Crosstalk between fatty acid metabolism and tumour-associated macrophages in cancer progression

Forkhead box M1 mediates metabolic reprogramming in human colorectal cancer cells

Metabolic reprogramming is recognized as a hallmark of cancer, enabling cancer cells to acquire essential biomolecules for cell growth, often characterized by upregulated glycolysis and/or fatty acid synthesis-related genes. The transcription factor forkhead box M1 (FOXM1) has been implicated in various cancers, contributing significantly to their development, including colorectal cancer (CRC), a major global health concern. Despite FOXM1's established role in cancer, its specific involvement in the Warburg effect and fatty acid biosynthesis in CRC remains unclear. We analyzed The Cancer Genome Atlas (TCGA) Colonic Adenocarcinoma and Rectal Adenocarcinoma (COADREAD) datasets to derive the correlation of the expression levels between FOXM1 and multiple genes and the survival prognosis based on FOXM1 expression. Using two human CRC cell lines, HT29 and HCT116, we conducted RNAi or plasmid transfection procedures, followed by a series of assays, including RNA extraction, quantitative real-time polymerase chain reaction, Western blot analysis, cell metabolic assay, glucose uptake assay, Oil Red O staining, cell viability assay, and immunofluorescence analysis. Higher expression levels of FOXM1 correlated with a poorer survival prognosis, and the expression of FOXM1 was positively correlated with glycolysis-related genes SLC2A1 and LDHA, de novo lipogenesis-related genes ACACA and FASN, and MYC. FOXM1 appeared to modulate AKT/mammalian target of rapamycin (mTOR) signaling, the expression of c-Myc, proteins related to glycolysis and fatty acid biosynthesis, and glucose uptake, as well as extracellular acidification rate in HT29 and HCT116 cells. In summary, FOXM1 plays a regulatory role in glycolysis, fatty acid biosynthesis, and cellular energy consumption, thereby influencing CRC cell growth and patient prognosis.NEW & NOTEWORTHY Transcription factor forkhead box M1 (FOXM1) regulates glycolysis, fatty acid biosynthesis, and cellular energy consumption, which, together, controls cell growth and patient prognosis in colorectal cancer (CRC).

CCL16 is a pro-tumor chemokine that recruits monocytes and macrophages to promote hepatocellular carcinoma progression

Intricate signaling cascades involving chemokines and their cognate receptors on neoplastic and immune constituents within tumor microenvironment have garnered substantial research interest. Our investigation delineates the contribution of Chemokine (C-C motif) ligand 16 (CCL16) to the clinico-pathological features and tumorigenesis of hepatocellular carcinoma (HCC). Analysis of 237 pairs of HCC specimens unraveled a significant association between CCL16 expression and vascular invasion, early-stage clinicopathological features, and diminished recurrence-free survival among HCC patients. Immunohistochemical (IHC) assays of the clinical HCC specimens indicated elevated CCL16 in tumorous versus normal hepatic tissues. Our in vivo experiments demonstrated CCL16 overexpression fostered tumor proliferation, whereas in vitro assays elucidated that CCL16-mediated chemotactic recruitment of monocytes and M2 macrophages was orchestrated via CCR1 and CCR5. In contrast to previous claims that CCL16 is physiologically irrelevant and has minimal affinity for its receptors (CCR1, CCR2, CCR5, CCR8), our findings unravel that inhibition of CCL16/CCR1 and CCL16/CCR5 interactions through receptor-specific antagonists markedly impeded CCL16-directed chemotaxis, migration, adhesion, and leukocyte recruitment. Moreover, CCL16-overexpression in HCCs significantly augmented levels of several cytokines implicated in tumor progression, namely IL-6, IL-10 and VEGFA. IHC analysis of CCL16-overexpressing xenografts elicited greatly enhanced levels of VEGFA and IL-6, while assessments of HCC specimens confirmed a positive correlation between CCL16 expression and IL-6 and VEGFA levels. Collectively, our study highlights oncogenic role of CCL16 in hepatocarcinogenesis and provides a foundational basis for novel therapeutic interventions targeting the CCL16/CCR1/CCR5 axis.

