Biological role of NK cells and immunotherapeutic approaches in breast cancer

Predictive value of lymphocyte subsets and lymphocyte-to-monocyte ratio in assessing the efficacy of neoadjuvant therapy in breast cancer

Lymphocyte subsets are the most intuitive expression of the body's immune ability, and the lymphocyte-to-monocyte ratio (LMR) also clearly reflect the degree of chronic inflammation activity. The purpose of this study is to investigate their predictive value of lymphocyte subsets and LMR to neoadjuvant therapy (NAT) efficacy in breast cancer patients. In this study, lymphocyte subsets and LMR were compared between breast cancer patients (n = 70) and benign breast tumor female populations (n = 48). Breast cancer patients were treated with NAT, and the chemotherapy response of the breast was evaluated using established criteria. The differences in lymphocyte subsets and LMR were also compared between pathological complete response (pCR) and non-pCR patients before and after NAT. Finally, data were analyzed using SPSS. The analytical results demonstrated that breast cancer patients showed significantly lower levels of CD3 + T cells, CD4 + T cells, CD4 + /CD8 + ratio, NK cells, and LMR compared to benign breast tumor women (P < 0.05). Among breast cancer patients, those who achieved pCR had higher levels of CD4 + T cells, NK cells, and LMR before NAT (P < 0.05). NAT increased CD4 + /CD8 + ratio and decreased CD8 + T cells in pCR patients (P < 0.05). Additionally, both pCR and non-pCR patients exhibited an increase in CD3 + T cells and CD4 + T cells after treatment, but the increase was significantly higher in pCR patients (P < 0.05). Conversely, both pCR and non-pCR patients experienced a decrease in LMR after treatment. However, this decrease was significantly lower in pCR patients (P < 0.05). These indicators demonstrated their predictive value for therapeutic efficacy. In conclusion, breast cancer patients experience tumor-related immunosuppression and high chronic inflammation response. But this phenomenon can be reversed to varying degrees by NAT. It has been found that lymphocyte subsets and LMR have good predictive value for pCR. Therefore, these markers can be utilized to identify individuals who are insensitive to NAT early on, enabling the adjustment of treatment plans and achieving precise breast cancer treatment.

Influence of tumor microenvironment on the different breast cancer subtypes and applied therapies

Despite the significant improvements made in breast cancer therapy during the last decades, this disease still has increasing incidence and mortality rates. Different targets involved in general processes, like cell proliferation and survival, have become alternative therapeutic options for this disease, with some of them already used in clinic, like the CDK4/6 inhibitors for luminal A tumors treatment. Nevertheless, there is a demand for novel therapeutic strategies focused not only on tumor cells, but also on their microenvironment. Tumor microenvironment (TME) is a very complex and dynamic system that, more than surrounding and supporting tumor cells, actively participates in tumor development and progression. During the last decades, it has become clear that the cellular and acellular components of TME differ between the various breast cancer subtypes and shape the differences regarding their severity and prognosis. The pivotal role of the TME in controlling tumor growth and influencing responses to therapy represents a potential source for novel targets and therapeutic strategies. In this review, we present a description of the multiple therapeutic options used for different breast cancer subtypes, as well as the influence that the TME may exert on the development of the disease and on the response to the distinct therapies, which in some cases may explain their failure by the occurrence of relapses and resistance. Furthermore, the ongoing studies focused on the use of TME components for developing potential cancer treatments are described.

Unraveling the role of natural killer cells in leishmaniasis

NK cells are known as frontline responders that are efficient in combating several maladies as well as leishmaniasis caused by Leishmania spp. As such they are being investigated to be used for adoptive transfer therapy and vaccine. In spite of the lack of antigen-specific receptors at their surface, NK cells can selectively recognize pathogens, accomplished by the activation of the receptors on the NK cell surface and also as the result of their effector functions. Activation of NK cells can occur through interaction between TLR-2 expressed on NK cells and. LPG of Leishmania parasites. In addition, NK cell activation can occur by cytokines (e.g., IFN-γ and IL-12) that also lead to producing cytokines and chemokines and lysis of target cells. This review summarizes several evidences that support NK cells activation for controlling leishmaniasis and the potentially lucrative roles of NK cells during leishmaniasis. Furthermore, we discuss strategies of Leishmania parasites in inhibiting NK cell functions. Leishmania LPG can utilizes TLR2 to evade host-immune responses. Also, Leishmania GP63 can directly binds to NK cells and modulates NK cell phenotype. Finally, this review analyzes the potentialities to harness NK cells effectiveness in therapy regimens and vaccinations.

