Diverse macrophages polarization in tumor microenvironment. Arch Pharm Res. 2016;39:1588-1596. [PMID: 27562774 DOI: 10.1007/s12272-016-0820-y]

Bone-metastatic lung adenocarcinoma cells bearing CD74-ROS1 fusion interact with macrophages to promote their dissemination

Approximately 40% of patients with lung adenocarcinoma (LUAD) often develop bone metastases during the course of their disease. However, scarcely any in vivo model of LUAD bone metastasis has been established, leading to a poor understanding of the mechanisms underlying LUAD bone metastasis. Here, we established a multiorgan metastasis model via the left ventricular injection of luciferase-labeled LUAD cells into nude mice and then screened out lung metastasis (LuM) and bone metastasis (BoM) cell subpopulations. BoM cells exhibited greater stemness and epithelial-mesenchymal transition (EMT) plasticity than LuM cells and initially colonized the bone and subsequently disseminated to distant organs after being reinjected into mice. Moreover, a CD74-ROS1 fusion mutation (C6; R34) was detected in BoM cells but not in LuM cells. Mechanistically, BoM cells bearing the CD74-ROS1 fusion highly secrete the C-C motif chemokine ligand 5 (CCL5) protein by activating STAT3 signaling, recruiting macrophages in tumor microenvironment and strongly inducing M2 polarization of macrophages. BoM cell-activated macrophages produce a high level of TGF-β1, thereby facilitating EMT and invasion of LUAD cells via TGF-β/SMAD2/3 signaling. Targeting the CD74-ROS1/CCL5 axis with Crizotinib (a ROS1 inhibitor) and Maraviroc (a CCL5 receptor inhibitor) in vivo strongly impeded bone metastasis and secondary metastasis of BoM cells. Our findings reveal the critical role of the CD74-ROS1/STAT3/CCL5 axis in the interaction between LUAD bone metastasis cells and macrophages for controlling LUAD cell dissemination, highlighting the significance of the bone microenvironment in LUAD bone metastasis and multiorgan secondary metastasis, and suggesting that targeting CD74-ROS1 and CCL5 is a promising therapeutic strategy for LUAD bone metastasis.

Recombinant Human IL-32θ Induces Polarization Into M1-like Macrophage in Human Monocytic Cells

The tumor microenvironment (TME) is formed by several immune cells. Notably, tumor-associated macrophages (TAMs) are existed in the TME that induce angiogenesis, metastasis, and proliferation of cancer cells. Recently, a point-mutated variant of IL-32θ was discovered in breast cancer tissues, which suppressed migration and proliferation through intracellular pathways. Although the relationship between cancer and IL-32 has been previously studied, the effects of IL-32θ on TAMs remain elusive. Recombinant human IL-32θ (rhIL-32θ) was generated using an Escherichia coli expression system. To induce M0 macrophage polarization, THP-1 cells were stimulated with PMA. After PMA treatment, the cells were cultured with IL-4 and IL-13, or rhIL-32θ. The mRNA level of M1 macrophage markers (IL-1β, TNFα, inducible nitric oxide synthase) were increased by rhIL-32θ in M0 macrophages. On the other hand, the M2 macrophage markers (CCL17, CCL22, TGFβ, CD206) were decreased by rhIL-32θ in M2 macrophages. rhIL-32θ induced nuclear translocation of the NF-κB via regulation of the MAPK (p38) pathway. In conclusion, point-mutated rhIL-32θ induced the polarization to M1-like macrophages through the MAPK (p38) and NF-κB (p65/p50) pathways.

Kinesin 26B modulates M2 polarization of macrophage by activating cancer-associated fibroblasts to aggravate gastric cancer occurrence and metastasis

BACKGROUND

The regulatory effects of KIF26B on gastric cancer (GC) have been confirmed, but the specific mechanism still needs further exploration. Pan-cancer analysis shows that the KIF26B expression is highly related to immune infiltration of cancer-associated fibroblasts (CAFs), and CAFs promote macrophage M2 polarization and affect cancers' progression.

AIM

To investigate the regulatory functions of KIF26B on immune and metastasis of GC.

METHODS

We analyzed genes' mRNA levels by quantitative real-time polymerase chain reaction. Expression levels of target proteins were detected by immunohistochemistry, ELISA, and Western blotting. We injected AGS cells into nude mice for the establishment of a xenograft tumor model and observed the occurrence and metastasis of GC. The degree of inflammatory infiltration in pulmonary nodes was observed through hematoxylin-eosin staining. Transwell and wound healing assays were performed for the evaluation of cell invasion and migration ability. Tube formation assay was used for detecting angiogenesis. M2-polarized macrophages were estimated by immunofluorescence and flow cytometry.

RESULTS

KIF26B was significantly overexpressed in cells and tissues of GC, and the higher expression of KIF26B was related to GC metastasis and prognosis. According to in vivo experiments, KIF26B promoted tumor formation and metastasis of GC. KIF26B expression was positively associated with CAFs' degree of infiltration. Moreover, CAFs could regulate M2-type polarization of macrophages, affecting GC cells' migration, angiogenesis, invasion, and epithelial-mesenchymal transition process.

CONCLUSION

KIF26B regulated M2 polarization of macrophage through activating CAFs, regulating the occurrence and metastasis of GC.

Defining three ferroptosis-based molecular subtypes and developing a prognostic risk model for high-grade serous ovarian cancer

BACKGROUND

As a newly defined regulated cell death, ferroptosis is a potential biomarker in ovarian cancer (OV). However, its underlying mechanism in tumor microenvironment (TME) and clinical prediction significance in OV remained to be elucidated.

METHODS

The transcriptome data of high-grade serous OV from The Cancer Genome Atlas (TCGA) database were downloaded. Molecular subtypes were classified based on ferroptosis-correlated genes from the FerrDb database by performing consensus clustering analysis. The associations between the subtypes and clinicopathologic characteristics, mutation, regulatory pathways and immune landscape were assessed. A ferroptosis-related prognostic model was constructed and verified using International Cancer Genome Consortium (ICGC) cohort and GSE70769.

RESULTS

Three molecular subtypes of OV were defined. Patients in subtype C3 tended to have the most favorable prognosis, while subtype C1 showing more mesenchymal cells, increased immune infiltration of Macrophages_M2, lower tumor purity, and epithelial-to-mesenchymal transition (EMT) features had the poorest prognosis. A ferroptosis-related risk model was constructed using 8 genes (PDP1, FCGBP, EPHA4, GAS1, SLC7A11, BLOC1S1, SPOCK2, and CXCL9) and manifested a strong prediction performance. High-risk patients had enriched EMT pathways, more Macrophages_M2, less plasma cells and CD8 cell infiltration, greater tendency of immune escape and worse prognosis. The risk score has negatively correlated relation with LAG3, TIGIT, CTLA4, IDO1, CD27, ICOS, and IL2RB but positively correlated with PVR, CD276, and CD28. Moreover, low-risk patients were more sensitive to Cisplatin and Gefitinib, Gemcitabine.

CONCLUSIONS

Our results could improve the understanding of ferroptosis in OV, providing promising insights for the clinical targeted therapy for the cancer.

The role of tumor-associated macrophages in the radioresistance of esophageal cancer cells via regulation of the VEGF-mediated angiogenic pathway

Tumor-associated macrophages (TAMs) are known to promote tumor growth, invasion, metastasis, and protumor angiogenesis, but the role of TAMs in evading radiotherapy in esophagus cancer remains unclear. In this study, we first induced TAMs from human monocytes (THP-1) and identified using immunofluorescence and Western blotting assays. We then co-cultured them with human esophageal cancer cell lines. CCK-8, colony formation, Transwell, scratch test, and TUNEL assays showed that TAMs could promote proliferation, survival rate, invasion, migration, and radioresistance and could inhibit apoptosis of the esophageal squamous carcinoma cell lines KYSE-150 and TE-1 before and after radiotherapy both in vivo and in vitro. Using LV-VEGFA-RNAi lentiviral vectors, we also found that TAMs could increase the expression of VEGFA and that inhibition of VEGFA could inhibit the biological function caused by TAMs. Finally, a Western blotting assay was used to evaluate the expression of various factors underlying the mechanism of TAMs. VEGFA, MAPK, P-MAPK, BCL-2, and Snail proteins were found to be overexpressed in co-cultured groups, whereas after VEGFA inhibition, MAPK, P-MAPK, BCL-2, and Snail proteins were found to be significantly downregulated in the radiotherapy group. These study results offer important information regarding the mechanism of radioresistance in esophageal cancer.

Intratumor microbiome-derived butyrate promotes lung cancer metastasis

Most recurrences of lung cancer (LC) occur within 3 years after surgery, but the underlying mechanism remains unclear. Here, we collect LC tissues with shorter (<3 years, recurrence group) and longer (>3 years, non-recurrence group) recurrence-free survival. By using 16S sequencing, we find that intratumor microbiome diversity is lower in the recurrence group and butyrate-producing bacteria are enriched in the recurrence group. The intratumor microbiome signature and circulating microbiome DNA can accurately predict LC recurrence. We prove that intratumor injection of butyrate-producing bacteria Roseburia can promote subcutaneous tumor growth. Mechanistically, bacteria-derived butyrate promotes LC metastasis by increasing expression of H19 in tumor cells through inhibiting HDAC2 and increasing H3K27 acetylation at the H19 promoter and inducing M2 macrophage polarization. Depletion of macrophages partially abolishes the metastasis-promoting effect of butyrate. Our results provide evidence for the cross-talk between the intratumor microbiome and LC metastasis and suggest the potential prognostic and therapeutic value of the intratumor microbiome.

