Macrophage balance fraction determines the degree of immunosuppression and metastatic ability of breast cancer

Effect of Extracellular Vesicles Derived From Tumor Cells on Immune Evasion

The crosstalk between immunity and cancer in the regulation of tumor growth is considered a hallmark of cancer. Antitumor immunity refers to the innate and adaptive immune responses that regulate cancer development and proliferation. Tumor immune evasion represents a major hindrance to effective anticancer treatment. Extracellular vesicles (EVs) are nano-sized and lipid-bilayer-enclosed particles that are secreted to the extracellular space by all cell types. They are critically involved in numerous biological functions including intercellular communication. Tumor-derived extracellular vesicles (TEVs) can transport a variety of cargo to modulate immune cells in the tumor microenvironment (TME). This review provides the latest update about how tumor cells evade immune surveillance by exploiting TEVs. First, the biogenesis of EVs and the cargo-sorting machinery are discussed. Second, how tumor cells modulate immune cell differentiation, activation, and function via TEVs to evade immune surveillance is illustrated. Last but not least, the novel antitumor strategies that can reverse immune escape are summarized.

Dysregulation of SIGLEC1 in non-small cell lung cancer: prognostic implications and immunomodulatory role-a multicenter cohort study

PURPOSE

To investigate the clinical significance and functional role of SIGLEC1-positive cells in non-small cell lungcancer (NSCLC) patients, focusing on their prognostic impact and therapeutic response.

METHODS

A multicenter retrospective cohort analysis was conducted, integrating data from multiple sources. Weanalyzed SIGLEC1 expression in NSCLC tissues, clinicopathological features, overall survival outcomes,chemotherapy responsiveness, and sensitivity to targeted therapies. We also developed a prognostic model basedon SIGLEC1 expression and clinical variables.

RESULTS

SIGLEC1 expression was significantly downregulated in NSCLC tissues, and the density of SIGLEC1-positivecells was inversely correlated with various clinicopathological features. Notably, patients with high infiltration ofSIGLEC1-positive cells exhibited significantly better overall survival outcomes. Furthermore, elevated SIGLEC1expression was associated with improved responsiveness to chemotherapy and demonstrated distinct patterns ofsensitivity to targeted therapies. A robust prognostic model was developed by integrating SIGLEC1 expression andclinical variables.

CONCLUSIONS

This study highlighted the downregulation of SIGLEC1 in NSCLC tissues and its significant associationwith patient prognosis and therapeutic response. The findings suggested that SIGLEC1 played a critical role inmodulating the tumor immune microenvironment and has potential as both a prognostic biomarker and therapeutictarget in NSCLC.

Unleashing nanotechnology to redefine tumor-associated macrophage dynamics and non-coding RNA crosstalk in breast cancer

Breast cancer is a significant global health issue. Tumor-associated macrophages (TAMs) are crucial in influencing the tumor microenvironment and the progression of the disease. TAMs exhibit remarkable plasticity in adopting distinct phenotypes ranging from pro-inflammatory and anti-tumorigenic (M1-like) to immunosuppressive and tumor-promoting (M2-like). This review elucidates the multifaceted roles of TAMs in driving breast tumor growth, angiogenesis, invasion, and metastatic dissemination. Significantly, it highlights the intricate crosstalk between TAMs and non-coding RNAs (ncRNAs), including microRNAs, long noncoding RNAs, and circular RNAs, as a crucial regulatory mechanism modulating TAM polarization and functional dynamics that present potential therapeutic targets. Nanotechnology-based strategies are explored as a promising approach to reprogramming TAMs toward an anti-tumor phenotype. Various nanoparticle delivery systems have shown potential for modulating TAM polarization and inhibiting tumor-promoting effects. Notably, nanoparticles can deliver ncRNA therapeutics to TAMs, offering unique opportunities to modulate their polarization and activity.

Nanoparticles in tumor microenvironment remodeling and cancer immunotherapy

Cancer immunotherapy and vaccine development have significantly improved the fight against cancers. Despite these advancements, challenges remain, particularly in the clinical delivery of immunomodulatory compounds. The tumor microenvironment (TME), comprising macrophages, fibroblasts, and immune cells, plays a crucial role in immune response modulation. Nanoparticles, engineered to reshape the TME, have shown promising results in enhancing immunotherapy by facilitating targeted delivery and immune modulation. These nanoparticles can suppress fibroblast activation, promote M1 macrophage polarization, aid dendritic cell maturation, and encourage T cell infiltration. Biomimetic nanoparticles further enhance immunotherapy by increasing the internalization of immunomodulatory agents in immune cells such as dendritic cells. Moreover, exosomes, whether naturally secreted by cells in the body or bioengineered, have been explored to regulate the TME and immune-related cells to affect cancer immunotherapy. Stimuli-responsive nanocarriers, activated by pH, redox, and light conditions, exhibit the potential to accelerate immunotherapy. The co-application of nanoparticles with immune checkpoint inhibitors is an emerging strategy to boost anti-tumor immunity. With their ability to induce long-term immunity, nanoarchitectures are promising structures in vaccine development. This review underscores the critical role of nanoparticles in overcoming current challenges and driving the advancement of cancer immunotherapy and TME modification.

