Cancer related inflammation: the macrophage connection

Human-derived Tumor-On-Chip model to study the heterogeneity of breast cancer tissue

One of the leading causes that complicate the treatment of some malignancies, including breast cancer, is tumor heterogeneity. In addition to inter-heterogeneity and intra-heterogeneity of tumors that reflect the differences between cancer cell characteristics, heterogeneity in the tumor microenvironment plays a critical role in tumor progression and could be considered an overlooked and a proper target for the effective selection of therapeutic approaches. Due to the difficulty of completely capturing tumor heterogeneity in conventional detection methods, Tumor-on-Chip (TOC) devices with culturing patient-derived spheroids could be an appropriate alternative. In this research, human-derived spheroids from breast cancer individuals were cultured for 6 days in microfluidic devices. To compare TOC data with conventional detection methods, immunohistochemistry (IHC) and ITRAQ data were employed, and various protein expressions were validated using the transcriptomic databases. The behavior of the spheroids in the collagen matrix and the cell viability were monitored over 6 days of culture. IHC and immunocytochemistry (ICC) results revealed that inter and intra-heterogeneity of tumor spheroids are associated with HER2/ER expression. HER2 expression levels revealed a more important biomarker associated with invasion in the 3D culturing of spheroids. The expression levels of CD163 (as a marker for Ma2 macrophages) and CD44 (a marker for cancer stem cells (CSCs)) were also evaluated. Interestingly, the levels of M2a macrophages and CSCs were higher in triple-negative specimens and samples that showed higher migration and invasion. Cell density and extracellular matrix (ECM) stiffness were also important factors affecting the migration and invasion of the spheroids through the matrix. Among these, rigid ECM revealed a more crucial role than cell density. To sum up, these research findings demonstrated that human-derived spheroids from breast cancer specimens in microfluidic devices provide a dynamic condition for predicting tumor heterogeneity in patients, which can help move the field forward for better and more accurate therapeutic strategies.

Interactions between platelets and the cancer immune microenvironment

Cancer is a leading cause of death in both China and developed countries due to its high incidence and low cure rate. Immune function is closely linked to the development and progression of tumors. Platelets, which are primarily known for their role in hemostasis, also play a crucial part in the spread and progression of tumors through their interaction with the immune microenvironment. The impact of platelets on tumor growth and metastasis depends on the type of cancer and treatment method used. This article provides an overview of the relationship between platelets and the immune microenvironment, highlighting how platelets can either protect or harm the immune response and cancer immune escape. We also explore the potential of available platelet-targeting strategies for tumor immunotherapy, as well as the promise of new platelet-targeted tumor therapy methods through further research.

Mechanisms underlying aryl hydrocarbon receptor-driven divergent macrophage function

Macrophages play an essential role in the innate immune system by differentiating into functionally diverse subsets in order to fight infection, repair damaged tissues, and regulate inappropriate immune responses. This functional diversity stems from their ability to adapt and respond to signals in the environment, which is in part mediated through aryl hydrocarbon receptor (AHR)-signaling. AHR, an environmental sensor, can be activated by various ligands, ranging from environmental contaminants to microbially derived tryptophan metabolites. This review discusses what is currently known about how AHR-signaling influences macrophage differentiation, polarization, and function. By discussing studies that are both consistent and divergent, our goal is to highlight the need for future research on the mechanisms by which AHR acts as an immunological switch in macrophages. Ultimately, understanding the contexts in which AHR-signaling promotes and/or inhibits differentiation, proinflammatory functions, and immunoregulatory functions, will help uncover functional predictions of immunotoxicity following exposure to environmental chemicals as well as better design AHR-targeted immunotherapies.

Tumor-associated macrophages in anti-PD-1/PD-L1 immunotherapy for hepatocellular carcinoma: recent research progress

Hepatocellular carcinoma (HCC) is one of the cancers that seriously threaten human health. Immunotherapy serves as the mainstay of treatment for HCC patients by targeting the programmed cell death protein 1/programmed cell death 1 ligand 1 (PD-1/PD-L1) axis. However, the effectiveness of anti-PD-1/PD-L1 treatment is limited when HCC becomes drug-resistant. Tumor-associated macrophages (TAMs) are an important factor in the negative regulation of PD-1 antibody targeted therapy in the tumor microenvironment (TME). Therefore, as an emerging direction in cancer immunotherapy research for the treatment of HCC, it is crucial to elucidate the correlations and mechanisms between TAMs and PD-1/PD-L1-mediated immune tolerance. This paper summarizes the effects of TAMs on the pathogenesis and progression of HCC and their impact on HCC anti-PD-1/PD-L1 immunotherapy, and further explores current potential therapeutic strategies that target TAMs in HCC, including eliminating TAMs in the TME, inhibiting TAMs recruitment to tumors and functionally repolarizing M2-TAMs (tumor-supportive) to M1-TAMs (antitumor type).

Effect of the lymphocyte-to-monocyte ratio on the prognosis of patients with obstructive colorectal cancer with a colonic stent: a retrospective multicenter study in Japan

PURPOSE

The prognostic value of the lymphocyte-to-monocyte (LMR) ratio has been reported for various cancers, including colorectal cancer (CRC). The insertion of colonic stents is considered effective for patients with surgically indicated obstructive CRC, but their LMR can vary depending on factors such as inflammation associated with stent dilation and improvement of obstructive colitis. However, the usefulness of the LMR in patients with obstructive CRC and colonic stents and the optimal timing for its measurement remain unclear. We conducted this study to investigate the relationship between the pre-stent LMR and the mid-term prognosis of patients with obstructive CRC and stents as a bridge to surgery (BTS).

METHODS

The subjects of this retrospective multicenter study were 175 patients with pathological stage 2 or 3 CRC. Patients were divided into a low pre-stent LMR group (n = 87) and a high pre-stent LMR group (n = 83).

RESULTS

Only 3-year relapse-free survival differed significantly between the low and high pre-stent LMR groups (39.9% vs. 63.6%, respectively; p = 0.015). The pre-stent LMR represented a prognostic factor for relapse-free survival in multivariate analyses (hazard ratio 2.052, 95% confidence interval 1.242-3.389; p = 0.005), but not for overall survival.

CONCLUSIONS

A low pre-stent LMR is a prognostic factor for postoperative recurrence in patients with obstructive CRC and a colonic stent as a BTS.

Comparative Analysis of Inflammatory Indexes in Lung Cancer Patients With and Without Brain Metastases

Introduction Lung cancer is the leading cause of oncological deaths worldwide. Various combined inflammatory indexes, such as the systemic immune-inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), and platelet-to-lymphocyte ratio (PLR) have shown associations with pretreatment survival prognosis in patients suffering of lung cancer with or without brain metastases. This study aimed to compare the average values of NLR, PLR, LMR, and SII in healthy patients, patients with lung cancer without any other metastases, and patients with lung cancer and brain metastases. Materials and methods In this prospective study, we have divided the patients into three groups: Group 1 included patients diagnosed with lung cancer and one or more brain metastases of lung cancer origin, Group 2 included patients diagnosed with lung cancer without known metastases, and Group 3 was the control group which included healthy subjects. Preoperative complete blood counts were extracted for all included patients and we calculated the values of SII, NLR, PLR, and LMR for each individual patient in each group. The next step was to calculate the average values of SII, NLR, PLR, and LMR for each group of patients and to identify the differences between groups. Results A total number of 228 patients were enrolled in the study. Group 1 included 67 patients with average values of SII = 2020.98, NLR = 7.25, PLR = 199.46, and LMR = 2.97. Group 2 included 88 patients with average values of SII = 1638.01, NLR = 4.58, PLR = 188.42, and LMR = 3.43. Group 3 included 73 subjects with the following average values of the inflammatory indexes: SII = 577.41, NLR = 2.34, PLR = 117.84, and LMR = 3.56. Conclusion We observed statistically significant differences in SII, NLR, and PLR among the three groups of patients, suggesting their potential role as prognostic markers. Furthermore, our analysis revealed significant correlations between inflammatory markers within lung cancer patients, highlighting their involvement in tumor microenvironment modulation. Our findings demonstrate an escalation in SII, NLR, and PLR values as the disease progresses. These parameters of inflammation and immune status are readily and cost-effectively, and repeatedly assessable in routine clinical practice.