Exploiting the immune system in hepatic tumor targeting: Unleashing the potential of drugs, natural products, and nanoparticles

Hepatic tumors present a formidable challenge in cancer therapeutics, necessitating the exploration of novel treatment strategies. In recent years, targeting the immune system has attracted interest to augment existing therapeutic efficacy. The immune system in hepatic tumors includes numerous cells with diverse actions. CD8+ T lymphocytes, T helper 1 (Th1) CD4+ T lymphocytes, alternative M1 macrophages, and natural killer (NK) cells provide the antitumor immunity. However, Foxp3+ regulatory CD4+ T cells (Tregs), M2-like tumor-associated macrophages (TAMs), and myeloid-derived suppressor cells (MDSCs) are the key immune inhibitor cells. Tumor stroma can also affect these interactions. Targeting these cells and their secreted molecules is intriguing for eliminating malignant cells. The current review provides a synopsis of the immune system components involved in hepatic tumor expansion and highlights the molecular and cellular pathways that can be targeted for therapeutic intervention. It also overviews the diverse range of drugs, natural products, immunotherapy drugs, and nanoparticles that have been investigated to manipulate immune responses and bolster antitumor immunity. The review also addresses the potential advantages and challenges associated with these approaches.

Liposome-based nanomedicine for immune checkpoint blocking therapy and combinatory cancer therapy

The discovery of immune checkpoint (IC) has led to a wave of leap forward in cancer immunotherapy that represents probably the most promising strategy for cancer therapy. However, the clinical use of immune checkpoint block (ICB) therapy is limited by response rates and side effects. A strategy that addresses the limitations of ICB therapies through combination therapies, using nanocarriers as mediators, has been mentioned in numerous research papers. Liposomes have been probably one of the most extensively used nanocarriers for clinical applications, with broad drug delivery and high safety. A timely review on this hot subject of research, i.e., the application of liposomes for ICB, is thus highly desirable for both fundamental and clinical translatable studies, but remains, to our knowledge, unexplored so far. For this purpose, this review is composed to address the dilemma of ICB therapy and the reasons for this dilemma. We later describe how other cancer treatments have broken this dilemma. Finally, we focus on the role of liposomes in various combinatory cancer therapy. This review is believed to serve as a guidance for the rational design and development of liposome for immunotherapy with enhanced therapeutic efficiency.

Engineered Bacterial Biomimetic Vesicles Reprogram Tumor-Associated Macrophages and Remodel Tumor Microenvironment to Promote Innate and Adaptive Antitumor Immune Responses

Tumor-associated macrophages (TAMs) are among the most abundant infiltrating leukocytes in the tumor microenvironment (TME). Reprogramming TAMs from protumor M2 to antitumor M1 phenotype is a promising strategy for remodeling the TME and promoting antitumor immunity; however, the development of an efficient strategy remains challenging. Here, a genetically modified bacterial biomimetic vesicle (BBV) with IFN-γ exposed on the surface in a nanoassembling membrane pore structure was constructed. The engineered IFN-γ BBV featured a nanoscale structure of protein and lipid vesicle, the existence of rich pattern-associated molecular patterns (PAMPs), and the costimulation of introduced IFN-γ molecules. In vitro, IFN-γ BBV reprogrammed M2 macrophages to M1, possibly through NF-κB and JAK-STAT signaling pathways, releasing nitric oxide (NO) and inflammatory cytokines IL-1β, IL-6, and TNF-α and increasing the expression of IL-12 and iNOS. In tumor-bearing mice, IFN-γ BBV demonstrated a targeted enrichment in tumors and successfully reprogrammed TAMs into the M1 phenotype; notably, the response of antigen-specific cytotoxic T lymphocyte (CTL) in TME was promoted while the immunosuppressive myeloid-derived suppressor cell (MDSC) was suppressed. The tumor growth was found to be significantly inhibited in both a TC-1 tumor and a CT26 tumor. It was indicated that the antitumor effects of IFN-γ BBV were macrophage-dependent. Further, the modulation of TME by IFN-γ BBV produced synergistic effects against tumor growth and metastasis with an immune checkpoint inhibitor in an orthotopic 4T1 breast cancer model which was insensitive to anti-PD-1 mAb alone. In conclusion, IFN-γ-modified BBV demonstrated a strong capability of efficiently targeting tumor and tuning a cold tumor hot through reprogramming TAMs, providing a potent approach for tumor immunotherapy.

Nano-enhanced immunotherapy: Targeting the immunosuppressive tumor microenvironment

The tumor microenvironment (TME), which is mostly composed of tumor cells, immune cells, signaling molecules, stromal tissue, and the vascular system, is an integrated system that is conducive to the formation of tumors. TME heterogeneity makes the response to immunotherapy different in different tumors, such as "immune-cold" and "immune-hot" tumors. Tumor-associated macrophages, myeloid-derived suppressor cells, and regulatory T cells are the major suppressive immune cells and their different phenotypes interact and influence cancer cells by secreting different signaling factors, thus playing a key role in the formation of the TME as well as in the initiation, growth, and metastasis of cancer cells. Nanotechnology development has facilitated overcoming the obstacles that limit the further development of conventional immunotherapy, such as toxic side effects and lack of targeting. In this review, we focus on the role of three major suppressive immune cells in the TME as well as in tumor development, clinical trials of different drugs targeting immune cells, and different attempts to combine drugs with nanomaterials. The aim is to reveal the relationship between immunotherapy, immunosuppressive TME and nanomedicine, thus laying the foundation for further development of immunotherapy.

Modulatory effects of point-mutated IL-32θ (A94V) on tumor progression in triple-negative breast cancer cells

Breast cancer is a frequently diagnosed cancer and the leading cause of death among women worldwide. Tumor-associated macrophages stimulate cytokines and chemokines, which induce angiogenesis, metastasis, proliferation, and tumor-infiltrating immune cells. Although interleukin-32 (IL-32) has been implicated in the development and modulation of several cancers, its function in breast cancer remains elusive. Mutation of interleukin-32θ (IL-32θ) in the tissues of patients with breast cancer was detected by Sanger sequencing. RT-qPCR was used to detect the mRNA levels of inflammatory cytokines, chemokines, and mediators. The secreted proteins were detected using respective enzyme-linked immunosorbent assays. Evaluation of the inhibitory effect of mutant IL-32θ on proliferation, migration, epithelial-mesenchymal transition (EMT), and cell cycle arrest in breast cancer cells was conducted using MTS assays, migration assays, and Western blotting. A point mutation (281C>T, Ala94Val) was detected in IL-32θ in both breast tumors and adjacent normal tissues, which suppressed the expression of pro-inflammatory factors, EMT factors, and cell cycle related factors. Mutated IL-32θ inhibited the expression of inflammatory factors by regulating the NF-κB pathway. Furthermore, mutated IL-32θ suppressed EMT markers and cell cycle related factors through the FAK/PI3K/AKT pathway. It was inferred that mutated IL-32θ modulates breast cancer progression. Mutated IL-32θ (A94V) inhibited inflammation, EMT, and proliferation in breast cancer by regulating the NF-κB (p65/p50) and FAK-PI3K-GSK3 pathways.

TRIM65 knockout inhibits the development of HCC by polarization tumor-associated macrophages towards M1 phenotype via JAK1/STAT1 signaling pathway

BACKGROUND & AIMS

Tumor-associated macrophages (TAMs) are main components of immune cells in tumor microenvironment (TME), and play a crucial role in tumor progression. Tripartite motif-containing protein 65 (TRIM65) has been associated with tumor progression. However, whether TRIM65 regulate the interaction of tumor cell and TAMs in HCC and the underlying mechanisms remain unknown. In this study, we investigated the role of TRIM65 in TME of HCC and explored its underlying mechanisms.

METHODS

The relation of TRIM65 expression level with tumor grades, TNM stages, and worse prognosis of HCC patients was evaluated by bioinformatics analysis, as well as immune infiltration level of macrophages. TRIM65 shRNA was transfected into HepG2 cells, and TRIM65 overexpression plasmid was transfected into Huh7 cells, and the effect of TRIM65 on cell growth was examined by EdU assay. The mouse subcutaneous Hep1-6 tumor-bearing model with WT and TRIM65-/- mice was established to study the role of TRIM65 in HCC. Immunohistochemistry staining, Immunofluorescence staining, qRT-PCR and western blot were performed to evaluate the effect of TRIM65 on TAM infiltration, TAM polarization and JAK1/STAT1 signaling pathway.

RESULTS

Bioinformatics analysis revealed that TRIM65 was upregulated in 16 types of cancer especially in HCC, and high level of TRIM65 was strongly correlated with higher tumor grades, TNM stages, and worse prognosis of patients with HCC as well as immune infiltration level of macrophages (M0, M1, and M2). Moreover, we observed that TRIM65 shRNA-mediated TRIM65 knockdown significantly inhibited the HepG2 cells growth while TRIM65 overexpression highly increased the Huh7 cells growth in vitro. TRIM65 knockout significantly inhibited the tumor growth as well as macrophages polarization towards M2 but promoted macrophages polarization towards M1 in vivo. Mechanistically, the results demonstrate that TRIM65 knockout promoted macrophage M1 polarization in conditioned medium-stimulated peritoneal macrophages and in tumor tissues by activating JAK1/STAT1 signaling pathway.

CONCLUSIONS

Taken together, our study suggests that tumor cells utilize TRIM65-JAK1/STAT1 axis to inhibit macrophage M1 polarization and promote tumor growth, reveals the role of TRIM65 in TAM-targeting tumor immunotherapy.

