Macrophages induce EMT to promote invasion of lung cancer cells through the IL-6-mediated COX-2/PGE2/β-catenin signalling pathway

Interactions and communications in lung tumour microenvironment: chemo/radiotherapy resistance mechanisms and therapeutic targets

The lung tumour microenvironment (TME) is composed of various cell types, including cancer cells, stromal and immune cells, as well as extracellular matrix (ECM). These cells and surrounding ECM create a stiff, hypoxic, acidic and immunosuppressive microenvironment that can augment the resistance of lung tumours to different forms of cell death and facilitate invasion and metastasis. This environment can induce chemo/radiotherapy resistance by inducing anti-apoptosis mediators such as phosphoinositide 3-kinase (PI3K)/Akt, signal transducer and activator of transcription 3 (STAT3) and nuclear factor kappa B (NF-κB), leading to the exhaustion of antitumor immunity and further resistance to chemo/radiotherapy. In addition, lung tumour cells can resist chemo/radiotherapy by boosting multidrug resistance mechanisms and antioxidant defence systems within cancer cells and other TME components. In this review, we discuss the interactions and communications between these different components of the lung TME and also the effects of hypoxia, immune evasion and ECM remodelling on lung cancer resistance. Finally, we review the current strategies in preclinical and clinical studies, including the inhibition of checkpoint molecules, chemoattractants, cytokines, growth factors and immunosuppressive mediators such as programmed death 1 (PD-1), insulin-like growth factor 2 (IGF-2) for targeting the lung TME to overcome resistance to chemotherapy and radiotherapy.

Decoding the complex web: cellular and molecular interactions in the lung tumour microenvironment

The lung tumour microenvironment (TME) or stroma is a dynamic space of numerous cells and their released molecules. This complicated web regulates tumour progression and resistance to different modalities. Lung cancer cells in conjunction with their stroma liberate a wide range of factors that dampen antitumor attacks by innate immunity cells like natural killer (NK) cells and also adaptive responses by effector T cells. These factors include numerous growth factors, exosomes and epigenetic regulators, and also anti-inflammatory cytokines. Understanding the intricate interactions between tumour cells and various elements within the lung TME, such as immune and stromal cells can help provide novel strategies for better management and treatment of lung malignancies. The current article discusses the complex network of cells and signalling molecules, which mediate communications in lung TME. By elucidating these multifaceted interactions, we aim to provide insights into potential therapeutic targets and strategies for lung cancer treatment.

Reciprocal Modulation of Tumour and Immune Cell Motility: Uncovering Dynamic Interplays and Therapeutic Approaches

Dysregulated cell movement is a hallmark of cancer progression and metastasis, the leading cause of cancer-related mortality. The metastatic cascade involves tumour cell migration, invasion, intravasation, dissemination, and colonisation of distant organs. These processes are influenced by reciprocal interactions between cancer cells and the tumour microenvironment (TME), including immune cells, stromal components, and extracellular matrix proteins. The epithelial-mesenchymal transition (EMT) plays a crucial role in providing cancer cells with invasive and stem-like properties, promoting dissemination and resistance to apoptosis. Conversely, the mesenchymal-epithelial transition (MET) facilitates metastatic colonisation and tumour re-initiation. Immune cells within the TME contribute to either anti-tumour response or immune evasion. These cells secrete cytokines, chemokines, and growth factors that shape the immune landscape and influence responses to immunotherapy. Notably, immune checkpoint blockade (ICB) has transformed cancer treatment, yet its efficacy is often dictated by the immune composition of the tumour site. Elucidating the molecular cross-talk between immune and cancer cells, identifying predictive biomarkers for ICB response, and developing strategies to convert cold tumours into immune-active environments is critical to overcoming resistance to immunotherapy and improving patient survival.

The role and clinical significance of tumor-associated macrophages in the epithelial-mesenchymal transition of lung cancer

Lung cancer remains the leading cause of cancer-related mortality worldwide. Tumor-associated macrophages (TAMs) and epithelial-mesenchymal transition (EMT) are key drivers of lung cancer metastasis and drug resistance. M2-polarized TAMs dominate the immunosuppressive tumor microenvironment (TME) and promote EMT through cytokines such as TGF-β, IL-6, and CCL2. Conversely, EMT-transformed tumor cells reinforce TAM recruitment and M2 polarization through immunomodulatory factors such as CCL2 and ZEB1, thereby establishing a bidirectional interplay that fuels tumor progression. Current evidence on this interaction remains fragmented, and a comprehensive review of the TAM-EMT regulatory network and its therapeutic implications is lacking. This review systematically integrates the bidirectional regulatory mechanisms between TAMs and EMT, highlighting their roles in lung cancer progression. It also summarizes emerging therapeutic strategies targeting TAM polarization and the EMT process, emphasizing their potential for clinical translation. This study fills the gap in systematic reviews on the interaction between TAMs and EMT, providing a comprehensive theoretical foundation for future research and the development of novel lung cancer therapies.

Intravital Imaging of Immune Responses in the Cancer Microenvironment

BACKGROUND

To date, many types of immune cells have been identified, but their precise role in cancer immunity remains unclear. Understanding the immune responses involved in cancer and the cancer microenvironment is becoming increasingly important for elucidating disease mechanisms. In recent years, the application of intravital imaging in cancer research has provided new insights into the mechanisms of cancer-specific immune events, including innate and adaptive immunity.

RESULTS

In this review, we focus on the emerging role of intravital imaging in cancer research and describe how cancer and immune cells can be observed using intravital imaging in vivo. We also discuss new insights gained by this state-of-the-art technique.

CONCLUSIONS

Intravital imaging is a relatively new field of research that offers significant advantages, including the ability to directly capture cell-cell interactions, pathophysiology, and immune cell dynamics in the cancer microenvironment in vivo.

Harnessing the tumor microenvironment: targeted cancer therapies through modulation of epithelial-mesenchymal transition

The tumor microenvironment (TME) is integral to cancer progression, impacting metastasis and treatment response. It consists of diverse cell types, extracellular matrix components, and signaling molecules that interact to promote tumor growth and therapeutic resistance. Elucidating the intricate interactions between cancer cells and the TME is crucial in understanding cancer progression and therapeutic challenges. A critical process induced by TME signaling is the epithelial-mesenchymal transition (EMT), wherein epithelial cells acquire mesenchymal traits, which enhance their motility and invasiveness and promote metastasis and cancer progression. By targeting various components of the TME, novel investigational strategies aim to disrupt the TME's contribution to the EMT, thereby improving treatment efficacy, addressing therapeutic resistance, and offering a nuanced approach to cancer therapy. This review scrutinizes the key players in the TME and the TME's contribution to the EMT, emphasizing avenues to therapeutically disrupt the interactions between the various TME components. Moreover, the article discusses the TME's implications for resistance mechanisms and highlights the current therapeutic strategies toward TME modulation along with potential caveats.

Macranthoidin B restrains the epithelial-mesenchymal transition through COX-2/PGE2 pathway in endometriosis

Introduction

Macranthoidin B is one of the primary and unique triterpenoid saponin metabolites from Lonicera macranthoides Hand. -Mazz, which is used to treat endometriosis (EMS) in traditional Chinese medicine. However, the effect of macranthoidin B remains unknown in EMS. This study aimed to elucidate the effect and mechanism of macranthoidin B in EMS.

Methods

Using rat autograft EMS model, the volume of ectopic endothelium, the histopathology, serum E2 and PROG were evaluated after macranthoidin B's treatment. In primary endometriotic stromal and HEC1-B cells, the invasion and metastasis were assessed by scratch wound and Transwell tests. The epithelial-mesenchymal transition and COX-2/PGE2 pathway were examined in vivo and in vitro. Macranthoidin B were combined with LPS or celecoxib.

Results

In a rat autograft EMS model, macranthoidin B suppressed ectopic lesion volume, improved histopathological morphology, and regulated serum estradiol (E2) and progesterone (PROG) levels. Additionally, macranthoidin B inhibited invasion and metastasis of primary endometriotic stromal cells and HEC1-B cells. Mechanistically, macranthoidin B suppressed COX-2/PGE2 pathway and epithelial-mesenchymal transition both in vivo and in vitro. LPS, the COX-2/PGE2 pathway activator, showed the promotion of epithelial-mesenchymal transition, invasion and metastasis. Macranthoidin B exhibited the antagonistic effects against LPS. Celecoxib, the COX-2/PGE2 pathway inhibitor, restrained the epithelial-mesenchymal transition, invasion and metastasis. This effect of celecoxib was enhanced by macranthoidin B.

