Interaction of tumor-associated macrophages and cancer chemotherapy

Simultaneous Tumor and Stroma Targeting by Oncolytic Viruses

Current cancer therapeutics often insufficiently eradicate malignant cells due to the surrounding dense tumor stroma. This multi-componential tissue consists of mainly cancer-associated fibroblasts, the (compact) extracellular matrix, tumor vasculature, and tumor-associated macrophages, which all exert crucial roles in maintaining a pro-tumoral niche. Their continuous complex interactions with tumor cells promote tumor progression and metastasis, emphasizing the challenges in tumor therapy development. Over the last decade, advances in oncolytic virotherapy have shown that oncolytic viruses (OVs) are a promising multi-faceted therapeutic platform for simultaneous tumor and stroma targeting. In addition to promoting tumor cell oncolysis and systemic anti-tumor immunity, accumulating data suggest that OVs can also directly target stromal components, facilitating OV replication and spread, as well as promoting anti-tumor activity. This review provides a comprehensive overview of the interactions between native and genetically modified OVs and the different targetable tumor stromal components, and outlines strategies to improve stroma targeting by OVs.

Legumain protease-activated tuftsin-functionalized nanoparticles for dual-targeting TAMs and cancer chemotherapy

M2 tumor-associated macrophages (TAMs) play a pivotal role in cancer progression and therapy resistance. Inhibition of TAMs is of great significance to reshape the protumor environment to benefit therapeutic outcomes. In this work, we developed a novel TAMs and tumor cells dual-targeting nanoparticle (AT_pep-NPs) system for cancer chemotherapy by integrating a docetaxel (DTX)-loaded nanocarrier and a multi-function peptide AT_pep, which is composed of a phagocytosis-stimulating peptide-tuftsin (T_pep) fused with a substrate peptide-alanine-alanine-asparagine (AAN) of endoprotease legumain. In vitro protelytic and cellular uptake assays confirmed AT_pep-NPs can be responsively activated into T_pep-NPs by cleavage of legumain that is overexpressed in both tumor cells and TAMs, which then promoted tumor cells internalization and TAMs phagocytosis through neuropilin-1/Fc receptor pathways. Due to AAN deactivation effect, AT_pep-NPs can effectively decrease the T_pep-induced non-specific uptake by M1-polarized and normal macrophage during systemic circulation. Our results of in vivo experiments demonstrated AT_pep-NPs outperformed T_pep-NPs in tumor and TAMs dual-targeting delivery efficiency with markedly enhanced efficacy against both tumor growth inhibition and TAMs depletion. Overall, this study offers a novel approach for development of multitargeted delivery vehicle for improved cancer chemotherapy.

Harnessing hyaluronic acid-based nanoparticles for combination therapy: A novel approach for suppressing systemic inflammation and to promote antitumor macrophage polarization

Anti-inflammatory drugs such as dexamethasone (DEX) are commonly administered to cancer patients along with anticancer drugs, however, the effect of DEX on human cancers is poorly understood. In this article, we have tailored self-assembled nanoparticles derived from hyaluronic acid (HA) wherein, anti-inflammatory DEX was used as a hydrophobic moiety for inducing amphiphilicity. The HA-DEX micelles were subsequently loaded with chemotherapeutic agent, doxorubicin (DOX) (HA-DEX-DOX) and was utilized to deliver drug cargo to human cancer cells expressing different levels of CD44 receptors. We found that DEX suppressed the cytotoxicity of DOX in HCT116, while it synergistically enhanced cytotoxicity in MCF-7 cells. When we tested DOX and HA-DEX-DOX in an ex-vivo human whole blood, we found activation of complement and the coagulation cascade in one group of donors. Encapsulation of DOX within the nanoparticle core eliminated such deleterious side-effects. The HA-DEX-DOX also polarized bone-marrow-derived anti-inflammatory M2 macrophages, to pro-inflammatory M1 phenotype with the upregulation of the cytokines TNF-α, iNOS and IL-1β.