Assessment of Tumor-Associated Tissue Eosinophilia (TATE) and Tumor-Associated Macrophages (TAMs) in Canine Transitional Cell Carcinoma of the Urinary Bladder

Transitional cell carcinoma of the urinary bladder is a significant neoplasm in dogs, characterized by a poor prognosis and a high metastatic potential. These canine spontaneous tumors share many characteristics with human transitional cell carcinoma, making them an excellent comparative model. The role of inflammatory infiltration in tumor development and progression is frequently contradictory, especially concerning tumor-associated tissue eosinophils (TATE) and tumor-associated macrophages (TAMs). This study aims to analyze TATE and TAMs in canine transitional cell carcinoma of the urinary bladder. Congo Red staining was used to identify TATE, and immunohistochemistry was performed to detect TAMs in 34 cases of canine transitional cell carcinoma of the bladder carcinomas, categorized into low and high grades. Statistically significant differences were observed between the number of eosinophils and macrophages in the two groups of tumors. The number of TATE was higher in low-grade malignant tumors, but the number of TAMs was higher in high-grade tumors. Our findings suggest the importance of TATEs and TAMs in the aggressiveness of canine transitional cell carcinoma and propose their potential use as therapeutic targets.

Tissue factor overexpression promotes resistance to KRAS-G12C inhibition in non-small cell lung cancer

The recently approved KRASG12C mutation-specific inhibitors sotorasib and adagrasib (KRASG12C-I) represent a promising therapy for KRASG12C-driven non-small cell lung cancer (NSCLC). However, many eligible patients do not benefit due to intrinsic or acquired drug resistance. Tissue factor (TF) is overexpressed in KRAS-mutated (KRASmut) NSCLC and is the target of the FDA-approved ADC Tivdak. Here, we employed HuSC1-39, the parent antibody of a clinical stage TF-ADC (NCT04843709), to investigate the role of TF in KRASmut NSCLC. We found that patients with TF-overexpression had poor survival, elevated P-ERK/P-AKT activity levels and low immune effector cell infiltration in the tumor. In a panel of KRASG12C cell lines, KRASG12C-I response correlated with suppression of TF mRNA, which was not observed in resistant cells. In the drug resistant cells, TF-overexpression relied on an mTORC2-mediated and proteasome-dependent pathway. Combination treatment of HuSC1-39 or mTORC1/2 inhibitor MTI-31 with KRASG12C-I each produced synergistic antitumor efficacy in cell culture and in an orthotopic lung tumor model. TF-depletion in the resistant cells diminished epithelial mesenchymal transition, reduced tumor growth and greatly sensitized KRASG12C-I response. Moreover, employing immunohistochemistry and coculture studies, we demonstrated that HuSC1-39 or MTI-31 reset the tumor microenvironment and restore KRASG12C-I sensitivity by reshaping an M1-like macrophage profile with greatly enhanced phagocytic capacity toward tumor cell killing. Thus, we have identified the TF/mTORC2 axis as a critical new mechanism for triggering immunosuppression and KRASG12C-I resistance. We propose that targeting this axis with HuSC1-39 or MTI-31 will improve KRASG12C-I response in KRAS-driven NSCLC.

Prognostic role of macrophages and mast cells in the microenvironment of hepatocellular carcinoma after resection

BACKGROUND

The prognostic significance of mast cells and different phenotypes of macrophages in the microenvironment of hepatocellular carcinoma (HCC) following resection is unclear. We aimed in this study to assess the local distribution of infiltrating macrophages and mast cells of specific phenotypes in tissues of HCC and to evaluate their prognostic values for survival of post-surgical patients.

METHODS

The clinicopathological and follow-up data of 70 patients with HCC, who underwent curative resection of tumor from 1997 to 2019, were collected. The infiltration of CD68+ and CD163+ macrophages and CD117+ mast cells was assessed immunohistochemically in representative resected specimens of HCC and adjacent tissues. The area fraction (AF) of positively stained cells was estimated automatically using QuPath image analysis software in several regions, such as tumor center (TC), inner margin (IM), outer margin (OM), and peritumor (PT) area. The prognostic significance of immune cells, individually and in associations, for time to recurrence (TTR), disease-free survival (DFS), and overall survival (OS) was evaluated using Kaplan-Meier and Cox regression analyses.

RESULTS

High AF of CD68+ macrophages in TC and IM and high AF of mast cells in IM and PT area were associated with a longer DFS. High AF of CD163+ macrophages in PT area correlated with a shorter DFS. Patients from CD163TChigh & CD68TClow group had a shorter DFS compared to all the rest of the groups, and cases with CD163IMlow & CD68IMhigh demonstrated significantly longer DFS compared to low AF of both markers. Patients from CD68IMhigh & CD163PTlow group, CD117IMhigh & CD163PTlow group, and CD117PThigh & CD163PTlow group had a significantly longer DFS compared to all other combinations of respective cells.

CONCLUSIONS

The individual prognostic impact of CD68+ and CD163+ macrophages and mast cells in the microenvironment of HCC after resection depends on their abundance and location, whereas the cumulative impact is built upon combination of different cell phenotypes within and between regions.

Potential role of epithelial-mesenchymal transition induced by periodontal pathogens in oral cancer

With the increasing incidence of oral cancer in the world, it has become a hotspot to explore the pathogenesis and prevention of oral cancer. It has been proved there is a strong link between periodontal pathogens and oral cancer. However, the specific molecular and cellular pathogenic mechanisms remain to be further elucidated. Emerging evidence suggests that periodontal pathogens-induced epithelial-mesenchymal transition (EMT) is closely related to the progression of oral cancer. Cells undergoing EMT showed increased motility, aggressiveness and stemness, which provide a pro-tumour environment and promote malignant metastasis of oral cancer. Plenty of studies proposed periodontal pathogens promote carcinogenesis via EMT. In the current review, we discussed the association between the development of oral cancer and periodontal pathogens, and summarized various mechanisms of EMT caused by periodontal pathogens, which are supposed to play an important role in oral cancer, to provide targets for future research in the fight against oral cancer.

AIM2 fosters lung adenocarcinoma immune escape by modulating PD-L1 expression in tumor-associated macrophages via JAK/STAT3

This work was devised to discuss the effect of AIM2 on the immunosuppression of LUAD tumors, as well as its molecular mechanism. An allograft mouse model was built. Mouse macrophages were isolated and collected. The infiltration level of Mø and expression of M1 Mø, M2 Mø markers, and PD-L1 were assayed by IHC and flow cytometry. Expression levels of M1 Mø and M2 Mø marker genes and PD-L1 were detected by qPCR. The expression of proteins linked with JAK/STAT3 was tested by western blot. CD8+T cells and NK cells were activated in vitro and co-cultured with mouse macrophages, and their cytotoxicity was detected by LDH method. The proportion of CD206+PD-L1+ cells and the activation and proliferation of CD8+T cells were assayed by flow cytometry. Multicolor immunofluorescence was utilized to assay the co-localization of proteins. AIM2 demonstrated a high expression in LUAD, exhibiting a conspicuous positive correlation with the expression of the M2 Mø markers as well as PD-L1. Expression of M1 markers was upregulated after knockdown of AIM2, while M2 markers expression and PD-L1 were downregulated, and the colocalization of proteins linked with PD-L1 and M2 Mø was decreased. The infiltration and cytotoxicity of CD8+T cells and NK cells increased after silencing AIM2. After the knockdown of AIM2, which was enriched in the JAK/STAT3 pathway, the phosphorylation levels of JAK1, JAK2, and STAT3 were reduced, the immune infiltration level of CD8+T cells increased, and the co-localization level of PD-L1 and PD-1 dropped. The activity and proliferation level of CD8+T cells were increased with the reduced PD-1 expression. AIM2 fosters M2 Mø polarization and PD-L1 expression via the JAK/STAT3 pathway. Moreover, AIM2 promotes the immune escape of LUAD via the PD-1/PD-L1 axis. Our work may blaze a trail for the clinical treatment of LUAD.

An AMPK agonist suppresses the progress of colorectal cancer by regulating the polarization of TAM to M1 through inhibition of HIF-1α and mTOR signal pathway

OBJECTIVE

This study aimed to evaluate the impact of an adenosine monophosphate-activated protein kinase (AMPK) agonist, metformin (MET), on the antitumor effects of macrophages and to determine the underlying mechanism involved in the process.

MATERIALS AND METHODS

M0 macrophages were derived from phorbol-12-myristate-13-acetate-stimulated THP-1 cells.

RESULTS

The levels of tumor necrosis factor-alpha (TNF-α) and human leukocyte antigen-DR (HLA-DR) were decreased in macrophages incubated with HCT116 cells, whereas those of arginase-1 (Arg-1), CD163, and CD206 were elevated; these effects were reversed by MET. The transfection of small interfering (si) RNA abrogated the influence of MET on the expression of the M1/M2 macrophage biomarkers. MET significantly suppressed the proliferation and migration abilities of HCT116 cells incubated with M0 macrophages; these actions were reversed by siRNA transfection against AMPK. The hypoxia-inducible factor 1-alpha (HIF-1α), phosphorylated protein kinase B (p-AKT), and phosphorylated mammalian target of rapamycin (p-mTOR) levels were reduced by the introduction of MET and promoted by siRNA transfection against AMPK. In addition, the levels of HIF-1α, p-AKT, and p-mTOR suppressed by MET were markedly increased following the transfection of siRNA against AMPK.

CONCLUSION

These findings indicate that MET can repress the progression of colorectal cancer by transforming tumor-associated macrophages to the M1phenotype via inhibition of the HIF-1α and mTOR signaling pathways.

