The dual effects of a novel peptibody on angiogenesis inhibition and M2 macrophage polarization on sarcoma

Immune Cells in the Tumor Microenvironment of Soft Tissue Sarcomas

Soft tissue sarcomas (STSs) are a rare heterogeneous group of malignant neoplasms characterized by their aggressive course and poor response to treatment. This determines the relevance of research aimed at studying the pathogenesis of STSs. By now, it is known that STSs is characterized by complex relationships between the tumor cells and immune cells of the microenvironment. Dynamic interactions between tumor cells and components of the microenvironment enhance adaptation to changing environmental conditions, which provides the high aggressive potential of STSs and resistance to antitumor therapy. Today, active research is being conducted to find effective antitumor drugs and to evaluate the possibility of using therapy with immune cells of STS. The difficulty in assessing the efficacy of new antitumor options is primarily due to the high heterogeneity of this group of malignant neoplasms. Studying the role of immune cells in the microenvironment in the progression STSs and resistance to antitumor therapies will provide the discovery of new biomarkers of the disease and the prediction of response to immunotherapy. In addition, it will help to initially divide patients into subgroups of good and poor response to immunotherapy, thus avoiding wasting precious time in selecting the appropriate antitumor agent.

Macrophage's role in solid tumors: two edges of a sword

The tumor microenvironment is overwhelmingly dictated by macrophages, intimately affiliated with tumors, exercising pivotal roles in multiple processes, including angiogenesis, extracellular matrix reconfiguration, cellular proliferation, metastasis, and immunosuppression. They further exhibit resilience to chemotherapy and immunotherapy via meticulous checkpoint blockades. When appropriately stimulated, macrophages can morph into a potent bidirectional component of the immune system, engulfing malignant cells and annihilating them with cytotoxic substances, thus rendering them intriguing candidates for therapeutic targets. As myelomonocytic cells relentlessly amass within tumor tissues, macrophages rise as prime contenders for cell therapy upon the development of chimeric antigen receptor effector cells. Given the significant incidence of macrophage infiltration correlated with an unfavorable prognosis and heightened resistance to chemotherapy in solid tumors, we delve into the intricate role of macrophages in cancer propagation and their promising potential in confronting four formidable cancer variants-namely, melanoma, colon, glioma, and breast cancers.

Advances of research of Fc-fusion protein that activate NK cells for tumor immunotherapy

The rapid development of bioengineering technology has introduced Fc-fusion proteins, representing a novel kind of recombinant protein, as promising biopharmaceutical products in tumor therapy. Numerous related anti-tumor Fc-fusion proteins have been investigated and are in different stages of development. Fc-fusion proteins are constructed by fusing the Fc-region of the antibody with functional proteins or peptides. They retain the bioactivity of the latter and partial properties of the former. This structural and functional advantage makes Fc-fusion proteins an effective tool in tumor immunotherapy, especially for the recruitment and activation of natural killer (NK) cells, which play a critical role in tumor immunotherapy. Even though tumor cells have developed mechanisms to circumvent the cytotoxic effect of NK cells or induce defective NK cells, Fc-fusion proteins have been proven to effectively activate NK cells to kill tumor cells in different ways, such as antibody-dependent cell-mediated cytotoxicity (ADCC), activate NK cells in different ways in order to promote killing of tumor cells. In this review, we focus on NK cell-based immunity for cancers and current research progress of the Fc-fusion proteins for anti-tumor therapy by activating NK cells.