Engineering CRISPR/Cas9 therapeutics for cancer precision medicine

The discovery of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR-associated protein 9 (Cas9) technology has revolutionized field of cancer treatment. This review explores usage of CRISPR/Cas9 for editing and investigating genes involved in human carcinogenesis. It provides insights into the development of CRISPR as a genetic tool. Also, it explores recent developments and tools available in designing CRISPR/Cas9 systems for targeting oncogenic genes for cancer treatment. Further, we delve into an overview of cancer biology, highlighting key genetic alterations and signaling pathways whose deletion prevents malignancies. This fundamental knowledge enables a deeper understanding of how CRISPR/Cas9 can be tailored to address specific genetic aberrations and offer personalized therapeutic approaches. In this review, we showcase studies and preclinical trials that show the utility of CRISPR/Cas9 in disrupting oncogenic targets, modulating tumor microenvironment and increasing the efficiency of available anti treatments. It also provides insight into the use of CRISPR high throughput screens for cancer biomarker identifications and CRISPR based screening for drug discovery. In conclusion, this review offers an overview of exciting developments in engineering CRISPR/Cas9 therapeutics for cancer treatment and highlights the transformative potential of CRISPR for innovation and effective cancer treatments.

The ins and outs of microglial cells in brain health and disease

Microglia are the brain's resident macrophages that play pivotal roles in immune surveillance and maintaining homeostasis of the Central Nervous System (CNS). Microglia are functionally implicated in various cerebrovascular diseases, including stroke, aneurysm, and tumorigenesis as they regulate neuroinflammatory responses and tissue repair processes. Here, we review the manifold functions of microglia in the brain under physiological and pathological conditions, primarily focusing on the implication of microglia in glioma propagation and progression. We further review the current status of therapies targeting microglial cells, including their re-education, depletion, and re-population approaches as therapeutic options to improve patient outcomes for various neurological and neuroinflammatory disorders, including cancer.

Clotrimazole reverses macrophage M2 polarization by disrupting the PI3K/AKT/mTOR pathway

Macrophages switch among different activation phenotypes according to distinct environmental stimuli, varying from pro-inflammatory (M1) to alternative (also named resolutive; M2) activation forms. M1-and M2-activated macrophages represent the two extremes of the activation spectrum involving multiple species, which vary in terms of function and the cytokines secreted. The consensus is that molecular characterization of the distinct macrophage population and the signals driving their activation will help in explaining disease etiology and formulating therapies. For instance, myeloid cells residing in the tumor microenvironment are key players in tumor progression and usually display an M2-like phenotype, which help tumor cells to evade local inflammatory processes. Therefore, these specific cells have been proposed as targets for tumor therapies by changing their activation profile. Furthermore, M2 polarized macrophages are phagocytic cells promoting tissue repair and wound healing and are therefore potential targets to treat different diseases. We have already shown that clotrimazole (CTZ) decreases tumor cell viability and thus tumor growth. The mechanism by which CTZ exerts its effects remains to be determined, but this drug is an inhibitor of the PI3K/AKT/mTOR pathway. In this study, we show that CTZ downregulated M2-activation markers in macrophages polarized to the M2 profile. This effect occurred without interfering with the expression of M1-polarized markers or pro-inflammatory cytokines and signaling. Moreover, CTZ suppressed NFkB pathway intermediates and disrupted PI3K/AKT/mTOR signaling. We concluded that CTZ reverses macrophage M2 polarization by disrupting the PI3K/AKT/mTOR pathway, which results in the suppression of NFkB induction of M2 polarization. In addition, we find that CTZ represents a promising therapeutic tool as an antitumor agent.

Melatonin modulates L-arginine metabolism in tumor-associated macrophages by targeting arginase 1 in lymphoma

L-Arginine metabolism plays a crucial role in determining the M1/M2 polarization of macrophages. The M1 macrophages express inducible nitric oxide synthase (iNOS), while the M2 macrophages express arginase 1 and metabolize arginine into nitric oxide and urea, respectively. The tumor microenvironment promotes M2 macrophage polarization and consequently switches the metabolic fate of arginine from nitric oxide towards urea production. Importantly, infiltration of M2 macrophages or tumor-associated macrophages (TAMs) has been correlated with poor prognosis of various cancer types. Melatonin is well reported to have antitumor and immunomodulatory properties. However, whether and how it impacts the polarization of TAMs has not been elucidated. Considering the crucial role of arginine metabolism in macrophage polarization, we were interested to know the fate of L-arginine in TAMs and whether it can be reinstated by melatonin or not. We used a murine model of Dalton's lymphoma and established an in vitro model of TAMs. For TAMs, we used the ascitic fluid of tumor-bearing hosts to activate the macrophages in the presence and absence of lipopolysaccharide (LPS). In these groups, L-arginine metabolism was evaluated, and then the effect of melatonin was assessed in these groups, wherein the metabolic fate of arginine as well as the expression of iNOS and arginase 1 were checked. Furthermore, in the in vivo system of the tumor-bearing host, the effect of melatonin was assessed. The in vitro model of TAMs showed a Th2 cytokine profile, reduced phagocytic activity, and increased wound healing ability. Upon investigating arginine metabolism, we observed high urea levels with increased activity and expression of arginase 1 in TAMs. Furthermore, we observed reduced levels of LPS-induced nitric oxide in TAMs; however, their iNOS expression was comparable. With melatonin treatment, urea level decreased significantly, while the reduction in nitric oxide level was not as significant as observed in its absence in TAMs. Also, melatonin significantly reduced arginase activity and expression at the transcriptional and translational levels, while iNOS expression was affected only at the translational level. This effect was further investigated in the in vivo system, wherein melatonin treatment reversed the metabolic fate of arginine, from urea towards nitric oxide, within the tumor microenvironment. This effect was further correlated with pro-apoptotic tumor cell death in the in vivo system. Our results reinforced the immunomodulatory role of melatonin and offered a strong prospect for activating the anti-tumor immune response in cancer conditions.

Expression analysis of lymphocyte subsets and lymphocyte-to-monocyte ratio: reveling immunosuppression and chronic inflammation in breast cancer

OBJECTIVE

To explore the immune status and chronic inflammation of breast cancer patients, this study aims to analyze the diagnostic value of peripheral blood lymphocyte subsets (CD3+T, CD4+T, CD8+T, CD3+CD4-CD8-T, CD19+B, and NK cells) and lymphocyte-to-monocyte ratio (LMR) for breast cancer. Furthermore, it seeks to examine the correlation between these subsets and LMR with clinicopathological features.

METHODS

A total of 100 breast cancer patients were selected as the experimental group, while 55 patients with benign breast diseases were included in the control group. Statistical analysis, including the Wilcoxon test, Kruskal-Wallis test and the receiver operating characteristic curve, was employed to investigate the association between these serum indexes and the clinicopathological characteristics of the patients.

RESULTS

The levels of CD3+T cells, CD4+T cells, CD8+T cells, CD4+/CD8+ ratio, NK cells, CD3+CD4-CD8-T cells, and LMR were found to be related to the occurrence of breast cancer when analyzing data from patients with benign and malignant breast diseases. Among these biomarkers, CD3+T cells, CD4+T cells, CD4+/CD8+ ratio, CD3+CD4-CD8-T cells, and LMR were identified as independent risk factors for breast cancer development, and the AUCs were 0.760, 0.750, 0.598, 0.697, and 0.761 (P < 0.05), respectively. Furthermore, we observed varying degrees of differences in the expression of CD3+T cells, CD4+T cells, CD8+T cells, CD4+/CD8+ ratio, and LMR in lymph node metastasis, clinical staging, molecular typing, Ki-67 level (P < 0.05). However, statistical differences in histologic grade and pathology type were not found (P ≥ 0.05).

CONCLUSION

Lymphocyte subsets and LMR reflect the immune status and chronic inflammation of the body, respectively. They have certain value in the diagnosis of benign and malignant breast diseases, and correlate with lymph node metastasis, clinical staging, molecular typing and other clinicopathological features of breast cancer. Therefore, monitoring the expression of lymphocyte subsets and LMR in the body may help the auxiliary diagnosis and condition analysis of breast cancer in the clinic.

The role of extracellular vesicles in cholangiocarcinoma tumor microenvironment

Cholangiocarcinoma (CCA) is a highly aggressive malignant tumor that originates from the biliary system. With restricted treatment options at hand, the challenging aspect of early CCA diagnosis leads to a bleak prognosis. Besides the intrinsic characteristics of tumor cells, the generation and progression of CCA are profoundly influenced by the tumor microenvironment, which engages in intricate interactions with cholangiocarcinoma cells. Of notable significance is the role of extracellular vesicles as key carriers in enabling communication between cancer cells and the tumor microenvironment. This review aims to provide a comprehensive overview of current research examining the interplay between extracellular vesicles and the tumor microenvironment in the context of CCA. Specifically, we will emphasize the significant contributions of extracellular vesicles in molding the CCA microenvironment and explore their potential applications in the diagnosis, prognosis assessment, and therapeutic strategies for this aggressive malignancy.