Discussion

Macranthoidin B prevents epithelial-mesenchymal transition through COX-2/PGE2 pathway in EMS. It will facilitate the macranthoidin B's development and broaden its potential application.

IDH2 regulates macrophage polarization and tumorigenesis by modulating mitochondrial metabolism in macrophages

BACKGROUND

Targeting the tumor microenvironment represents an emerging therapeutic strategy for cancer. Macrophages are an essential part of the tumor microenvironment. Macrophage polarization is modulated by mitochondrial metabolism, including oxidative phosphorylation (OXPHOS), the tricarboxylic acid (TCA) cycle, and reactive oxygen species content. Isocitrate dehydrogenase 2 (IDH2), an enzyme involved in the TCA cycle, reportedly promotes cancer progression. However, the mechanisms through which IDH2 influences macrophage polarization and modulates tumor growth remain unknown.

METHODS

In this study, IDH2-deficient knockout (KO) mice and primary cultured bone marrow-derived macrophages (BMDMs) were used. Both in vivo subcutaneous tumor experiments and in vitro co-culture experiments were performed, and samples were collected for analysis. Western blotting, RNA quantitative analysis, immunohistochemistry, and flow cytometry were employed to confirm changes in mitochondrial function and the resulting polarization of macrophages exposed to the tumor microenvironment. To analyze the effect on tumor cells, subcutaneous tumor size was measured, and growth and metastasis markers were identified.

RESULTS

IDH2-deficient macrophages co-cultured with cancer cells were found to possess increased mitochondrial dysfunction and fission than wild-type BMDM. Additionally, the levels of M2-associated markers decreased, whereas M1-associated factor levels increased in IDH2-deficient macrophages. IDH2-deficient macrophages were predominantly M1. Tumor sizes in the IDH2-deficient mouse group were significantly smaller than in the wild-type mouse group. IDH2 deficiency in macrophages was associated with inhibited tumor growth and epithelial-mesenchymal transition.

CONCLUSIONS

Our findings suggest that IDH2 deficiency inhibits M2 macrophage polarization and suppresses tumorigenesis. This study underlines the potential contribution of IDH2 expression in macrophages and tumor microenvironment remodeling, which could be useful in clinical cancer research.

Dissection of pro-tumoral macrophage subtypes and immunosuppressive cells participating in M2 polarization

Alternatively activated macrophage (M2) polarization can result in one of four subtypes based on cytokines and signaling pathways associated with macrophage activation: M2a, M2b, M2c, and M2d macrophages. The majority of M2 subtypes are anti-inflammatory and pro-angiogenic, secreting growth factors (VEGF, PDGF) and matrix metalloproteinases (MMP2, MMP9) which boost tumor growth, metastasis, and invasion. M2-polarized macrophages are associated with immune suppressor cells harboring Myeloid derived suppressor cells, Regulatory T cells (Tregs), Regulatory B cells as well as alternatively activated (N2) neutrophils. Treg cells selectively support the metabolic stability, mitochondrial integrity, and survival rate of M2-like TAMs in an indirect environment. Also, the contribution of Breg cells influences macrophage polarization towards the M2 direction. TAM is activated when TAN levels in the tumor microenvironment are insufficient or vice versa, suggesting that macrophage and its polarization are fine-tuned. Understanding the functions of immune suppressive cells, mediators, and signaling pathways involved with M2 polarization will allow us to identify potential strategies for targeting the TAM repolarization phenotype for innovative immunotherapy approaches. In this review, we have highlighted the critical factors for M2 macrophage polarization, differential cytokine/chemokine profiles of M1 and M2 macrophage subtypes, and other immune cells' impact on the polarization within the immunosuppressive niche.

Nrf1 Reduces COX-2 Expression and Maintains Cellular Homeostasis After Cerebral Ischemia/Reperfusion By Targeting IL-6/TNF-α Protein Production

Neuroinflammation has been considered involved in the process of cerebral ischemia-reperfusion injury (CIRI). Transcription factors play a crucial role in regulating gene transcription and the expressions of specific proteins during the progression of various neurological diseases. Evidence showed that transcription factor nuclear factor erythroid 2-related factor 1 (NFE2L1, also known as Nrf1) possessed strong biological activities including antioxidant, anti-inflammatory and neuroprotective properties. However, its role and potential molecular mechanisms in CIRI remain unclear. In our study, we observed a significant elevation of Nrf1 in the cerebral cortex following cerebral ischemia-reperfusion in rats. The Nrf1 downregulation markedly raised COX-2, TNF-α, IL-1β, and IL-6 protein levels during middle cerebral artery occlusion/reperfusion in rats, which led to worsened neurological deficits, higher cerebral infarct volume, and intensified cortical histopathological damage. In subsequent in vitro studies, the expression of Nrf1 protein increased following oxygen-glucose deprivation/reperfusion treatment on neurons. Subsequently, Nrf1 knockdown resulted in a significant upregulation of inflammatory factors, leading to a substantial increase in the cell death rate. Through analyzing the alterations in the expression of inflammatory factors under diverse interventions, it is indicated that Nrf1 possesses the capacity to discern variations in inflammatory factors via specific structural domains. Our findings demonstrate the translocation of the Nrf1 protein from the cytoplasm to the nucleus, thereby modulating the protein expression of IL-6/TNF-α and subsequently reducing the expression of multiple inflammatory factors. This study signifies, for the first time, that during cerebral ischemia-reperfusion, Nrf1 translocases to the nucleus to regulate the protein expression of IL-6/TNF-α, consequently suppressing COX-2 expression and governing cellular inflammation, ultimately upholding cellular homeostasis.

PGE2 induced miR365/IL-6/STAT3 signaling mediates dendritic cell dysfunction in cancer

AIM

To understand the mechanism of prostaglandin E2 (PGE2)-mediated immunosuppression in dendritic cells (DCs).

MAIN METHODS

In vivo experiments were conducted on 4T1 tumor bearing mice (TBM). In vitro experiments were performed in bone marrow-derived DCs (BMDCs), or spleen cells. Cytokines were monitored by ELISA/ELIspot. Gene expression was monitored by RT-PCR/flow cytometry.

KEY FINDINGS

In silico, in vitro, and in vivo experiments in 4T1 TBM revealed that PGE2 induced IL-6/pSTAT3 signaling through EP4 receptors in DCs, resulting in their dysfunction. These effects were reversed by EP4 antibody neutralization, EP4 antagonist, and STAT3 inhibitory peptides. PGE2 induced IL-6 was regulated by miR-365, as its mimic inhibited PGE2 induced IL-6 and the inhibitor increased lL-6 levels in DC. Bio-informatic analysis in human mammary cancers also revealed a strong compared co-relation between PGE2 and IL-6 (Correlation AnalyzeR) (R = 0.94). Mice bearing PTGS-2 KD 4T1 tumors had decreased tumor burden, PGE2, EP4, IL-6, and pSTAT3 signaling, along with improved DCs and T cell functions. Treatment of mice with a cyclooxygenase-2 (COX-2) inhibitor or EP4 antagonist decreased tumor burden, and this effect of EP4 antagonist was abrogated upon in vivo depletion of CD11c cells, indicating the crucial role of PGE2 signaling in DCs in tumor progression.

SIGNIFICANCE

In summary, our data highlights the importance of dendritic cells in mediating PGE2-mediated immunosuppression and the use of EP4 or STAT3 inhibitors or miR365 mimics can restore immunogenicity in cancer.

Roles of prostaglandins in immunosuppression

Prostaglandins (PGs) play a crucial and multifaceted role in various physiological processes such as intercellular signaling, inflammation regulation, neurotransmission, vasodilation, vasoconstriction, and reproductive functions. The diversity and biological significance of these effects are contingent upon the specific types or subtypes of PGs, with each PG playing a crucial role in distinct physiological and pathological processes. Particularly within the immune system, PGs are essential in modulating the function of immune cells and the magnitude and orientation of immune responses. Hence, a comprehensive comprehension of the functions PG signaling pathways in immunosuppressive regulation holds substantial clinical relevance for disease prevention and treatment strategies. The manuscript provides a review of recent developments in PG signaling in immunosuppressive regulation. Furthermore, the potential clinical applications of PGs in immunosuppression are also discussed. While research into the immunosuppressive effects of PGs required further exploration, targeted therapies against their immunosuppressive pathways might open new avenues for disease prevention and treatment.