New Insights into Therapy-Induced Progression of Cancer

The malignant tumor is a complex heterogeneous set of cells functioning in a no less heterogeneous microenvironment. Like any dynamic system, cancerous tumors evolve and undergo changes in response to external influences, including therapy. Initially, most tumors are susceptible to treatment. However, remaining cancer cells may rapidly reestablish the tumor after a temporary remission. These new populations of malignant cells usually have increased resistance not only to the first-line agent, but also to the second- and third-line drugs, leading to a significant decrease in patient survival. Multiple studies describe the mechanism of acquired therapy resistance. In past decades, it became clear that, in addition to the simple selection of pre-existing resistant clones, therapy induces a highly complicated and tightly regulated molecular response that allows tumors to adapt to current and even subsequent therapeutic interventions. This review summarizes mechanisms of acquired resistance, such as secondary genetic alterations, impaired function of drug transporters, and autophagy. Moreover, we describe less obvious molecular aspects of therapy resistance in cancers, including epithelial-to-mesenchymal transition, cell cycle alterations, and the role of intercellular communication. Understanding these molecular mechanisms will be beneficial in finding novel therapeutic approaches for cancer therapy.

Breast cancer cells and macrophages in a paracrine-juxtacrine loop

Breast cancer cells (BCC) and macrophages are known to interact via epidermal growth factor (EGF) produced by macrophages and colony stimulating factor-1 (CSF-1) produced by BCC. Despite contradictory findings, this interaction is perceived as a paracrine loop. Further, the underlying mechanism of interaction remains unclear. Here, we investigated interactions of BCC with macrophages in 2D and 3D. While both BCC and macrophages showed invasion/chemotaxis to fetal bovine serum, only macrophages showed chemotaxis to BCC in custom designed 3D cell-on-a-chip devices. These results were in agreement with gradient simulation results and ELISA results showing that macrophage-derived-EGF was not secreted into macrophage-conditioned-medium. Live cell imaging of BCC in the presence and absence of iressa showed that macrophages but not macrophage-derived-matrix modulated adhesion and motility of BCC in 2D. 3D co-culture experiments in collagen and matrigel showed that BCC changed their multicellular organization in the presence of macrophages. In custom designed 3D co-culture cell-on-a-chip devices, macrophages promoted and reduced migration of BCC in collagen and matrigel, respectively. Furthermore, adherent but not suspended BCC endocytosed EGFR when in contact with macrophages. Collectively, our data revealed that macrophages showed chemotaxis towards BCC whereas BCC required direct contact to interact with macrophage-derived-EGF. Therefore, we propose that the interaction between cancer cells and macrophages is a paracrine-juxtacrine loop of CSF-1 and EGF, respectively.

Tumor-Associated Macrophages in Human Breast, Colorectal, Lung, Ovarian and Prostate Cancers

Tumor-associated macrophages (TAMs) are major innate immune cells that constitute up to 50% of the cell mass of human tumors. TAMs are highly heterogeneous cells that originate from resident tissue-specific macrophages and from newly recruited monocytes. TAMs' variability strongly depends on cancer type, stage, and intratumor heterogeneity. Majority of TAMs are programmed by tumor microenvironment to support primary tumor growth and metastatic spread. However, TAMs can also restrict tumor growth and metastasis. In this review, we summarized the knowledge about the role of TAMs in tumor growth, metastasis and in the response to cancer therapy in patients with five aggressive types of cancer: breast, colorectal, lung, ovarian, and prostate cancers that are frequently metastasize into distant organs resulting in high mortality of the patients. Two major TAM parameters are applied for the evaluation of TAM correlation with the cancer progression: total amount of TAMs and specific phenotype of TAMs identified by functional biomarkers. We summarized the data generated in the wide range of international patient cohorts on the correlation of TAMs with clinical and pathological parameters of tumor progression including lymphatic and hematogenous metastasis, recurrence, survival, therapy efficiency. We described currently available biomarkers for TAMs that can be measured in patients' samples (tumor tissue and blood). CD68 is the major biomarker for the quantification of total TAM amounts, while transmembrane receptors (stabilin-1, CD163, CD206, CD204, MARCO) and secreted chitinase-like proteins (YKL-39, YKL-40) are used as biomarkers for the functional TAM polarization. We also considered that specific role of TAMs in tumor progression can depend on the localization in the intratumoral compartments. We have made the conclusion for the role of TAMs in primary tumor growth, metastasis, and therapy sensitivity for breast, colorectal, lung, ovarian, and prostate cancers. In contrast to other cancer types, majority of clinical studies indicate that TAMs in colorectal cancer have protective role for the patient and interfere with primary tumor growth and metastasis. The accumulated data are essential for using TAMs as biomarkers and therapeutic targets to develop cancer-specific immunotherapy and to design efficient combinations of traditional therapy and new immunomodulatory approaches.