Specific changes in amino acid profiles in monocytes of patients with breast, lung, colorectal and ovarian cancers

Introduction

Immunometabolism is essential factor of tumor progression, and tumor-associated macrophages are characterized by substantial changes in their metabolic status. In this study for the first time, we applied targeted amino acid LC-MS/MS analysis to compare amino acid metabolism of circulating monocytes isolated from patients with breast, ovarian, lung, and colorectal cancer.

Methods

Monocyte metabolomics was analyzed by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/ MS) analysis of amino acid extracts. The targeted analysis of 26 amino acids was conducted by LCMS/MS on an Agilent 6460 triple quadrupole mass spectrometer equipped with an electrospray ionization source and an Agilent 1260 II liquid chromatograph.

Results

Comparison of monocytes of cancer patients with monocytes of healthy control individuals demonstrated that in breast cancer most pronounced changes were identified for tryptophan (AUC = 0.76); for ovarian cancer, aminobutyric acid was significantly elevated (AUC= 1.00); for lung cancer significant changes we indented for citrulline (AUC = 0.70). In order to identify key amino acids that are characteristic for monocytes in specific cancer types, we compared each individual cancer with other 3 types of cancer. We found, that aspartic acid and citrulline are specific for monocytes of patients with colorectal cancer (p<0.001, FC = 1.40 and p=0.003, FC = 1.42 respectively). Citrulline, sarcosine and glutamic acid are ovarian cancer-specific amino acids (p = 0.003, FC = 0.78, p = 0.003, FC = 0.62, p = 0.02, FC = 0.78 respectively). Glutamine, methionine and phenylalanine (p = 0.048, FC = 1.39. p = 0.03, FC = 1.27 and p = 0.02, FC = 1.41) are lung cancer-specific amino acids. Ornithine in monocytes demonstrated strong positive correlation (r = 0.63) with lymph node metastasis incidence in breast cancer patients. Methyl histidine and cysteine in monocytes had strong negative correlation with lymph node metastasis in ovarian cancer patients (r = -0.95 and r = -0.95 respectively). Arginine, citrulline and ornithine have strong negative correlation with tumor size (r = -0.78, citrulline) and lymph node metastasis (r = -0.63 for arginine and r = -0.66 for ornithine).

Discussion

These alterations in monocyte amino acid metabolism can reflect the reaction of systemic innate immunity on the growing tumor. Our data indicate that this metabolic programming is cancer specific and can be inhibiting cancer progression. Cancer-specific differences in citrulline, as molecular link between metabolic pathways and epigenetic programing, provide new option for the development and validation of anti-cancer therapies using inhibitors of enzymes catalyzing citrullination.

Targeting the immune microenvironment for ovarian cancer therapy

Ovarian cancer (OC) is an aggressive malignancy characterized by a complex immunosuppressive tumor microenvironment (TME). Immune checkpoint inhibitors have emerged as a breakthrough in cancer therapy by reactivating the antitumor immune response suppressed by tumor cells. However, in the case of OC, these inhibitors have failed to demonstrate significant improvements in patient outcomes, and existing biomarkers have not yet identified promising subgroups. Consequently, there remains a pressing need to understand the interplay between OC tumor cells and their surrounding microenvironment to develop effective immunotherapeutic approaches. This review aims to provide an overview of the OC TME and explore its potential as a therapeutic strategy. Tumor-infiltrating lymphocytes (TILs) are major actors in OC TME. Evidence has been accumulating regarding the spontaneous TILS response against OC antigens. Activated T-helpers secrete a wide range of inflammatory cytokines with a supportive action on cytotoxic T-cells. Simultaneously, mature B-cells are recruited and play a significant antitumor role through opsonization of target antigens and T-cell recruitment. Macrophages also form an important subset of innate immunity (M1-macrophages) while participating in the immune-stimulation context. Finally, OC has shown to engage a significant natural-killer-cells immune response, exerting direct cytotoxicity without prior sensitization. Despite this initial cytotoxicity, OC cells develop various strategies to induce an immune-tolerant state. To this end, multiple immunosuppressive molecules are secreted to impair cytotoxic cells, recruit regulatory cells, alter antigen presentation, and effectively evade immune response. Consequently, OC TME is predominantly infiltrated by immunosuppressive cells such as FOXP3+ regulatory T-cells, M2-polarized macrophages and myeloid-derived suppressor cells. Despite this strong immunosuppressive state, PD-1/PD-L1 inhibitors have failed to improve outcomes. Beyond PD-1/PD-L1, OC expresses multiple other immune checkpoints that contribute to immune evasion, and each representing potential immune targets. Novel immunotherapies are attempting to overcome the immunosuppressive state and induce specific immune responses using antibodies adoptive cell therapy or vaccines. Overall, the OC TME presents both opportunities and obstacles. Immunotherapeutic approaches continue to show promise, and next-generation inhibitors offer exciting opportunities. However, tailoring therapies to individual immune characteristics will be critical for the success of these treatments.

Mutations in the DNA polymerase binding pathway affect the immune microenvironment of patients with small-cell lung cancer and enhance the efficacy of platinum-based chemotherapy

Background

Small-cell lung cancer (SCLC) is characterized by its high malignancy and is associated with a poor prognosis. In the early stages of the disease, platinum-based chemotherapy is the recommended first-line treatment and has demonstrated efficacy. However, SCLC is prone to recurrence and is generally resistant to chemotherapy in its later stages.

Methods

Here, we collected samples from SCLC patients who received platinum-based chemotherapy, performed genomic and transcriptomic analyses, and validated our results with publicly available data.

Results

SCLC patients with DNA polymerase binding pathway mutations had an improved prognosis after platinum chemotherapy compared with patients without such mutations. Patients in the mutant (MT) group had higher infiltration of T cells, B cells, and M1 macrophages compared with patients without DNA polymerase binding pathway mutations.

Conclusions

DNA polymerase binding pathway mutations can be used as prognostic markers for platinum-based chemotherapy in SCLC.

The Evolving Landscape of Antibody-Drug Conjugates: In Depth Analysis of Recent Research Progress

Antibody-drug conjugates (ADCs) are targeted immunoconjugate constructs that integrate the potency of cytotoxic drugs with the selectivity of monoclonal antibodies, minimizing damage to healthy cells and reducing systemic toxicity. Their design allows for higher doses of the cytotoxic drug to be administered, potentially increasing efficacy. They are currently among the most promising drug classes in oncology, with efforts to expand their application for nononcological indications and in combination therapies. Here we provide a detailed overview of the recent advances in ADC research and consider future directions and challenges in promoting this promising platform to widespread therapeutic use. We examine data from the CAS Content Collection, the largest human-curated collection of published scientific information, and analyze the publication landscape of recent research to reveal the exploration trends in published documents and to provide insights into the scientific advances in the area. We also discuss the evolution of the key concepts in the field, the major technologies, and their development pipelines with company research focuses, disease targets, development stages, and publication and investment trends. A comprehensive concept map has been created based on the documents in the CAS Content Collection. We hope that this report can serve as a useful resource for understanding the current state of knowledge in the field of ADCs and the remaining challenges to fulfill their potential.

Histological spatial analysis on the induction of PD-L1+ macrophages by CD8+ T cells at the marginal microenvironment of triple-negative breast cancer

BACKGROUND

Programmed death-ligand 1 (PD-L1) plays important roles in the evasion of antitumor immunity. Because we observed the localization of PD-L1-positive (PD-L1+) cells in the marginal region of triple-negative breast cancer (TNBC) specimens, we hypothesized that the marginal microenvironment of TNBC would involve the induction of PD-L1+ cells.

METHODS

One hundred and one TNBC surgical specimens were examined. We performed immunohistochemical (IHC) studies of PD-L1, CD68, CD8, and pan-cytokeratin in these specimens. We analyzed the localization of IHC-positive cells and the distance between these cells by histological spatial analysis.

RESULTS

In 30.7% of TNBC specimens, PD-L1+ cells were located in the marginal region. Approximately three PD-L1+ cells accumulated around a single TNBC cell. Most PD-L1+ cells were located within 50 μm of TNBC cells. PD-L1+ cells were indicated to interact with TNBC cells in the marginal region. PD-L1+CD68+ cells were located in the marginal region, while CD68+ macrophages (MΦs) were observed either in the marginal region or the core region. PD-L1 expression in MΦs was induced in the marginal region. The colocalization of CD8+ T cells in the marginal region indicates that PD-L1 expression in MΦs would be induced by interaction with CD8+ T cells. Because CD8+ T cells are positive for CCL2, CCL2 may induce PD-L1 expression in MΦs.