Reciprocal Interactions of Human Monocytes and Cancer Cells in Co-Cultures In Vitro

The tumor microenvironment (TME) includes immune and stromal cells and noncellular extracellular matrix (ECM) components. Tumor-associated macrophages (TAMs) are the most important immune cells in TME and are crucial for carcinomas' progression. The purpose was to analyze direct and indirect interactions in co-culture of tumor cells with monocytes/macrophages and, additionally, to indicate which interactions are more important for cancer development. Cytokines, reactive oxygen species, nitric oxide level, tumor cell cycle and changes in tumor cell morphology after human tumor cells (Hep-2 and RK33 cell lines) with human monocyte/macrophage (THP-1 cell line) interactions were tested. Morphology and cytoskeleton organization of tumor cells did not change after co-culture with macrophages. In co-culture of tumor cells with human monocyte, changes in the percentage of tumor cells in cell cycle phases was observed. No significant changes in reactive oxygen species (ROS) were found in the co-culture as compared to the tumor cell mono-culture. Monocytes produced about three times higher ROS than tumor cells. In co-cultures, a lower nitric oxide (NOx) level was found as compared to the sum of the production by both mono-cultures. Co-culture conditions limited the production of cytokines (IL-4, IL-10 and IL-13) as compared to the sum of their level in mono-cultures. In conclusion, macrophages influence tumor cell growth and functions. Mutual (direct and paracrine) interactions between tumor cells and macrophages changed cytokine production and tumor cell cycle profile. The data obtained may allow us to initially indicate which kind of interactions may have a greater impact on cancer development processes.

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

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

Vulvo-vaginal epithelial tumors in mares: A preliminary investigation on epithelial-mesenchymal transition and tumor-immune microenvironment

Vulvo-vaginal epithelial tumors are uncommon in mares, and data on the epithelial-to-mesenchymal transition (EMT) and the tumor-immune microenvironment (TIME) are still lacking. This is a study investigating the equus caballus papillomavirus type 2 (EcPV2) infection state as well as the EMT process and the tumor microenvironment in vulvo-vaginal preneoplastic/ benign (8/22) or malignant (14/22) epithelial lesions in mares. To do this, histopathological, immunohistochemical, transcriptomic, in situ hybridization, and correlation analyses were carried out. Immunohistochemistry quantification showed that cytoplasmic E-cadherin and β-catenin expression as well as nuclear β-catenin expression were features of malignant lesions, while benign/preneoplastic lesions were mainly characterized by membranous E-cadherin and β-catenin expression. Despite this, there were no differences between benign and malignant equine vulvo-vaginal lesions in the expression of downstream genes involved in the canonical and noncanonical wnt/β-catenin pathways. In addition, malignant lesions were characterized by a lower number of cells with cytoplasmic cytokeratin expression as well as a slightly higher cytoplasmic vimentin immunolabeling. The TIME of malignant lesions was characterized by more numerous CD204+ M2-polarized macrophages. Altogether, our results support the hypothesis that some actors in TIME such as CD204+ M2-polarized macrophages may favor the EMT process in equine vulvo-vaginal malignant lesions providing new insights for future investigations in the field of equine EcPV2-induced genital neoplastic lesions.

The arachidonic acid metabolome reveals elevation of prostaglandin E2 biosynthesis in colorectal cancer

Arachidonic acid metabolites are a family of bioactive lipids derived from membrane phospholipids. They are involved in cancer progression, but arachidonic acid metabolite profiles and their related biosynthetic pathways remain uncertain in colorectal cancer (CRC). To compare the arachidonic acid metabolite profiles between CRC patients and healthy controls, quantification was performed using a liquid chromatography-mass spectrometry-based analysis of serum and tissue samples. Metabolomics analysis delineated the distinct oxidized lipids in CRC patients and healthy controls. Prostaglandin (PGE2)-derived metabolites were increased, suggesting that the PGE2 biosynthetic pathway was upregulated in CRC. The qRT-PCR and immunohistochemistry analyses showed that the expression level of PGE2 synthases, the key protein of PGE2 biosynthesis, was upregulated in CRC and positively correlated with the CD68+ macrophage density and CRC development. Our study indicates that the PGE2 biosynthetic pathway is associated with macrophage infiltration and progression of CRC tumors.

The role of stromal cells in epithelial-mesenchymal plasticity and its therapeutic potential

The epithelial-mesenchymal transition (EMT) is a critical tumor invasion and metastasis process. EMT enables tumor cells to migrate, detach from their original location, enter the circulation, circulate within it, and eventually exit from blood arteries to colonize in foreign sites, leading to the development of overt metastases, ultimately resulting in death. EMT is intimately tied to stromal cells around the tumor and is controlled by a range of cytokines secreted by stromal cells. This review summarizes recent research on stromal cell-mediated EMT in tumor invasion and metastasis. We also discuss the effects of various stromal cells on EMT induction and focus on the molecular mechanisms by which several significant stromal cells convert from foes to friends of cancer cells to fuel EMT processes via their secretions in the tumor microenvironment (TME). As a result, a better knowledge of the role of stromal cells in cancer cells' EMT may pave the path to cancer eradication.

The role of tumor-associated macrophages in lung cancer: From mechanism to small molecule therapy

Tumor-associated macrophages (TAMs) are the main component of tumor-infiltrating immune cells in the lung tumor microenvironment. TAMs recruited to the lung cancer can create a suitable microenvironment for the growth and metastasis of lung cancer by secreting tumor promoting factors and interfering with the function of T cells. Currently, numerous studies have reported that small molecular drugs affect lung cancer progression by selectively targeting TAMs. The main ways include blocking the recruitment of monocytes or eliminating existing TAMs in tumor tissue, reprogramming TAMs into pro-inflammatory M1 macrophages or inhibiting M2 polarization of macrophages, interrupting the interaction between tumor cells and macrophages, and modulating immune function. Signaling pathways or cytokines such as CCL8, CCL2/CCR2, CSF-1/CSF-1R, STAT3, STAT6, MMPs, Caspase-8, AMPK α1, TLR3, CD47/SIRPα, have been reported to be involved in this process. Based on summarizing the role and mechanisms of TAMs in lung cancer progression, this paper particularly focuses on systematically reviewing the effects and mechanisms of small molecule drugs on lung cancer TAMs, and classified the small molecular drugs according to the way they affect TAMs. The study aims to provide new perspectives and potential therapeutic drugs for targeted macrophages treatment in lung cancer, which is of great significance and will provide more options for immunotherapy of lung cancer.

Targeting Fatty Acid Amide Hydrolase Counteracts the Epithelial-to-Mesenchymal Transition in Keratinocyte-Derived Tumors

The endocannabinoid system regulates physiological processes, and the modulation of endogenous endocannabinoid (eCB) levels is an attractive tool to contrast the development of pathological skin conditions including cancers. Inhibiting FAAH (fatty acid amide hydrolase), the degradation enzyme of the endocannabinoid anandamide (AEA) leads to the increase in AEA levels, thus enhancing its biological effects. Here, we evaluated the anticancer property of the FAAH inhibitor URB597, investigating its potential to counteract epithelial-to-mesenchymal transition (EMT), a process crucially involved in tumor progression. The effects of the compound were determined in primary human keratinocytes, ex vivo skin explants, and the squamous carcinoma cell line A431. Our results demonstrate that URB597 is able to hinder the EMT process by downregulating mesenchymal markers and reducing migratory potential. These effects are associated with the dampening of the AKT/STAT3 signal pathways and reduced release of pro-inflammatory cytokines and tumorigenic lipid species. The ability of URB597 to contrast the EMT process provides insight into effective approaches that may also include the use of FAAH inhibitors for the treatment of skin cancers.

Applications of lung cancer organoids in precision medicine: from bench to bedside

As the leading cause of cancer-related mortality, lung cancer continues to pose a menacing threat to human health worldwide. Lung cancer treatment options primarily rely on chemoradiotherapy, surgery, targeted therapy, or immunotherapy. Despite significant progress in research and treatment, the 5-year survival rate for lung cancer patients is only 10-20%. There is an urgent need to develop more reliable preclinical models and valid therapeutic approaches. Patient-derived organoids with highly reduced tumour heterogeneity have emerged as a promising model for high-throughput drug screening to guide treatment of lung cancer patients. Organoid technology offers a novel platform for disease modelling, biobanking and drug development. The expected benefit of organoids is for cancer patients as the subsequent precision medicine technology. Over the past few years, numerous basic and clinical studies have been conducted on lung cancer organoids, highlighting the significant contributions of this technique. This review comprehensively examines the current state-of-the-art technologies and applications relevant to the formation of lung cancer organoids, as well as the potential of organoids in precision medicine and drug testing. Video Abstract.