The role of the natural killer (NK) cell modulation in breast cancer incidence and progress

The importance of the immune system on tumor surveillance has been investigated for many years, and its impact on controlling tumor progression has been verified. An important subgroup of the innate immune system is natural killer (NK) cells, whose essential function in modulating tumor behavior and suppressing metastasis and tumor growth has been demonstrated. The first idea of NK cells' crucial biological processes was demonstrated through their potent ability to conduct direct cellular cytotoxicity, even without former sensitization. These properties of NK cells allow them to recognize transformed cells that have attenuated self-ligand and express stress-induced ligands. Furthermore, secretion of various cytokines and chemokines after their activation leads to tumor elimination via either direct cytotoxic effect on malignant cells or activation of the adaptive immune system. In addition, novel immunotherapeutic approaches tend to take advantage of NK cells' ability, leading to antibody-based approaches, the formation of engineered CAR-NK cells, and adoptive cell transfer. However, the restricted functionality of NK cells and the inability to infiltrate tumors are its blind spots in breast cancer patients. In this review, we gathered newly acquired data on the biology and functions of NK cells in breast cancer and proposed ways to employ this knowledge for novel therapeutic approaches in cancers, particularly breast cancer.

Advancements in Human Breast Cancer Targeted Therapy and Immunotherapy

Human breast cancer treatment regimens have evolved greatly due to the significant advances in understanding the molecular mechanisms and pathways of the common subtypes of breast cancer. In this review, we discuss recent progress in breast cancer targeted therapy and immunotherapy as well as ongoing clinical trials. We also highlight the potential of combination therapies and personalized approaches to improve clinical outcomes. Targeted therapies have surpassed the hormone receptors and the human epidermal growth factor receptor 2 (HER2) to include many other molecules in targetable pathways such as the epidermal growth factor receptor (EGFR), poly (adenosine diphosphate-ribose) polymerase (PARP), and cyclin-dependent kinase 4/6 (CDK4/6). However, resistance to targeted therapy persists, underpinning the need for more efficacious therapies. Immunotherapy is considered a milestone in breast cancer treatments, including the engineered immune cells (CAR-T cell therapy) to better target the tumor cells, vaccines to stimulate the patient's immune system against tumor antigens, and checkpoint inhibitors (PD-1, PD-L1, and CTLA4) to block molecules that mediate immune inhibition. Targeted therapies and immunotherapy tested in breast cancer clinical trials are discussed here, with special emphasis on combinatorial approaches which are believed to maximize treatment efficacy and enhance patient survival.

Tumor microenvironment of human breast cancer, and feline mammary carcinoma as a potential study model

In recent years, the tumor microenvironment (TME) has been a research hotspot, as it is composed of distinct cellular and non-cellular elements that may influence the diagnosis, prognosis, and treatment of breast cancer patients. Cancer cells are able to escape immune control through an immunoediting process which depends on complex communication networks between immune and cancer cells. Thus, a better understanding of the immune cell infiltrate in the breast cancer microenvironment is crucial for the development of more effective therapeutic approaches. In this review article, we overview the different actors that orchestrate the complexity of the TME, including tumor infiltrating lymphocytes (TILs), natural killer cells, tumor infiltrating dendritic cells (TIDCs), tumor associated macrophages (TAMs), tumor associated neutrophils (TANs), cancer associated fibroblasts (CAFs), myeloid-derived suppressor cells (MDSCs), distinct pro-angiogenic factors and immune checkpoint biomarkers. Additionally, we summarize the recent advances in the TME of feline mammary carcinoma (FMC). FMC has been proposed as a reliable cancer model for the study of human breast cancer, as they share clinicopathological, histopathological and epidemiological features, as well as the pathways involved in cancer initiation and progression.

White blood cell subsets in HER2-positive breast cancer patients treated with trastuzumab in relation to clinical outcome

To examine whether HER2+ breast cancer patients who have decreased immune effector cells could respond well to trastuzumab, we evaluated the alterations in circulating immune system cell subsets: CD16+ and/or CD56+ lymphocytes, lymphocytes and granulocytes in these patients before and after treatment with trastuzumab-based regimens in relation to clinical response to therapy. The study involved 55 patients with HER2+ breast cancer before and 2 months after the initiation of the therapy. Progressive disease was confirmed in nine out of 55 patients (non-responders), while other patients achieved complete or partial response, or stable disease (responders). Control group consisted of up to 52 healthy individuals. Significantly lower percentages of total lymphocytes, CD16+, CD56+, and CD16+CD56+ lymphocytes as well as higher percentage of granulocytes and a higher ratio of granulocyte to lymphocyte percentages were found in patients before therapy and 2 months after the initiation of the therapy, compared with those in healthy individuals. Responder subgroup showed significantly lower percentages of CD16+, CD56+, and CD16+CD56+ lymphocytes before therapy, compared with those in healthy controls. Two months after the initiation of the therapy, the percentages of immune cell subsets remained significantly lower in responders in comparison with those in the healthy donors, while a significantly decreased percentages of CD56+ and CD16+CD56+ lymphocytes were observed in non-responders, in comparison with those in healthy controls. Our study demonstrated that HER2+ breast cancer patients who have decreased percentages of CD16+, CD56+, and CD16+CD56+ lymphocytes may achieve response to trastuzumab-containing treatment.