CONCLUSION

At the marginal microenvironment of TNBC, PD-L1 expression would be induced in MΦs by interaction with CD8+ T cells through CCL2. The interaction between PD-L1+ MΦs and TNBC cells would facilitate the growth of TNBC under antitumor immunity. These interactions would be potential targets for restoring antitumor immunity and suppressing TNBC progression.

Tumor-Infiltrating Lymphocytes and Adoptive Cell Therapy: State of the Art in Colorectal, Breast and Lung Cancer

Our knowledge of tumor-infiltrating lymphocytes (TILs) is dramatically expanding. These cells have proven prognostic and therapeutic value for many cancer outcomes and potential to treat also disseminated breast, colorectal, or lung cancer. However, the therapeutical outcome of TILs is negatively affected by tumor mutational burden and neoantigens. On the other hand, it can be improved in combination with checkpoint blockade therapy. This knowledge and rapid detection techniques alongside gene editing allow us to classify and modify T cells in many ways. Hence, to tailor them precisely to the patient´s needs as to program T cell receptors to recognize specific tumor-associated neoantigens and to insert them into lymphocytes or to select tumor neoantigen-specific T cells, for the development of vaccines that recognize tumor-specific antigens in tumors or metastases. Further studies and clinical trials in the field are needed for an even better-detailed understanding of TILs interactions and aiming in the fight against multiple cancers.

Modifiable risk factors linked to the development of rheumatoid arthritis: evidence, immunological mechanisms and prevention

Rheumatoid Arthritis (RA) is a common autoimmune disease that targets the synovial joints leading to arthritis. Although the etiology of RA remains largely unknown, it is clear that numerous modifiable risk factors confer increased risk to developing RA. Of these risk factors, cigarette smoking, nutrition, obesity, occupational exposures and periodontal disease all incrementally increase RA risk. However, the precise immunological mechanisms by which these risk factors lead to RA are not well understood. Basic and translational studies have provided key insights into the relationship between inflammation, antibody production and the influence in other key cellular events such as T cell polarization in RA risk. Improving our general understanding of the mechanisms which lead to RA will help identify targets for prevention trials, which are underway in at-risk populations. Herein, we review the modifiable risk factors that are linked to RA development and describe immune mechanisms that may be involved. We highlight the few studies that have sought to understand if modification of these risk factors reduces RA risk. Finally, we speculate that modification of risk factors may be an appealing avenue for prevention for some at-risk individuals, specifically those who prefer lifestyle interventions due to safety and economic reasons.

Ethnic disparities in the immune microenvironment of triple negative breast cancer and its role in therapeutic outcomes

In 2020, newly diagnosed breast cancer (BC) cases surpassed that of lung cancer among women, making it the most common female cancer globally. In spite of recent increases in incidence rates, mortality due to BC has declined since 1989. These declines have been attributed to advancements in treatment modalities as well as increased mammography surveillance. Despite these advances, African American (AA) women are 40% more likely to die from BC than Caucasian women. Multifactorial etiology has been implicated in the disparity of BC mortality rates among AA women. As an example, AA women have a disproportionate incidence of triple negative breast cancer (TNBC), which has a poor prognosis and marginal treatment options. Increasingly, the tumor microenvironment (TME) has gained relevance as it relates to primary tumor progression, metastasis and treatment possibilities. The treatment outcomes or pathological complete response (pCR) in TNBC among AA women are affected by differences in TME. The TME of AA women exhibit several variances in acellular and cellular components associated with pro-tumorigenic effects. For example, increased levels of the adipocyte-related hormone, resistin, the pro-inflammatory cytokine, IL-6, and the CC chemokine, CCL2, within the TME of AA women gives rise to an increased density of M2 macrophages, also known as tumor-associated macrophages. Elevated levels of vascular endothelial growth factor in the TME of AA women increase the vascular density or vascularity, which facilitate aggressive tumor growth and metastasis. Furthermore, a pro-tumorigenic TME is supported by increased levels of the CXC chemokine, CXCL12 that results in the recruitment of regulatory T lymphocytes (Tregs ). Due to these and other differences in the TME of AA women, precision oncology can target specific aspects of the TME that may contribute to a poorer prognosis. In addition to the discrepancies in the TME, AA women face socio-economic barriers that limit their ability to access state-of-the-art, novel therapies against metastatic TNBC. In this review, we will provide a brief overview of the tumor immune microenvironment, immune-based treatment options for TNBC and their potential to decrease health disparities due to ethnicity.

Function and clinical application of exosome-how to improve tumor immunotherapy?

In recent years, immunotherapy has been increasingly used in clinical practice to treat tumors. However, immunotherapy's efficacy varies between tumor types and patient populations, and long-term drug resistance often occurs during treatment. Therefore, it is essential to explore the molecular mechanisms of immunotherapy to improve its efficacy. In this review, we focus on the significance of tumor-derived exosomes in the clinical treatment of tumors and how modifying these exosomes may enhance immune effectiveness. Specifically, we discuss exosome components, such as RNA, lipids, and proteins, and the role of membrane molecules on exosome surfaces. Additionally, we highlight the importance of engineered exosomes for tumor immunotherapy. Our goal is to propose new strategies to improve the efficacy of tumor immunotherapy.

Shedding light on macrophage immunotherapy in lung cancer

The search for therapeutic options for lung cancer continues to advance, with rapid advances in the search for therapies to improve patient prognosis. At present, systemic chemotherapy, immune checkpoint inhibitor therapy, antiangiogenic therapy, and targeted therapy for driver gene positivity are available in the clinic. Common clinical treatments fail to achieve desired outcomes due to immunosuppression of the tumor microenvironment (TME). Tumor immune evasion is mediated by cytokines, chemokines, immune cells, and other cells such as vascular endothelial cells within the tumor immune microenvironment. Tumor-associated macrophages (TAMs) are important immune cells in the TME, inducing tumor angiogenesis, encouraging tumor cell proliferation and migration, and suppressing antitumor immune responses. Thus, TAM targeting becomes the key to lung cancer immunotherapy. This review focuses on macrophage phenotype, polarization mechanism, role in lung cancer, and advances in macrophage centric immunotherapies.

Epithelial multicellular clustering enabled by polarized macrophages on soft matrices

Formation of epithelial structures of variegated geometries and sizes is essential for organogenesis, tumor growth, and wound repair. Although epithelial cells are predisposed with potential for multicellular clustering, it remains unclear whether immune cells and mechanical cues from their microenvironment influence this process. To explore this possibility, we cocultured human mammary epithelial cells with prepolarized macrophages on soft or stiff hydrogels. In the presence of M1 (proinflammatory) macrophages on soft matrices, epithelial cells migrated faster and subsequently formed larger multicellular clusters compared to cocultures with M0 (unpolarized) or M2 (anti-inflammatory) macrophages. By contrast, stiff matrices disabled active clustering of epithelial cells due to their enhanced migration and cell-ECM adhesion, regardless of macrophage polarization. We found that the copresence of soft matrices and M1 macrophages reduced focal adhesions, but enhanced fibronectin deposition and nonmuscle myosin-IIA expression, which altogether optimize conditions for epithelial clustering. Upon ROCK inhibition, epithelial clustering was abrogated, indicating a requirement for optimized cellular forces. In these cocultures, TNF-α secretion was the highest with M1 macrophages and TGF-β secretion was exclusively detectable in case of M2 macrophages on soft gels, which indicated potential role of macrophage secreted factors in the observed epithelial clustering. Indeed, exogenous addition of TGF-β promoted epithelial clustering with M1 coculture on soft gels. According to our findings, optimization of both mechanical and immune factors can tune epithelial clustering responses, which could have implications in tumor growth, fibrosis, and would healing.

Tumor Immune Microenvironment in Gynecologic Cancers

Gynecologic cancers have varying response rates to immunotherapy due to the heterogeneity of each cancer's molecular biology and features of the tumor immune microenvironment (TIME). This article reviews key features of the TIME and its role in the pathophysiology and treatment of ovarian, endometrial, cervical, vulvar, and vaginal cancer. Knowledge of the role of the TIME in gynecologic cancers has been rapidly developing with a large body of preclinical studies demonstrating an intricate yet dichotomous role that the immune system plays in either supporting the growth of cancer or opposing it and facilitating effective treatment. Many targets and therapeutics have been identified including cytokines, antibodies, small molecules, vaccines, adoptive cell therapy, and bacterial-based therapies but most efforts in gynecologic cancers to utilize them have not been effective. However, with the development of immune checkpoint inhibitors, we have started to see the rapid and successful employment of therapeutics in cervical and endometrial cancer. There remain many challenges in utilizing the TIME, particularly in ovarian cancer, and further studies are needed to identify and validate efficacious therapeutics.

