diagnosis (p<0.0001), suggesting a possible involvement of blood-brain barrier cell permeability in the pathogenesis of cerebral B-cell lymphomas. The highly significant differences between CSF and paired peripheral blood lymphoid phenotype (p<0.0001) confirms the existence of an active mechanism of lymphoid migration through the meninges.

STAT3 Silencing and TLR7/8 Pathway Activation Repolarize and Suppress Myeloid-Derived Suppressor Cells From Breast Cancer Patients

Cancer cells escape immune destruction. From this perspective, myeloid-derived suppressor cells (MDSCs), which are immunosuppressive in various cancers including breast cancer (BC), are significant. However, the precise mechanisms are unknown. We isolated HLA-DR^-CD33⁺ MDSCs and CD3⁺ T cells from BC patients’ peripheral blood and healthy donors through MACS and immunophenotyped by flow cytometry. Transfection of short-interfering RNAs and treatment with a TLR7/8 agonist altered pathway activities in vitro. Gene expression was analyzed using qRT-PCR, western blotting, and immunohistochemistry. Our findings showed an association between the progression of BC and increased levels of circulating HLA-DR^-CD33⁺ MDSCs. These cells strongly suppress both autologous and analogous CD3⁺ T cell proliferation and enter the tumor microenvironment. We also identified increased STAT3 signaling and increased IDO and IL-10 expression in BC-derived MDSCs as immunosuppression mechanisms. Further, STAT3 inhibition and TLR7/8 pathway stimulation reduce the immunosuppressive activity of patient-derived MDSCs on T cells by inducing MDSC repolarization and differentiation into mature myeloid cells. This also alters the expression of critical cytokines and transcription factors in CD3⁺ T cells and, importantly, reduces breast cancer cells’ proliferation. Finally, while chemotherapy is able to significantly reduce circulating MDSCs’ level in patients with breast cancer, these MDSCs remained highly T cell-suppressive. We identified a novel molecular mechanism of MDSC-mediated immunosuppression. STAT3 inhibition and TLR7/8 pathway stimulation in MDSCs repolarize and suppress MDSCs from breast cancer patients. This offers new opportunities for BC immunotherapy.

Cancer Stem Cells in the Immune Microenvironment

Cancer stem cells are a subpopulation of cancer cells responsible for the most demanding and aggressive cancer cell phenotypes: therapy resistance, a self-protective feature of stem cells; distant metastasis, requiring anchorage independence for survival in the circulation; and recurrence, which is related to the dormant-active cycling of stem cells. Normal tissues are composed of parenchymal cells, supportive connective components, and cellular disposal systems for removing the products of physiological wear and tear. Cancer stem cells develop from normal counterparts and progressively interact with their microenvironments, modifying and conditioning the cancer microenvironment. Cancer-associated myeloid cells constitute a major element of the cancer microenvironment. During the process of carcinogenesis, cancer stem cells and their intimately associated myeloid cells mutually interact and evolve, such that the cancer cells potentiate the activity of the myeloid cells and, in return, the myeloid cells increase cancer stem cell characteristics. Normal myeloid cells function as key accessory cells to maintain homeostasis in normal tissues and organs; in cancers, these cells co-evolve with the malignant parenchymal cells and are involved in every aspect of cancer cell biology, including proliferation, invasion, distant metastasis, and the development of resistance to therapy. In this way, cancer-associated myeloid cells provide two of the key hallmarks of cancer: evasion of immune destruction and cancer-promoting inflammation.

Mindfulness based stress reduction provides psychological benefit and restores immune function of women newly diagnosed with breast cancer: A randomized trial with active control

BACKGROUND

Women newly diagnosed with breast cancer experience psychological distress, accompanied by reduced Natural Killer Cell Activity (NKCA) and altered levels of cytokines, which may compromise cancer control. Few studies have evaluated psycho-immune outcomes of mindfulness-based stress reduction (MBSR) for women newly diagnosed with breast cancer in comparison to an active control condition.

OBJECTIVE

The purpose of this study was to determine whether MBSR benefits psychological, behavioral, and immunological function in women recently diagnosed with breast cancer.