The Peripheral Immune Landscape of Breast Cancer: Clinical Findings and In Vitro Models for Biomarker Discovery

Breast cancer is the deadliest female malignancy worldwide and, while much is known about phenotype and function of infiltrating immune cells, the same attention has not been paid to the peripheral immune compartment of breast cancer patients. To obtain faster, cheaper, and more precise monitoring of patients' status, it is crucial to define and analyze circulating immune profiles. This review compiles and summarizes the disperse knowledge on the peripheral immune profile of breast cancer patients, how it departs from healthy individuals and how it changes with disease progression. We propose this data to be used as a starting point for validation of clinically relevant biomarkers of disease progression and therapy response, which warrants more thorough investigation in patient cohorts of specific breast cancer subtypes. Relevant clinical findings may also be explored experimentally using advanced 3D cellular models of human cancer-immune system interactions, which are under intensive development. We review the latest findings and discuss the strengths and limitations of such models, as well as the future perspectives. Together, the scientific advancement of peripheral biomarker discovery and cancer-immune crosstalk in breast cancer will be instrumental to uncover molecular mechanisms and putative biomarkers and drug targets in an all-human setting.

Natural Killer Cell Defects in Breast Cancer: A Key Pathway for Tumor Evasion

As the most important innate immune component cancers invader, natural killer (NK) cells have a magnificent role in antitumor immunity without any prior sensitization. Different subsets of NK cells have distinct responses during tumor cell exposure, according to their phenotypes and environments. Their function is induced mainly by the activity of both inhibitory and activating receptors against cancerous cells. Since the immunosuppression in the tumor microenvironment of breast cancer patients has directly deteriorated the phenotype and disturbed the function of NK cells, recruiting compensatory mechanisms indicate promising outcomes for immunotherapeutic approaches. These evidences accentuate the importance of NK cell distinct features in protection against breast tumors. In this review, we discuss the several mechanisms involved in NK cells suppression which consequently promote tumor progression and disease recurrence in patients with breast cancer.

Inflammasome Deletion Promotes Anti-tumor NK Cell Function in an IL-1/IL-18 Independent Way in Murine Invasive Breast Cancer

Inflammasomes are molecular complexes that trigger an inflammatory response upon detection of pathogens or danger signals. Recent studies suggest that they are also involved in cancer progression. However, their roles during tumorigenesis remain poorly understood and controversial. Here, we investigated whether inflammasome activation supports mammary tumor growth. Using mouse models of invasive breast cancer, our results demonstrate that the absence of a functional inflammasome impairs tumor growth. Importantly, tumors implanted into inflammasome-deficient mice recruited significantly less neutrophils and more natural killer (NK) cells, and these latter cells displayed a more active phenotype. Interestingly, NK cell depletion abolished the anti-tumoral effect observed in inflammasome-deficient mice, although inflammasome-regulated cytokine neutralization had no effect. Thus, our work identifies a novel role for the inflammasome in supporting mammary tumor growth by attenuating NK cell recruitment and activity. These results suggest that inflammasome inhibition could be a putative target for treating invasive breast cancers.

The Multifaceted Nature of Tumor Microenvironment in Breast Carcinomas

Heterogeneity in breast carcinomas can be appreciated at various levels, from morphology to molecular alterations, and there are well-known genotypic-phenotypic correlations. Clinical decision-making is strictly focused on the evaluation of tumor cells and is based on the assessment of hormone receptors and of the HER2 status, by means of a combination of immunohistochemical and in situ hybridization techniques. The tumor microenvironment (TME) also shows a multifaceted nature stemming from the different actors populating the intratumoral and the peritumoral stroma of breast carcinomas. Of note, we have now evidence that tumor-infiltrating lymphocytes (TILs) are clinically meaningful as their quantification in the intratumoral stroma strongly correlates with good prognosis, in particular in triple-negative and HER2-positive breast cancer patients. Nevertheless, TILs are just one of the many actors orchestrating the complexity of the TME, which is populated by immune and non-immune cells (cancer-associated fibroblasts, cancer-associated adipocytes), as well as non-cellular components such as chemical inflammation mediators. In this review article we will overview the main features of the distinct cell compartments by discussing (i) the potential impact the TME may have on the prognostic stratification of breast cancers and (ii) the possible predictive value of some markers in the context of immunotherapy in light of the recent results of phase III studies in advanced and early triple-negative breast cancer patients.

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.