Mannose receptor 1 expression does not determine the uptake of high-density mannose dendrimers by activated macrophages populations

The presence of a high number of macrophages within solid tumors is often significantly associated with poor prognosis and predict treatment failure for chemotherapy and radiotherapy. Macrophages are innate immune cells capable of performing diverse functions depending on the different signals from the microenvironment. The classically activated macrophage is commonly present during the early stages of tumor development while alternatively activated macrophages are associated with more advanced tumors. The distinction of the antitumoral macrophages from the pro-tumoral macrophages is not absolute. However, they have different cell surface markers such as mannose receptor (MRC1 or CD206) abundantly expressed by macrophages treated with interleukin-4 (IL-4). The important roles of macrophages in cancers suggest that it is important to develop novel therapies that target these cells. In the present study, we designed a probe using Polyamidoamine (PAMAM) fifth-generation (G5) dendrimers conjugated with mannose, Cyanine 7 (Cy7), and hydrazinonicotinamide (HYNIC) for target macrophages with high expression of MRC1 in the tumor. The intracellular uptake of 99mTc-HYNIC-dendrimer-mannose-Cy7 through the interaction with MRC1 in bone marrow-derived macrophages (BMDMs) untreated or treated with lipopolysaccharides (LPS) + interferon (IFN)γ or IL-4 was analyzed. Our results show that high-density mannose dendrimers are preferentially bound by macrophages treated by IFNγ and LPS that express lower levels of MRC1 than for macrophages treated by IL-4 that express high levels of MRC1. Furthermore, the intracellular 99mTc-HYNIC-dendrimer-mannose-Cy7 uptake in BMDMs was not inhibited in the presence of free mannose or glucose. This result suggests that 99mTc-HYNIC-dendrimer-mannose-Cy7 is not internalized via macrophage MRC1. Based on these findings, we concluded that MRC1 expression does not determine the uptake of high-density mannose dendrimers.

CtBP1 promotes tumour-associated macrophage infiltration and progression in non-small-cell lung cancer

The progression of lung cancer is majorly facilitated by TAMs (tumour-associated macrophages). However, how the TAMs infiltrate the NSCLC microenvironment and the associated biochemical are not fully elaborated. Research has revealed that changes in CtBP1 modulates innate immunity. Here, we investigated if CtBP1 facilitates infiltration of TAM and the subsequent progression of NSCLC. Immunohistochemical analysis was carried out in 96 NSCLC patients to estimate the clinicopathological importance of CtBP1 in the disease. CtBP1 overexpression and knockdown were carried out to assess the activity of CtBP1 in NSCLC cells. Elevated expression of CtBP1 correlated positively with TAMs infiltration into NSCLC tissues, induced EMT (epithelial-mesenchymal transition) in NSCLC cells and modulated the activated NF-κB signalling pathway leading to increase in CCL2 secretion from NSCLC cells, thus promoting TAM recruitment and polarization. TAM induction and polarization reduced significantly on exhausting p65 in NSCLC cells with CtBP1. Moreover, infiltration of TMAs was reduced remarkably on antagonist-mediated blocking of CCR2 and impeded the progression of NSCLC in a mouse model. These findings thus show a novel insight into the process of CtBP1-regulated TAM infiltration in NSCLC.

Targeting tumor-associated macrophages in the tumor microenvironment

Tumor-associated macrophages (TAMs) are the most abundant population type of tumor-infiltrating immune cells found in the tumor microenvironment (TME), and are evolutionarily associated with microvessel density in tumor tissues. TAMs can be broadly divided into M1-like and M2-like TAMs, which demonstrate antitumor and pro-tumor activity in the TME, respectively. Studies have indicated that: i) The predominate presence of M2-like TAMs in the TME can result in tumor immunosuppression and chemoresistance; ii) the ratio of M1-like to M2-like TAMs in the TME is positively correlated with better long-term prognosis of patients with cancer; iii) epigenetic silencing, preventing the secretion of M1-like TAM-associated molecules, is an important immune evasion mechanism during tumor progression; and iv) the transformation from M2-like to M1-like TAMs following exposure to specific conditions can result in tumor regression. The present study discusses the molecular events underlying the recruitment of macrophages and their polarization into M1-like or M2-like TAMs, and their differential roles in angiogenesis, angiostasis, invasion, metastasis and immune activity in the TME. This insight may inform the improved design of TAM-targeted cancer immunotherapy. Some of these therapeutic strategies show promising effects; however, challenges remain.

