TCEB2 promotes M2 polarization of macrophages in triple negative breast cancer by mediating ubiquitination degradation of Slit2 through recruiting NEDD4

To explore the oncogenic mechanism of FOXM1 in the tumor microenvironment (TME) regarding triple-negative breast cancer (TNBC) promotion, the mRNA and protein levels of target genes in TNBC cells and their exosomes were detected by RT-qPCR and western blot. A co-culture model of TNBC cells and THP-1/M0 macrophages was established to detect the impact of co-culture on FOXM1 expression and the direction of macrophage polarization. A bioinformatics website was used to predict FOXM1 binding sites in the IDO1 promoter, which were further validated using dual-luciferase reporter and chromatin immunoprecipitation assays. Next, after erastin-induced ferroptosis, we conducted cell viability assays, apoptosis assays and other experiments to investigate whether the FOXM1/IDO1 axis regulates M2 macrophage polarization through ferroptosis. We found that FOXM1 was abundant in exosomes derived from TNBC cells, and that TNBC cells upregulated FOXM1 expression in THP-1 cells through exosomes to promote M2 macrophage polarization. Furthermore, FOXM1 upregulated IDO1 in M2-type tumor-associated macrophages (TAMs) by stimulating its transcription. Finally, FOXM1/IDO1 inhibited ferroptosis, promoting M2 macrophage polarization, thereby advancing TNBC progression. In conclusion, FOXM1 carried by TNBC cell-derived exosomes activated IDO1 transcription in TAMs to inhibit ferroptosis, promoting M2 polarization of TAMs and exerting carcinogenic effects.

BackgroundHepatocellular carcinoma (HCC) cells-secreted exosomes (exo) could stimulate M2 macrophage polarization and promote HCC progression, but the related mechanism of long non-coding RNA distal-less homeobox 6 antisense 1 (DLX6-AS1) with HCC-exo-mediated M2 macrophage polarization is largely ambiguous. Thereafter, this research was started to unearth the role of DLX6-AS1 in HCC-exo in HCC through M2 macrophage polarization and microRNA (miR)-15a-5p/C-X-C motif chemokine ligand 17 (CXCL17) axis.MethodsDLX6-AS1, miR-15a-5p and CXCL17 expression in HCC tissues and cells were tested. Exosomes were isolated from HCC cells with overexpressed DLX6-AS1 and co-cultured with M2 macrophages. MiR-15a-5p/CXCL17 down-regulation assays were performed in macrophages. The treated M2 macrophages were co-cultured with HCC cells, after which cell migration, invasion and epithelial mesenchymal transition were examined. The targeting relationships between DLX6-AS1 and miR-15a-5p, and between miR-15a-5p and CXCL17 were explored. In vivo experiment was conducted to detect the effect of exosomal DLX6-AS1-induced M2 macrophage polarization on HCC metastasis.ResultsPromoted DLX6-AS1 and CXCL17 and reduced miR-15a-5p exhibited in HCC. HCC-exo induced M2 macrophage polarization to accelerate migration, invasion and epithelial mesenchymal transition in HCC, which was further enhanced by up-regulated DLX6-AS1 but impaired by silenced DLX6-AS1. Inhibition of miR-15a-5p promoted M2 macrophage polarization to stimulate the invasion and metastasis of HCC while that of CXCL17 had the opposite effects. DLX6-AS1 mediated miR-15a-5p to target CXCL17. DLX6-AS1 from HCC-exo promoted metastasis in the lung by inducing M2 macrophage polarization in vivo.ConclusionDLX6-AS1 from HCC-exo regulates CXCL17 by competitively binding to miR-15a-5p to induce M2 macrophage polarization, thus promoting HCC migration, invasion and EMT.