Specific molecular weight of Lycium barbarum polysaccharide for robust breast cancer regression by repolarizing tumor-associated macrophages

The pro-tumorigenic M2-type tumor-associated macrophages (TAMs) in the immunosuppressive tumor microenvironment (TME) promote the progression, angiogenesis, and metastasis of breast cancer. The repolarization of TAMs from an M2-type toward an M1-type holds great potential for the inhibition of breast cancer. Here, we report that Lycium barbarum polysaccharides (LBPs) can significantly reconstruct the TME by modulating the function of TAMs. Specifically, we separated four distinct molecular weight segments of LBPs and compared their repolarization effects on TAMs in TME. The results showed that LBP segments within 50-100 kDa molecular weight range exhibited the prime effect on the macrophage repolarization, augmented phagocytosis effect of the repolarized macrophages on breast cancer cells, and regression of breast tumor in a tumor-bearing mouse model. In addition, RNA-sequencing confirms that this segment of LBP displays an enhanced anti-breast cancer effect through innate immune responses. This study highlights the therapeutic potential of LBP segments within the 50-100 kDa molecular weight range for macrophage repolarization, paving ways to offer new strategies for the treatment of breast cancer.

Tryptophan metabolism regulates inflammatory macrophage polarization as a predictive factor for breast cancer immunotherapy

Metabolic reprogramming plays a pivotal role in regulating macrophage polarization and function. However, the impact of macrophage tryptophan metabolism on polarization within the breast cancer microenvironment remains elusive. In this study, we used single-cell transcriptome analysis and found that macrophages had the highest tryptophan metabolic activity in breast cancer, melanoma, and head and neck squamous cell carcinoma (HNSC). Further analysis revealed that the tryptophan metabolic activity of macrophages was positively correlated with the M1 macrophage scores in breast cancer. Pancancer analysis found positive correlations between tryptophan metabolism and the M1 macrophage score in almost all tumor types. Spatial transcriptome analysis revealed higher tryptophan metabolism in regions with higher M1 macrophage score in breast cancer tissues. Immune infiltration analysis revealed that the high tryptophan metabolism group exhibited a higher immune score, an increased proportion of CD8+ T cells, augmented cytolytic activity mediated by CD8+ T cells, and elevated expression of immune checkpoint molecules. Spatial immunophenotype cohort analysis exhibited that breast cancer patients expected to respond to immunotherapy had stronger tryptophan metabolism, with a 73.8 % area under the ROC curve. Single-cell transcriptome analysis of the immunotherapy cohort found that patients responding to immunotherapy had higher macrophage tryptophan metabolism prior to treatment initiation. Finally, in vitro experiments demonstrated elevated expression of tryptophan metabolic enzymes in M1 macrophages. Moreover, tryptophan facilitated the expression of M1 polarization markers, whereas inhibitors of tryptophan metabolic enzymes, such as NLG919, LM10, and Ro 61-8048, inhibited the expression of M1 polarization markers. In conclusion, this study identified a dual role for macrophage tryptophan metabolism in breast cancer; on the one hand, it promotes macrophage M1 polarization, while on the other hand, it serves as a promising predictor for the effectiveness of immunotherapy in breast cancer.

Circadian pattern subtyping unveiling distinct immune landscapes in breast cancer patients for better immunotherapy

BACKGROUND

While epidemiological studies have established a firm link between circadian disruption and tumorigenesis, the role and mechanism are not fully understood, complicating the design of therapeutic targets related to circadian rhythms (CR). Here, we aimed to explore the intertumoral heterogeneity of CR and elucidate its impact on the tumor microenvironment (TME), drug sensitivity, and immunotherapy.

METHODS

Based on unsupervised clustering of 28 CR genes, two distinct CR subtypes (cluster-A and cluster-B) were identified in the TCGA cohort. We further constructed a circadian rhythm signature (CRS) based on the CR genes primarily responsible for clustering to quantify CR activity and to distinguish CR subtypes of individual patients from external datasets. CR subtypes were evaluated by TME characteristics, functional annotation, clinical features, and therapeutic response.