Tumor-associated macrophages: Role in the pathological process of tumorigenesis and prospective therapeutic use (Review)

The aim of the present study was to evaluate the current body of knowledge regarding tumor-associated macrophages (TAMs) and their potential use in antitumor therapy, based on their role in the pathological process of tumorigenesis. For this purpose, a critical analysis of published data and summarization of the findings available from original studies, focusing on the role of TAMs in the pathological process, and their potential therapeutic application was performed. Promising key avenues of research were identified in this field. The following issues seem the most promising and thus worth further investigation: i) The process of M1/M2 macrophage polarization, macrophage characteristics at intermediate polarization steps and their role in the tumor process; ii) determining the conditions necessary for transitions between the M1 and M2 macrophage phenotypes and the role of signals from the microenvironment in this process; iii) cause-and-effect associations between the quantity and quality of macrophages, and the prognosis and outcome of the pathological process; iv) modulation of macrophages and stimulation of their phagocytic activity with drugs; v) targeted vector-based systems for drug delivery to macrophages; and vi) targeted drug delivery systems with macrophages as carriers, thus potentially combining chemotherapy and immunotherapy.

Mitomycin C enhanced the efficacy of PD-L1 blockade in non-small cell lung cancer

Programmed death ligand 1 (PD-L1) immune checkpoint inhibitors are promising therapeutic agents for treating cancers but the response rate is <20%. Some chemotherapeutic drugs could also activate an anticancer immune response to kill cancer cells, apart from their direct cytotoxicity. Our study investigated the combination of chemotherapeutic drugs with PD-L1 antibody to enhance the response rate of PD-L1 blockade. Non-small cell lung cancer (NSCLC) cells were pre-treated with mitomycin C (MMC) and then co-cultured with peripheral blood mononuclear cells (PBMCs) to investigate the effect of the combination of MMC with PD-L1 antibody. The drug combination was also evaluated in vivo in Lewis lung cancer (LLC) cells-bearing C57BL/6 mice. MMC increased the expressions of PD-L1 and MHC-I in NSCLC cells in vitro and in vivo and enhanced the cytotoxic effect of lymphocytes on NSCLC in vitro. In LLC-bearing mouse model, the combination of MMC and PD-L1 antibody was found to be more effective in retarding tumor growth and prolonging overall survival than either single treatment alone, which was associated with increased lymphocyte infiltration and granzyme B release. Mechanistically, MMC activated the ERK pathway, which subsequently enhanced the binding of c-JUN to the PD-L1 promoter and recruited its co-factor STAT3 to increase PD-L1 expression. The upregulated ERK pathway was shown to activate p65 to increase the MHC-I expression. MMC was shown to enhance the efficacy of PD-L1 blockade in NSCLC cells. Further study is warranted to translate the findings to clinical application.

Prognostic value of neutrophil-to-lymphocyte ratio in human epidermal growth factor receptor 2-negative breast cancer patients who received neoadjuvant chemotherapy

We aimed to investigate the correlation between neutrophil-to-lymphocyte ratio (NLR) and pathologic complete response (pCR) and survival outcomes in human epidermal growth factor receptor 2 (HER2)-negative breast cancer patients who received neoadjuvant chemotherapy. The baseline NLR was evaluated in non-metastatic, HER2-negative breast cancer patients who received neoadjuvant chemotherapy. Baseline NLR was calculated as absolute neutrophil per lymphocyte count from pre-treatment blood samples. Any value ≥ 2.74 was considered to be a high NLR. In the 1,097 patients studied, 272 (24.4%) had high NLR and 825 (75.6%) had low NLR. The high NLR was an independent factor for pCR (OR 0.595; 95% CIs 0.398–0.890; P = 0.011). Furthermore, high NLR was a significant independent parameter affecting DFS (HR 2.298; 95% CIs 1.691–3.124; P < 0.001) and OS (HR 1.905; 95% CIs 1.167–3.108; P = 0.010). Regardless of the baseline NLR, survival outcomes were excellent in patients who achieved pCR, but high NLR was associated with worse survival for patients with residual invasive disease. Our study showed that NLR was predictive for treatment response and a prognostic factor in patients with HER2-negative breast cancer who received neoadjuvant chemotherapy. Moreover, we identified that high NLR was associated with poor survival outcomes in patients who did not achieve pCR.