Suppressing epithelial-mesenchymal-transition blue light therapy for reducing macrophage-mediated cancerous pulmonary fibrosis: An in-vitro study

Lung cancer is the leading killer among all types of cancer globally. As a key factor, epithelial-mesenchymal transition (EMT) plays a crucial role in pathological fibrosis and lung cancer metastasis. This study endeavors to investigate the effect of blue light at specific wavelengths of 405 nm and 415 nm (54 J/cm2 ) on EMT induced by TGF-β1 in A549 cells. The results revealed that the blue light irradiation reduced the morphological characteristics of EMT in the A549 cells, and cell-to-cell connections were weakened significantly. Molecular analysis showed upregulation of epithelial marker E-cadherin and downregulation of EMT marker vimentin. Additionally, exposure to blue light irradiation at 405 nm and 415 nm significantly decelerated the ability of invasion and migration. Moreover, cell viability was also investigated. Based on these findings, blue light can serve as a useful therapeutic option for inhibiting EMT in cases of lung cancer and fibrotic lung disease.

Cucurbitacin I Reverses Tumor-Associated Macrophage Polarization to Affect Cancer Cell Metastasis

The tumor microenvironment plays a critical role in tumor progression and immune regulation. As one of the most important components of the tumor microenvironment, macrophages have become a new therapeutic target for inhibiting tumor progression. Despite the well-documented anticancer activity of cucurbitacin I, its effect on macrophages remains unclear. In this study, we established a coculture system of macrophages and cancer cells under hypoxic conditions to simulate the tumor-promoting environment mediated by M2-like macrophages. We determined whether cucurbitacin I modulates M2-like polarization in macrophages in vitro and conducted RNA sequencing to identify gene expression changes induced by cucurbitacin I in macrophages. The results indicated a remarkable inhibition of the M2-like polarization phenotype in macrophages following treatment with cucurbitacin I, which was accompanied by the significant downregulation of heme oxygenase-1. Moreover, we found that cucurbitacin I-treated macrophages reduced the migration of cancer cells by inhibiting the M2 polarization in vitro. These findings highlight the potential of cucurbitacin I as a therapeutic agent that targets M2-like macrophages to inhibit cancer cell metastasis. Our study provides novel insights into the intricate interplay among macrophage polarization, cucurbitacin I, and heme oxygenase-1, thereby opening new avenues for cancer treatment.

The strategies to cure cancer patients by eradicating cancer stem-like cells

Cancer stem-like cells (CSCs), a subpopulation of cancer cells, possess remarkable capability in proliferation, self-renewal, and differentiation. Their presence is recognized as a crucial factor contributing to tumor progression and metastasis. CSCs have garnered significant attention as a therapeutic focus and an etiologic root of treatment-resistant cells. Increasing evidence indicated that specific biomarkers, aberrant activated pathways, immunosuppressive tumor microenvironment (TME), and immunoevasion are considered the culprits in the occurrence of CSCs and the maintenance of CSCs properties including multi-directional differentiation. Targeting CSC biomarkers, stemness-associated pathways, TME, immunoevasion and inducing CSCs differentiation improve CSCs eradication and, therefore, cancer treatment. This review comprehensively summarized these targeted therapies, along with their current status in clinical trials. By exploring and implementing strategies aimed at eradicating CSCs, researchers aim to improve cancer treatment outcomes and overcome the challenges posed by CSC-mediated therapy resistance.

(-)-Guaiol inhibit epithelial-mesenchymal transition in lung cancer via suppressing M2 macrophages mediated STAT3 signaling pathway

In the context of cancer expansion, epithelial-mesenchymal transition (EMT) plays an essential role in driving invasion and metastasis potential of cancer cells. Tumor-associated macrophages (TAMs)-derived factors involved in the initiation and progression of EMT. We assess the role of M2 macrophage in suppressing lung tumors of a natural compound (-)-Guaiol by using macrophage depleted model. Bone marrow-derived monocytes (BMDMs) were extracted and induced to M2-like phenotype in vitro. The co-culture of M2 macrophage and lung cancer cells was established to observe that inhibition of lung tumor growth by (-)-Guaiol requires presence of macrophages. This suppressed effect of (-)-Guaiol was alleviated when mice macrophage was depleted. The expression of M2-like macrophages was strongly reduced by (-)-Guaiol treated mice, but not the changes of M1-like macrophages. In vitro studies, we demonstrated that (-)-Guaiol suppressed M2 polarization of BMDMs, as well as migration, invasion, and EMT of lung cancer cells in co-culture. M2 macrophage-derived interleukin 10 (IL-10) was investigated as a critical signaling molecule between M2 macrophage and lung cancer cells. We have also verified that the mechanism of (-)-Guaiol inhibiting the EMT process of lung cancer is related to the activation of IL-10-mediated signal transducer and activator of transcription 3 (STAT3). These results suggested that the suppressive effect role of (-)-Guaiol in M2 macrophage promoting EMT of lung cancer, which was associated with inhibition of IL-10 mediated STAT3 signaling pathway.

The epithelial-mesenchymal plasticity landscape: principles of design and mechanisms of regulation

Epithelial-mesenchymal plasticity (EMP) enables cells to interconvert between several states across the epithelial-mesenchymal landscape, thereby acquiring hybrid epithelial/mesenchymal phenotypic features. This plasticity is crucial for embryonic development and wound healing, but also underlies the acquisition of several malignant traits during cancer progression. Recent research using systems biology and single-cell profiling methods has provided novel insights into the main forces that shape EMP, which include the microenvironment, lineage specification and cell identity, and the genome. Additionally, key roles have emerged for hysteresis (cell memory) and cellular noise, which can drive stochastic transitions between cell states. Here, we review these forces and the distinct but interwoven layers of regulatory control that stabilize EMP states or facilitate epithelial-mesenchymal transitions (EMTs) and discuss the therapeutic potential of manipulating the EMP landscape.

Bioinformatic Analysis of the CXCR2 Ligands in Cancer Processes

Human CXCR2 has seven ligands, i.e., CXCL1, CXCL2, CXCL3, CXCL5, CXCL6, CXCL7, and CXCL8/IL-8-chemokines with nearly identical properties. However, no available study has compared the contribution of all CXCR2 ligands to cancer progression. That is why, in this study, we conducted a bioinformatic analysis using the GEPIA, UALCAN, and TIMER2.0 databases to investigate the role of CXCR2 ligands in 31 different types of cancer, including glioblastoma, melanoma, and colon, esophageal, gastric, kidney, liver, lung, ovarian, pancreatic, and prostate cancer. We focused on the differences in the regulation of expression (using the Tfsitescan and miRDB databases) and analyzed mutation types in CXCR2 ligand genes in cancers (using the cBioPortal). The data showed that the effect of CXCR2 ligands on prognosis depends on the type of cancer. CXCR2 ligands were associated with EMT, angiogenesis, recruiting neutrophils to the tumor microenvironment, and the count of M1 macrophages. The regulation of the expression of each CXCR2 ligand was different and, thus, each analyzed chemokine may have a different function in cancer processes. Our findings suggest that each type of cancer has a unique pattern of CXCR2 ligand involvement in cancer progression, with each ligand having a unique regulation of expression.

The Activation of PPARγ by (2Z,4E,6E)-2-methoxyocta-2,4,6-trienoic Acid Counteracts the Epithelial–Mesenchymal Transition Process in Skin Carcinogenesis

Cutaneous squamous cell carcinoma (cSCC) is the most common UV-induced keratinocyte-derived cancer, and its progression is characterized by the epithelial–mesenchymal transition (EMT) process. We previously demonstrated that PPARγ activation by 2,4,6-octatrienoic acid (Octa) prevents cutaneous UV damage. We investigated the possible role of the PPARγ activators Octa and the new compound (2Z,4E,6E)-2-methoxyocta-2,4,6-trienoic acid (A02) in targeting keratinocyte-derived skin cancer. Like Octa, A02 exerted a protective effect against UVB-induced oxidative stress and DNA damage in NHKs. In the squamous cell carcinoma A431 cells, A02 inhibited cell proliferation and increased differentiation markers’ expression. Moreover, Octa and even more A02 counteracted the TGF-β1-dependent increase in mesenchymal markers, intracellular ROS, the activation of EMT-related signal transduction pathways, and cells’ migratory capacity. Both compounds, especially A02, counterbalanced the TGF-β1-induced cell membrane lipid remodeling and the release of bioactive lipids involved in EMT. In vivo experiments on a murine model useful to study cell proliferation in adult animals showed the reduction of areas characterized by active cell proliferation in response to A02 topical treatment. In conclusion, targeting PPARγ may be useful for the prevention and treatment of keratinocyte-derived skin cancer.