Long non-coding RNA NBR2 suppresses the progression of colorectal cancer by downregulating miR-19a to regulate M2 macrophage polarization

Colorectal cancer (CRC) is a malignant tumor of the gastrointestinal tract that significantly impacts the health of patients and lacks promising methods of diagnosis. Tumor-associated macrophages (TAMs) are involved in CRC progression, and their function is regulated by long non-coding RNAs (lncRNAs). The lncRNA NBR2 was recently reported as an oncogene, whose function in CRC remains uncertain. The present study aimed to investigate the biological function of lncRNA NBR2 in the progression of CRC and its underlying molecular mechanisms. Ten pairs of clinical CRC and para-carcinoma tissues were collected to determine the expression levels of lncRNA NBR2 and miR-19a, and the polarization state of TAMs. Quantitative reverse transcriptase-polymerase chain reaction was used to evaluate the expression of miR-19a, and western blotting was used to determine the expression levels of tumor necrosis factor-α, human leukocyte antigen-DR, arginase-1, CD163, CD206, interleukin-4, AMP-activated protein kinase (AMPK), p-AMPK, hypoxia-inducible factor-1α (HIF-1α), protein kinase B (AKT), p-AKT, mechanistic target of rapamycin (mTOR), and p-mTOR in TAMs. The proliferative ability of HCT-116 cells was detected using the CCK8 assay, and the migratory ability of HCT-116 cells was evaluated using the Transwell assay. The interaction between lncRNA NBR2 and miR-19a was determined using the luciferase assay. The lncRNA NBR2 was downregulated and miR-19a was highly expressed in CRC cells, accompanied by a high M2 polarization. Downregulated miR-19a promoted M1 polarization, activated AMPK, suppressed HIF-1α and AKT/mTOR signaling pathways, and promoted antitumor properties in NBR2-overexpressed TAMs, which were all reversed by the introduction of the miR-19a mimic. LncRNA NBR2 was verified to target miR-19a in macrophages according to the results of the luciferase assay. Collectively, lncRNA NBR2 may suppress the progression of CRC by downregulating miR-19a to regulate M2 macrophage polarization.

Recent Advances in Anti-Atherosclerosis and Potential Therapeutic Targets for Nanomaterial-Derived Drug Formulations

Atherosclerosis, the leading cause of death worldwide, is responsible for ≈17.6 million deaths globally each year. Most therapeutic drugs for atherosclerosis have low delivery efficiencies and significant side effects, and this has hampered the development of effective treatment strategies. Diversified nanomaterials can improve drug properties and are considered to be key for the development of improved treatment strategies for atherosclerosis. The pathological mechanisms underlying atherosclerosis is summarized, rationally designed nanoparticle-mediated therapeutic strategies, and potential future therapeutic targets for nanodelivery. The content of this study reveals the potential and challenges of nanoparticle use for the treatment of atherosclerosis and highlights new effective design ideas.

M2 macrophage inhibits the antitumor effects of Lenvatinib on intrahepatic cholangiocarcinoma

Background and objectives

The relationship between the tumor microenvironment and the network of key signaling pathways in cancer plays a key role in the occurrence and development of tumors. Tumor-associated macrophages (TAMs) are important inflammatory cells in the tumor microenvironment and play an important role in tumorigenesis and progression. Macrophages in malignant tumors, mainly the M2 subtype, promote tumor progression by producing cytokines and down-regulating anti-inflammatory immune responses. Several articles have investigated the effect of macrophages on the sensitivity of cancer chemotherapeutic agents, but few such articles have been reported in cholangiocarcinoma, so we investigated the effect of M2 macrophage on the sensitivity of cholangiocarcinoma cells to Lenvatinib compared to M1.

Methods

THP-1 monocytes were polarized to M0 macrophage by phorbol 12-myristate 13-acetate (PMA) and then induced to differentiate into M1 and M2 macrophages by LPS, IFN-γ and IL-4 and IL-13, respectively. Macrophages and cholangiocarcinoma cells were co-cultured prior to 24 hours of Lenvatinib administration, cancer cell apoptosis was detected by western-blot, FACS analysis of Annexin V and PI staining. Furthermore, we use xCELLigence RTCA SP Instrument (ACEA Bio-sciences) to monitor cell viability of Lenvatinib administration in co-culture of cholangiocarcinoma cells and macrophages. After tumorigenesis in immunodeficient mice, Lenvatinib was administered, and the effects of M2 on biological characteristics of cholangiocarcinoma cells were investigated by immuno-histochemistry.

Results

mRNA and protein expression of M1 and M2 markers confirmed the polarization of THP-1 derived macrophages, which provided a successful and efficient model of monocyte polarization to TAMs. Lenvatinib-induced apoptosis of cholangiocarcinoma cells was significantly reduced when co-cultured with M2 macrophage, whereas apoptosis of cholangiocarcinoma cells co-cultured with M1 macrophage was increased. In the CDX model, Lenvatinib-induced cancer cell apoptosis was markedly reduced, and proliferative cells increased in the presence of M2 macrophages. Angiogenesis related factors was significantly increased in cholangiocarcinoma cells co-cultured with M2.

Conclusion

Compared with M1, M2 macrophages can inhibit the anti-tumor effect of Lenvatinib on cholangiocarcinoma through immune regulation, which may be related to the tumor angiogenesis factor effect of M2 macrophage.

Expression of tumor-associated macrophages and PD-L1 in patients with hepatocellular carcinoma and construction of a prognostic model

BACKGROUND

Hepatocellular carcinoma (HCC) is an inflammation-associated tumor involved in immune tolerance and evasion in the immune microenvironment. Immunotherapy can enhance the immune response of the body, break immune tolerance, and then recognize and kill tumor cells. The polarization homeostasis of M1 and M2 macrophages in tumor microenvironment (TME) is involved in the occurrence and development of tumors and has been considered a hot topic in tumor research. Programmed cell death ligand 1 (PD-L1) plays an important role in the polarity of TAM and affects the prognosis of HCC patients as a target of immunotherapy. To this end, efforts were hereby made to further explore the application value of PD-L1, M1 macrophages (CD86), and M2 macrophages (CD206) in the prognosis assessment of HCC, their correlation with immune cell infiltration in HCC tissues, and their bioenrichment function.

METHODS

The gene expression omnibus (GEO) and the Cancer Genome Atlas (TCGA) database were used to analyze the expression of PD-L1, CD86, and CD206 in different tumor tissues. The correlation between the expression of PD-L1, CD86, and CD206 and the infiltration of immune cells was analyzed using the Tumor Immune Estimation Resource (TIMER). The tissue specimens and clinicopathological data of hepatocellular carcinoma patients having undergone surgical treatment in our hospital were collected. Immunohistochemistry was used to verify the expression of PD-L1, CD86, and CD206, and analyze the relationship with clinicopathological features and prognosis of patients. Besides, nomogram was constructed to predict the overall survival (OS) of patients at 3 and 5 years. Finally, the protein-protein interaction network information was analyzed using STRING database, and GO analysis and KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis were performed to study the biological functions of PD-L1, CD86, and CD206.

RESULT

Bioinformatics analysis found that PD-L1, CD86, and CD206 were underexpressed in various tumor tissues including liver cancer, while the present immunohistochemical detection found that PD-L1, CD86, and CD206 were overexpressed in liver cancer tissues. Expressions of PD-L1, CD86, and CD206 were positively correlated with the infiltration level of immune cells in liver cancer, while the expression of PD-L1 was positively correlated with the degree of tumor differentiation. Meanwhile, the expression level of CD206 was positively correlated with gender and preoperative hepatitis, and patients with high expression of PD-L1 or low expression of CD86 had poor prognosis. AJCC stage, preoperative hepatitis, and the expression levels of PD-L1 and CD86 in cancer tissues were independent risk factors affecting survival of patients after radical hepatoma surgery. KEGG pathway enrichment analysis showed that PD-L1 was significantly enriched in T cell aggregation and lymphocyte aggregation, and might be involved in the formation of T cell antigen receptor CD3 complex and cell membrane. Besides, CD86 was significantly enriched in positive regulation of cell adhesion, regulation of mononuclear cell proliferation, regulation of leukocyte proliferation, and transduction of T cell receptor signaling pathway, while CD206 was significantly enriched in type 2 immune response, cellular response to LPS, cellular response to LPS, and involvement in cellular response to LPS.

CONCLUSION

In conclusion, these results suggest that PD-L1, CD86, and CD206 may be involved not only in the occurrence and development of HCC, but also in immune regulation, indicating the potential role of PD-L1 and CD86 as potential biomarkers and new therapeutic targets for prognosis assessment of liver cancer.

Challenges and new technologies in adoptive cell therapy

Adoptive cell therapies (ACTs) have existed for decades. From the initial infusion of tumor-infiltrating lymphocytes to the subsequent specific enhanced T cell receptor (TCR)-T and chimeric antigen receptor (CAR)-T cell therapies, many novel strategies for cancer treatment have been developed. Owing to its promising outcomes, CAR-T cell therapy has revolutionized the field of ACTs, particularly for hematologic malignancies. Despite these advances, CAR-T cell therapy still has limitations in both autologous and allogeneic settings, including practicality and toxicity issues. To overcome these challenges, researchers have focused on the application of CAR engineering technology to other types of immune cell engineering. Consequently, several new cell therapies based on CAR technology have been developed, including CAR-NK, CAR-macrophage, CAR-γδT, and CAR-NKT. In this review, we describe the development, advantages, and possible challenges of the aforementioned ACTs and discuss current strategies aimed at maximizing the therapeutic potential of ACTs. We also provide an overview of the various gene transduction strategies employed in immunotherapy given their importance in immune cell engineering. Furthermore, we discuss the possibility that strategies capable of creating a positive feedback immune circuit, as healthy immune systems do, could address the flaw of a single type of ACT, and thus serve as key players in future cancer immunotherapy.