CD56 expression in breast cancer induces sensitivity to natural killer-mediated cytotoxicity by enhancing the formation of cytotoxic immunological synapse

We examined the potential value of the natural killer (NK) cell line; NK-92, as immunotherapy tool for breast cancer (BC) treatment and searched for biomarker(s) of sensitivity to NK-92-mediated cytotoxicity. The cytotoxic activity of NK-92 cells towards one breast precancerous and nine BC cell lines was analyzed using calcein-AM and degranulation assays. The molecules associated with NK-92-responsiveness were determined by differential gene expression analysis using RNA-sequencing and validated by RT-PCR, immunostaining and flow cytometry. NK-target interactions and immunological synapse formation were assessed by fluorescence microscopy. Potential biomarker expression was determined by IHC in 99 patient-derived BC tissues and 10 normal mammary epithelial tissues. Most (8/9) BC cell lines were resistant while only one BC and the precancerous cell lines were effectively killed by NK-92 lymphocytes. NK-92-sensitive target cells specifically expressed CD56, which ectopic expression in CD56-negative BC cells induced their sensitivity to NK-92-mediated killing, suggesting that CD56 is not only a biomarker of responsiveness but actively regulates NK function. CD56 adhesion molecules which are also expressed on NK cells accumulate at the immunological synapse enhancing NK-target interactions, cytotoxic granzyme B transfer from NK-92 to CD56-expressing target cells and induction of caspase 3 activation in targets. Interestingly, CD56 expression was found to be reduced in breast tumor tissues (36%) with strong inter- and intratumoral heterogeneity in comparison to normal breast tissues (80%). CD56 is a potential predictive biomarker for BC responsiveness to NK-92-cell based immunotherapy and loss of CD56 expression might be a mechanism of escape from NK-immunity.

Immune Tumor Microenvironment in Breast Cancer and the Participation of Estrogen and Its Receptors in Cancer Physiopathology

Breast cancer is characterized by cellular and molecular heterogeneity. Several molecular events are involved in controlling malignant cell process. In this sense, the importance of studying multiple cell alterations in this pathology is overriding. A well-identified fact on immune response is that it can vary depend on sex. Steroid hormones and their receptors may regulate different functions and the responses of several subpopulations of the immune system. Few reports are focused on the function of estrogen receptors (ERs) on immune cells and their roles in different breast cancer subtypes. Thus, the aim of this review is to investigate the immune infiltrating tumor microenvironment and prognosis conferred by it in different breast cancer subtypes, discuss the current knowledge and point out the roles of estrogens and its receptors on the infiltrating immune cells, as well as to identify how different immune subsets are modulated after anti-hormonal treatments in breast cancer patients.

Expression of NK Cell Surface Receptors in Breast Cancer Tissue as Predictors of Resistance to Antineoplastic Treatment

Background:

Currently, one of the most used strategies for the treatment of newly diagnosed patients with breast cancer is neoadjuvant chemotherapy based on the application of taxanes and anthracyclines. However, despite the high number of patients who develop a complete pathological clinical response, resistance and relapse following this therapy continue to be a clinical challenge. As a component of the innate immune system, the cytotoxic function of Natural Killer (NK) cells plays an important role in the elimination of tumor cells. However, the role of NK cells in resistance to systemic therapy in breast cancer remains unclear. The present project aims to evaluate the gene expression profile of human NK cells in breast cancer tissue resistant to treatment with taxanes–anthracyclines.

Methods:

Biopsies from tumor tissues were obtained from patients with breast cancer without prior treatment. Histopathological analysis and ex vivo exposure to antineoplastic chemotherapeutics were carried out. Alamar blue and lactate dehydrogenase release assays were performed for quantitative analysis of tumor viability. Gene expression profiles from tumor tissues without prior exposure to therapeutic drugs were analyzed by gene expression microarrays and verified by polymerase chain reaction.

Results:

A significant decrease in gene expression of cell-surface receptors related to NK cells was observed in tumor samples resistant to antineoplastic treatment compared with those that were sensitive to treatment.

Conclusion:

A decrease in NK cell infiltration into tumor tissue might be a predictive marker for failure of chemotherapeutic treatment in breast cancer.

Control of triple-negative breast cancer using ex vivo self-enriched, costimulated NKG2D CAR T cells

Background

Triple-negative breast cancer (TNBC) is an aggressive disease that currently lacks effective targeted therapy. NKG2D ligands (NKG2DLs) are expressed on various tumor types and immunosuppressive cells within tumor microenvironments, providing suitable targets for cancer therapy.

Methods

We applied a chimeric antigen receptor (CAR) approach for the targeting of NKG2DLs expressed on human TNBCs. Lentiviral vectors were used to express the extracellular domain of human NKG2D that binds various NKG2DLs, fused to signaling domains derived from T cell receptor CD3 zeta alone or with CD27 or 4-1BB (CD137) costimulatory domain.

Results

Interleukin-2 (IL-2) promoted the expansion and self-enrichment of NKG2D-redirected CAR T cells in vitro. High CD25 expression on first-generation NKG2D CAR T cells was essential for the self-enrichment effect in the presence of IL-2, but not for CARs containing CD27 or 4-1BB domains. Importantly, self-enriched NKG2D CAR T cells effectively recognized and eliminated TNBC cell lines in vitro, and adoptive transfer of T cells expressing NKG2D CARs with CD27 or 4-1BB specifically enhanced NKG2D CAR surface expression, T cell persistence, and the regression of established MDA-MB-231 TNBC in vivo. NKG2D-z CAR T cells lacking costimulatory domains were less effective, highlighting the need for costimulatory signals.