Therapeutic Approaches Targeting Proteins in Tumor-Associated Macrophages and Their Applications in Cancers

Tumor-associated macrophages (TAMs) promote tumor proliferation, invasion, angiogenesis, stemness, therapeutic resistance, and immune tolerance in a protein-dependent manner. Therefore, the traditional target paradigms are often insufficient to exterminate tumor cells. These pro-tumoral functions are mediated by the subsets of macrophages that exhibit canonical protein markers, while simultaneously having unique transcriptional features, which makes the proteins expressed on TAMs promising targets during anti-tumor therapy. Herein, TAM-associated protein-dependent target strategies were developed with the aim of either reducing the numbers of TAMs or inhibiting the pro-tumoral functions of TAMs. Furthermore, the recent advances in TAMs associated with tumor metabolism and immunity were extensively exploited to repolarize these TAMs to become anti-tumor elements and reverse the immunosuppressive tumor microenvironment. In this review, we systematically summarize these current studies to fully illustrate the TAM-associated protein targets and their inhibitors, and we highlight the potential clinical applications of targeting the crosstalk among TAMs, tumor cells, and immune cells in anti-tumor therapy.

A bi-directional dialog between vascular cells and monocytes/macrophages regulates tumor progression

Cancer progression largely depends on tumor blood vessels as well on immune cell infiltration. In various tumors, vascular cells, namely endothelial cells (ECs) and pericytes, strongly regulate leukocyte infiltration into tumors and immune cell activation, hence the immune response to cancers. Recently, a lot of compelling studies unraveled the molecular mechanisms by which tumor vascular cells regulate monocyte and tumor-associated macrophage (TAM) recruitment and phenotype, and consequently tumor progression. Reciprocally, TAMs and monocytes strongly modulate tumor blood vessel and tumor lymphatic vessel formation by exerting pro-angiogenic and lymphangiogenic effects, respectively. Finally, the interaction between monocytes/TAMs and vascular cells is also impacting several steps of the spread of cancer cells throughout the body, a process called metastasis. In this review, the impact of the bi-directional dialog between blood vascular cells and monocytes/TAMs in the regulation of tumor progression is discussed. All together, these data led to the design of combinations of anti-angiogenic and immunotherapy targeting TAMs/monocyte whose effects are briefly discussed in the last part of this review.

Immunotherapy for sarcomas: new frontiers and unveiled opportunities

Sarcomas are a rare malignancy of mesenchymal tissues, comprizing a plethora of unique subtypes, with more than 60 types. The sheer heterogeneity of disease phenotype makes this a particularly difficult cancer to treat. Radiotherapy, chemotherapy and surgery have been employed for over three decades and, although effective in early disease (stages I–II), in later stages, where metastatic tumors are present, these treatments are less effective. Given the spectacular results obtained by cancer immunotherapy in a variety of solid cancers and leukemias, there is now a great interest in appliying this new realm of therapy for sarcomas. The widespread use of immunotherapy for sarcoma relies on immuno-profiling of subtypes, immunomonitoring for prognosis, preclinical studies and insight into the safety profile of these novel therapies. Herein, we discuss preclinical and clinical data highlighting how immunotherapy is being used in soft tissue sarcoma and bone sarcomas.

Tumor-Associated Macrophages in Pancreatic Ductal Adenocarcinoma: Origin, Polarization, Function, and Reprogramming

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy. PDAC is only cured by surgical resection in its early stage, but there remains a relatively high possibility of recurrence. The development of PDAC is closely associated with the tumor microenvironment. Tumor-associated macrophages (TAMs) are one of the most abundant immune cell populations in the pancreatic tumor stroma. TAMs are inclined to M2 deviation in the tumor microenvironment, which promotes and supports tumor behaviors, including tumorigenesis, immune escape, metastasis, and chemotherapeutic resistance. Herein, we comprehensively reviewed the latest researches on the origin, polarization, functions, and reprogramming of TAMs in PDAC.