An overview of the role of interleukin-8 in colorectal cancer

Colorectal Cancer (CRC), a common malignancy, is developing globally among people. Mutagenic insults activate peripheral nucleated cells to secrete chemokines in order to cause an inflammatory state. Despite the presence of multi-retrieving factors, elevated production of minor cytokines may speed-up the sever stages of the baseline inflammation targeting normal compensatory mechanism. IL-8 is a pro-inflammatory cytokine that is believed to be up-regulated in CRC to proceed primary condition into tumor behavior via induction of proliferation, angiogenesis and metastasis. Here, we assess the role of IL-8 in every step of CRC from signaling pathway and formation to invasion and discuss around new perspective therapy that targets IL-8 to manage CRC worldwide incidence and survival rate, more precisely.

Immunomodulation via macrophages to fight solid tumor malignancies

The paper 'A C-Terminal Fragment of Adhesion Protein Fibulin-7 Inhibits Growth of Murine Breast Tumor by Regulating Macrophage Reprogramming' by Chakraborty et al. highlights that Fbln7-C could be explored as a potential immunomodulatory agent against various solid cancers and have shown its abilities to regulate tumor microenvironment reprogramming of TAMs in a breast cancer model. Fbln7, which is a secreted glycoprotein, has been shown to be anti-angiogenic and has an immunomodulatory role regulating various functional properties of monocytes, macrophages, and neutrophils, thereby influencing inflammation. In this study, the authors have shown that in a murine breast tumor model, intravenous administration of Fbln7-C significantly reduces the size of tumors via macrophage reprogramming. Comment on: https://doi.org/10.1111/febs.15333.

Cancer Stem Cells in Soft-Tissue Sarcomas

Soft tissue sarcomas (STS) are a rare group of mesenchymal solid tumors with heterogeneous genetic profiles and clinical features. Systemic chemotherapy is the backbone treatment for advanced STS; however, STS frequently acquire resistance to standard therapies, which highlights the need to improve treatments and identify novel therapeutic targets. Increases in the knowledge of the molecular pathways that drive sarcomas have brought to light different molecular alterations that cause tumor initiation and progression. These findings have triggered a breakthrough of targeted therapies that are being assessed in clinical trials. Cancer stem cells (CSCs) exhibit mesenchymal stem cell (MSC) features and represent a subpopulation of tumor cells that play an important role in tumor progression, chemotherapy resistance, recurrence and metastasis. In fact, CSCs phenotypes have been identified in sarcomas, allied to drug resistance and tumorigenesis. Herein, we will review the published evidence of CSCs in STS, discussing the molecular characteristic of CSCs, the commonly used isolation techniques and the new possibilities of targeting CSCs as a way to improve STS treatment and consequently patient outcome.

Transcriptional, Epigenetic and Metabolic Programming of Tumor-Associated Macrophages

Macrophages are key innate immune cells in the tumor microenvironment (TME) that regulate primary tumor growth, vascularization, metastatic spread and tumor response to various types of therapies. The present review highlights the mechanisms of macrophage programming in tumor microenvironments that act on the transcriptional, epigenetic and metabolic levels. We summarize the latest knowledge on the types of transcriptional factors and epigenetic enzymes that control the direction of macrophage functional polarization and their pro- and anti-tumor activities. We also focus on the major types of metabolic programs of macrophages (glycolysis and fatty acid oxidation), and their interaction with cancer cells and complex TME. We have discussed how the regulation of macrophage polarization on the transcriptional, epigenetic and metabolic levels can be used for the efficient therapeutic manipulation of macrophage functions in cancer.