The stimulation of exosome generation by visfatin polarizes M2 macrophages and enhances the motility of chondrosarcoma

Chondrosarcoma is a malignant bone tumor that arises from abnormalities in cartilaginous tissue and is associated with lung metastases. Extracellular vesicles called exosomes are primarily used as mediators of intercellular signal transmission to control tumor metastasis. Visfatin is an adipokine reported to enhance tumor metastasis, but its relationship with exosome generation in chondrosarcoma motility remains undetermined. Our results found that overexpressing visfatin augments the production of exosomes from chondrosarcoma cells. Visfatin-treated chondrosarcoma exosomes educate macrophage polarization towards the M2 but not M1 phenotype. Interestingly, M2 macrophages polarized by exosomes return to chondrosarcoma cells to facilitate cell motility. According to these findings, chondrosarcoma cells emit more exosomes when treated with visfatin. The stimulation of exosome generation by visfatin polarizes M2 macrophages and enhances the motility of chondrosarcoma.

From monocyte-derived macrophages to resident macrophages-how metabolism leads their way in cancer

Macrophages are innate immune cells that play key roles during both homeostasis and disease. Depending on the microenvironmental cues sensed in different tissues, macrophages are known to acquire specific phenotypes and exhibit unique features that, ultimately, orchestrate tissue homeostasis, defense, and repair. Within the tumor microenvironment, macrophages are referred to as tumor-associated macrophages (TAMs) and constitute a heterogeneous population. Like their tissue resident counterpart, TAMs are plastic and can switch function and phenotype according to the niche-derived stimuli sensed. While changes in TAM phenotype are known to be accompanied by adaptive alterations in their cell metabolism, it is reported that metabolic reprogramming of macrophages can dictate their activation state and function. In line with these observations, recent research efforts have been focused on defining the metabolic traits of TAM subsets in different tumor malignancies and understanding their role in cancer progression and metastasis formation. This knowledge will pave the way to novel therapeutic strategies tailored to cancer subtype-specific metabolic landscapes. This review outlines the metabolic characteristics of distinct TAM subsets and their implications in tumorigenesis across multiple cancer types.

In vitro and in silico evaluation of Andrographis paniculata ethanolic crude extracts on fatty acid synthase expression on breast cancer cells

Background

Fatty acid synthase (FASN), a key rate-limiting enzyme in the fatty acid biosynthesis pathway has been identified to be overexpressed in breast cancer. This overexpression has been affiliated with poor prognosis and resistance to chemotherapeutics. Consequently, FASN has come into focus as an appealing potential target for breast cancer treatment. Available FASN inhibitors, however, are unstable and have been correlated with adverse side effects.

Objective

This present study aims to investigate the potential of Andrographis paniculata ethanolic crude extract (AP) as a potent FASN inhibitor in breast cancer cells.

Materials & methods

This study used MTT assay and flow cytometry analysis to measure cell viability and apoptosis following AP treatment (0-500 μg/mL). Furthermore, FASN protein expression was evaluated using immunocytochemistry whereas lipid droplet formation was quantified using Oil Red O staining. Literature-based identified AP phytochemicals were subjected to the prediction of molecular docking and ADMET properties.

Results

This study demonstrated that AP significantly reduced cell viability while inducing apoptosis in breast cancer cells. In addition, for the first time, exposure to AP was demonstrated to drastically reduce intracellular FASN protein expression and lipid droplet accumulation in EMT6 and MCF-7 breast cancer cells. Docking simulation analysis demonstrated AP phytochemicals may have exerted an inhibitory effect by targeting the FASN Thioesterase (TE) domain similarly to the known FASN inhibitor, Orlistat. Moreover, all AP phytochemicals also possessed drug-likeness properties which are in accordance with Lipinski's rule of five.

Conclusions

These results highlight the potential of A. paniculata ethanolic crude extract as a FASN inhibitor and hence might have the potential to be further developed as a potent chemotherapeutic drug for breast cancer treatment.