Conclusions

These results demonstrate that CD27 or 4-1BB costimulated, self-enriched NKG2D CAR-redirected T cells mediate anti-tumor activity against TNBC tumor, which represent a promising immunotherapeutic approach to TNBC treatment.

Electronic supplementary material

The online version of this article (10.1186/s13045-018-0635-z) contains supplementary material, which is available to authorized users.

Clinical efficacy of percutaneous cryoablation combined with allogenic NK cell immunotherapy for advanced non-small cell lung cancer

In this study, the safety and clinical efficacy of cryosurgery combined with allogenic NK cell immunotherapy for the treatment of advanced non-small cell lung cancer (NSCLC) were evaluated. From July 2016 to March 2017, we enrolled 60 patients who met the enrollment criteria and divided them into two groups: (1) the simple cryoablation group (n = 30) and (2) the cryoablation combined with allogenic NK cell group (n = 30). The changes in immune function, quality of life, and clinical response were evaluated. We found that allogenic NK cells combined with cryosurgical treatment for advanced NSCLC have a synergistic effect, which not only enhancing the immune function of patients, improving the quality of life, and significantly increasing the response rate (RR) and disease control rate (DCR) compared to cryoablation group. This study is the first clinical trial of allogenic NK cells combined with cryosurgery for the treatment of advanced NSCLC and preliminaily its safety and efficacy.

Beyond the vicious cycle: The role of innate osteoimmunity, automimicry and tumor-inherent changes in dictating bone metastasis

Bone metastasis is a fatal consequence of a subset of solid malignancies that fail to respond to conventional therapies. While a myriad of factors contribute to osteotropism and disseminated cell survival and outgrowth in bone, efforts to inhibit tumor cell growth in the bone-metastatic niche have largely relied on measures that disrupt the bi-directional interactions between bone resident and tumor cells. However, the targeting of isolated stromal interactions has proven ineffective to date in inhibiting bone-metastatic progression and patient mortality. Osteoimmune regulation is now emerging as a critical determinant of metastatic growth in the bone microenvironment. While this has highlighted the importance of innate immune populations in dictating the temporal development of overt bone metastases, the osteoimmunological processes that underpin tumor cell progression in bone remain severely underexplored. Along with tumor-intrinsic alterations that occur specifically within the bone microenvironment, innate osteoimmunological crosstalk poses an exciting area of future discovery and therapeutic development. Here we review current knowledge of the unique exchange that occurs between bone resident cells, innate immune populations and tumor cells that leads to the establishment of a tumor-permissive milieu.

CD56+ immune cell infiltration and MICA are decreased in breast lobules with fibrocystic changes

Purpose

While the role of natural killer (NK) cells in breast cancer therapy has been investigated, little information is known about NK cell function and presence in nonmalignant and premalignant breast tissue. Here, we investigate and quantify NK cell marker CD56 and activating ligand MICA in breast tissue with benign breast disease.

Methods

Serial tissue sections from 88 subjects, 44 with benign breast disease (BBD) who remained cancer-free, and 44 with BBD who later developed cancer, were stained with H&E, anti-MICA, and anti-CD56. Up to ten representative lobules were identified on each section. Using digital image analysis, MICA and CD56 densities were determined for each lobule, reported as percent of pixels in the lobule that registered as stained by each antibody. Analyses were performed on a per-subject and per-lobule basis.

Results

Per-subject multivariate analyses showed associations of CD56 and MICA with age: CD56 was increased in older subjects (p = 0.03), while MICA was increased in younger subjects (p = 0.005). Per-lobule analyses showed that CD56 and MICA levels were both decreased in lobules with fibrocystic change, with median levels of CD56 and MICA staining, respectively, at 0.31 and 7.0% in fibrocystic lobules compared to 0.76 and 12.2% in lobules without fibrocystic change (p < 0.001 for each). Among fibrocystic lobules, proliferative/atypical lobules showed significantly lower expression compared to nonproliferative lobules for MICA (p = 0.02) but not for CD56 (p = 0.80).

Conclusion

Levels of CD56+ NK cells and activating ligand MICA were decreased in breast lobules with fibrocystic change, and MICA levels showed a significant stepwise decrease with increasing histopathologic abnormality. MICA levels were also significantly decreased in older subjects, who generally have higher risk of developing cancer. These findings advance a model in which MICA promotes cytotoxic activity in CD56+ NK cells to protect against tumorigenesis in breast lobules, and suggest further research is warranted.

Electronic supplementary material

The online version of this article (10.1007/s10549-017-4558-0) contains supplementary material, which is available to authorized users.