Interleukin-6 and Hypoxia Synergistically Promote EMT-Mediated Invasion in Epithelial Ovarian Cancer via the IL-6/STAT3/HIF-1α Feedback Loop

Extensive peritoneal spread and capacity for distant metastasis account for the majority of mortality from epithelial ovarian cancer (EOC). Accumulating evidence shows that interleukin-6 (IL-6) promotes tumor invasion and migration in EOC, although the molecular mechanisms remain to be fully elucidated. Meanwhile, the hypoxic microenvironment has been recognized to cause metastasis by triggering epithelial-mesenchymal transition (EMT) in several types of cancers. Here, we studied the synergy between IL-6 and hypoxia in inducing EMT in two EOC cell lines, A2780 cells and SKOV3 cells. Exogenous recombination of IL-6 and autocrine production of IL-6 regulated by plasmids both induced EMT phenotype in EOC cells characterized by downregulated E-cadherin as well as upregulated expression of vimentin and EMT-related transcription factors. The combined effects of IL-6 and hypoxia were more significant than those of either one treatment on EMT. Suppression of hypoxia-inducible factor-1α (HIF-1α) before IL-6 treatment inhibited the EMT phenotype and invasion ability of EOC cells, indicating that HIF-1α occupies a key position in the regulatory pathway of EMT associated with IL-6. EMT score was found positively correlated with mRNA levels of IL-6, signal transducer and activator of transcription 3 (STAT3), and HIF-1α, respectively, in 489 ovarian samples from The Cancer Genome Atlas dataset. Next, blockade of the abovementioned molecules by chemical inhibitors reversed the alteration in the protein levels of EMT markers induced by either exogenous or endogenous IL-6. These findings indicate a positive feedback loop between IL-6 and HIF-1α, and induce and maintain EMT phenotype through STAT3 signaling, which might provide a novel rationale for prognostic prediction and therapeutic targets in EOC.

Lipid Metabolic Alterations in KRAS Mutant Tumors: Unmasking New Vulnerabilities for Cancer Therapy

KRAS is one of the most commonly mutated genes, an event that leads to development of highly aggressive and resistant to any type of available therapy tumors. Mutated KRAS drives a complex network of lipid metabolic rearrangements to support the adaptation of cancer cells to harsh environmental conditions and ensure their survival. Because there has been only a little success in the continuous efforts of effectively targeting KRAS-driven tumors, it is of outmost importance to delineate the exact mechanisms of how they get rewired, leading to this distinctive phenotype. Therefore, the aim of this review is to summarize the available data acquired over the last years with regard to the lipid metabolic regulation of KRAS-driven tumors and elucidate their specific characteristics in an attempt to unravel novel therapeutic targets.

Regulation of epithelial-mesenchymal transition by tumor microenvironmental signals and its implication in cancer therapeutics

Epithelial-mesenchymal transition (EMT) has been implicated in various aspects of tumor development, including tumor invasion and metastasis, cancer stemness, and therapy resistance. Diverse stroma cell types along with biochemical and biophysical factors in the tumor microenvironment impinge on the EMT program to impact tumor progression. Here we provide an in-depth review of various tumor microenvironmental signals that regulate EMT in cancer. We discuss the molecular mechanisms underlying the role of EMT in therapy resistance and highlight new therapeutic approaches targeting the tumor microenvironment to impact EMT and tumor progression.

Macrophages as a Potential Immunotherapeutic Target in Solid Cancers

The revolution in cancer immunotherapy over the last few decades has resulted in a paradigm shift in the clinical care of cancer. Most of the cancer immunotherapeutic regimens approved so far have relied on modulating the adaptive immune system. In recent years, strategies and approaches targeting the components of innate immunity have become widely recognized for their efficacy in targeting solid cancers. Macrophages are effector cells of the innate immune system, which can play a crucial role in the generation of anti-tumor immunity through their ability to phagocytose cancer cells and present tumor antigens to the cells of adaptive immunity. However, the macrophages that are recruited to the tumor microenvironment predominantly play pro-tumorigenic roles. Several strategies targeting pro-tumorigenic functions and harnessing the anti-tumorigenic properties of macrophages have shown promising results in preclinical studies, and a few of them have also advanced to clinical trials. In this review, we present a comprehensive overview of the pathobiology of TAMs and their role in the progression of solid malignancies. We discuss various mechanisms through which TAMs promote tumor progression, such as inflammation, genomic instability, tumor growth, cancer stem cell formation, angiogenesis, EMT and metastasis, tissue remodeling, and immunosuppression, etc. In addition, we also discuss potential therapeutic strategies for targeting TAMs and explore how macrophages can be used as a tool for next-generation immunotherapy for the treatment of solid malignancies.

Nicotinamide N-Methyltransferase Remodeled Cell Metabolism and Aggravated Proinflammatory Responses by Activating STAT3/IL1β/PGE2 Pathway

Nicotinamide N-methyltransferase (NNMT) is a cytosolic methyltransferase, catalyzing N-methylation of nicotinamide (NAM) to form 1-methylnicotinamide (1-MNAM), in which S-adenosyl-l-methionine (SAM) is the methyl donor. It has been well documented that NNMT is elevated in multiple cancers and promotes tumor aggressiveness. In the present study, we investigated the effects of NNMT overexpression on cellular metabolism and proinflammatory responses. We found that NNMT overexpression reduced NAD⁺ and SAM levels, and activated the STAT3 signaling pathway. Consequently, STAT3 activation upregulated interleukin 1β (IL1β) and cyclooxygenase-2 (COX2), leading to prostaglandin E2 (PGE₂) accumulation. On the other hand, NNMT downregulated 15-hydroxyprostaglandin dehydrogenase (15-PGDH) which catalyzes PGE₂ into inactive molecules. Moreover, secretomic data indicated that NNMT promoted secretion of collagens, pro-inflammatory cytokines, and extracellular matrix proteins, confirming NNMT aggravated inflammatory responses to promote cell growth, migration, epithelial-mesenchymal transition (EMT), and chemoresistance. Taken together, we showed that NNMT played a pro-inflammatory role in cancer cells by activating the STAT3/IL1β/PGE₂ axis and proposed that NNMT was a potential therapeutic target for cancer treatment.

Progress of tumor-associated macrophages in the epithelial-mesenchymal transition of tumor

As a significant public health problem with high morbidity and mortality worldwide, tumor is one of the major diseases endangering human life. Moreover, metastasis is the most important contributor to the death of tumor patients. Epithelial-mesenchymal transition (EMT) is an essential biological process in developing primary tumors to metastasis. It underlies tumor progression and metastasis by inducing a series of alterations in tumor cells that confer the ability to move and migrate. Tumor-associated macrophages (TAMs) are one of the primary infiltrating immune cells in the tumor microenvironment, and they play an indispensable role in the EMT process of tumor cells by interacting with tumor cells. With the increasing clarity of the relationship between TAMs and EMT and tumor metastasis, targeting TAMs and EMT processes is emerging as a promising target for developing new cancer therapies. Therefore, this paper reviews the recent research progress of tumor-associated macrophages in tumor epithelial-mesenchymal transition and briefly discusses the current anti-tumor therapies targeting TAMs and EMT processes.