MCP-1 controls IL-17-promoted monocyte migration and M1 polarization in osteoarthritis

Osteoarthritis (OA) is a low-grade inflammatory joint illness in which monocytes migrate and infiltrate synovial tissue, differentiating into the pro-inflammatory M1 macrophage phenotype. IL-17 is a proinflammatory mediator principally generated by Th17 cells, which is elevated in OA patients; nevertheless, investigators have yet to elucidate the function of IL-17 in M1 polarization during OA development. Our analysis of clinical tissues and results from the open online dataset discovered that the level of M1 macrophage markers is elevated in human OA tissue samples than in normal tissue. High-throughput screening demonstrated that MCP-1 is a potential candidate factor after IL-17 treatment in OA synovial fibroblasts (OASFs). Immunohistochemistry data revealed that the level of MCP-1 is higher in humans and mice with OA than in normal tissues. IL-17 stimulation facilitates MCP-1-dependent macrophage polarization to the M1 phenotype. It also appears that IL-17 enhances MCP-1 synthesis in human OASFs, enhancing monocyte migration via the JAK and STAT3 signaling cascades. Our findings indicate the IL-17/MCP-1 axis as a novel strategy for the remedy of OA.

Apigenin Suppresses MED28-Mediated Cell Growth in Human Liver Cancer Cells

Flavonoids exhibit health-promoting benefits against multiple chronic diseases, including cancer. Apigenin (4',5,7-trihydroxyflavone), one flavonoid present in fruits and vegetables, is potentially applicable to chemoprevention. Despite considerable progress in the therapeutic regimen of liver cancer, its prognosis remains poor. MED28, a Mediator subunit for transcriptional activation, is implicated in the development of several types of malignancy; however, its role in liver cancer is unknown at present. In liver cancer, the AKT/mammalian target of rapamycin (mTOR) is one major pathway involved in the oncogenic process. The aim of this study is to investigate the role of apigenin and MED28 in AKT/mTOR signaling in liver cancer. We first identified a connectivity score of 92.77 between apigenin treatment and MED28 knockdown in several cancer cell lines using CLUE, a cloud-based software platform to assess connectivity among compounds and genetic perturbagens. Higher expression of MED28 predicted a poorer survival prognosis; MED28 expression in liver cancer tissue was significantly higher than that of normal tissue, and it was positively correlated with tumor stage and grade in The Cancer Genome Atlas Liver Cancer (TCGA-LIHC) data set. Knockdown of MED28 induced cell cycle arrest and suppressed the AKT/mTOR signaling in two human liver cancer cell lines, HepG2 and Huh 7, accompanied by less lipid accumulation and lower expression and nuclear localization of sterol regulatory element binding protein 1 (SREBP1). Apigenin inhibited the expression of MED28, and the effect of apigenin mimicked that of the MED28 knockdown. On the other hand, the AKT/mTOR signaling was upregulated when MED28 was overexpressed. These data indicated that MED28 was associated with the survival prognosis and the progression of liver cancer by regulating AKT/mTOR signaling and apigenin appeared to inhibit cell growth through MED28-mediated mTOR signaling, which may be applicable as an adjuvant of chemotherapy or chemoprevention in liver cancer.

NGF facilitates ICAM-1-dependent monocyte adhesion and M1 macrophage polarization in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disorder in which monocytes adhering to synovial tissue differentiate into the pro-inflammatory M1 macrophage phenotype. Nerve growth factors (NGF) referred to as neurotrophins have been associated with inflammatory events; however, researchers have yet to elucidate the role of NGF in RA. Our examination of clinical tissue samples and analysis of data sourced from the Gene Expression Omnibus dataset unveiled elevated expression levels of M1 macrophage markers in human RA synovial tissue samples compared to normal tissue, with no such distinction observed for M2 markers. Furthermore, immunofluorescence data depicted increased expression levels of NGF and M1 macrophages in RA mice in contrast to normal mice. It appears that NGF stimulation facilitates macrophage polarization from the M0 to the M1 phenotype. It also appears that NGF promotes ICAM-1 production in human RA synovial fibroblasts, which enhances monocyte adhesion through the TrkA, MEK/ERK, and AP-1 signaling cascades. Our findings indicate NGF/TrkA axis as a novel target for the treatment of RA.