Therapies Targeting Immune Cells in Tumor Microenvironment for Non-Small Cell Lung Cancer

The tumor microenvironment (TME) plays critical roles in immune modulation and tumor malignancies in the process of cancer development. Immune cells constitute a significant component of the TME and influence the migration and metastasis of tumor cells. Recently, a number of therapeutic approaches targeting immune cells have proven promising and have already been used to treat different types of cancer. In particular, PD-1 and PD-L1 inhibitors have been used in the first-line setting in non-small cell lung cancer (NSCLC) with PD-L1 expression ≥1%, as approved by the FDA. In this review, we provide an introduction to the immune cells in the TME and their efficacies, and then we discuss current immunotherapies in NSCLC and scientific research progress in this field.

Evaluation of the association of chronic inflammation and cancer: Insights and implications

Among the most extensively researched processes in the development and treatment of cancer is inflammatory condition. Although acute inflammation is essential for the wound healing and reconstruction of tissues that have been damaged, chronic inflammation may contribute to the onset and growth of a number of diseases, including cancer. By disrupting the signaling processes of cells, which result in cancer induction, invasion, and development, a variety of inflammatory molecules are linked to the development of cancer. The microenvironment surrounding the tumor is greatly influenced by inflammatory cells and their subsequent secretions, which also contribute significantly to the tumor's growth, survivability, and potential migration. These inflammatory variables have been mentioned in several publications as prospective diagnostic tools for anticipating the onset of cancer. Targeting inflammation with various therapies can reduce the inflammatory response and potentially limit or block the proliferation of cancer cells. The scientific medical literature from the past three decades has been studied to determine how inflammatory chemicals and cell signaling pathways related to cancer invasion and metastasis are related. The current narrative review updates the relevant literature while highlighting the specifics of inflammatory signaling pathways in cancer and their possible therapeutic possibilities.

Cancer immune exclusion: breaking the barricade for a successful immunotherapy

Immunotherapy has changed the course of cancer treatment. The initial steps were made through tumor-specific antibodies that guided the setup of an antitumor immune response. A new and successful generation of antibodies are designed to target immune checkpoint molecules aimed to reinvigorate the antitumor immune response. The cellular counterpart is the adoptive cell therapy, where specific immune cells are expanded or engineered to target cancer cells. In all cases, the key for achieving positive clinical resolutions rests upon the access of immune cells to the tumor. In this review, we focus on how the tumor microenvironment architecture, including stromal cells, immunosuppressive cells and extracellular matrix, protects tumor cells from an immune attack leading to immunotherapy resistance, and on the available strategies to tackle immune evasion.

Barrier permeation and improved nanomedicine delivery in tumor microenvironments

Nanomedicines can effectively penetrate tumor sites compared to traditionally used drugs. However, effective drugs that reach the interior of tumors remain limited. Based on studies of the complex tumor microenvironment, we summarized the barriers restricting tumor penetration of nanomedicines in this review. Penetration barriers are mainly caused by tumor blood vessels, stroma, and cell abnormalities. The repair of abnormal tumor blood vessels and tumor stroma and adjusting the physicochemical properties of nanoparticles are considered promising strategies to improve the tumor permeation of nanomedicines. The effects of nanoparticle properties, including size, shape, and surface charge, on tumor penetration were also reviewed. We expect to provide research ideas and a scientific basis for nanomedicines to increase intratumoral permeability and improve anti-tumor effects.

Association between Posttreatment Serum Platelet-to-Lymphocyte Ratio and Distant Metastases in Patients with Hepatocellular Carcinoma Receiving Curative Radiation Therapy

Background: We sought to investigate whether serum immune and inflammatory parameters can help to predict distant metastasis (DM) in patients with unresectable hepatocellular carcinoma (HCC) undergoing curative radiation therapy (RT). Methods: A total of 76 RT courses were analyzed. The following variables were included in the analysis: systemic inflammation index, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio (PLR), prognostic nutritional index (PNI), absolute lymphocyte count, lymphocyte-to-monocyte ratio, albumin, albumin-to-alkaline phosphatase ratio, RT-related parameters, and levels of total protein, hemoglobin, α-fetoprotein, and PIVKA-II. Distant control (DC) and overall survival (OS) rates were calculated and compared. Results: The mean age was 61.4 years, and most patients were men (n = 62, 81.6%). The median RT fraction number and fractional doses were 12 (range, 4–30) and 5 (range, 2–12) Gy, respectively. With a median follow-up of 12 (range, 3.1–56.7) months, the 1-year DC and OS rates were 64.4% and 55.2%, respectively. The development of DM significantly deteriorated OS (p = 0.013). In the multivariate analysis, significant independent prognostic indicators for DC and OS rates were the highest posttreatment PLR (≤235.7 vs. >235.7, p = 0.006) and the lowest posttreatment PNI (≤25.4 vs. >25.4, p < 0.001), respectively. Conclusions: Posttreatment serum PLR might be helpfully used as a predictive biomarker of DM in unresectable HCC patients undergoing RT. Future research is necessary to confirm our findings.

Vorinostat decrease M2 macrophage polarization through ARID1A6488delG/HDAC6/IL-10 signaling pathway in endometriosis-associated ovarian carcinoma

Endometriosis is a common disease in women and may be one of the factors that induces malignant epithelial ovarian tumors. Previous studies suggested that endometriosis is related to ARID1A mutation mediating the expression of HDAC6, but the detailed pathogenic mechanism is still unclear. First, we collected endometriosis-associated ovarian carcinoma (EAOC) clinical samples and examined the expression of HDAC6. Our results found that the high HDAC6 expression group was positively correlated with EAOC histology (P = 0.015), stage (P < 0.000), and tumor size (P < 0.000) and inversely correlated with survival (P < 0.000). We also found that ARID1A^6488delG/HDAC6 induced M2 polarization of macrophages through IL-10. In addition, the HDAC inhibitor (HDACi) vorinostat inhibited cell growth and blocked the effect of HDAC6. Tomographic microscopy was used to monitor the live cell morphology of these treated cells, and we found that vorinostat treatment resulted in substantial cell apoptosis by 3 h 42 min. Next, we established a transgenic mouse model of EAOC and found that vorinostat significantly reduced the size of ovarian tumors by inhibiting M2 macrophage polarization in mice. Together, these data demonstrate that the signaling pathway of E4F1/ARID1A^6488delG/HDAC6/GATA3 mediates macrophage polarization and provides a novel immune cell-associated therapeutic strategy targeting IL-10 in EAOC.

A positive feedback loop driven by fibronectin and IL-1β sustains the inflammatory microenvironment in breast cancer

Inflammatory alterations of the extracellular matrix shape the tumor microenvironment and promote all stages of carcinogenesis. This study aims to determine the impact of cellular fibronectin on inflammatory facets of tumor-associated macrophages (TAMs) in breast cancer. Cellular fibronectin (FN) harboring the alternatively spliced extra domain A (FN-EDA) was determined to be a matrix component produced by the triple-negative breast cancer (TNBC) cells. High levels of FN-EDA correlated with poor survival in breast cancer patients. The proinflammatory cytokine IL-1β enhanced the expression of cellular fibronectin including FN-EDA. TAMs were frequently observed in the tumor areas rich in FN-EDA. Conditioned media from TNBC cells induced the differentiation of CD206⁺CD163⁺ macrophages and stimulated the STAT3 pathway, ex vivo. In the macrophages, the STAT3 pathway enhanced FN-EDA-induced IL-1β secretion and NF-κB signaling. In conclusion, our data indicate a self-reinforcing mechanism sustained by FN-EDA and IL-1β through NF-κB and STAT3 signaling in TAMs which fosters an inflammatory environment in TNBC.