Natural compounds: A new perspective on targeting polarization and infiltration of tumor-associated macrophages in lung cancer

With the development in tumor immunology, people are gradually understanding the complexity and diversity of the tumor microenvironment immune status and its important effect on tumors. Tumor-associated macrophages (TAMs), an important part of the tumor immune microenvironment, have a double effect on tumor growth and metastasis. Many studies have focused on lung cancer, especially non-small cell lung cancer and other "hot tumors" with typical inflammatory characteristics. The polarization and infiltration of TAMs is an important mechanism in the occurrence and development of malignant tumors, such as lung cancer, and in the tumor immune microenvironment. Therapeutic drugs designed for these reasons are key to targeting TAMs in the treatment of lung cancer. A large number of reports have suggested that natural compounds have a strong potential of affecting immunity by targeting the polarization and infiltration of TAMs to improve the immune microenvironment of lung cancer and exert a natural antitumor effect. This paper discusses the infiltration and polarization effects of natural compounds on lung cancer TAMs, provides a detailed classification and systematic review of natural compounds, and summarizes the bias of different kinds of natural compounds by affecting their antitumor mechanism of TAMs, with the aim of providing new perspectives and potential therapeutic drugs for targeted macrophages in the treatment of lung cancer.

Impact of the Tumor Microenvironment for Esophageal Tumor Development—An Opportunity for Prevention?

Simple Summary

Researchers increasingly appreciate the tumor microenvironment (TME) for its role in the development and therapy resistance of cancers like esophageal adenocarcinoma. A better understanding of the TME fueling carcinogenesis is necessary for tailored prevention and therapies. Here, we highlight recent insights into tumor initiation, interactions with the immune system and possible novel preventative measures.

Abstract

Despite therapeutical advancements, and in contrast to other malignancies, esophageal adenocarcinoma (EAC) prognosis remains dismal while the incidence has markedly increased worldwide over the past decades. EAC is a malignancy of the distal esophageal squamous epithelium at the squamocolumnar junction with gastric cells expanding into the esophagus. Most EAC patients have a history of Barret’s esophagus (BE), a metaplastic adaption to chronic reflux, initially causing an inflammatory microenvironment. Thus, the immune system is highly involved early on in disease development and progression. Normally, anti-tumor immunity could prevent carcinogenesis but in rare cases BE still progresses over a dysplastic intermediate state to EAC. The inflammatory milieu during the initial esophagitis phase changes to a tolerogenic immune environment in BE, and back to pro-inflammatory conditions in dysplasia and finally to an immune-suppressive tumor microenvironment in EAC. Consequently, there is a huge interest in understanding the underpinnings that lead to the inflammation driven stepwise progression of the disease. Since knowledge about the constellations of the various involved cells and signaling molecules is currently fragmentary, a comprehensive description of these changes is needed, allowing better preventative measures, diagnosis, and novel therapeutic targets.

Effect of taking aspirin before diagnosis on the prognosis of esophageal squamous cell carcinoma and analysis of prognostic factors

Objective

The 5-year survival rate of patients with esophageal squamous cell cancer (ESCC) is very low. However, long-term aspirin use has been suggested to have an adjuvant therapeutic effect. We therefore investigated the effect of long-term aspirin use before ESCC diagnosis on postoperative patient survival.

Methods

We carried out a retrospective cohort study of patients who underwent esophageal cancer resection in our hospital from 2008 to 2018. Patients were divided into an aspirin group (n = 79) and control group (n = 79), and were followed up until December 2019. We analyzed the clinicopathological and follow-up data of the patients during hospitalization, and the cyclooxygenase-2 (COX-2) protein expression levels by immunohistochemistry, and related these to postoperative survival.

Results

Patients who took aspirin had significantly lower survival rates than those who did not. COX-2-negative patients had better survival than patients with either low or high COX-2 expression levels. T stage was the only independent predictor of survival in patients who took aspirin.

Conclusions

Long-term regular use of aspirin before diagnosis had an adverse effect on postoperative survival in patients with ESCC. Different COX-2 protein expression levels were associated with significantly different postoperative survival rates, with COX-2-positive patients having the poorest survival.

PACER lncRNA regulates COX-2 expression in lung cancer cells

Long noncoding RNAs (lncRNAs) are known to regulate gene expression; however, in many cases, the mechanism of this regulation is unknown. One novel lncRNA relevant to inflammation and arachidonic acid (AA) metabolism is the p50-associated COX-2 extragenic RNA (PACER). We focused our research on the regulation of PACER in lung cancer. While the function of PACER is not entirely understood, PACER is known to play a role in inflammation-associated conditions. Our data suggest that PACER is critically involved in COX-2 transcription and dysregulation in lung cancer cells. Our analysis of The Cancer Genome Atlas (TCGA) expression data revealed that PACER expression is significantly higher in lung adenocarcinomas than normal lung tissues. Additionally, we discovered that elevated PACER expression strongly correlates with COX-2 expression in lung adenocarcinoma patients. Specific siRNA-mediated knockdown of PACER decreases COX-2 expression indicating a direct relationship. Additionally, we show that PACER expression is induced upon treatment with proinflammatory cytokines to mimic inflammation. Treatment with prostaglandin E2 (PGE2) induces both PACER and COX-2 expression, suggesting a PGE2-mediated feedback loop. Inhibition of COX-2 with celecoxib decreased PACER expression, confirming this self-regulatory process. Significant overlap between the COX-2 promotor and the PACER promotor led us to investigate their transcriptional regulatory mechanisms. Treatment with pharmacologic inhibitors of NF-κB or AP-1 showed a modest effect on both PACER and COX-2 expression but did not eliminate expression. These data suggest that the regulation of expression of both PACER and COX-2 is complex and intricately linked.

Analysis of the glyco-code in pancreatic ductal adenocarcinoma identifies glycan-mediated immune regulatory circuits

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most aggressive malignancies with a 5-year survival rate of only 9%. Despite the fact that changes in glycosylation patterns during tumour progression have been reported, no systematic approach has been conducted to evaluate its potential for patient stratification. By analysing publicly available transcriptomic data of patient samples and cell lines, we identified here two specific glycan profiles in PDAC that correlated with progression, clinical outcome and epithelial to mesenchymal transition (EMT) status. These different glycan profiles, confirmed by glycomics, can be distinguished by the expression of O-glycan fucosylated structures, present only in epithelial cells and regulated by the expression of GALNT3. Moreover, these fucosylated glycans can serve as ligands for DC-SIGN positive tumour-associated macrophages, modulating their activation and inducing the production of IL-10. Our results show mechanisms by which the glyco-code contributes to the tolerogenic microenvironment in PDAC.

LINC01094 Predicts Poor Prognosis in Patients With Gastric Cancer and is Correlated With EMT and Macrophage Infiltration

Objectives: The novel long non-coding RNA (lncRNA) LINC01094 is often upregulated in renal cell carcinoma and glioma; however, its role in gastric cancer remains unclear. Here, we aim to demonstrate the relationship between LINC01094 and gastric cancer. Method: The gene expression (RNASeq) data of 375 patients with localized, locally advanced, and metastatic gastric cancer were extracted from The Cancer Genome Atlas. The Kruskal–Wallis test, Wilcoxon signed-rank test, and logistic regression were used to analyze the relationship between the clinicopathological characteristics and LINC01094 expression. Cox regression analysis and the Kaplan–Meier method were used to assess prognostic factors of gastric cancer. A nomogram based on Cox multivariate analysis was used to predict the impact of LINC01094 on gastric cancer prognosis. Gene set enrichment analysis (GSEA) was used to identify key LINC01094-associated signaling pathways. Fluorescence in situ hybridization (FISH) was performed to detect the location of LINC01094 in the tissue, and a competing endogenous (ce)RNA network was constructed to identify LINC01094-related genes. Spearman's rank correlation was used to elucidate the association between LINC01094 expression level and immune cell infiltration level. Result: LINC01094 expression was upregulated in gastric cancer tissues and strongly associated with overall survival using univariate Cox regression (hazard ratio [HR]  =  1.476, 95% CI  =  1.060-2.054, P  =  .021) and multivariate Cox regression analysis (HR  =  1.535, 95% CI  =  1.021-2.308, P  =  .039). The area under the receiver operating characteristic curve of LINC01094 was 0.910. GSEA showed a strong relationship between LINC01094 and the epithelial-mesenchymal transition pathway. RNA-FISH demonstrated that LINC01094 localized in the cytoplasm. It was closely related to the epithelial-mesenchymal transition (EMT) marker SNAI2, according to ceRNA (R  =  0.61, P < .001), and macrophage-related gene FCGR2A. Macrophages were also significantly positively correlated with LINC01094 expression (R  =  0.747, P < .001). Conclusion: High LINC01094 expression predicts poor prognosis in gastric cancer and is correlated with the epithelial-mesenchymal transition pathway and macrophage infiltration.