Tumor-associated macrophages play a critical role in regulating the progression of lung adenocarcinoma (LUAD). Platelet-derived protein thrombospondin-2 (THBS2) has been identified as a tumor marker and is known to be overexpressed in LUAD. However, the specific role of THBS2 in M2 macrophage polarization within LUAD remains unclear. We conducted bioinformatics analyses to assess the clinical significance of THBS2 expression in LUAD, which was subsequently validated using quantitative PCR. We examined the relationship between THBS2 expression and M2 macrophage infiltration. A coculture system of LUAD cells and M0 macrophages was established to investigate the influence of THBS2 on macrophage infiltration and polarization through immunofluorescence and ELISA. We explored the impact of THBS2 on fatty acid metabolism (FAM) using oil red O staining and relevant kits and elucidated the role of THBS2 in regulating M2 macrophage polarization and LUAD proliferation through cell counting kit-8 (CCK-8) and colony formation assays. Western blot was employed to assess expression changes of Bax and Bcl-2. THBS2 was highly expressed in LUAD and was associated with poor prognosis in patients. In-vitro experiments demonstrated that silencing THBS2 significantly inhibited macrophage infiltration and polarization. THBS2 primarily activated FAM pathways, inducing M2 macrophage polarization and promoting LUAD cell proliferation. THBS2 enhanced LUAD proliferation by regulating FAM to induce M2 macrophage polarization. These findings provide a theoretical basis for targeting THBS2 as a novel therapeutic strategy in LUAD.

Objective To explore the mechanism of ubiquitin specific peptidase 21 (USP21) increasing the stability of forkhead box protein M1 (FOXM1) and promoting M2 polarization of macrophages in endometriosis (EM). Methods Eutopic endometrial stromal cells (EESC) collected from patients and normal endometrial stromal cells (NESC) from routine health examiners were cultured in vitro, and the expression levels of USP21 and FOXM1 were detected using RT-qPCR and Western blot. EESCs were co-cultured with macrophages. M1 polarization markers of interleukin 6 (IL-6) and CXC chemokine ligand 10 (CXCL10) and M2 polarization markers of CD206 and fibronectin 1 (FN1) were tested using RT-qPCR. M2 marker CD206 was further detected by flow cytometry. IL-6, tumor necrosis factor-alpha (TNF-α), IL-10, and transforming growth factor-beta (TGF-β) levels in cell supernatant were detected by ELISA. Co-immunoprecipitation was used to assess the interaction between USP21 and FOXM1, and the ubiquitination level of FOXM1. FOXM1 protein stability was detected through cycloheximide (CHX) assay. Results USP21 and FOXM1 expression levels in the EESC group were significantly increased compared with those in the NESC group; compared with the NESC + M0 group, the EESC + M0 group showed no significant difference in the expression of M1 polarization markers (IL-6 and CXCL10), but increased expression of M2 polarization markers (CD206 and FN1), along with notably increased number of M2 macrophages; there was no significant difference in IL-6 and TNF-α levels, but increased levels of IL-10 and TGF-β in the cell supernatant. The above findings indicated that the deubiquitinase USP21 was highly expressed in EM, promoting M2 polarization of macrophages. Knocking down USP21 or FOXM1 can inhibit M2 polarization of EM macrophages. USP21 interacted with FOXM1 in EESC, leading to a decrease in FOXM1 ubiquitination level and an increase in FOXM1 protein stability. Overexpression of FOXM1 reversed the inhibitory effect of knocking down USP21 on M2 polarization of EM macrophages. Conclusion The deubiquitinase USP21 interacts with FOXM1 to increase the stability of FOXM1 and promote M2 polarization of EM macrophages.

BackgroundSphingosine kinase 1 (SphK1) has distinct roles in the activation of Kupffer cells (KCs) and hepatic stellate cells (HSCs) in liver fibrosis. This study aims to examine the role of...