Arsenic trioxide elicits anti-tumor activity by inhibiting polarization of M2-like tumor-associated macrophages via Notch signaling pathway in lung adenocarcinoma

Drug-resistant advanced lung adenocarcinoma (LUAD) is an aggressive malignancy with limited treatment options. A therapeutic strategy for drug-resistant LUAD is to target the tumor associated macrophages (TAMs), because they play an important role in tumor immune escape, progression and metastasis. In this study, we conducted in vivo and in vitro investigation of the inhibitory effect of arsenic trioxide (ATO) on polarization of TAMs educated by LUAD. We found that ATO at a concentration of 4 μM disrupted the Notch-dependent positive feedback loop between LUAD and TAMs. In this loop, ATO inhibited the expression of Jagged1 and Notch1 in LUAD and suppressed M2 polarization via down-regulating Notch-dependent paracrine of CCL2 and IL1β. As a result, the secretion of M2-derived TGF-β1 decreased, thus inducing inhibitions of LUAD proliferation, migration, invasion, colony formation and epithelial-mesenchymal transition. In xenograft mouse models, ATO significantly inhibited tumor growth and down-regulated infiltration of M2-like TAMs in tumor tissues. In clinical LUAD biopsy samples, high Jagged1/Notch1 expression positively correlated with tumor-infiltrated M2-like TAMs, leading to poor prognosis. In conclusion, our results identified a novel tumor immunomodulating function for ATO, which can inhibit the polarization of M2-type TAMs to exert anti-tumor effects in the tumor microenvironment. Our results demonstrated the translational potential of repurposing ATO to target TAMs for lung adenocarcinoma treatment.

Epithelial multicellular clustering enabled by polarized macrophages on soft matrices

Formation of epithelial structures of variegated geometries and sizes is essential for organogenesis, tumor growth, and wound repair. Although epithelial cells are predisposed with potential for multicellular clustering, it remains unclear whether immune cells and mechanical cues from their microenvironment influence this process. To explore this possibility, we co-cultured human mammary epithelial cells with pre-polarized macrophages on soft or stiff hydrogels. In the presence of M1 (proinflammatory) macrophages on soft matrices, epithelial cells migrated faster and subsequently formed larger multicellular clusters, compared to co-cultures with M0 (unpolarized) or M2 (anti-inflammatory) macrophages. By contrast, stiff extracellular matrix (ECM) disabled active clustering of epithelial cells due to their enhanced migration and cell-ECM adhesion, regardless of macrophage polarization. We found that the co-presence of soft matrices and M1 macrophages reduced focal adhesions, but enhanced fibronectin deposition and non-muscle myosin-IIA expression, which altogether optimize conditions for epithelial clustering. Upon Rho-associated kinase (ROCK) inhibition, epithelial clustering was abrogated, indicating a requirement for optimized cellular forces. In these co-cultures, Tumor Necrosis Factor (TNF)-α secretion was the highest with M1 macrophages and Transforming growth factor (TGF)-β secretion was exclusively detectable in case of M2 macrophages on soft gels, which indicated potential role of macrophage secreted factors in the observed epithelial clustering. Indeed, exogenous addition of TGB-β promoted epithelial clustering with M1 co-culture on soft gels. According to our findings, optimization of both mechanical and immune factors can tune epithelial clustering responses, which could have implications in tumor growth, fibrosis, and would healing.

Summary

Authors show proinflammatory macrophages on soft matrices enable epithelial cells to form multicellular clusters. This phenomenon is disabled on stiff matrices due to increased stability of focal adhesions. Inflammatory cytokine secretion is macrophage-dependent, and external addition of cytokines accentuates epithelial clustering on soft matrices.

Impact Statement

Formation of multicellular epithelial structures is critical to tissue homeostasis. However, it has not been shown how the immune system and mechanical environment affect these structures. The present work illustrates how macrophage type affects epithelial clustering in soft and stiff matrix environments.

Fashionable, but What is Their Real Clinical Usefulness? NLR, LMR, and PLR as a Promising Indicator in Colorectal Cancer Prognosis: A Systematic Review

The link between inflammation and cancer is still an attractive subject of many studies because systemic inflammatory response has been proven to play a pivotal role in cancer progression and metastasis. The strongest relationship between chronic inflammation and cancer development is observed in colorectal cancer (CRC). The evaluation of ratios derived from the routinely performed inflammatory biomarkers shows limited performances and limited clinical utility when individually used as prognostic factors for patients with CRC. In this review, we would like to summarize the latest knowledge about the diagnostic utility of systemic inflammatory ratios: neutrophil/lymphocyte (NLR), lymphocyte/monocyte (LMR), and platelet/lymphocyte (PLR) in CRC. We focused on the papers that assessed the diagnostic utility of blood cell parameters on the basis of the area under the ROC curve published in the recent 6 years. Identification of biomarkers that are significantly associated with prognostic in cancer would help the selection of patients with a high risk of poor outcomes.

Synergistic effect of CD47 blockade in combination with cordycepin treatment against cancer

Cordycepin is widely considered a direct tumor-suppressive agent. However, few studies have investigated as the effect of cordycepin therapy on the tumor microenvironment (TME). In our present study, we demonstrated that cordycepin could weaken the function of M1-like macrophages in the TME and also contribute to macrophage polarization toward the M2 phenotype. Herein, we established a combined therapeutic strategy combining cordycepin and an anti-CD47 antibody. By using single-cell RNA sequencing (scRNA-seq), we showed that the combination treatment could significantly enhance the effect of cordycepin, which would reactivate macrophages and reverse macrophage polarization. In addition, the combination treatment could regulate the proportion of CD8⁺ T cells to prolong the progression-free survival (PFS) of patients with digestive tract malignancies. Finally, flow cytometry validated the changes in the proportions of tumor-associated macrophages (TAMs) and tumor-infiltrating lymphocytes (TILs). Collectively, our findings suggested that the combination treatment of cordycepin and the anti-CD47 antibody could significantly enhance tumor suppression, increase the proportion of M1 macrophages, and decrease the proportion of M2 macrophages. In addition, the PFS in patients with digestive tract malignancies would be prolonged by regulating CD8 ⁺ T cells.

Effects of the interactions between platelets with other cells in tumor growth and progression

It has been confirmed that platelets play a key role in tumorigenesis. Tumor-activated platelets can recruit blood cells and immune cells to migrate, establish an inflammatory tumor microenvironment at the sites of primary and metastatic tumors. On the other hand, they can also promote the differentiation of mesenchymal cells, which can accelerate the proliferation, genesis and migration of blood vessels. The role of platelets in tumors has been well studied. However, a growing number of studies suggest that interactions between platelets and immune cells (e.g., dendritic cells, natural killer cells, monocytes, and red blood cells) also play an important role in tumorigenesis and tumor development. In this review, we summarize the major cells that are closely associated with platelets and discuss the essential role of the interaction between platelets with these cells in tumorigenesis and tumor development.

Behavioral factors to modulate immunotherapy efficacy in cancer

Immune checkpoint inhibitors, including anti-PD-1 and anti-CTLA-4 therapies, are used to (re)activate the immune system to treat cancer. Despite promising results, a large group of patients does not respond to checkpoint inhibition. In the vulnerability-stress model of behavioral medicine, behavioral factors, such as stress, exercise and classical pharmacological conditioning, predict cancer incidence, recurrence and the efficacy of conventional cancer treatments. Given the important role of the immune system in these processes, certain behavior may be promising to complement immune checkpoint inhibition therapy. Here, we discuss the preliminary evidence and suitability of three behavioral mechanisms, i.e. stress modulation, exercise and classical pharmacological conditioning for the benefit of immunotherapy. It is crucial to study the potential beneficial effects of behavioral strategies that support immunotherapeutic anti-tumor effects with rigorous experimental evidence, to exploit behavioral mechanisms in improving checkpoint inhibition efficacy.

Psychosocial stress and cancer risk: a narrative review

BACKGROUND

It is unclear which psychological factors (stressors, emotional correlates, and psychophysiological markers) induce cancer risk. This currently limits the potential for prevention strategies.

PURPOSE

The aim of this review is to bring forth evidence of stress as a determinant of cancer risk from a public health perspective, written for a broad public of practitioners and scientists.

METHODS

Based on a semisystematic literature search, the impact of different aspects/types of stress and the potential physiological and behavioral pathways are summarized, while highlighting further research, public health and clinical implications.

RESULTS

Between 2007 and 2020, 65 case-control or cohort studies have been identified. Apart from overall cancer ( N = 24), 12 cancer types have been associated with psychological stress with most for breast ( N = 21), colorectal ( N = 11) and lung/prostate/pancreas cancer ( N = 8 each). Although the evidence regarding the mechanisms is still scarce, cancer development in relation to stress might be due to interacting and combined effects of different stress(or) types, but such interaction has not really been tested yet. The path from stress towards cancer incidence consists of a biological pathway with endocrinology and immunology as well as stress-induced behavioral pathways, including smoking, alcoholism, sleep disruption, an unhealthy diet, and low physical activity together with the related phenomenon of obesity.