The role of tumor-associated macrophages (TAMs) in tumor progression and relevant advance in targeted therapy

Macrophages have a leading position in the tumor microenvironment (TME) which paves the way to carcinogenesis. Initially, monocytes and macrophages are recruited to the sites where the tumor develops. Under the guidance of different microenvironmental signals, macrophages would polarize into two functional phenotypes, named as classically activated macrophages (M1) and alternatively activated macrophages (M2). Contrary to the anti-tumor effect of M1, M2 exerts anti-inflammatory and tumorigenic characters. In progressive tumor, M2 tumor-associated macrophages (TAMs) are in the majority, being vital regulators reacting upon TME. This review elaborates on the role of TAMs in tumor progression. Furthermore, prospective macrophage-focused therapeutic strategies, including drugs not only in clinical trials but also at primary research stages, are summarized followed by a discussion about their clinical application values. Nanoparticulate systems with efficient drug delivery and improved antitumor effect are also summed up in this article.

Tumor-associated macrophages: A promising target for a cancer immunotherapeutic strategy

Macrophages, a type of myeloid immune cell, play essential roles in fighting against pathogenic invasion and activating T cell-mediated adaptive immune responses. As a major constituent of the tumor microenvironment (TME), macrophages play a complex role in tumorigenesis and tumor progression. They can inhibit tumor growth by releasing proinflammatory cytokines and exerting cytotoxic activities but principally contribute to tumor progression by promoting tumor proliferation, angiogenesis, and metastasis. The tumor-promoting hallmarks of macrophages have aroused widespread interest in targeting tumor-associated macrophages (TAMs) for cancer immunotherapy. Increasing preclinical and clinical studies suggest that TAMs are a promising target for cancer immunotherapy. To date, TAM-targeted therapeutic strategies have mainly been divided into two kinds: inhibiting pro-tumor TAMs and activating anti-tumor TAMs. We reviewed the heterogeneous and plastic characteristics of macrophages in the TME and the feasible strategies to target TAMs in cancer immunotherapy and summarized the complementary effect of TAM-targeted therapy with traditional treatments or other immunotherapies.

Physical Activity of ≥7.5 MET-h/Week Is Significantly Associated with a Decreased Risk of Cervical Neoplasia

Cervical cancer is one of the most prevalent malignant neoplasms worldwide. We investigated whether leisure-time physical activity is sufficient to decrease the cervical neoplasia risk and provide suggested guidance of metabolic equivalents of task–hours per week (MET-h/week) spent on leisure-time physical activity to prevent cervical neoplasia. Ultimately, 433 participants, including 126 participants with cervical intraepithelial neoplasia I or higher disease (≥CIN 1) and 307 healthy controls, were recruited. All participants completed a standardized questionnaire about leisure-time physical activity engagement (MET-h/week) and a general health questionnaire and had cervical specimens taken to detect human papillomavirus (HPV) infection. CIN 1 staging was identified from the specimens. Participants with physical activity of ≥3.75 MET-h/week had a significantly lower CIN risk compared to those with physical activity of <3.75 MET-h/week (p = 0.01). However, among participants with HPV infection or smokers, the minimal requirement of leisure-time physical actively to lessen the CIN risk was ≥7.5 MET-h/week. Lifetime leisure-time physical activity of ≥0.12 MET-h/week–year also significantly decreased the CIN risk, but women with HPV infection needed ≥13.2 MET-h/week–year to protect them from a CIN risk. We concluded that regular leisure-time physical activity of ≥7.5 MET-h/week and sustained lifetime leisure-time physical activity ≥13.2 MET-h/week–year are vital factors for protecting women against cervical neoplasia risk.

Forkhead Box O1-p21 Mediates Macrophage Polarization in Postoperative Cognitive Dysfunction Induced by Sevoflurane

PURPOSE

The current study was conducted in order to investigate the role of Forkhead box O1 and p21-mediated macrophage polarization in postoperative cognitive dysfunction induced by sevoflurane.

METHODS

There involved a total of 30 healthy mice that were randomly divided into two groups: control group (without any treatment) and anaesthesia group (treated with sevoflurane inhalation). The effects of sevoflurane on cognitive function (memory) in mice were studied by trace fear conditioned reflex, and the effects of systemic inflammation and behavior after operation were measured by enzyme-linked immunosorbent assay (ELISA), the concentrations of CD163 and tumor necrosis factor-α (TNF-α) were measured. The expression of macrophage phenotype was observed by immunofluorescence staining, the expression levels of M1 and M2 markers mRNA were detected by real-time fluorescence quantitative PCR (RT-PCR), and the expression levels of FoxO1 and p21 were analyzed by immunoblotting (Western blot).