Tumor-associated macrophages in lung carcinoma: From mechanism to therapy

Tumor-associated macrophages (TAMs), which could be classified into the classical (M1-like) and alternatively activated (M2-like) phenotype, were considered to be important tumor-promoting components in lung cancer microenvironment. Several studies reported that TAMs in lung tumor islet or stroma are usually correlated with poor prognosis. Further studies showed that TAMs could promote the initiation of tumor cells, inhibit antitumor immune responses, and stimulate tumor angiogenesis and subsequently tumor metastasis of lung carcinoma. Currently, TAMs have been considered as penitential targets of lung cancer. This review summarizes from the fundamental information of TAMs to the its role in metastasis and present evidence for TAMs as a potential target of cancer therapy.

MicroRNA-106a-5p promotes the proliferation, autophagy and migration of lung adenocarcinoma cells by targeting LKB1/AMPK

It has previously been reported that lung cancer has the highest morbidity and mortality rate worldwide; however, the pathogenesis underlying lung cancer has not been fully elucidated. The aim of the present was primarily to assess the influence of microRNA (miR)-106a-5p on the biological behaviors of lung cancer cells. In the present study, bioinformatics analysis was used to analyze the expression characteristics of miR-106a-5p and its relationship with the prognosis of patients with lung adenocarcinoma (LUAD) in The Cancer Genome Atlas. A dual luciferase reporter assay was performed to verify the binding of miR-106a-5p and liver kinase B1 (LKB1). The Cell Counting Kit-8, colony formation and Transwell assays were utilized to detect cell viability, proliferation and migration, respectively. Protein and RNA expression levels were examined by western blotting and reverse transcription-quantitative PCR analysis, respectively. It was observed that miR-106a-5p was highly expressed in LUAD and associated with poor prognosis. miR-106a-5p promoted the proliferation and migration of LUAD cells, and inhibited autophagy. By contrast, LKB1 inhibited cell proliferation and migration, promoted autophagy and blocked the cancer-promoting effects of miR-106a-5p. Overexpression of miR-106a-5p inhibited the phosphorylation of AMP-activated protein kinase (AMPK) and tuberin (TSC2), and promoted the phosphorylation of mTOR. By contrast, overexpression of LKB1 blocked the promotion of mTOR phosphorylation, and the inhibition of AMPK and TSC2 phosphorylation caused by miR-106a-5p. In summary, the results of the present study indicated that miR-106a-5p regulated the phosphorylation of the AMPK pathway by targeting LKB1, and was involved in the proliferation, migration and autophagy of LUAD cells.

Core genes involved in the regulation of acute lung injury and their association with COVID-19 and tumor progression: A bioinformatics and experimental study

Acute lung injury (ALI) is a specific form of lung damage caused by different infectious and non-infectious agents, including SARS-CoV-2, leading to severe respiratory and systemic inflammation. To gain deeper insight into the molecular mechanisms behind ALI and to identify core elements of the regulatory network associated with this pathology, key genes involved in the regulation of the acute lung inflammatory response (Il6, Ccl2, Cat, Serpine1, Eln, Timp1, Ptx3, Socs3) were revealed using comprehensive bioinformatics analysis of whole-genome microarray datasets, functional annotation of differentially expressed genes (DEGs), reconstruction of protein-protein interaction networks and text mining. The bioinformatics data were validated using a murine model of LPS-induced ALI; changes in the gene expression patterns were assessed during ALI progression and prevention by anti-inflammatory therapy with dexamethasone and the semisynthetic triterpenoid soloxolone methyl (SM), two agents with different mechanisms of action. Analysis showed that 7 of 8 revealed ALI-related genes were susceptible to LPS challenge (up-regulation: Il6, Ccl2, Cat, Serpine1, Eln, Timp1, Socs3; down-regulation: Cat) and their expression was reversed by the pre-treatment of mice with both anti-inflammatory agents. Furthermore, ALI-associated nodal genes were analysed with respect to SARS-CoV-2 infection and lung cancers. The overlap with DEGs identified in postmortem lung tissues from COVID-19 patients revealed genes (Saa1, Rsad2, Ifi44, Rtp4, Mmp8) that (a) showed a high degree centrality in the COVID-19-related regulatory network, (b) were up-regulated in murine lungs after LPS administration, and (c) were susceptible to anti-inflammatory therapy. Analysis of ALI-associated key genes using The Cancer Genome Atlas showed their correlation with poor survival in patients with lung neoplasias (Ptx3, Timp1, Serpine1, Plaur). Taken together, a number of key genes playing a core function in the regulation of lung inflammation were found, which can serve both as promising therapeutic targets and molecular markers to control lung ailments, including COVID-19-associated ALI.

Tumour microenvironment: a non-negligible driver for epithelial-mesenchymal transition in colorectal cancer

Cancer remains the leading cause of death worldwide, and metastasis is still the major cause of treatment failure for cancer patients. Epithelial-mesenchymal transition (EMT) has been shown to play a critical role in the metastasis cascade of epithelium-derived carcinoma. Tumour microenvironment (TME) refers to the local tissue environment in which tumour cells produce and live, including not only tumour cells themselves, but also fibroblasts, immune and inflammatory cells, glial cells and other cells around them, as well as intercellular stroma, micro vessels and infiltrated biomolecules from the nearby areas, which has been proved to widely participate in the occurrence and progress of cancer. Emerging and accumulating studies indicate that, on one hand, mesenchymal cells in TME can establish 'crosstalk' with tumour cells to regulate their EMT programme; on the other, EMT-tumour cells can create a favourable environment for their own growth via educating stromal cells. Recently, our group has conducted a series of studies on the interaction between tumour-associated macrophages (TAMs) and colorectal cancer (CRC) cells in TME, confirming that the interaction between TAMs and CRC cells mediated by cytokines or exosomes can jointly promote the metastasis of CRC by regulating the EMT process of tumour cells and the M2-type polarisation process of TAMs. Herein, we present an overview to describe the current knowledge about EMT in cancer, summarise the important role of TME in EMT, and provide an update on the mechanisms of TME-induced EMT in CRC, aiming to provide new ideas for understanding and resisting tumour metastasis.

Zhikang Capsule Ameliorates Inflammation, Drives Polarization to M2 Macrophages, and Inhibits Apoptosis in Lipopolysaccharide-induced RAW264.7 Cells

OBJECTIVE

To explore the anti-inflammatory effect of the traditional Chinese medicine Zhikang capsule (ZKC) on lipopolysaccharide (LPS)-induced RAW264.7 cells.

METHODS

Safe concentrations of ZKC (0.175, 0.35, and 0.7 mg/mL) were used after the half-maximal inhibitory concentration (IC₅₀) of RAW264.7 cells was calculated through the CCK-8 assay. In addition, the optimal intervention duration of ZKC (0.7 mg/mL) on RAW264.7 cells was determined to be 6 h, since all proinflammatory mediators [tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), inteleukin-6 (IL-6), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and monocyte chemotactic protein-1 (MCP-1)] had a decreasing tendency and relatively down-regulated mRNA expression levels as compared with other durations (4, 8, and 12 h). RAW264.7 cells were pretreated with ZKC at various concentrations (0.175, 0.35 and 0.7 mg/mL) for 6 h and then stimulated with LPS (1 µg/mL) for an additional 12 h.

RESULTS

In terms of inflammation, ZKC could reverse LPS-induced upregulation of TNF-α, IL-1β, IL-6, COX-2, iNOS, and MCP-1 at both the mRNA and protein levels in RAW264.7 cells in a dose-dependent manner. In terms of the NF-κB signaling pathway, ZKC could reduce phosphorylated p65 and promote M2 polarization of RAW264.7 cells under LPS stimulation in a dose-dependent manner. Moreover, ZKC exhibited a protective effect on macrophages from apoptosis.

CONCLUSION

ZKC exhibited obvious antiinflammatory and anti-apoptotic effects on LPS-induced RAW264.7 cells at the cellular level, and a weakened NF-κB signaling pathway may be a potential significant target.