CONCLUSION

Not only the stress but also the stress-induced lifestyle should be targeted for cancer prevention and treatment. Future research should include a more diverse spectrum of cancer types (not only hormonal related like breast cancer) and of stress measures while also considering behavioral covariates.

Engineered exosomes for studies in tumor immunology

Exosomes are a type of extracellular vesicle (EV) with diameters of 30-150 nm secreted by most of the cells into the extracellular spaces and can alter the microenvironment through cell-to-cell interactions by fusion with the plasma membrane and subsequent endocytosis and release of the cargo. Because of their biocompatibility, low toxicity and immunogenicity, permeability (even through the blood-brain barrier (BBB)), stability in biological fluids, and ability to accumulate in the lesions with higher specificity, investigators have started making designer's exosomes or engineered exosomes to carry biologically active protein on the surface or inside the exosomes as well as using exosomes to carry drugs, micro RNA, and other products to the site of interest. In this review, we have discussed biogenesis, markers, and contents of various exosomes including exosomes of immune cells. We have also discussed the current methods of making engineered and designer's exosomes as well as the use of engineered exosomes targeting different immune cells in the tumors, stroke, as well as at peripheral blood. Genetic engineering and customizing exosomes create an unlimited opportunity to use in diagnosis and treatment. Very little use has been discovered, and we are far away to reach its limits.

Self-Renewal of Macrophages: Tumor-Released Factors and Signaling Pathways

Macrophages are the most abundant immune cells of the tumor microenvironment (TME) and have multiple important functions in cancer. During tumor growth, both tissue-resident macrophages and newly recruited monocyte-derived macrophages can give rise to tumor-associated macrophages (TAMs), which have been associated with poor prognosis in most cancers. Compelling evidence indicate that the high degree of plasticity of macrophages and their ability to self-renew majorly impact tumor progression and resistance to therapy. In addition, the microenvironmental factors largely affect the metabolism of macrophages and may have a major influence on TAMs proliferation and subsets functions. Thus, understanding the signaling pathways regulating TAMs self-renewal capacity may help to identify promising targets for the development of novel anticancer agents. In this review, we focus on the environmental factors that promote the capacity of macrophages to self-renew and the molecular mechanisms that govern TAMs proliferation. We also highlight the impact of tumor-derived factors on macrophages metabolism and how distinct metabolic pathways affect macrophage self-renewal.

A microfluidic model of human vascularized breast cancer metastasis to bone for the study of neutrophil-cancer cell interactions

The organ-specific metastatization of breast cancer to bone is driven by specific interactions between the host microenvironment and cancer cells (CCs). However, it is still unclear the role that circulating immune cells, including neutrophils, play during bone colonization (i.e. pro-tumoral vs. anti-tumoral). Here, we aimed at analyzing the migratory behavior of neutrophils when exposed to breast CCs colonizing the bone and their contribution to the growth of breast cancer micrometastases. Based on our previous bone metastasis models, we designed a microfluidic system that allows to independently introduce human vascularized breast cancer metastatic seeds within a bone-mimicking microenvironment containing osteo-differentiated mesenchymal stromal cells and endothelial cells (ECs). ECs self-assembled into microvascular networks and connected the bone-mimicking microenvironment with the metastatic seed. Compared to controls without CCs, metastatic seeds compromised the architecture of microvascular networks resulting in a lower number of junctions (5.7 ​± ​1.2 vs. 18.8 ​± ​4.5, p ​= ​0.025) and shorter network length (10.5 ​± ​1.0 vs. 13.4 ​± ​0.8 [mm], p ​= ​0.042). Further, vascular permeability was significantly higher with CCs (2.60 ​× ​10^-8 ​± ​3.59 ​× ​10^-8 ​vs. 0.53 ​× ​10^-8 ​± ​0.44 ​× ​10^-8 [cm/s], p ​= ​0.05). Following metastatic seed maturation, neutrophils were injected into microvascular networks resulting in a higher extravasation rate when CCs were present (27.9 ​± ​13.7 vs. 14.7 ​± ​12.4 [%], p ​= ​0.01). Strikingly, the percentage of dying CCs increased in presence of neutrophils, as confirmed by confocal imaging and flow cytometry on isolated cells from the metastatic seeds. The biofabricated metastatic niche represents a powerful tool to analyze the mechanisms of interaction between circulating immune cells and organ-specific micrometastases and to test novel drug combinations targeting the metastatic microenvironment.

Antitumor effects of Chinese herbal medicine compounds and their nano-formulations on regulating the immune system microenvironment

Traditional Chinese medicine (TCM), including herbal medicine, acupuncture and meditation, has a wide range of applications in China. In recent years, herbal compounding and active ingredients have been used to control tumor growth, reduce suffering, improve quality of life, and prolong the life span of cancer patients. To reduce side effects, herbal medicine can be used in conjunction with radiotherapy and chemotherapy or can be used as an adjuvant to strengthen the immune effect of anticancer vaccines. In particular, in the immunosuppressed tumor microenvironment, herbal medicine can have antitumor effects by stimulating the immune response. This paper reviews the advances in research on antitumor immunomodulation in Chinese herbal medicine, including the regulation of the innate immune system, which includes macrophages, MDSCs, and natural killer cells, and the adaptive immune system, which includes CD4+ T cells, CD8+ T cells, and regulatory T cells (Tregs), to influence tumor-associated inflammation. In addition, a combination of active ingredients of herbal medicine and modern nanotechnology alter the tumor immune microenvironment. In recent years, immunological antitumor therapy in TCM has been applied on a reasonably large scale both nationally and internationally, and there is potential for further clinical expansion. Investigation of immune modulation mechanisms in Chinese herbal medicine will provide novel perspectives of how herbal medicine controls tumor growth and metastasis, which will contribute to the evolution of tumor research.

AQP9 transports lactate in tumor-associated macrophages to stimulate an M2-like polarization that promotes colon cancer progression

Macrophages play a major role in the immune defense against pathogenic factors; however, they can lead to tumor exacerbation and metastasis, as the tumor microenvironment (TME) polarizes tumor-associated macrophages (TAMs) into the M2 subtype. Lactate, a metabolite produced by carcinoma cells at high concentrations in the TME, induces an M2-polarization in macrophages, which ultimately leads to the secretion of factors, such as vascular endothelial growth factor (VEGF), and promotes tumor progression. However, the effect of TAM lactate import on tumor progression has not been fully elucidated. Aquaporin 9 (AQP9) is a transporter of water and glycerol expressed in macrophages. Here, we used a tumor allograft mouse model to show that AQP9 knockout (AQP9^−/−) mice were more resistant against tumor cell growth and exhibited a suppressive M2-like polarization in tumor tissue than wild-type mice. Moreover, we discovered that the primary bone marrow-derived macrophages from AQP9^−/− mice were less sensitive to lactate stimulation and exhibited reduced M2-like polarization as well as decreased VEGF production. To further investigate the role of AQP9 in macrophage polarization, we overexpressed AQP9 in Chinese hamster ovary cells and found that AQP9 functioned in lactate import. In contrast, primary AQP9^−/− macrophages and AQP9 knockdown RAW264.7 cells exhibited a reduced lactate transport rate, suggesting the involvement of AQP9 in lactate transport in macrophages. Together, our results reveal the mechanism by which the TME modifies the polarization and function of tumor-infiltrating macrophages via AQP9 transport function.

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Tumor growth was suppressed in AQP9-deficient mice.

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M2-like TAMs were reduced in tumor tissues of AQP9-deficient mice.

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AQP9 deficiency attenuated lactate-induced M2 polarization in macrophages.

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AQP9 is a lactate transporter in macrophages.

Mer Tyrosine Kinase (MERTK) modulates liver fibrosis progression and hepatocellular carcinoma development

MerTK is a tyrosine kinase receptor that belongs to the TAM (Tyro3/Axl/Mer) receptor family. It is involved in different processes including cellular proliferation/survival, cellular adhesion/migration, and release of the inflammatory/anti-inflammatory cytokines. Although it is reported that MERTK polymorphisms affect the severity of viral and metabolic liver diseases, being able to influence fibrosis progression and hepatocellular carcinoma development, the mechanisms remain unknown. Methods: using a microarray approach, we evaluated the liver expression of genes involved in fibrogenesis and hepatocarcinogenesis in patient with chronic hepatitis C (CHC), stratified for MERTK genotype and MERTK expression. Results: we found that the rs 4374383 AA homozygosity is associated with lower MERTK expression in CHC patients and that, depending on MERTK genotype, Matrix Metallopeptidase 9 (MMP9), Matrix Metallopeptidase 7 (MMP7), Secreted Frizzled Related Protein 1 (SFRP1) and WNT gene family 11(WNT11) show differential expression in patients with CHC with or without neoplastic progression. Conclusions: our results confirm that MERTK represents a genetic biomarker for progression of liver disease and are suggestive of translational relevance for the study of downstream pathways involved in fibrogenesis and hepatocarcinogenesis.