Tumor cryoablation in combination with natural killer cells therapy and Herceptin in patients with HER2-overexpressing recurrent breast cancer

In this study, we investigated the clinical benefits of a combination of tumor cryoablation with natural killer (NK) cells therapy and Herceptin for human epidermal growth factor (HER) 2-overexpressing recurrent breast cancer. From May 2015 to May 2016, 48 patients who met the enrollment criteria were assigned to three groups (n=16): cryoablation group (group I), cryoablation-NK cells therapy group (group II) and cryoablation-NK cells therapy-Herceptin group (group III). Safety and short-term effects were evaluated. All the adverse effects were manageable and acceptable. The three-therapy combination treatment not only yielded good clinical efficacy, it also improved the quality of life; reduced levels of circulating tumor cells (CTCs); reduced carcino-embryonic antigen (CEA) and cancer antigen 15-3 (CA15-3) expression; enhanced immune function significantly. Furthermore, it can resulte in significant prolongation of progression free survival (PFS). This is the first clinical study to demonstrate the benefit of the three-therapy combination of tumor cryoablation, NK cells therapy, and Herceptin for HER2-overexpressing recurrent breast cancer.

Circulating tumor cell as a biomarker for evaluating allogenic NK cell immunotherapy on stage IV non-small cell lung cancer

In this study, we determined the number of peripheral blood circulating tumor cells (CTCs) pre- and post-NK in patients with stage IV non- small cell lung cancer (NSCLC) as a reference for understanding the relevance of any changes to the efficacy of NK cells therapy. The patients were given one to three courses of immunotherapy. CTC numbers and CTC-related gene expression were measured in the peripheral blood of 31 patients with stage IV NSCLC at 1day before and 7 and 30d after NK cells therapy using magnetic activated cell sorting (MACS) and fluorescence activated cell sorting (FACS) combined with real-time quantitative PCR (RT-qPCR). Throughout the research, fever was the most common reaction (34.6%). The number of CTCs was 18.11±5.813, 15.13±5.984 and 10.32±5.623, respectively, and this decreased significantly over time. ΔCt values for the CTC-related genes CEA, MAGE-3 and CK18 increased significantly after NK cells infusion. The expression of CEA, CK18 and MAGE-3 decreased significantly with time after NK. CTC was a useful biomarker for evaluating the efficacy of NK cells therapy on stage IV NSCLC.

Comparison of autogeneic and allogeneic natural killer cells immunotherapy on the clinical outcome of recurrent breast cancer

In the present study, we aimed to compare the clinical outcome of autogeneic and allogeneic natural killer (NK) cells immunotherapy for the treatment of recurrent breast cancer. Between July 2016 and February 2017, 36 patients who met the enrollment criteria were randomly assigned to two groups: autogeneic NK cells immunotherapy group (group I, n=18) and allogeneic NK cells immunotherapy group (group II, n=18). The clinical efficacy, quality of life, immune function, circulating tumor cell (CTC) level, and other related indicators were evaluated. We found that allogeneic NK cells immunotherapy has better clinical efficacy than autogeneic therapy. Moreover, allogeneic NK cells therapy improves the quality of life, reduces the number of CTCs, reduces carcinoembryonic antigen and cancer antigen 15-3 (CA15-3) expression, and significantly enhances immune function. To our knowledge, this is the first clinical trial to compare the clinical outcome of autogeneic and allogeneic NK cells immunotherapy for recurrent breast cancer.

Prospective study of percutaneous cryoablation combined with allogenic NK cell immunotherapy for advanced renal cell cancer

In this study, the clinical efficacy of cryosurgery combined with allogenic NK cell immunotherapy for advanced renal cell cancer was evaluated. From July to December 2016, we enrolled 60 patients who met the enrollment criteria and divided them into two groups: (1) the simple cryoablation group (n=30); and (2) the cryoablation combined with allogenic NK cells group (n=30). The clinical efficacy, quality of life, immune function, and other related indicators were evaluated. Combining allogeneic NK cells with cryoablation had a synergistic effect, not only enhancing the immune function and improving the quality of life of the patients, but also significantly exhibiting good clinical efficacy of the patients. This study is the first clinical trial that has evaluated the safety and efficacy of allogenic NK cells combined with cryosurgery for the treatment of renal cell cancer.

Dendritic cells infected by Ad-sh-SOCS1 enhance cytokine-induced killer (CIK) cell immunotherapeutic efficacy in cervical cancer models

BACKGROUND AIMS

Cervical cancer constitutes a major problem in women's health worldwide, but the efficacy of the standard therapy is unsatisfactory. Cytokine-induced killer (CIK) cells exhibit antitumor activity against a variety of malignancies in preclinical models and have proven safe and effective in clinical trials. However, current CIK therapy has limitations and needs to be improved to meet the clinical requirements. The aim of this study was to investigate whether suppressing the expression of cytokine signaling 1 (SOCS1) in dendritic cells (DCs) can shorten in vitro CIK culture time and improve its antitumor efficacy.

METHODS

DCs were pre-cultured for 3 days before infected with adenovirus-mediated-SOCS1 short hairpin RNA (Ad-sh-SOCS1) and pulsed with CTL epitope peptides E7. The DCs infected by Ad-sh-SOCS1 (gmDCs) and CIKs were then co-cultured for 5 or 9 days, and CIK proliferation and antitumor activity were evaluated both in vitro and in vivo.