Exploring the regulatory role of lncRNA in cancer immunity

Imbalanced immune homeostasis in cancer microenvironment is a hallmark of cancer. Increasing evidence demonstrated that long non-coding RNAs (lncRNAs) have emerged as key regulatory molecules in directly blocking the cancer immunity cycle, apart from activating negative regulatory pathways for restraining tumor immunity. lncRNAs reshape the tumor microenvironment via the recruitment and activation of innate and adaptive lymphoid cells. In this review, we summarized the versatile mechanisms of lncRNAs implicated in cancer immunity cycle, including the inhibition of antitumor T cell activation, blockade of effector T cell recruitment, disruption of T cell homing, recruitment of immunosuppressive cells, and inducing an imbalance between antitumor effector cells (cytotoxic T lymphocytes, M1 macrophages, and T helper type 1 cells) versus immunosuppressive cells (M2 macrophages, T helper type 2 cells, myeloid derived suppressor cells, and regulatory T cells) that infiltrate in the tumor. As such, we would highlight the potential of lncRNAs as novel targets for immunotherapy.

Metabolites and Immune Response in Tumor Microenvironments

The remodeled cancer cell metabolism affects the tumor microenvironment and promotes an immunosuppressive state by changing the levels of macro- and micronutrients and by releasing hormones and cytokines that recruit immunosuppressive immune cells. Novel dietary interventions such as amino acid restriction and periodic fasting mimicking diets can prevent or dampen the formation of an immunosuppressive microenvironment by acting systemically on the release of hormones and growth factors, inhibiting the release of proinflammatory cytokines, and remodeling the tumor vasculature and extracellular matrix. Here, we discuss the latest research on the effects of these therapeutic interventions on immunometabolism and tumor immune response and future scenarios pertaining to how dietary interventions could contribute to cancer therapy.

Macrophage-Based Therapeutic Strategies in Hematologic Malignancies

Macrophages are types of immune cells, with ambivalent functions in tumor growth, which depend on the specific environment in which they reside. Tumor-associated macrophages (TAMs) are a diverse population of immunosuppressive myeloid cells that play significant roles in several malignancies. TAM infiltration in malignancies has been linked to a poor prognosis and limited response to treatments, including those using checkpoint inhibitors. Understanding the precise mechanisms through which macrophages contribute to tumor growth is an active area of research as targeting these cells may offer potential therapeutic approaches for cancer treatment. Numerous investigations have focused on anti-TAM-based methods that try to eliminate, rewire, or target the functional mediators released by these cells. Considering the importance of these strategies in the reversion of tumor resistance to conventional therapies and immune modulatory vaccination could be an appealing approach for the immunosuppressive targeting of myeloid cells in the tumor microenvironment (TME). The combination of reprogramming and TAM depletion is a special feature of this approach compared to other clinical strategies. Thus, the present review aims to comprehensively overview the pleiotropic activities of TAMs and their involvement in various stages of cancer development as a potent drug target, with a focus on hematologic tumors.

Uncoding the interdependency of tumor microenvironment and macrophage polarization: insights from a continuous network approach

The balance between pro- and anti-inflammatory immune system responses is crucial to preventing complex diseases like cancer. Macrophages are essential immune cells that contribute to this balance constrained by the local signaling profile of the tumor microenvironment. To understand how pro- and anti-inflammatory unbalance emerges in cancer, we developed a theoretical analysis of macrophage differentiation that is derived from activated monocytes circulating in the blood. Once recruited to the site of inflammation, monocytes can be polarized based on the specific interleukins and chemokines in the microenvironment. To quantify this process, we used a previous regulatory network reconstructed by our group and transformed Boolean Network attractors of macrophage polarization to an ODE scheme, it enables us to quantify the activation of their genes in a continuous fashion. The transformation was developed using the interaction rules with a fuzzy logic approach. By implementing this approach, we analyzed different aspects that cannot be visualized in the Boolean setting. For example, this approach allows us to explore the dynamic behavior at different concentrations of cytokines and transcription factors in the microenvironment. One important aspect to assess is the evaluation of the transitions between phenotypes, some of them characterized by an abrupt or a gradual transition depending on specific concentrations of exogenous cytokines in the tumor microenvironment. For instance, IL-10 can induce a hybrid state that transits between an M2c and an M2b macrophage. Interferon- γ can induce a hybrid between M1 and M1a macrophage. We further demonstrated the plasticity of macrophages based on a combination of cytokines and the existence of hybrid phenotypes or partial polarization. This mathematical model allows us to unravel the patterns of macrophage differentiation based on the competition of expression of transcriptional factors. Finally, we survey how macrophages may respond to a continuously changing immunological response in a tumor microenvironment.

A novel scoring model based on RNA modification "writers" can predict the prognosis and guide immunotherapy in gastric cancer

Although extensive research has been carried out on the epigenetic regulation of single RNA modifications in gastric cancer, little is known regarding the crosstalk of four major RNA adenosine modifications, namely, m6A, m1A, alternative polyadenylation and adenosine-to-inosine RNA editing. By analyzing 26 RNA modification "writers" in 1750 gastric cancer samples, we creatively constructed a scoring model called the "Writers" of the RNA Modification Score (WRM_Score), which was able to quantify the RNA modification subtypes of individual patients. In addition, we explored the relationship between WRM_Score and transcriptional and posttranscriptional regulation, tumor microenvironment, clinical features and molecular subtypes. We constructed an RNA modification scoring model including two different subgroups: WRM_Score_low and WRM_Score_high. The former was associated with survival benefit and good efficacy of immune checkpoint inhibitors (ICIs) due to gene repair and immune activation, while the latter was related to poor prognosis and bad efficacy of ICIs because of stromal activation and immunosuppression. The WRM score based on immune and molecular characteristics of the RNA modification pattern is a reliable predictor of the prognosis of gastric cancer and the therapeutic efficacy of immune checkpoint inhibitors in gastric cancer.

Rational Design of Cu-Doped Tetrahedron of Spinel Oxide for High-Performance Nitric Oxide Electrochemical Sensor

The real-time detection of nitric oxide (NO) in living cells is essential to reveal its physiological processes. However, the popular electrochemical detection strategy is limited to the utilization of noble metals. The development of new detection candidates without noble metal species still maintaining excellent catalytic performance has become a big challenge. Herein, we propose a spinel oxide doped with heteroatom-Cu-doped Co₃O₄ (Cu-Co₃O₄) for the sensitive and selective detection of NO release from the living cells. The material is strategically designed with Cu occupying the tetrahedral (T_d) center of Co₃O₄ through the formation of a Cu-O bond. The introduced Cu regulates the local coordination environment and optimizes the electronic structure of Co₃O₄, hybridizing with the N 2p orbital to enhance charge transfer. The Cu_Td site can well inhibit the current response to nitrite (NO₂^-), resulting in a high improvement in the electrochemical oxidation of NO. The selectivity of Cu-Co₃O₄ can be markedly improved by the pore size of the molecular sieve and the negative charge on the surface. The rapid transmission of electrons is due to the fact that Cu-Co₃O₄ can be uniformly and densely in situ grown on Ti foil. The rationally designed Cu-Co₃O₄ sensor displays excellent catalytic activity toward NO oxidation with a low limit of detection of 2.0 nM (S/N = 3) and high sensitivity of 1.9 μA nM^-1 cm^-2 in cell culture medium. The Cu-Co₃O₄ sensor also shows good biocompatibility to monitor the real-time NO release from living cells (human umbilical vein endothelial cells: HUVECs; macrophage: RAW 264.7 cells). It was found that a remarkable response to NO was obtained in different living cells when stimulated by l-arginine (l-Arg). Moreover, the developed biosensor could be used for real-time monitoring of NO released from macrophages polarized to a M1/M2 phenotype. This cheap and convenient doping strategy shows universality and can be used for sensor design of other Cu-doped transition metal materials. The Cu-Co₃O₄ sensor presents an excellent example through the design of proper materials to implement unique sensing requirements and sheds light on the promising strategy for electrochemical sensor fabrication.

Immune modulations of the tumor microenvironment in response to phototherapy

The tumor microenvironment (TME) promotes pro-tumor and anti-inflammatory metabolisms and suppresses the host immune system. It prevents immune cells from fighting against cancer effectively, resulting in limited efficacy of many current cancer treatment modalities. Different therapies aim to overcome the immunosuppressive TME by combining various approaches to synergize their effects for enhanced anti-tumor activity and augmented stimulation of the immune system. Immunotherapy has become a major therapeutic strategy because it unleashes the power of the immune system by activating, enhancing, and directing immune responses to prevent, control, and eliminate cancer. Phototherapy uses light irradiation to induce tumor cell death through photothermal, photochemical, and photo-immunological interactions. Phototherapy induces tumor immunogenic cell death, which is a precursor and enhancer for anti-tumor immunity. However, phototherapy alone has limited effects on long-term and systemic anti-tumor immune responses. Phototherapy can be combined with immunotherapy to improve the tumoricidal effect by killing target tumor cells, enhancing immune cell infiltration in tumors, and rewiring pathways in the TME from anti-inflammatory to pro-inflammatory. Phototherapy-enhanced immunotherapy triggers effective cooperation between innate and adaptive immunities, specifically targeting the tumor cells, whether they are localized or distant. Herein, the successes and limitations of phototherapy combined with other cancer treatment modalities will be discussed. Specifically, we will review the synergistic effects of phototherapy combined with different cancer therapies on tumor elimination and remodeling of the immunosuppressive TME. Overall, phototherapy, in combination with other therapeutic modalities, can establish anti-tumor pro-inflammatory phenotypes in activated tumor-infiltrating T cells and B cells and activate systemic anti-tumor immune responses.