The immunoregulation effect of tumor microenvironment in pancreatic ductal adenocarcinoma

Pancreatic cancer has the seventh highest death rate of all cancers. The absence of any serious symptoms, coupled with a lack of early prognostic and diagnostic markers, makes the disease untreatable in most cases. This leads to a delay in diagnosis and the disease progresses so there is no cure. Only about 20% of cases are diagnosed early. Surgical removal is the preferred treatment for cancer, but chemotherapy is standard for advanced cancer, although patients can eventually develop drug resistance and serious side effects. Chemoresistance is multifactorial because of the interaction among pancreatic cancer cells, cancer stem cells, and the tumor microenvironment (TME). Nevertheless, more pancreatic cancer patients will benefit from precision treatment and targeted drugs. This review focuses on the immune-related components of TME and the interactions between tumor cells and TME during the development and progression of pancreatic cancer, including immunosuppression, tumor dormancy and escape. Finally, we discussed a variety of immune components-oriented immunotargeting drugs in TME from a clinical perspective.

Hormone replacement therapy is associated with reduced hepatocellular carcinoma risk and improved survival in postmenopausal women with hepatitis B: A nationwide long-term population-based cohort study

Postmenopausal women with hepatitis B virus (HBV) infection are more likely to have accelerated liver fibrosis, eventually advancing to liver cirrhosis or hepatocellular carcinoma (HCC). The association between sex hormones and HBV-related HCC risk is unclear. We investigated whether hormone replacement therapy (HRT) is beneficial to postmenopausal women with HBV infection. This retrospective study selected the data of 44,465patients with HBV infection between January 2000 and December 2018 from Taiwan’s National Health Insurance Research Database. After excluding patients with preexisting liver diseases, liver cirrhosis, or liver malignancies, we grouped the remaining 10,474 patients by whether they had undergone HRT for at least 3 months (n = 5,638) and whether they had not received HRT (n = 4,836). After propensity score matching, we assigned 3080 patients to an HRT cohort and matched them (1:1) with those in a non-HRT cohort. The incidence of HCC (P < 0.022) and all-cause mortality rate (P < 0.001) were lower in the HRT cohort than in the non-HRT cohort. The liver cirrhosis risk was not significantly higher in the HRT cohort (P = 0.355). HRT is associated with reduced HCC risk and improved survival outcomes but is unrelated to liver cirrhosis development in postmenopausal women.

Peritoneal GATA6+ macrophage drives hepatic immunopathogenesis and maintains the Treg cell niche in the liver

The source of macrophages that contribute to human liver disease remains poorly understood. The purpose of this study is to investigate the functional mechanism of peritoneal macrophages in the development of hepatic immunopathology. By performing the natural infection with the blood fluke Schistosoma japonicum (S. japonicum) and the chemically carbon tetrachloride (CCl₄ )-induced liver injured mouse model, we identified the peritoneal cavity as an essential source of hepatic macrophages. Here, we show that a large number of F4/80⁺ macrophages was accumulated in the peritoneal cavity during liver injury. An unknown source population of macrophages, which highly expressed GATA6 that is specific to peritoneal macrophages, was found to exist in the injured livers. Peritoneal macrophage deletion by injection with clodronate-containing liposomes led to an attenuated hepatic pathology and the inflammatory microenvironment, while adoptive transfer of macrophages into the abdominal cavity, by contrast, results in restoring liver pathology. Importantly, there are set genes of monocyte chemoattractant protein (MCP)-1, -2, and -3 that are highly related to recruit GATA6⁺ macrophages during S. japonicum infection, while administration of bindarit, a selective inhibitor of MCPs synthesis, dramatically decreased the hepatic expression of GATA6⁺ macrophages and thus attenuated hepatic pathology. Furthermore, in vivo study showed that peritoneal macrophages promote hepatic immunopathology is dependent on the accumulation of regulatory T cells (Tregs) in the liver. Altogether, these data provide the first clear evidence that GATA6⁺ peritoneal macrophages play critical roles in both the formation of hepatic immunopathology and the accumulation of Tregs cells.

Current Strategies for the Treatment of Hepatocellular Carcinoma by Modulating the Tumor Microenvironment via Nano-Delivery Systems: A Review

Liver cancer remains a global health challenge with a projected incidence of over one million cases by 2025. Hepatocellular carcinoma (HCC) is a common primary liver cancer, accounting for about 90% of all liver cancer cases. The tumor microenvironment (TME) is the internal and external environment for tumor development, which plays an important role in tumorigenesis, immune escape and treatment resistance. Knowing that TME is a unique setting for HCC tumorigenesis, exploration of strategies to modulate TME has attracted increasing attention. Among them, the use of nano-delivery systems to deliver therapeutic agents to regulate TME components has shown great potential. TME-modulating nanoparticles have the advantages of protecting therapeutic agents from degradation, enhancing the ability of targeting HCC and reducing systemic toxicity. In this article, we summarize the TME components associated with HCC, including cancer-associated fibroblasts (CAFs), extracellular matrix (ECM), endothelial cells and immune cells, discuss their impact on the HCC progression, and highlight recent studies on nano-delivery systems that modulate these components. Finally, we also discuss opportunities and challenges in this field.

Anti-cancer activity of an ethanolic extract of red okra pods (Abelmoschus esculentus L. Moench) in rats induced by N-methyl-N-nitrosourea

Background and Aim: Breast cancer is the most frequent malignancy in women. The consumption of phytochemical components from plants may play an essential role in preventing and treating this cancer. This study aimed to investigate the anti-cancer activity of an ethanolic extract of red okra pods (EEROP) in rats (Rattus norvegicus) induced by N-methyl-N-nitrosourea (MNU). Materials and Methods: The experimental animals were divided into six groups (n=5/group), namely, KN (normal control, without any treatment), K– (negative control, exposed to MNU without EEROP), K+ (positive control, exposed to MNU and Methotrexate), and the treatment Groups P1, P2, and P3 (exposed to MNU and EEROP at doses of 50, 100, and 200 mg/kg body weight [BW], respectively). Intraperitoneal delivery of MNU and EEROP oral administration was carried out for 8 weeks. After the end of treatment, the parameters of cytokines, CD4+ and CD8+ T cells, and mammary gland histology were measured. Results: The results showed that EEROP at doses of 100 and 200 mg/kg BW significantly downregulated interleukin (IL)-6, IL-1β, tumor necrosis factor (TNF)-α, IL-17, IL-10, and tumor growth factor-β (p<0.05). In addition, doses of 200 mg/kg BW significantly increased the activity of CD4+ and CD8+ T cells, prevented the proliferation of mammary gland epithelial cells, and yielded a significantly thinner epithelium of the mammary gland (p<0.05). Conclusion: It can be concluded that EEROP was an effective anti-cancer agent by modulating the immune response. Further studies using a nanoparticle system are warranted to achieve optimal working conditions for these bioactive compounds.

Isolation, Identification, and Immunomodulatory Mechanism of Peptides from Lepidium meyenii (Maca) Protein Hydrolysate

Maca is a protein-enriched edible plant with immunomodulatory activity. However, the role of proteins in the immunomodulatory activity of maca is unclear. In this study, peptide products of maca proteins obtained through in vitro gastrointestinal digestion were isolated and purified, and the immunomodulatory activities of these peptides were assessed in macrophages (RAW 264.7 cells). The results show that the maca protein hydrolysate enhanced the phagocytic capacity and NO, TNF-α, and IL-6 secretion of RAW 264.7 cells. Forty-five peptides from known proteins of maca or the cruciferous family were identified by ultraperformance liquid chromatography-tandem mass spectrometry in the hydrolysate, and the peptide RNPFLP exhibited the strongest immunomodulatory activity. Antibody blocking, siRNA, pathway inhibitors, and western blot assays showed that RNPFLP-activated RAW 264.7 cells through the NF-κB and MAPK signaling pathways mediated by TLR2 and TLR4 receptors. An analysis of the structure-activity relationship showed that the N₉-H₆₀ active site in arginine plays an important role in the immunomodulatory activity of RNPFLP. This study provides a new understanding of the immunomodulatory activity of maca.