RESULTS

Our data show that gmDCs significantly stimulated the expansion of co-cultured CIKs and increased the secretion of interferon-γ and interleukin-12. Moreover, gmDCs-activated CIKs showed higher cytotoxic activity against TC-1 cells expressing HPV16E6 and E7. Our in vivo study showed that the mice infused with gmDCs-activated CIKs on day 10 had an increased survival rate and prolonged survival time compared with the controls.

CONCLUSIONS

Taken together, these results indicate that DCs modified by adenovirus-mediated SOCS1 silencing can promote CIKs expansion and enhance the efficacy of antitumor immunotherapy both in vitro and in vivo, which represents an effective therapeutic approach for cervical cancer and other tumors.

Potential Therapeutic Effect of Natural Killer Cells on Doxorubicin-Resistant Breast Cancer Cells In Vitro

OBJECTIVE

The aim of this study was to explore the therapeutic effect of natural killer (NK) cells on human doxorubicin-sensitive and resistant breast adenocarcinoma.

METHODS

Human doxorubicin-sensitive and resistant breast cancer cell lines (MCF-7 and MCF-7/ADR) were tagged with renilla luciferase (Rluc) (MCF-7/RC and MCF-7/ADR/RC). NK cells were tagged with enhanced firefly luciferase (effluc) using a recombinant retrovirus transfection (NKF). Expression of Rluc, effluc, and NK cell surface markers CD16, CD56 as well as death receptors, DR4 and DR5, were assessed by using flow cytometry. In vitro cytotoxic effect of NK to MCF-7 and MCF-7/ADR was measured and in vivo bioluminescence imaging was also performed to visualize MCF-7/RC, MCF-7/ADR, and NKF in an animal model.

RESULTS

NK92-MI, MCF-7, and MCF-7/ADR cells were successfully labeled with Rluc or effluc. Both the target breast cancer cells (with Rluc) and therapeutic NK cells (with effluc) were noninvasively visualized in nude mice. Doxorubicin-resistant breast cancer cells (MCF-7/ADR) presented a higher expression of DR5 and were more sensitive to NK cells compared with doxorubicin-sensitive breast cancer cells (MCF-7).

CONCLUSION

The results of present study suggest that NK cell therapy has a therapeutic effect on doxorubicin-sensitive and resistant breast cancer cells.

Establishment of a heterotypic 3D culture system to evaluate the interaction of TREG lymphocytes and NK cells with breast cancer

Three-dimensional (3D) culture approaches to investigate breast tumour progression are yielding information more reminiscent of the in vivo microenvironment. We have established a 3D Matrigel system to determine the interactions of luminal phenotype MCF-7 cells and basal phenotype MDA-MB-231 cells with regulatory T lymphocytes and Natural Killer cells. Immune cells were isolated from peripheral blood using magnetic cell sorting and their phenotype validated using flow cytometry both before and after activation with IL-2 and phytohaemagglutinin. Following the establishment of the heterotypic culture system, tumour cells displayed morphologies and cell-cell associations distinct to that observed in 2D monolayer cultures, and associated with tissue remodelling and invasion processes. We found that the level of CCL4 secretion was influenced by breast cancer phenotype and immune stimulation. We further established that for RNA extraction, the use of proteinase K in conjunction with the Qiagen RNeasy Mini Kit and only off-column DNA digestion gave the best RNA yield, purity and integrity. We also investigated the efficacy of the culture system for immunolocalisation of the biomarkers oestrogen receptor-α and the glycoprotein mucin 1 in luminal phenotype breast cancer cells; and epidermal growth factor receptor in basal phenotype breast cancer cells, in formalin-fixed, paraffin-wax embedded cultures. The expression of these markers was shown to vary under immune mediation. We thus demonstrate the feasibility of using this co-culture system for downstream applications including cytokine analysis, immunolocalisation of tumour biomarkers on serial sections and RNA extraction in accordance with MIQE guidelines.

Natural killer (NK) cell profiles in blood and tumour in women with large and locally advanced breast cancer (LLABC) and their contribution to a pathological complete response (PCR) in the tumour following neoadjuvant chemotherapy (NAC): differential restoration of blood profiles by NAC and surgery

Background

NK cells contribute to tumour surveillance, inhibition of growth and dissemination by cytotoxicity, secretion of cytokines and interaction with immune cells. Their precise role in human breast cancer is unclear and the effect of therapy poorly studied. The purpose of our study was to characterise NK cells in women with large (≥3 cm) and locally advanced (T3–4, N1–2, M0) breast cancers (LLABCs) undergoing neoadjuvant chemotherapy (NAC) and surgery, and to ascertain their possible contribution to a pathological complete response (pCR).

Methods

Women with LLABCs (n = 25) and healthy female donors [HFDs (n = 10)] were studied. Pathological responses in the breast were assessed using established criteria. Blood samples were collected pre and post NAC and surgery. Flow cytometry and labelled monoclonal antibodies established absolute numbers (AbNs) and percentages (%) of NK cells, and expressing granzyme B/perforin and NKG2D. In vitro NK cytotoxicity was assessed and NK cells and cytokines (IL-2, INF-γ, TGF-β) documented in tumours using immunohistochemical techniques. Data was analysed by SPSS.