β-Glucan produced by Lentinus edodes suppresses breast cancer progression via the inhibition of macrophage M2 polarization by integrating autophagy and inflammatory signals

BACKGROUND

β-Glucan from Lentinus edodes (LNT), an edible mushroom, possesses strong anticancer activity. However, the therapeutic effects of LNT during the occurrence and progression of breast cancer and their underlying molecular mechanisms have not been elucidated.

METHODS

Mouse mammary tumor virus-polyoma middle tumor-antigen (MMTV-PyMT) transgenic mice were used as a breast cancer mouse model. Hematoxylin and eosin, immunohistochemical, and immunofluorescence staining were performed for histopathological analysis. Moreover, we developed an inflammatory cell model using tumor necrosis factor-α (TNF-α). Macrophage polarization was assessed using western blot analysis and immunofluorescence.

RESULTS

Orphan nuclear receptor 77 (Nur77) and sequestosome-1 (p62) were highly expressed and positively correlated with each other in breast cancer tissues. LNT significantly inhibited tumor growth, ameliorated inflammatory cell infiltration, and induced tumor cell apoptosis in PyMT transgenic mice. Moreover, LNT attenuated the ability of tumors to metastasize to lung tissue. Mechanistically, LNT treatment restrained macrophage polarization from M1 to M2 phenotype and promoted autophagic cell death by inhibiting Nur77 expression, AKT/mTOR signaling, and inflammatory signals in breast tumor cells. However, LNT did not exhibit a direct pro-autophagic effect on tumor cell death, except for its inhibitory effect on Nur77 expression. LNT-mediated autophagic tumor cell death depends on M1 macrophage polarization. In in vitro experiments, LNT inhibited the upregulation of p62, autophagy activation, and inflammatory signaling pathways in Nur77 cells.

CONCLUSION

LNT inhibited macrophage M2 polarization and subsequently blocked the AKT/mTOR and inflammatory signaling axes in breast cancer cells, thereby promoting autophagic tumor cell death. Thus, LNT may be a promising therapeutic strategy for breast cancer.

Pulsatilla Saponins Inhibit Experimental Lung Metastasis of Melanoma via Targeting STAT6-Mediated M2 Macrophages Polarization

Pulsatilla saponins (PS) extracts from Pulsatilla chinensis (Bge.) Regel, are a commonly used traditional Chinese medicine. In the previous study, we found Pulsatilla saponins displayed anti-tumor activity without side effects such as bone marrow suppression. However, the mechanism of the anti-tumor effect was not illustrated well. Since M2-like tumor-associated macrophages (TAMs) that required activation of the signal transducer and activator of transcription 6 (STAT6) for polarization are the important immune cells in the tumor microenvironment and play a key role in tumor progress and metastasis, this study aimed to confirm whether Pulsatilla saponins could inhibit the development and metastasis of tumors by inhibiting the polarization of M2 macrophages. We investigated the relevance of M2 macrophage polarization and the anti-tumor effects of Pulsatilla saponins in vitro and in vivo. In vitro, Pulsatilla saponins could decrease the mRNA level of M2 marker genes Arg1, Fizz1, Ym1, and CD206, and the down-regulation effect of phosphorylated STAT6 induced by IL-4; moreover, the conditioned medium (CM) from bone marrow-derived macrophages (BMDM) treated with Pulsatilla saponins could inhibit the proliferation and migration of B16-F0 cells. In vivo, Pulsatilla saponins could reduce the number of lung metastasis loci, down-regulate the expression of M2 marker genes, and suppress the expression of phosphorylated STAT6 in tumor tissues. Furthermore, we used AS1517499 (AS), a STAT6 inhibitor, to verify the role of PS on M2 macrophage polarization both in vitro and in vivo. We found that Pulsatilla saponins failed to further inhibit STAT6 activation; the mRNA level of Arg1, Fizz1, Ym1, and CD206; and the proliferation and migration of B16-F0 cells after AS1517499 intervention in vitro. Similar results were obtained in vivo. These results illustrated that Pulsatilla saponins could effectively suppress tumor progress by inhibiting the polarization of M2 macrophages via the STAT6 signaling pathway; this revealed a novel mechanism for its anti-tumor activity.

Autoimmunity and Carcinogenesis: Their Relationship under the Umbrella of Autophagy

The immune system and autophagy share a functional relationship. Both innate and adaptive immune responses involve autophagy and, depending on the disease’s origin and pathophysiology, it may have a detrimental or positive role on autoimmune disorders. As a “double-edged sword” in tumors, autophagy can either facilitate or impede tumor growth. The autophagy regulatory network that influences tumor progression and treatment resistance is dependent on cell and tissue types and tumor stages. The connection between autoimmunity and carcinogenesis has not been sufficiently explored in past studies. As a crucial mechanism between the two phenomena, autophagy may play a substantial role, though the specifics remain unclear. Several autophagy modifiers have demonstrated beneficial effects in models of autoimmune disease, emphasizing their therapeutic potential as treatments for autoimmune disorders. The function of autophagy in the tumor microenvironment and immune cells is the subject of intensive study. The objective of this review is to investigate the role of autophagy in the simultaneous genesis of autoimmunity and malignancy, shedding light on both sides of the issue. We believe our work will assist in the organization of current understanding in the field and promote additional research on this urgent and crucial topic.

FGFR2 upregulates PAI-1 via JAK2/STAT3 signaling to induce M2 polarization of macrophages in colorectal cancer

Fibroblast growth factor receptor 2 (FGFR2) is frequently activated by overexpression or mutation, and an abnormal fibroblast growth factor (FGF)/FGFR signaling pathway is associated with the occurrence, development, and poor prognosis of colorectal cancer (CRC). Our preliminary analysis found that plasminogen activator inhibitor-1 (PAI-1) expression may be related to FGF/FGFR signaling, however, their role in the tumor immune microenvironment remains unclear. In this study, we observed markedly higher PAI-1 expression in CRC patients with poor survival rates. PAI-1 is regulated by FGF/FGFR2 in colon cancer cells and is involved in M2 macrophage polarization. Mechanistically, inhibiting the JAK2/STAT3 signaling pathway could cause PAI-1 downregulation. Furthermore, the activation of phosphorylated STAT3 upregulated PAI-1. In vivo, FGFR2 overexpression in tumor-bearing mouse models suggested that a PAI-1 inhibitor could rescue FGFR2/PAI-1 axis-induced M2 macrophage polarization, which leads to effective immune activity and tumor suppression. Moreover, the combination of a PAI-1 inhibitor and anti-PD-1 therapy exhibited superior antitumor activity in mice. These findings offer novel insights into the molecular mechanisms underlying tumor deterioration and provide potential therapeutic targets for CRC treatment.

Knocking Down Gm16685 Decreases Liver Granuloma in Murine Schistosomiasis Japonica

Long noncoding RNAs (lncRNAs) can regulate key genes and pathways in liver disease development. Moreover, macrophages are speculated to play an important role in regulating granulomatous inflammation during schistosomiasis. However, the role of lncRNAs in the formation of liver granulomas by influencing the polarization of macrophages in Schistosoma japonicum infection is unclear. Our study aimed to determine whether lncRNAs can play a role in S. japonicum-induced hepatic egg granulomas and elucidate their effect on macrophages. We established S. japonicum infection models and screened the target lncRNA Gm16685 highly expressed in schistosomiasis mice using high-throughput sequencing. Hematoxylin and eosin staining revealed that the knockdown of Gm16685 reduced the area of egg granulomas. Moreover, M1 macrophage factor genes were significantly downregulated in Gm16685 knockdown livers. Meanwhile, M2 macrophage factor genes were significantly upregulated, which was consistent with the protein detection results. Hepatocytes, hepatic stellate cells, and macrophages were isolated from mouse models infected with S. japonicum, with Gm16685 being significantly upregulated in macrophages. Moreover, the knockdown of Gm16685 in RAW264.7 cells revealed similar results to in liver tissue. RNA fluorescence in situ hybridization (FISH) and nucleocytoplasmic separation experiments revealed that Gm16685 was predominantly localized in the cytoplasm of cells. We found that miR-205-5p was upregulated after Gm16685 was knocked down. After overexpression of miR-205-5p, the expression of Gm16685 and inflammatory factors was significantly downregulated. These results indicate that Gm16685 can participate in the pathogenesis of hepatic disease in schistosomiasis and promote M1 macrophage polarization by regulating miR-205-5p. Thus, our study may provide a new target for schistosomiasis japonica treatment.

Macrophage Polarization: An Important Candidate Regulator for Lung Diseases

Macrophages are crucial components of the immune system and play a critical role in the initial defense against pathogens. They are highly heterogeneous and plastic and can be polarized into classically activated macrophages (M1) or selectively activated macrophages (M2) in response to local microenvironments. Macrophage polarization involves the regulation of multiple signaling pathways and transcription factors. Here, we focused on the origin of macrophages, the phenotype and polarization of macrophages, as well as the signaling pathways associated with macrophage polarization. We also highlighted the role of macrophage polarization in lung diseases. We intend to enhance the understanding of the functions and immunomodulatory features of macrophages. Based on our review, we believe that targeting macrophage phenotypes is a viable and promising strategy for treating lung diseases.