RESULTS

The cluster-B (low-CRS) group was characterized by highly enriched immune-related pathways, high immune cell infiltration, and high anti-tumor immunity, while the cluster-A (high-CRS) group was associated with immunosuppression, synaptic transmission pathways, EMT activation, poor prognosis, and drug resistance. Immunohistochemistry (IHC) results demonstrated that high CD8+ T cell infiltration was associated with low-CR-protein expression. Importantly, patients with low CRS were more likely to benefit from immune checkpoint blockade (ICB) treatment, possibly due to their higher tumor mutation burden (TMB), increased immune checkpoint expression, and higher proportion of "hot" immunophenotype.

CONCLUSION

In a nutshell, the cross talk in CR could reflect the TME immunoreactivity in breast cancer. Besides providing the first comprehensive pathway-level analysis of CR in breast cancer, this work highlights the potential clinical utility of CR for immunotherapy.

Lactate from glycolysis regulates inflammatory macrophage polarization in breast cancer

Globally, breast cancer is one of the leading causes of cancer death in women. Metabolic reprogramming and immune escape are two important mechanisms supporting the progression of breast cancer. Lactate in tumors mainly comes from glycolysis and glutaminolysis. Using multiomics data analysis, we found that lactate is mainly derived from glycolysis in breast cancer. Single-cell transcriptome analysis found that breast cancer cells with higher malignancy, especially those in the cell cycle, have higher expression levels of glycolytic metabolic enzymes. Combined with clinical data analysis, it was found that the expression of the lactate transporter SLC16A3 is correlated with breast cancer molecular subtypes and immune infiltration. Among 22 immune cells, macrophages are the most abundant immune cells in breast cancer tissues, and the proportion of M1 macrophages is lower in the high SLC16A3 expression group. Finally, in vitro experiments confirmed that lactate could inhibit the expression of M1 macrophage markers at both RNA and protein levels. In conclusion, we found that lactate produced by glycolysis regulates the polarization of inflammatory macrophages in breast cancer.

Antitumor therapy for breast cancer: Focus on tumor-associated macrophages and nanosized drug delivery systems

BACKGROUND

In breast cancer (BC), tumor-associated macrophages (TAMs) are an important component of the tumor microenvironment and are closely related to poor prognosis. A growing number of studies have focused on the role of TAMs in BC progression and therapeutic strategies targeting TAMs. As an emerging treatment, the application of nanosized drug delivery systems (NDDSs) in the treatment of BC by targeting TAMs has attracted much attention.

AIMS

This review is to summarize the characteristics and treatment strategies targeting TAMs in BC and to clarify the applications of NDDSs targeting TAMs in the treatment of BC by targeting TAMs.

MATERIALS & METHODS

The existing results related to characteristics of TAMs in BC, BC treatment strategies by targeting TAMs, and the applications of NDDSs in these strategies are described. Through analyzing these results, the advantages and disadvantages of the treatment strategies using NDDSs are discussed, which could provide advices on designing NDDSs for BC treatment.

RESULTS

TAMs are one of the most prominent noncancer cell types in BC. TAMs not only promote angiogenesis, tumor growth and metastasis but also lead to therapeutic resistance and immunosuppression. Mainly four strategies have been used to target TAMs for BC therapy, which include depleting macrophages, blocking recruitment, reprogramming to attain an anti-tumor phenotype, and increasing phagocytosis. Since NDDSs can efficiently deliver drugs to TAMs with low toxicity, they are promising approaches for targeting TAMs in tumor therapy. NDDSs with various structures can deliver immunotherapeutic agents and nucleic acid therapeutics to TAMs. In addition, NDDSs can realize combination therapies.

DISCUSSION

TAMs play a critical role in the progression of BC. An increasing number of strategies have been proposed to regulate TAMs. Compared with free drugs, NDDSs targeting TAMs improve drug concentration, reduce toxicity and realize combination therapies. However, in order to achieve better therapeutic efficacy, there are still some disadvantages that need to be considered in the design of NDDSs.

CONCLUSION

TAMs play an important role in the progression of BC, and targeting TAMs is a promising strategy for BC therapy. In particular, NDDSs targeting TAMs have unique advantages and are potential treatments for BC.