Results

Women with LLABCs had significantly reduced AbNs (160.00 ± 40.00 cells/µl) but not % of NK cells, compared with HFDs (NK: 266.78 ± 55.00 cells/µl; p = 0.020). NAC enhanced the AbN (p = 0.001) and % (p = 0.006) of NK cells in patients with good pathological responses. Granzyme B⁺/perforin⁺ cells were significantly reduced (43.41 ± 4.00%), compared with HFDs (60.26 ± 7.00%; p = 0.003). NAC increased the % in good (p = 0.006) and poor (p = 0.005) pathological responders. Pretreatment NK cytotoxicity was significantly reduced in good (37.80 ± 8.05%) and poor (22.80 ± 7.97%) responders (p = 0.001) but remained unchanged following NAC. NK-NKG2D⁺ cells were unaltered and unaffected by NAC; NKG2D expression was increased in patients with a pCR (p = 0.001). Surgery following NAC was not beneficial, except in those with a pCR. Tumour-infiltrating NK cells were infrequent but increased peritumourally (p = 0.005) showing a significant correlation (p = 0.004) between CD56⁺ cells and grade of response. Tumour cytokines had no effect.

Conclusion

Women with LLABCs have inhibited blood innate immunity, variably reversed by NAC (especially with tumour pCRs), which returned to pretreatment levels following surgery. These and in situ tumour findings suggest a role for NK cells in NAC-induced breast pCR.

NZ28-induced inhibition of HSF1, SP1 and NF-κB triggers the loss of the natural killer cell-activating ligands MICA/B on human tumor cells

The activity of natural killer (NK) cells is regulated by activating and inhibiting receptors, whereby the C-type lectin natural killer group 2D (NKG2D) receptor serves as the major activating receptor on NK cells which recognizes major histocompatibility class I chain-related proteins A and B (MICA/B). The MICA/B expression has been described to be regulated by the transcription factor heat shock factor 1 (HSF1). Inhibition of heat shock protein 90 (Hsp90) is known to induce the heat shock response via activation of HSF1 which is associated with tumor development, metastasis and therapy resistance and also with an increased susceptibility to NK cell-mediated lysis. Therefore, we compared the effects of Hsp90 inhibitor NVP-AUY922, HSF1 inhibitor NZ28 and HSF1 knockdown on the sensitivity of lung (H1339) and breast (MDA-MB-231, T47D) cancer cells to NK cell-mediated cytotoxicity and the expression of the NKG2D ligands MICA/B. Although NVP-AUY922 activates HSF1, neither the MICA/B surface density on tumor cells nor their susceptibility to NK cell-mediated lysis was affected. A single knockdown of HSF1 by shRNA decreased the surface expression of MICB but not that of MICA, and thereby, the NK cell-mediated lysis was only partially blocked. In contrast, NZ28 completely blocked the MICA/B membrane expression on tumor cells and thereby strongly inhibited the NK cell-mediated cytotoxicity. This effect might be explained by a simultaneous inhibition of the transcription factors HSF1, Sp1 and NF-κB by NZ28. These findings suggest that new anticancer therapeutics should be investigated with respect to their effects on the innate immune system.

Lack of in vivo antibody dependent cellular cytotoxicity with antibody containing gold nanoparticles

Antibody-dependent cellular cytotoxicity (ADCC) is a cytolytic mechanism that can elicit in vivo antitumor effects and can play a significant role in the efficacy of antibody treatments for cancer. Here, we prepared cetuximab, panitumumab, and rituximab containing gold nanoparticles and investigated their ability to produce an ADCC effect in vivo. Cetuximab treatment of EGFR-expressing H1975 tumor xenografts showed significant tumor regression due to the ADCC activity of the antibody in vivo, while the control antibody, panitumumab, did not. However, all three antibody containing nanoparticles are not able to suppress tumor growth in the same in vivo mouse model. The antibody containing nanoparticles localized in the tumors and did not suppress the immune function of the animals, so the lack of tumor growth suppression of the cetuximab containing nanoparticle suggests that immobilizing antibodies onto a nanoparticle significantly decreases the ability of the antibody to promote an ADCC response.

The tumor microenvironment: a pitch for multiple players

The cancer microenvironment may be conceptually regarded as a pitch where the main players are resident and non-resident cellular components, each covering a defined role and interconnected by a complex network of soluble mediators. The crosstalk between these cells and the tumor cells within this environment crucially determines the fate of tumor progression. Immune cells that infiltrate the tumor bed are transported there by blood circulation and exert a variety of effects, either counteracting or favoring tumor outgrowth. Here, we review and discuss the multiple populations composing the tumor bed, with special focus on immune cells subsets that positively or negatively dictate neoplastic progression. In this scenario, the contribution of cancer stem cells within the tumor microenvironment will also be discussed. Finally, we illustrate recent advances on new integrated approaches to investigate the tumor microenvironment in vitro.