Adenoid cystic carcinoma of the salivary glands: a pilot study of potential therapeutic targets and characterization of the immunological tumor environment and angiogenesis

BACKGROUND

Adenoid cystic carcinoma (ACC) is a rare type of cancer commonly occurring in salivary glands. It is characterized by slow but infiltrative growth, nerve infiltration and overall poor prognosis, with late recurrence and distant metastasis. The treatment of ACC is still limited to surgery and/or (adjuvant) radiotherapy. Till now no promising systemic therapy option exists. However, various studies deliver promising results after treatment with anti-angiogenetic agents, such as anti-EGFR-antibody Cetuximab or Tyrosinkinase inhibitor Lenvatinib.

METHODS

By using of immunohistological methods we analyzed and compared the macrophage and lymphocyte populations, vascularization, and PD-L1-status in 12 ACC of the salivary glands.

RESULTS

All cases showed a significant elevation of macrophages with M2 polarization and a higher vascularization in ACC compared to normal salivary gland tissue. The CD4/CD8 quotient was heterogenous. ACC does not show relevant PD-L1 expression.

CONCLUSIONS

The predominant M2 polarization of macrophages in ACC could be responsible for elevated vascularization, as already been proved in other cancer types, that M2 macrophages promote angiogenesis.

Radiomics: A review of current applications and possibilities in the assessment of tumor microenvironment

With the recent success in the application of immunotherapy for treating various advanced cancers, the tumor microenvironment has rapidly become an important field of research. The tumor microenvironment is complex and its characteristics strongly influence disease biology and potentially responses to systemic therapy. Accurate preoperative assessment of tumor microenvironment is of great significance for the formulation of an immunotherapy strategy and evaluation of patient prognosis. As a research hotspot in medical image analysis technology, radiomics has been applied in the auxiliary diagnosis of the tumor microenvironment. This article reviews the current status of radiomics in the elective application on tumor microenvironment and discusses potential prospects.

Tumor Immune Microenvironment Heterogeneity at the Invasion Front and Tumor Center in Oral Squamous Cell Carcinoma as a Perspective of Managing This Cancer Entity

BACKGROUND

Evaluating the tumor microenvironment and its influence on clinical management and therapy response is becoming increasingly important. However, only a few studies deal with the spatial distribution of immune cells within the tumor. This study aimed to describe the topology of immune cells in the microenvironment of oral squamous cell carcinoma (OSCC) sectioned by tumor invasion front and tumor center and to test their prognostic relevance regarding patient survival.

METHODS

A total of 55 OSCC patient specimens were collected retrospectively. The cancer tissue was immunohistochemically stained using an automated tissue stainer Ventana Benchmark Ultra (Roche) and analyzed using discrete expression marker profiles on immune cells. We investigated CD4+ lymphocytes, CD8+ lymphocytes, CD68+ macrophages, CD163+ macrophages, and M1 macrophages regarding their spatial distribution.

RESULTS

The statistical analysis revealed that the quantity and distribution of CD4+ (p = 0.007), CD8+ (p < 0.001), CD68+ (p < 0.001), CD163+ cells (p = 0.004), and M1 (p < 0.001) macrophages were significantly higher at the invasion front compared to the tumor center in all observed cases. However, high and low immune cell counts in the tumor center and invasion front were not associated with overall survival.

CONCLUSION

Our results show two distinct immune microenvironments of the tumor center compared to the invasion front. Future studies are needed to explore how these results can be leveraged to improve patient therapy and outcome.

M2 macrophages-derived exosomal miR-3917 promotes the progression of lung cancer via targeting GRK6

Macrophages in the tumor microenvironment (TME) can serve as potential targets for therapeutic intervention. The aim of this study was to investigate the molecular mechanism by which M2 macrophage-derived exosomes (M2-Ex) affect lung cancer progression through miRNA transport. The THP-1 cells were differentiated into M0 and M2 macrophages. M2-Ex were isolated and identified by transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA). Cancer tissues and adjacent tissues of non-small-cell lung cancer (NSCLC) patients were collected. H1299 and A549 cells were co-cultured with M2-Ex. Subcutaneous xenograft mouse model was established. miR-3917 is highly expressed in lung cancer tissues and M2-Ex. Interference of miR-3917 in M2-Ex inhibits H1299 cell proliferation, migration and invasion, while overexpression of miR-3917 had the opposite effect in A549 cells. M2-Ex promote tumor growth by delivering miR-3917 in vivo. miR-3917 could target G protein-coupled receptor kinase 6 (GRK6), and interference of miR-3917 in M2-Ex inhibits H1299 cells proliferation, migration and invasion by up-regulating GRK6 level, while overexpression of miR-3917 had the opposite effect in A549 cells. M2-Ex can transfer miR-3917 into lung cancer cells and promote lung cancer progression, providing theoretical basis for the diagnosis and effective treatment of lung cancer.

Targeting the Tumor Immune Microenvironment Could Become a Potential Therapeutic Modality for Aggressive Pituitary Adenoma

OBJECT

This study aimed to explore the relationship between the aggressiveness and immune cell infiltration in pituitary adenoma (PA) and to provide the basis for immuno-targeting therapies.

METHODS

One hundred and three patients with PA who underwent surgery at a single institution were retrospectively identified. The infiltration of macrophages and T-lymphocytes was quantitatively assessed.

RESULTS

The number of CD68+ macrophages was positively correlated with Knosp (p = 0.003) and MMP-9 expression grades (p = 0.00). The infiltration of CD163+ macrophages differed among Knosp (p = 0.022) and MMP-9 grades (p = 0.04). CD8+ tumor-infiltrating lymphocytes (TILs) were also positively associated with Knosp (p = 0.002) and MMP-9 grades (p = 0.01). Interestingly, MGMT expression was positively correlated with MMP-9 staining extent (p = 0.000). The quantities of CD8+ TILs (p = 0.016), CD68+ macrophages (p = 0.000), and CD163+ macrophages (p = 0.043) were negatively associated with MGMT expression levels. The number of CD68+ macrophages in the PD-L1 negative group was significantly more than that in the PD-L1 positive group (p = 0.01). The rate of PD-L1 positivity was positively correlated with the Ki-67 index (p = 0.046) and p53 expression (p = 0.029).

CONCLUSION

Targeted therapy for macrophages and CD8+ TILs could be a helpful treatment in the future for aggressive PA. Anti-PD-L1 therapy may better respond to PAs with higher Ki-67 and p53 expression and more infiltrating CD68+ macrophages. Multiple treatment modalities, especially combined with immunotherapy could become a novel therapeutic strategy for aggressive PA.

Tumor-derived exosomes elicit cancer-associated fibroblasts shaping inflammatory tumor microenvironment in head and neck squamous cell carcinoma

OBJECTIVES

Exosome-mediated reciprocal crosstalk between tumor and stromal cells plays a crucial role in tumor development and progression. This study investigated whether exosomes released from head and neck squamous cell carcinoma (HNSCC) tumor cells can convert normal fibroblasts into cancer-associated fibroblasts (CAF)-like cells and further analyzed the functional characterization of fibroblasts educated by tumor-derived exosomes.

MATERIALS AND METHODS

Exosomes secreted from HNSCC cell lines were isolated and normal fibroblasts were established from normal oropharyngeal mucosa. The effects of the exosomes on fibroblasts were examined by proliferation and migration assays, and exosome-educated fibroblasts were analyzed for the expression of eight genes (IL1B, IL6, CXCL8, TGFB1, ACTA2, FAP, CD274, and PDCD1LG2) by RT-qPCR. Moreover, T cells or CD14-positive cells were co-cultured with culture supernatants from exosome-educated fibroblasts. T-cell proliferation and macrophage polarization were examined using flow cytometry. Then, RNA sequencing (RNA-seq) of exosome-educated fibroblasts and the corresponding control fibroblasts was performed.

RESULTS

Tumor-derived exosomes enhanced fibroblast proliferation and migration. Moreover, gene expression analysis revealed upregulation of the gene expression of proinflammatory cytokines and immunoregulatory genes, and activated fibroblast marker genes. The culture supernatants of tumor-derived exosome-educated fibroblasts suppressed T cell proliferation and the induction of protumoral macrophages compared with those of control fibroblasts. Next, comprehensive RNA-seq analysis data revealed the activation of 11 signaling pathways, including IL-6- and IL-17-related signaling.

CONCLUSION

These results indicate that HNSCC tumor cells induce and/or differentiate into CAFs through exosome-based cell-to-cell communication to create an inflammatory tumor microenvironment.

Shenqi Fuzheng injection reverses M2 macrophage-mediated cisplatin resistance through the PI3K pathway in breast cancer

BACKGROUND

Shenqi Fuzheng injection (SQFZ) combined with chemotherapy can sensitize tumour cells. However, the mechanisms underlying SQFZ's effects remain unknown. In human breast cancer cell lines and M2 macrophages, we showed that SQFZ was a significantly potent agent of sensitization.

METHODS

The human breast cancer cell line, MDA-MB-231/DDP, and the human acute leukaemia mononuclear cell line, THP-1, were used. MDA-MB-231/DDP breast cancer xenografts were established to monitor tumour growth. Resistance-associated proteins were examined by western blotting. Levels of cytokines and chemokines were detected by ELISA. Cell viability was measured using the MTT assay. Apoptosis was detected by flow cytometric analysis.