Activated HIF1α of tumor cells promotes chemoresistance development via recruiting GDF15-producing tumor-associated macrophages in gastric cancer

Chemotherapy is the preferred treatment for advanced stage gastric cancer (GC) patients, and developing chemoresistance is a tremendous challenge to efficacy of GC treatment. The treatments of anti-tumor chemo-agents recruit more tumor-associated macrophages (TAMs) which are highly implicated in the chemoresistance development, but the underlying molecular mechanism is unclear. Here, we demonstrate that hypoxia-inducible factor 1α (HIF1α) in GC cells is activated upon 5-fluorouracil (5-FU) treatment and results in much more accumulation of M2-type TAMs which protect tumor cells from chemo-agents. Mechanistically, in the GC cells under the 5-FU treatment, reactive oxygen species is accumulated and then induces the activation of HIF1α signaling to drive the expression of high-mobility group box 1, which leads to more macrophage's infiltration into GC tumor. In turn, the recruited TAMs exhibit tumor-protected M2-type phenotype and promote the chemoresistance of GC cells via producing growth differentiation factor 15 (GDF15) to exacerbate the fatty acid β-oxidation in tumor cells. Blocking GDF15 using antibody or inhibiting FAO of tumor cells by etomoxir efficiently gave rise to the tumor cell sensitivity to 5-FU. Therefore, our study demonstrates a novel insight in understanding the cross talking between tumor cells and immune microenvironment and provides new therapeutic targets for clinic treatments of gastric cancer.

Immune landscape in Burkitt lymphoma reveals M2-macrophage polarization and correlation between PD-L1 expression and non-canonical EBV latency program

BACKGROUND

The Tumor Microenviroment (TME) is a complex milieu that is increasingly recognized as a key factor in multiple stages of disease progression and responses to therapy as well as escape from immune surveillance. However, the precise contribution of specific immune effector and immune suppressor components of the TME in Burkitt lymphoma (BL) remains poorly understood.

METHODS

In this paper, we applied the computational algorithm CIBERSORT to Gene Expression Profiling (GEP) datasets of 40 BL samples to draw a map of immune and stromal components of TME. Furthermore, by multiple immunohistochemistry (IHC) and multispectral immunofluorescence (IF), we investigated the TME of additional series of 40 BL cases to evaluate the role of the Programmed Death-1 and Programmed Death Ligand-1 (PD-1/PD-L1) immune checkpoint axis.

RESULTS

Our results indicate that M2 polarized macrophages are the most prominent TME component in BL. In addition, we investigated the correlation between PD-L1 and latent membrane protein-2A (LMP2A) expression on tumour cells, highlighting a subgroup of BL cases characterized by a non-canonical latency program of EBV with an activated PD-L1 pathway.

CONCLUSION

In conclusion, our study analysed the TME in BL and identified a tolerogenic immune signature highlighting new potential therapeutic targets.

The roles of tumor-associated macrophages in tumor angiogenesis and metastasis

Tumor associated macrophages (TAMs) are the most frequent immune cells within tumor microenvironment (TME). There is growing evidence that TAMs are involved in tumor progression via multiple mechanisms. TAMs create an immunosuppressive TME by producing growth factors, chemokines, and cytokines which modulate recruitment of immune cells and inhibit anti-tumor responses. They also serve as angiogenesis promoting cells by production of pro-angiogenic factors and matrix metalloproteinases (MMPs) and vascular constructing which guarantee supplying oxygen and nutrients to solid tumor cells. Furthermore, TAMs play important functions in tumor metastasis through contributing to invasion, extravasation, survival, intravasation, and colonization of tumor cells. In this review, we summarized macrophage classification, TAMs polarization, and mechanisms underlying TAM-promoting angiogenesis and metastasis.

Tumor microenvironment complexity and therapeutic implications at a glance

The dynamic interactions of cancer cells with their microenvironment consisting of stromal cells (cellular part) and extracellular matrix (ECM) components (non-cellular) is essential to stimulate the heterogeneity of cancer cell, clonal evolution and to increase the multidrug resistance ending in cancer cell progression and metastasis. The reciprocal cell-cell/ECM interaction and tumor cell hijacking of non-malignant cells force stromal cells to lose their function and acquire new phenotypes that promote development and invasion of tumor cells. Understanding the underlying cellular and molecular mechanisms governing these interactions can be used as a novel strategy to indirectly disrupt cancer cell interplay and contribute to the development of efficient and safe therapeutic strategies to fight cancer. Furthermore, the tumor-derived circulating materials can also be used as cancer diagnostic tools to precisely predict and monitor the outcome of therapy. This review evaluates such potentials in various advanced cancer models, with a focus on 3D systems as well as lab-on-chip devices. Video abstract.