Designing Lactate Dehydrogenase-Mimicking SnSe Nanosheets To Reprogram Tumor-Associated Macrophages for Potentiation of Photothermal Immunotherapy

Rapid glycolysis of tumor cells produces excessive lactate to trigger acidification of the tumor microenvironment (TME), leading to the formation of immunosuppressive TME and tumor-associated macrophage (TAM) dysfunction. Therefore, reprogramming TAMs by depleting lactate with nanodrugs is expected to serve as an effective means of tumor-targeted immunotherapy. Herein, we report the use of lactic acid dehydrogenase (LDH)-mimicking SnSe nanosheets (SnSe NSs) loaded with a carbonic anhydrase IX (CAIX) inhibitor to reconstruct an acidic and immunosuppressive TME. As expected, this nanosystem could reprogram the TAM to achieve M1 macrophage activation and could also restore the potent tumor-killing activity of macrophages while switching their metabolic mode from mitochondrial oxidative phosphorylation to glycolysis. In addition, the repolarizing effect of SnSe NSs on macrophages was validated in a coculture model of bone marrow-derived macrophages, in three patient-derived malignant pleural effusion and in vivo mouse model. This study proposes a feasible therapeutic strategy for depleting lactate and thus ameliorating acidic TME employing Se-containing nanosheets, which could further amply the effects of TAM-based antitumor immunotherapy.

Tumor-associated macrophages of the M1/M2 phenotype are involved in the regulation of malignant biological behavior of breast cancer cells through the EMT pathway

Triple negative breast cancer (TNBC) is the most aggressive subtype of breast cancer. More and more studies have shown that the tumor immune microenvironment (TME) of TNBC is closely related to its poor prognosis and early metastasis. We try to explain how tumor-associate macrophages (TAMs), an important component of the TME, function in the matrix of TNBC. Therefore, we induced THP-1 cells to become M1-TAMs and M2-TAMs, investigated their influence on breast cancer cells. 82 TNBC paraffin samples were made into tissue microarrays. The expression of macrophages makers were measured by immunohistochemistry. Scratch assay, Transwell assay, CCK-8 cell proliferation assay were performed in the co-culture system of breast cancer cells lines and macrophages to observe the invasion and proliferation ability of breast cancer cell lines. Western Blot (WB) was performed to detect the expression of E-cadherin (CDH1) and N-cadherin (CDH2). M2-TAMs were more numerous than M1-TAMs in the matrix of TNBC cancer nests and associated with poor prognosis. M2-TAMs promoted the invasion, migration, and proliferation of TNBC cells. M1-TAMs had inhibitory effects. In MCF-7 cells, WB showed a decrease in CDH1 and an increase in CDH2. In MDA-MB-231 cells and BT549 cells, CDH2 expression was reduced and CDH1 expression was increased. All of the above results were statistically significant, p < 0.001. M2-TAMs were more numerous in TNBC and associated with poor prognosis. M2-TAMs promoted the invasion, migration, and proliferation of breast cancer cells. The mechanism may be related to the epithelial-mesenchymal transition.

Preoperative Systemic Inflammatory Biomarkers Are Independent Predictors of Disease Recurrence in ER+ HER2- Early Breast Cancer

The host's immune system plays a crucial role in determining the clinical outcome of many cancers, including breast cancer. Peripheral blood neutrophils and lymphocytes counts may be surrogate markers of systemic inflammation and potentially reflect survival outcomes. The aim of the present study is to assess the role of preoperative systemic inflammatory biomarkers to predict local or distant relapse in breast cancer. In particular we investigated ER+ HER2- early breast cancer, considering its challenging risk stratification. A total of 1,763 breast cancer patients treated at tertiary referral Breast Unit were reviewed. Neutrophil-to-lymphocyte (NLR), platelet-to-lymphocyte (PLR) and lymphocyte-to-monocyte (LMR) ratios were assessed from the preoperative blood counts. Multivariate analyses for 5-years locoregional recurrence-free (LRRFS), distant metastases-free (DMFS) and disease-free survivals (DFS) were performed, taking into account both blood inflammatory biomarkers and clinical-pathological variables. Low NLR and high LMR were independent predictors of longer LRRFS, DMFS and DFS, and low PLR was predictive of better LRRFS and DMFS in the study population. In 999 ER+ HER2- early breast cancers, high PLR was predictive of worse LRRFS (HR 0.42, p=0.009), while high LMR was predictive of improved LRRFS (HR 2.20, p=0.02) and DFS (HR 2.10, p=0.01). NLR was not an independent factor of 5-years survival in this patients' subset. Inflammatory blood biomarkers and current clinical assessment of the disease were not in agreement in terms of estimate of relapse risk (K-Cohen from -0.03 to 0.02). In conclusion, preoperative lymphocyte ratios, in particular PLR and LMR, showed prognostic relevance in ER+ HER2- early breast cancer. Therefore, they may be used in risk stratification and therapy escalation/de-escalation in patients with this type of tumor.