DESIGN

After confirmation of breast cancer staging, women diagnosed with early-stage breast cancer (n = 192) were randomized to an 8-week MBSR program or an 8-week active control condition (ACC). The ACC consisted of a series of cancer recovery and health education classes. Both MBSR and the ACC were administered in group format.

METHODS

Women completed psychometric instruments and provided blood for NKCA and cytokine levels at pre-, mid-, and completion of program, as well as at 1- and 6-months post-program. One hundred and twenty four women completed all five-assessments (MBSR, n = 63; ACC, n = 61). Hierarchical linear modeling was used to analyze trajectories of outcomes over time and between groups.

RESULTS

Compared to the ACC group, women randomized to MBSR exhibited decreasing trajectories of perceived stress, fatigue, sleep disturbance, and depressive symptoms. Further, compared to women randomized to ACC, MBSR women exhibited trajectories demonstrating significantly more rapid restoration of NKCA, accompanied by lower circulating TNF-alpha levels, lower IL-6 production, and greater IFN-gamma production.

CONCLUSIONS

These results demonstrate early provision of MBSR for women newly diagnosed with breast cancer provides not only psychological benefit, but also optimizes immune function supportive of cancer control.

A tetravalent single chain diabody (CD40/HER2) efficiently inhibits tumor proliferation through recruitment of T cells and anti-HER2 functions

Our aim was to construct a CD40×HER2 single chain diabody (ScDb) and determine its tumor-specific immune activation and anti-HER2 function. Overlap extension-polymerase chain reaction was applied in the construction of ScDb, and the protein was expressed with the pET28a (+)-Rosetta prokaryotic expression system. Soluble ScDb was purified by a nickel-nitrilotriacetic acid column. Dendritic cells (DC) was stimulated by ScDb and inhibited 4T1 cells proliferation in vitro. In 4T1 tumor mice model, lymphocyte infiltration was prominently detected in ScDb group, Caspase-3 expression was significantly upregulated. ScDb was labeled using quantum dots. Immunofluorescence assay indicated ScDb exhibited high affinity to HER2. T6-17 cells were inhibited by ScDb in vitro. The phosphorylation and expression levels of AKT, ERK were markedly decreased. In T6-17 tumor mice model. Compared to CD40 ScFv, HER2 ScFv and normal saline groups, tumor volume diminished significantly in ScDb group, and tumor cells showed extensive deformation, and pervasive karyopyknosis and karyorrhexis were found. In the present study, we successfully constructed a ScDb fragment and expressed it using a prokaryotic expression system. The in vivo and in vitro experimental results indicated that ScDb could inhibit the proliferation of tumor cells by stimulating the tumor-specific immunoreaction and blocking the HER2-related signaling pathway.

Overexpression of syndecan-1, MUC-1, and putative stem cell markers in breast cancer leptomeningeal metastasis: a cerebrospinal fluid flow cytometry study

Background

Cancer is a mosaic of tumor cell subpopulations, where only a minority is responsible for disease recurrence and cancer invasiveness. We focused on one of the most aggressive circulating tumor cells (CTCs) which, from the primitive tumor, spreads to the central nervous system (CNS), evaluating the expression of prognostic and putative cancer stem cell markers in breast cancer (BC) leptomeningeal metastasis (LM).

Methods

Flow cytometry immunophenotypic analysis of cerebrospinal fluid (CSF) samples (4.5 ml) was performed in 13 consecutive cases of BCLM. Syndecan-1 (CD138), MUC-1 (CD227) CD45, CD34, and the putative cancer stem cell markers CD15, CD24, CD44, and CD133 surface expression were evaluated on CSF floating tumor cells. The tumor-associated leukocyte population was also characterized.