Tumor-infiltrating M2 macrophage in pretreatment biopsy sample predicts response to chemotherapy and survival in esophageal cancer

The association between the tumor microenvironment (TME) and treatment response or survival has been a recent focus in several types of cancer. However, most study materials are resected specimens that were completely modified by prior chemotherapy; therefore, the unmodified host immune condition has not yet been clarified. The aim of the present study was to evaluate the relationship between TME assessed in pre-therapeutic biopsy samples and chemoresistance in esophageal cancer (EC). A total of 86 endoscopic biopsy samples from EC patients who received neoadjuvant chemotherapy (NAC) prior to surgery were evaluated for the number of intratumoral CD4+ lymphocytes (with/without Foxp3 expression), CD8+ lymphocytes (with/without PD-1 expression), monocytes (CD14+ ) and macrophages (CD86+ , CD163+ and CD206+ ) by multiplex immunohistochemistry (IHC). The number of tumor-infiltrating CD206+ macrophages I significantly correlated with cT, cM, cStage and neutrophil/lymphocyte ratio (NLR), whereas the number of lymphocytes (including expression of Foxp3 and PD-1) was not associated with clinico-pathological features. The high infiltration of CD163+ or CD206+ macrophages was significantly associated with poor pathological response to NAC (P = 0.0057 and 0.0196, respectively). Expression of arginase-1 in CD163+ macrophages tended to be higher in non-responders (29.4% vs 18.2%, P = 0.17). In addition, patients with high infiltration of M2 macrophages exhibited unfavorable overall survival compared to those without high infiltration of M2 macrophages (5-year overall survival 57.2% vs 71.0%, P = 0.0498). Thus, a comprehensive analysis of TME using multiplex IHC revealed that M2 macrophage infiltration would be useful in predicting the response to NAC and long-term survival in EC patients.

Tumor immune microenvironment in head and neck cancers

Head and neck cancers are a heterogeneous group of tumors that are highly aggressive and collectively represent the sixth most common cancer worldwide. Ninety percent of head and neck cancers are squamous cell carcinomas (HNSCCs). The tumor microenvironment (TME) of HNSCCs consists of many different subsets of cells that infiltrate the tumors and interact with the tumor cells or with each other through various networks. Both innate and adaptive immune cells play a crucial role in mediating immune surveillance and controlling tumor growth. Here, we discuss the different subsets of immune cells and how they contribute to an immunosuppressive TME of HNSCCs. We also briefly summarize recent advances in immunotherapeutic approaches for HNSCC treatment. A better understanding of the multiple factors that play pivotal roles in HNSCC tumorigenesis and tumor progression may help define novel targets to develop more effective immunotherapies for patients with HNSCC.

YKL-39 as a Potential New Target for Anti-Angiogenic Therapy in Cancer

YKL-39 belongs to the evolutionarily conserved family of Glyco_18-containing proteins composed of chitinases and chitinase-like proteins. Chitinase-like proteins (CLPs) are secreted lectins that lack hydrolytic activity due to the amino acid substitutions in their catalytic domain and combine the functions of cytokines and growth factors. One of the major cellular sources that produce CLPs in various pathologies, including cancer, are macrophages. Monocytes recruited to the tumor site and programmed by tumor cells differentiate into tumor-associated macrophages (TAMs), which are the primary source of pro-angiogenic factors. Tumor angiogenesis is a crucial process for supplying rapidly growing tumors with essential nutrients and oxygen. We recently determined that YKL-39 is produced by tumor-associated macrophages in breast cancer. YKL-39 acts as a strong chemotactic factor for monocytes and stimulates angiogenesis. Chemotherapy is a common strategy to reduce tumor size and aggressiveness before surgical intervention, but chemoresistance, resulting in the relapse of tumors, is a common clinical problem that is critical for survival in cancer patients. Accumulating evidence indicates that TAMs are essential regulators of chemoresistance. We have recently found that elevated levels of YKL-39 expression are indicative of the efficiency of the metastatic process in patients who undergo neoadjuvant chemotherapy. We suggest YKL-39 as a new target for anti-angiogenic therapy that can be combined with neoadjuvant chemotherapy to reduce chemoresistance and inhibit metastasis in breast cancer patients.