Anti-Inflammation and Protective Effects of Anethum graveolens L. (Dill Seeds) on Esophageal Mucosa Damages in Reflux Esophagitis-Induced Rats

Anethum graveolens L. (dill seeds) are important medicinal and functional foods in Europe and central and south Asia, often used as a seasoning in daily diets. Anethum graveolens L. seeds (AGS) are used to treat indigestion and have shown physiological activities such as those against hypoglycemia and gastroesophageal disease. This study explored the protective effects of AGS extract on mucosal damages and inflammation in reflux esophagitis rats. AGS inhibited cellular inflammation including NO production and the expression of inflammatory proteins (iNOS and COX2 etc.), cytokines (IL-1β and TNF-α) and nuclear transfer factor related to NF-κB signaling caused by LPS stimulation in vitro. Furthermore, reflux esophagitis-induced rats were used to observe the anti-inflammatory effect of AGS. Tissue staining and inflammation-related protein expression of rats with acute reflux esophagitis indicated that AGS improved this inflammatory response, such as COX-2 and TNF-α in mucosa. In conclusion, AGS have good physiological activity and the possibility of being used as a medicinal food and a functional resource for the prevention and therapy of gastroesophageal diseases.

Dynamic EMT: a multi-tool for tumor progression

The process of epithelial-mesenchymal transition (EMT) is fundamental for embryonic morphogenesis. Cells undergoing it lose epithelial characteristics and integrity, acquire mesenchymal features, and become motile. In cancer, this program is hijacked to confer essential changes in morphology and motility that fuel invasion. In addition, EMT is increasingly understood to orchestrate a large variety of complementary cancer features, such as tumor cell stemness, tumorigenicity, resistance to therapy and adaptation to changes in the microenvironment. In this review, we summarize recent findings related to these various classical and non-classical functions, and introduce EMT as a true tumorigenic multi-tool, involved in many aspects of cancer. We suggest that therapeutic targeting of the EMT process will-if acknowledging these complexities-be a possibility to concurrently interfere with tumor progression on many levels.

Modulation of the tumor microenvironment (TME) by melatonin

The tumor microenvironment (TME) includes a number of non-cancerous cells that affect cancer cell survival. Although CD8+ T lymphocytes and natural killer (NK) cells suppress tumor growth through induction of cell death in cancer cells, there are various immunosuppressive cells such as regulatory T cells (Tregs), tumor-associated macrophages (TAMs), cancer-associated fibroblasts (CAFs), myeloid-derived suppressor cells (MDSCs), etc., which drive cancer cell proliferation. These cells may also support tumor growth and metastasis by stimulating angiogenesis, epithelial-mesenchymal transition (EMT), and resistance to apoptosis. Interactions between cancer cells and other cells, as well as molecules released into EMT, play a key role in tumor growth and suppression of antitumoral immunity. Melatonin is a natural hormone that may be found in certain foods and is also available as a drug. Melatonin has been demonstrated to modulate cell activity and the release of cytokines and growth factors in TME. The purpose of this review is to explain the cellular and molecular mechanisms of cancer cell resistance as a result of interactions with TME. Next, we explain how melatonin affects cells and interactions within the TME.

7S,15R-Dihydroxy-16S,17S-Epoxy-Docosapentaenoic Acid, a Novel DHA Epoxy Derivative, Inhibits Colorectal Cancer Stemness through Repolarization of Tumor-Associated Macrophage Functions and the ROS/STAT3 Signaling Pathway

Colorectal cancer is a highly malignant cancer that is inherently resistant to many chemotherapeutic drugs owing to the complicated tumor-supportive microenvironment (TME). Tumor-associated macrophages (TAM) are known to mediate colorectal cancer metastasis and relapse and are therefore a promising therapeutic target. In the current study, we first confirmed the anti-inflammatory effect of 7S,15R-dihydroxy-16S,17S-epoxy-docosapentaenoic acid (diHEP-DPA), a novel DHA dihydroxy derivative synthesized in our previous work. We found that diHEP-DPA significantly reduced lipopolysaccharide (LPS)-induced inflammatory cytokines secretion of THP1 macrophages, IL-6, and TNF-α. As expected, diHEP-DPA also modulated TAM polarization, as evidenced by decreased gene and protein expression of the TAM markers, CD206, CD163, VEGF, and TGF-β1. During the polarization process, diHEP-DPA treatment decreased the concentration of TGF-β1, IL-1β, IL-6, and TNF-α in culture supernatants via inhibiting the NF-κB pathway. Moreover, diHEP-DPA blocked immunosuppression by reducing the expression of SIRPα in TAMs and CD47 in colorectal cancer cells. Knowing that an inflammatory TME largely serves to support epithelial-mesenchymal transition (EMT) and cancer stemness, we tested whether diHEP-DPA acted through polarization of TAMs to regulate these processes. The intraperitoneally injected diHEP-DPA inhibited tumor growth when administered alone or in combination with 5-fluorouracil (5-FU) chemotherapy in vivo. We further found that diHEP-DPA effectively reversed TAM-conditioned medium (TCCM)-induced EMT and enhanced colorectal cancer stemness, as evidenced by its inhibition of colorectal cancer cell migration, invasion and expression of EMT markers, as well as cancer cell tumorspheres formation, without damaging colorectal cancer cells. DiHEP-DPA reduced the population of aldehyde dehydrogenase (ALDH)-positive cells and expression of colorectal stemness marker proteins (CD133, CD44, and Sox2) by modulating TAM polarization. Additionally, diHEP-DPA directly inhibited cancer stemness by inducing the production of reactive oxygen species (ROS), which, in turn, reduced the phosphorylation of nuclear signal transducer and activator of transcription 3 (STAT3). These data collectively suggest that diHEP-DPA has the potential for development as an anticancer agent against colorectal cancer.

Tumor-initiating stem cell shapes its microenvironment into an immunosuppressive barrier and pro-tumorigenic niche

Tumor-initiating stem cells (TSCs) are critical for drug resistance and immune escape. However, the mutual regulations between TSC and tumor microenvironment (TME) remain unclear. Using DNA-label retaining, single-cell RNA sequencing (scRNA-seq), and other approaches, we investigated intestinal adenoma in response to chemoradiotherapy (CRT), thus identifying therapy-resistant TSCs (TrTSCs). We find bidirectional crosstalk between TSCs and TME using CellPhoneDB analysis. An intriguing finding is that TSCs shape TME into a landscape that favors TSCs for immunosuppression and propagation. Using adenoma-organoid co-cultures, niche-cell depletion, and lineaging tracing, we characterize a functional role of cyclooxygenase-2 (Cox-2)-dependent signaling, predominantly occurring between tumor-associated monocytes and macrophages (TAMMs) and TrTSCs. We show that TAMMs promote TrTSC proliferation through prostaglandin E2 (PGE2)-PTGER4(EP4) signaling, which enhances β-catenin activity via AKT phosphorylation. Thus, our study shows that the bidirectional crosstalk between TrTSC and TME results in a pro-tumorigenic and immunosuppressive contexture.

Delta-5-desaturase: A novel therapeutic target for cancer management

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D5D is an independent prognostic factor in cancer.

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D5D aggravates cancer progression via mediating AA/PGE₂ production from DGLA.

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AA/PGE₂ promotes cancer progression via regulating the tumor microenvironment.

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Inhibition of D5D redirects COX-2 catalyzed DGLA peroxidation, producing 8-HOA.

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8-HOA suppress cancer by regulating proliferation, apoptosis, and metastasis.

Delta-5 desaturase (D5D) is a rate-limiting enzyme that introduces double-bonds to the delta-5 position of the n-3 and n-6 polyunsaturated fatty acid chain. Since fatty acid metabolism is a vital factor in cancer development, several recent studies have revealed that D5D activity and expression could be an independent prognostic factor in cancers. However, the mechanistic basis of D5D in cancer progression is still controversial. The classical concept believes that D5D could aggravate cancer progression via mediating arachidonic acid (AA)/prostaglandin E₂ production from dihomo-γ-linolenic acid (DGLA), resulting in activation of EP receptors, inflammatory pathways, and immunosuppression. On the contrary, D5D may prevent cancer progression through activating ferroptosis, which is iron-dependent cell death. Suppression of D5D by RNA interference and small-molecule inhibitor has been identified as a promising anti-cancer strategy. Inhibition of D5D could shift DGLA peroxidation pattern from generating AA to a distinct anti-cancer free radical byproduct, 8-hydroxyoctanoic acid, resulting in activation of apoptosis pathway and simultaneously suppression of cancer cell survival, proliferation, migration, and invasion. Hence, understanding the molecular mechanisms of D5D on cancer may therefore facilitate the development of novel therapeutical applications. Given that D5D may serve as a promising target in cancer, in this review, we provide an updated summary of current knowledge on the role of D5D in cancer development and potentially useful therapeutic strategies.