Results

Despite a low absolute cell number (8 cell/μl, range 1–86), the flow cytometry characterization was successfully conducted in all the samples. Syndecan-1 and MUC-1 overexpression was documented on BC cells in all the samples analyzed; CD44, CD24, CD15, and CD133 in 77%, 75%, 70%, and 45% of cases, respectively. A strong syndecan-1 and MUC-1 expression was also documented by immunohistochemistry on primary breast cancer tissues, performed in four patients. The CSF tumor population was flanked by T lymphocytes, with a different immunophenotype between the CSF and peripheral blood samples (P ≤ 0.02).

Conclusions

Flow cytometry can be successfully employed for solid tumor LM characterization even in CSF samples with low cell count. This in vivo study documents that CSF floating BC cells overexpress prognostic and putative cancer stem cell biomarkers related to tumor invasiveness, potentially representing a molecular target for circulating tumor cell detection and LM treatment monitoring, as well as a primary target for innovative treatment strategies. The T lymphocyte infiltration, documented in all CSF samples, suggests a possible involvement of the CNS lymphatic system in both lymphoid and cancer cell migration into and out of the meninges, supporting the extension of a new form of cellular immunotherapy to LM. Due to the small number of cases, validation on large cohorts of patients are warranted to confirm these findings and to evaluate the impact and value of these results for diagnosis and management of LM.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-017-0827-4) contains supplementary material, which is available to authorized users.

Breast cancer circulating biomarkers: advantages, drawbacks, and new insights

As of today, the level of individualization of cancer therapies has reached a level that 20 years ago would be considered visionary. However, most of the diagnostic, prognostic, and therapy-predictive procedures which aim to improve the overall level of personalization are based on the evaluation of tumor tissue samples, therefore requiring surgical operations with consequent low compliance for patients and high costs for the hospital. Hence, the research of a panel of circulating indicators which may serve as source of information about tumor characteristics and which may be obtainable by a simple withdrawal of peripheral blood today represents a growing field of interest. This review aims to objectively summarize the characteristics of the currently available breast cancer circulating biomarkers, also providing an overview about the multitude of novel potential soluble predictors which are still under evaluation. Specifically, the usefulness of a so-called "liquid biopsy" will be discussed in terms of improvements of diagnosis, prognosis, and therapy-prediction, but an overview will be given also on the potentiality of the molecular characterization arising from the isolation of circulating biomarkers and cells. Although this review will focus on the specific case of the breast, in the future liquid biopsies will hopefully be available for virtually any type of neoplasms.

Inhibition of tumor progression during allergic airway inflammation in a murine model: significant role of TGF-β

Introduction

TGF-β is an important mediator of pulmonary allergic inflammation, and it has been recently reported to be a potential inhibitor of lung tumor progression. The correlation between cancer and allergic inflammatory diseases remains controversial. Thus, the aim of the present study was to evaluate the effects of pulmonary allergic inflammation and in particular the role of TGF-β on cancer progression.

Methods

Cancer cells were implanted in a BALB/c mice model of allergic airway inflammation, and tumor growth was measured. Apoptosis was evaluated by TUNEL assay, and TGF-β was measured by ELISA. Expression of proliferating cell nuclear antigen, TGF-β, TGF-β receptors I and II, phospho-Smad2 and phospho-Smad4 was evaluated by immunohistochemistry and quantified using digital pathology. The effect of a TGF-β activity inhibitor and recombinant TGF-β on tumor growth was analyzed. The effect of exogenous TGF-β on cell proliferation and apoptosis was evaluated in vitro.

Results

Mice with allergic airway inflammation exhibited decreased tumor volumes due to cell proliferation inhibition and increased apoptosis. TGF-β was increased in the sera and tumor tissues of allergic mice. TGF-β activity inhibition increased tumor progression in allergic mice by enhancing proliferation and decreasing apoptosis of tumor cells. The administration of TGF-β resulted in reduced tumor growth.

Conclusion

This study is the first to establish an inverse relationship between allergic airway inflammation and tumor progression. This effect appears to be mediated by TGF-β, which is overexpressed in tumor cells during pulmonary allergic inflammation. This study indicates that TGF-β is a potential target for antitumor therapy.

Electronic supplementary material

The online version of this article (doi:10.1007/s00262-015-1722-4) contains supplementary material, which is available to authorized users.