Hypoxia-regulated exosomes mediate M2 macrophage polarization and promote metastasis in chondrosarcoma

Chondrosarcoma is a primary malignant bone tumor. Traditional therapy is not very effective, and it is prone to metastasis in the late stage. The tumor microenvironment (TME) plays a key role in the progression and metastasis of chondrosarcoma, and hypoxia is one of the key factors in the formation of TME. However, the detailed mechanism of how hypoxia affects tumor progression and metastasis in chondrosarcoma is still not fully understood. In this study, we focused on the mechanism of interaction between hypoxic chondrosarcoma cells (SW1353) and macrophages. Our results suggest that hypoxia enhances the release of exosomes from chondrosarcoma cells. These hypoxia-induced exosomes promoted macrophage polarization towards the M2 phenotype, characterized by the expression of CD163 and CD206, but not the M1 phenotype, characterized by CD86 expression. Further analysis revealed that M2 macrophages polarized by exosomes expressed arginase-1 and feedback to chondrosarcoma cells to promote migration. These results suggest that chondrosarcoma cells secrete more exosomes in a hypoxic microenvironment, and these hypoxia-derived exosomes induce the polarization of macrophages into an M2 phenotype, ultimately promoting the metastatic behavior of chondrosarcoma cells.

Omentin-1 ameliorates the progress of osteoarthritis by promoting IL-4-dependent anti-inflammatory responses and M2 macrophage polarization

Osteoarthritis (OA) is a prevalent joint disease commonly associated with aging and obesity, which can lead to pain, stiffness, joint dysfunction, and disability. Omentin-1 (also called intelectin-1) is a newly discovered adipokine, which plays a protective role in suppressing the secretion of pro-inflammatory cytokines. Based on data from the Gene Expression Omnibus (GEO) dataset and clinical samples obtained at our institution revealed, determined that omentin-1 and IL-4 (an anti-inflammatory cytokine) levels were significantly lower in OA patients than in normal controls. Omentin-1 was shown to induce IL-4-depedent anti-inflammatory responses and M2 macrophage polarization in OA synovial fibroblasts via the PI3K, ERK, and AMPK pathways. Administering omentin-1 was shown to block cartilage degradation and bone erosion resulting from anterior cruciate ligament transection by inhibiting the production of pro-inflammatory cytokines and promoting M2 macrophage polarization in vivo. Our findings indicate omentin-1 as a promising therapeutic avenue for the treatment for OA.

IOX-1 suppresses metastasis of osteosarcoma by upregulating histone H3 lysine trimethylation

New therapeutic approaches are needed for metastatic osteosarcoma (OS), as survival rates remain low despite surgery and chemotherapy. Epigenetic changes, such as histone H3 methylation, play key roles in many cancers including OS, although the underlying mechanisms are not clear. In this study, human OS tissue and OS cell lines displayed lower levels of histone H3 lysine trimethylation compared with normal bone tissue and osteoblast cells. Treating OS cells with the histone lysine demethylase inhibitor 5-carboxy-8-hydroxyquinoline (IOX-1) dose-dependently increased histone H3 methylation and inhibited cellular migratory and invasive capabilities, suppressed matrix metalloproteinase expression, reversed epithelial-to-mesenchymal transition by increasing levels of epithelial markers E-cadherin and ZO-1 and decreasing the expression of mesenchymal markers N-cadherin, vimentin, and TWIST, and also reduced stemness properties. An analysis of cultivated MG63 cisplatin-resistant (MG63-CR) cells revealed lower histone H3 lysine trimethylation levels compared with levels in MG63 cells. Exposing MG63-CR cells to IOX-1 increased histone H3 trimethylation and ATP-binding cassette transporter expression, potentially sensitizing MG63-CR cells to cisplatin. In conclusion, our study suggests that histone H3 lysine trimethylation is associated with metastatic OS and that IOX-1 or other epigenetic modulators present promising strategies to inhibit metastatic OS progression.