Chemical and physical chitosan hydrogels as prospective carriers for drug delivery: a review

This review summarizes and discusses recent research progress in chemical and physical chitosan hydrogels for drug delivery.

Extracellular Hsp70 Reduces the Pro-Tumor Capacity of Monocytes/Macrophages Co-Cultivated with Cancer Cells

Cancer cells are known to contain high levels of the heat shock protein 70 kDa (Hsp70), which mediates increased cell proliferation, escape from programmed cell death, enhanced invasion, and metastasis. A part of Hsp70 molecules may release from cancer cells and affect the behavior of adjacent stromal cells. To explore the effects of Hsp70 on the status of monocytes/macrophages in the tumor locale, we incubated human carcinoma cells of three distinct lines with normal and reduced content of Hsp70 with THP1 monocytes. Using two methods, we showed that the cells with knock-down of Hsp70 released a lower amount of protein in the extracellular medium. Three cycles of the co-cultivation of cancer and monocytic cells led to the secretion of several cytokines typical of the tumor microenvironment (TME) and to pro-cancer activation of the monocytes/macrophages as established by elevation of F4/80 and arginase-1 markers. Unexpectedly, the efficacy of epithelial–mesenchymal transition and resistance of carcinoma cells to anticancer drugs after incubation with monocytic cells were more pronounced in cells with lower Hsp70, e.g., releasing less Hsp70 into the extracellular milieu. These data suggest that Hsp70 released from tumor cells into the TME is able, together with the development of an anti-cancer immune response, to limit the conversion of a considerable part of monocytic cells to the pro-tumor phenotype.

Selenium and selenoproteins in prostanoid metabolism and immunity

Selenium (Se) is an essential trace element that functions in the form of the 21st amino acid, selenocysteine (Sec) in a defined set of proteins. Se deficiency is associated with pathological conditions in humans and animals, where incorporation of Sec into selenoproteins is reduced along with their expression and catalytic activity. Supplementation of Se-deficient population with Se has shown health benefits suggesting the importance of Se in physiology. An interesting paradigm to explain, in part, the health benefits of Se stems from the observations that selenoprotein-dependent modulation of inflammation and efficient resolution of inflammation relies on mechanisms involving a group of bioactive lipid mediators, prostanoids, which orchestrate a concerted action toward maintenance and restoration of homeostatic immune responses. Such an effect involves the interaction of various immune cells with these lipid mediators where cellular redox gatekeeper functions of selenoproteins further aid in not only dampening inflammation, but also initiating an effective and active resolution process. Here we have summarized the current literature on the multifaceted roles of Se/selenoproteins in the regulation of these bioactive lipid mediators and their immunomodulatory effects.

Paclitaxel's Mechanistic and Clinical Effects on Breast Cancer

Paclitaxel (PTX), the most widely used anticancer drug, is applied for the treatment of various types of malignant diseases. Mechanisms of PTX action represent several ways in which PTX affects cellular processes resulting in programmed cell death. PTX is frequently used as the first-line treatment drug in breast cancer (BC). Unfortunately, the resistance of BC to PTX treatment is a great obstacle in clinical applications and one of the major causes of death associated with treatment failure. Factors contributing to PTX resistance, such as ABC transporters, microRNAs (miRNAs), or mutations in certain genes, along with side effects of PTX including peripheral neuropathy or hypersensitivity associated with the vehicle used to overcome its poor solubility, are responsible for intensive research concerning the use of PTX in preclinical and clinical studies. Novelties such as albumin-bound PTX (nab-PTX) demonstrate a progressive approach leading to higher efficiency and decreased risk of side effects after drug administration. Moreover, PTX nanoparticles for targeted treatment of BC promise a stable and efficient therapeutic intervention. Here, we summarize current research focused on PTX, its evaluations in preclinical research and application clinical practice as well as the perspective of the drug for future implication in BC therapy.