RESULTS

Compared with the control group, the freezing time in the anesthesia group was lower than that in the control group (P<0.01), indicating that sevoflurane anesthesia led to the decrease of cognitive ability. The blood concentrations of CD163 and TNF-α increased significantly at 24 h after the operation with sevoflurane anesthesia (P<0.05). Fluorescence microscopic observation showed that M2 was the main type of macrophages in normal tissues, while M1 and M2 phenotypes were highly expressed in sevoflurane anesthetized tissues at the same time, especially in M1 phenotypes (P<0.01). The polarization of macrophages in the anesthetic group showed the high level of M1 mRNA, and the expression levels of TNF-α, monocyte chemotactic protein 1(MCP-1) and Interleukin-6 (IL-6)mRNA in the anesthetic group were significantly higher than those in the control group (P<0.05). The expression levels of M2 mRNA such as transforming growth factor-β (TGF-β) and IL-10 were significantly lower than those in the control group (P<0.05). Compared with the control group, the expression of FoxO1 and p21 protein in the anesthesia group was significantly lower than that in the control group with a significant statistical difference (P<0.01).

CONCLUSION

This study offers a theoretical basis and insight for further understanding of the prevention and treatment of cognitive dysfunction induced by anesthetic drugs.

Lachnum polysaccharide suppresses S180 sarcoma by boosting anti-tumor immune responses and skewing tumor-associated macrophages toward M1 phenotype

Therapeutic strategies that targeting tumor-associated macrophages (TAMs) reprogramming play a crucial role in ameliorating the immunosuppressive tumor microenvironment and boosting anti-tumor immune responses. In this study, we demonstrated that Lachnum polysaccharide (LEP) could work as an immunomodulator to reset TAMs from pro-tumor M2 to anti-tumor M1 phenotype. Mechanistically, LEP promoted Th1 polarization and the secretion of IFN-γ, which played a key role in M1 phenotype polarization. In parallel, LEP might directly activate M1 macrophages via TLR4 mediated NF-κB signaling pathway. Moreover, LEP also resulted in the accumulation of anti-tumor immune cells and decreased the infiltration of immunosuppressive cells such as myeloid-derived suppressor cells (MDSCs) and Treg cells, thereby potentiating anti-tumor immunity. In summary, these results revealed a novel mechanism of the anti-tumor effect of LEP and provided a potential new avenue targeting TAMs and cancer immunotherapy.

Rapamycin suppresses angiogenesis and lymphangiogenesis in melanoma by downregulating VEGF-A/VEGFR-2 and VEGF-C/VEGFR-3 expression

Background: Cutaneous melanoma is a highly malignant tumor which tends to metastasize in the early stage and leads to poor prognosis. Hematogenous and lymphatic metastasis are common in the dissemination of melanoma. Rapamycin, an mTOR inhibitor, was reported to have anti-angiogenic and anti-lymphangiogenic properties.

Aim: The aim of this study was to investigate if rapamycin can inhibit the formation of blood vessels and lymphatic vessels in melanoma.

Methods: A melanoma xenograft model was generated by subcutaneously transplanting A375 human melanoma cells into the back of immunodeficient mice. Two weeks after cell transplantation, rapamycin was injected intraperitoneally every other day seven times. Then, tumors were harvested. Hematoxylin-eosin (H-E) staining, immunohistochemical staining, Western blot, and quantitative PCR were performed to observe the pathological structure of the tumor, the distribution of blood vessels and lymphatic vessels, and the expression of mTOR signal pathway, VEGF-A/VEGFR-2, and VEGF-C/VEGFR-3.