RESULTS

SQFZ significantly enhanced the capability of cisplatin to reduce tumour mass. SQFZ and cisplatin decreased the expression of CD206 by 1.89-fold and increased that of CD86 by 1.76-fold as compared to cisplatin alone. The levels of PGE2, IL-6, and CCL1 decreased significantly, and the activation of p-PI3K and the expressions of P-gp and ABCG2 were also inhibited by SQFZ in combination with cisplatin treatment in vivo. The survival following cisplatin administration of 60 μM and 120 μM reduced significantly in the presence of SQFZ in MDA-MB-231/DDP and M2 co-cultured cells. IGF-1, a PI3K activator, combined with SQFZ weakened the effects of SQFZ-induced apoptosis from 28.7% to 10.5%. The effects of IGF-1 on increasing the expressions of P-gp, ABCG2, and Bcl-2, and decreasing that of Bax were reversed by SQFZ.

CONCLUSION

Our findings provide evidence that SQFZ is a potential therapeutic drug for cancer therapy.

Boolean modeling reveals that cyclic attractors in macrophage polarization serve as reservoirs of states to balance external perturbations from the tumor microenvironment

Cyclic attractors generated from Boolean models may explain the adaptability of a cell in response to a dynamical complex tumor microenvironment. In contrast to this idea, we postulate that cyclic attractors in certain cases could be a systemic mechanism to face the perturbations coming from the environment. To justify our conjecture, we present a dynamic analysis of a highly curated transcriptional regulatory network of macrophages constrained into a cancer microenvironment. We observed that when M1-associated transcription factors (STAT1 or NF-κB) are perturbed and the microenvironment balances to a hyper-inflammation condition, cycle attractors activate genes whose signals counteract this effect implicated in tissue damage. The same behavior happens when the M2-associated transcription factors are disturbed (STAT3 or STAT6); cycle attractors will prevent a hyper-regulation scenario implicated in providing a suitable environment for tumor growth. Therefore, here we propose that cyclic macrophage phenotypes can serve as a reservoir for balancing the phenotypes when a specific phenotype-based transcription factor is perturbed in the regulatory network of macrophages. We consider that cyclic attractors should not be simply ignored, but it is necessary to carefully evaluate their biological importance. In this work, we suggest one conjecture: the cyclic attractors can serve as a reservoir to balance the inflammatory/regulatory response of the network under external perturbations.

[Melanoma-associated macrophages-from molecular signals to therapeutic application]

BACKGROUND

Macrophages are an important component of the innate immune system. They are abbreviated as Mφ, MΦ, or MP. The name is derived from Greek: large eaters, μακρóς (makrós) = large, φαγεῖν (phagein) = to eat, because they engulf and digest pathogens. Tumor-associated macrophages (TAMs) are associated with drug resistance in cancers, including melanoma, and targeting them may improve cancer treatment.

OBJECTIVES

The purpose of this article is to examine the role of TAMs in cancer, particularly in melanoma. The relationship between TAM and treatment resistance and their potential application in the treatment of melanoma are discussed.

MATERIALS AND METHODS

A literature search in PubMed and Google Scholar databases for TAM and melanoma was performed. Clinical trials were searched via clinicaltrials.gov and graphical representations were created using BioRender.

RESULTS

In melanoma, macrophages are among the most abundant immune cells in the tumor microenvironment (TME). TAMs are associated with poor prognosis and resistance. They are involved in tumorigenesis and metastasis development. M2 is the predominant type of TAM and the M2 markers CD163 and CD204 are unfavorable prognostic biomarkers. Therapeutic approaches aim to decrease their recruitment, modulate their function, or reprogram them. Treatment using chimeric antigen receptor (CAR)-M cells and nanoparticles are currently being investigated. Drugs being tested for melanoma include signal transducer and activator of transcription 3 (STAT3) inhibitors, macrophage colony-stimulating factor (M-CSF) antagonists, interferons (IFN), talimogene laherparepvec (TVEC), histone deacetylase (HDAC) inhibitors, indoleamine 2,3-dioxygenase (IDO) inhibitors, colony-stimulating factor 1 receptor (CSF-1R) antagonists, CD40 agonists, arginase 1 (ARG-1) inhibitors, and phosphoinositide 3‑kinase γ (PI3K-γ) inhibitors.

CONCLUSIONS

TAMs participate in developing resistance to current melanoma therapies. Treatment directed against them may help reduce the development of resistance and improve survival.

FSCN1 induced PTPRF-dependent tumor microenvironment inflammatory reprogramming promotes lung adenocarcinoma progression via regulating macrophagic glycolysis

PURPOSE

Macrophages (MΦs) play a dual role in the promotion and suppression of lung adenocarcinoma (LUAD), the function of which is influenced by the metabolic status. The role of protein tyrosine phosphatase receptor type F (PTPRF) in cancer has not been elucidated, and its role in MΦs remains to be seen.

METHODS

The Seahorse XFe 96 Cell Flow Analyzer detected glucose metabolism in tumor cells and macrophages. The expressions of FSCN1, M-CSF, IL4, PTPRF and IGF1 in macrophages were detected by Western blotting and qRT-PCR. Binding of FSCN1 and IGF1R was detected by co-immunoprecipitation. The tumor status in animals was observed using the IVIS Lumina III imaging system.

RESULTS

We found that Fascin Actin-Bundling Protein 1 (FSCN1) activates the PI3K-AKT and JAK-STAT signaling pathways in LUAD cells via binding to IGF-1R, thereby promoting the secretion of cytokines such as IL4 and M-CSF. IL4 and M-CSF promote the expression of PTPRF in MΦs, leading to M2 polarization of MΦs by increasing glucose intake and lactate production. In return, M2-type MΦs act on LUAD cells by secreting cytokines such as IGF-1, CCL2, and IL10, which ultimately promote tumor progression. In vivo experiments proved that the knockdown of FSCN1 in A549 cells and PTPRF in MΦs greatly reduced LUAD proliferative and metastatic capacity, which was consistent with the in vitro findings.

CONCLUSIONS

This study investigated the reprogramming effects of FSCN1 and PTPRF on inflammatory cytokines in the LUAD microenvironment, revealing potential mechanisms by which FSCN1 and PTPRF promote tumor progression and providing a new experimental basis for LUAD treatment.

Exosomal lncRNA HOTAIR induce macrophages to M2 polarization via PI3K/ p-AKT /AKT pathway and promote EMT and metastasis in laryngeal squamous cell carcinoma

Exosomes are a new way of the communication between the tumor cell and macrophage in the micro-environment. The macrophage can be induced to different phenotypes according to the different tumors. In the present study, long-chain noncoding RNA HOTAIR (lncRNA HOTAIR) was highly expressed in LSCC and exosomes. The pathway of exosomal lncRNA HOTAIR inducing macrophage to M2 polarization in the LSCC was investigated. The carcinoma tissues and adjacent tissues were collected from 104 LSCC cases, and the positive relationship between CD163-/CD206-M2 macrophage infiltration and clinical phase, lymph node spreading and pathological phase in LSCC was observed. To examine the role of exosomal lncRNA HOTAIR, macrophages were co-cultured with LSCC-exosomes of high lncRNA HOTAIR expression or transferred with HOTAIR mimics. It was suggested that exosomal lncRNA HOTAIR can induce macrophages to M2 polarization by PI3K/p-AKT/AKT signaling pathway. Furthermore, exo-treated M2 macrophages facilitate the migration, proliferation, and EMT of LSCC.

The Role of the Microbiome on the Pathogenesis and Treatment of Colorectal Cancer

The gut microbiome has long been known to play a role in various aspects of health modulation, including the pathogenesis of colorectal cancer (CRC). With immunotherapy recently emerging as a successful treatment in microsatellite instability high (MSI-high) CRC, and with a newly demonstrated involvement of the gut microbiome in the modulation of therapeutic responses, there has been an explosion of research into the mechanisms of microbial effects on CRC. Harnessing and reprogramming the microbiome may allow for the expansion of these successes to broader categories of CRC, the prevention of CRC in high-risk patients, and the enhancement of standard treatments. In this review, we pull together both well-documented phenomena and recent discoveries that pertain to the microbiome and CRC. We explore the microbial mechanisms associated with CRC pathogenesis and progression, recent advancements in CRC systemic therapy, potential options for diagnosis and prevention, as well as directions for future research.

Manipulation of the crosstalk between tumor angiogenesis and immunosuppression in the tumor microenvironment: Insight into the combination therapy of anti-angiogenesis and immune checkpoint blockade

Immunotherapy has been recognized as an effective and important therapeutic modality for multiple types of cancer. Nevertheless, it has been increasing recognized that clinical benefits of immunotherapy are less than expected as evidenced by the fact that only a small population of cancer patients respond favorably to immunotherapy. The structurally and functionally abnormal tumor vasculature is a hallmark of most solid tumors and contributes to an immunosuppressive microenvironment, which poses a major challenge to immunotherapy. In turn, multiple immune cell subsets have profound consequences on promoting neovascularization. Vascular normalization, a promising anti-angiogenic strategy, can enhance vascular perfusion and promote the infiltration of immune effector cells into tumors via correcting aberrant tumor blood vessels, resulting in the potentiation of immunotherapy. More interestingly, immunotherapies are prone to boost the efficacy of various anti-angiogenic therapies and/or promote the morphological and functional alterations in tumor vasculature. Therefore, immune reprograming and vascular normalization appear to be reciprocally regulated. In this review, we mainly summarize how tumor vasculature propels an immunosuppressive phenotype and how innate and adaptive immune cells modulate angiogenesis during tumor progression. We further highlight recent advances of anti-angiogenic immunotherapies in preclinical and clinical settings to solidify the concept that targeting both tumor blood vessels and immune suppressive cells provides an efficacious approach for the treatment of cancer.