Results: The results showed that CD34(+) blood vessels and LYVE-1(+) lymphatic vessels decreased in the peritumor and intratumor region in rapamycin-treated tumors. Expression of p-4EBP1 and p-S6K1 proteins was downregulated. Expression of both proteins and mRNAs of VEGF-A/VEGFR-2 and VEGF-C/VEGFR-3 was downregulated.

Conclusion: In conclusion, rapamycin suppresses angiogenesis and lymphangiogenesis in melanoma by blocking the mTOR signal pathway and subsequently downregulating the expression of VEGF-A/VEGFR-2 and VEGF-C/VEGFR-3. Therefore, targeted therapy via mTOR signal pathway may control the hematogenous and lymphatic metastasis of melanoma, and even prolong patients’ survival time.

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Diamonds in the Rough: Harnessing Tumor-Associated Myeloid Cells for Cancer Therapy

Therapeutic approaches that engage immune cells to treat cancer are becoming increasingly utilized in the clinics and demonstrated durable clinical benefit in several solid tumor types. Most of the current immunotherapies focus on manipulating T cells, however, the tumor microenvironment (TME) is abundantly infiltrated by a heterogeneous population of tumor-associated myeloid cells, including tumor-associated macrophages (TAMs), tumor-associated dendritic cells (TADCs), tumor-associated neutrophils (TANs), and myeloid-derived suppressor cells (MDSCs). Educated by signals perceived in the TME, these cells often acquire tumor-promoting properties ultimately favoring disease progression. Upon appropriate stimuli, myeloid cells can exhibit cytoxic, phagocytic, and antigen-presenting activities thereby bolstering antitumor immune responses. Thus, depletion, reprogramming or reactivation of myeloid cells to either directly eradicate malignant cells or promote antitumor T-cell responses is an emerging field of interest. In this review, we briefly discuss the tumor-promoting and tumor-suppressive roles of myeloid cells in the TME, and describe potential therapeutic strategies in preclinical and clinical development that aim to target them to further expand the range of current treatment options.

PD-L1-Expressing Radiation-Associated Angiosarcoma after Primary Breast Cancer

Radiation-associated angiosarcoma (RAAS) is a type of radiation-associated sarcoma (RAS) that develops at the previous field of radiation in breast cancer patients. Although several reports have suggested a poor prognosis for RAAS, the 5-year overall survival of RAAS is better than that of cutaneous angiosarcoma (CAS), suggesting that the prognostic factors of RAAS and CAS might be different, at least in part. In this report, we describe a case of RAAS, and employed immunohistochemical (IHC) staining of PD-L1 and MMP9 as well as periostin, IL-4, and CD163. Interestingly, IHC staining revealed that the RAAS in our case was positive for PD-L1 and negative for MMP9. Moreover, the predominant stromal factor of our case was periostin, suggesting that TAMs in the present case was not immunosuppressive, but an inflammatory subtype. These results might explain, at least in part, the better prognosis of RAAS compared to CAS.

Tumor-Associated Macrophages: Therapeutic Targets for Skin Cancer

Tumor-associated macrophages (TAMs) and regulatory T cells (Tregs) are significant components of the microenvironment of solid tumors in the majority of cancers. TAMs sequentially develop from monocytes into functional macrophages. In each differentiation stage, TAMs obtain various immunosuppressive functions to maintain the tumor microenvironment (e.g., expression of immune checkpoint molecules, production of Treg-related chemokines and cytokines, production of arginase I). Although the main population of TAMs is immunosuppressive M2 macrophages, TAMs can be modulated into M1-type macrophages in each differential stage, leading to the suppression of tumor growth. Because the administration of certain drugs or stromal factors can stimulate TAMs to produce specific chemokines, leading to the recruitment of various tumor-infiltrating lymphocytes, TAMs can serve as targets for cancer immunotherapy. In this review, we discuss the differentiation, activation, and immunosuppressive function of TAMs, as well as their benefits in cancer immunotherapy.