To investigate the regulatory effect of Serpin Family E Member 1 (SERPINE1) on immune microenvironment and paclitaxel (PTX) resistance of triple-negative breast cancer (TNBC) cells. CCK-8 assay was used to determine the half-maximal inhibitory concentration of PTX in TNBC cell line MDA-MB-231. In wild-type MDA-MB-231 cells and a PTX-resistant MDA-MB-231 cell line (MDA-MB-231/PTX) established by stepwise increasing low-dose PTX treatment, the effects of Western blot-verified transfection with SERPINE1 overexpression plasmids or SERPINE1 siRNAs on cell apoptosis were evaluated using Hoechst 33258 staining and by detecting expression levels of cleaved caspase-3 using Western blotting. The changes in proliferation of the transfected cells were assessed using EdU and CCK-8 assays. The breast cancer cells with different treatments were co-cultured with macrophages, and M1 and M2 polarization of the macrophages were analyzed with flow cytometry and Western blotting. In nude mouse models bearing subcutaneous breast cancer cell xenografts, the effects of SERPINE1 overexpression and knockdown in the engrafted cells on tumor growth and PTX resistance were evaluated. SERPINE1 overexpression significantly inhibited apoptosis and promoted proliferation of MDA-MB-231 cells, and SERPINE1 knockdown obviously promoted apoptosis and inhibited proliferation of MDA-MB-231/PTX cells. The macrophages co-cultured with SERPINE1-overexpressing breast cancer cells showed enhanced M2 polarization and suppressed M1 polarization with a lowered M1/M2 ratio. In the tumor-bearing nude mouse models, SERPINE1 overexpression in the engrafted cells resulted in significantly accelerated tumor growth. In MDA-MB-231 cells, SERPINE1 overexpression promotes cell proliferation, inhibits apoptosis, and enhances PTX resistance. SERPINE1 plays a regulatory role in macrophage polarization in the immune microenvironment of breast cancer, and its high expression promotes M2 polarization of the macrophages.

Exosomes are pivotal in triple-negative breast cancer (TNBC) development, and accumulating evidence underscores their potential as therapeutic targets and diagnostic indicators. In this study, we revealed a significant enrichment of the POU domain, class 5, transcription factor 1 (POU5F1) in TNBC cells-derived exosomes. Functionally, silencing endogenous POU5F1 in TNBC cells substantially inhibited their aggressive phenotypes. Moreover, exosomes derived from TNBC cells contributed to macrophage M2 polarization by transferring POU5F1 to the recipient macrophages. Mechanistically, POU5F1 within these exosomes prevented the tumor necrosis factor receptor-associated factor 6 (TRAF6) degradation in macrophages, thereby activating the protein kinase B (AKT) signaling cascade and driving M2 polarization. Furthermore, in vivo experiments provided evidence that POU5F1 knockdown significantly reduced tumor growth and macrophage M2 polarization in a mouse model of TNBC cells by modulating the TRAF6/AKT signaling axis. Our study concludes that POU5F1 in TNBC cells-derived exosomes is vital for promoting macrophage M2 polarization by inhibiting TRAF6 ubiquitination and activating AKT signaling, thereby contributing to TNBC progression.

STAT6 up-regulation amplifies M2 macrophage anti-inflammatory capacity through mesenchymal stem cells

Oculomotor nerve injury impairs eye movement and pupil control. Intraorbital electroacupuncture (IEA) is a promising treatment, but its mechanisms remain unclear. This study investigates whether IEA promotes nerve recovery by inducing M2 macrophage polarization through the JAK1/STAT6 pathway. Sprague-Dawley (SD) rats with oculomotor nerve injury were divided into four groups: sham, control, IEA, and IEA + AS1517499 (JAK1/STAT6 inhibitor). Pupil diameter and abduction deviation were measured. Nerve structure was assessed with Luxol fast blue and Nissl staining. Western blotting analyzed JAK1/STAT6 pathway activation, and immunofluorescence quantified M1/M2 macrophages. The IEA group showed significant functional recovery in the oculomotor nerve, as evidenced by improvements in pupil diameter and abduction deviation compared to the control group. Histological analysis revealed better preservation of nerve structure in the IEA group, with reduced signs of damage. Western blot results demonstrated increased phosphorylation of STAT6 in the IEA group, indicating activation of the JAK1/STAT6 pathway. Immunofluorescence double staining revealed a higher ratio of M2 (CD206+, CD163+) macrophages relative to M1(CD86+ , iNOS+) macrophages in the IEA group. This effect was diminished in the IEA + AS1517499 group, suggesting that the therapeutic benefits of IEA are mediated through the JAK1/STAT6 pathway and M2 macrophage polarization. IEA promotes oculomotor nerve repair by inducing M2 macrophage polarization via the JAK1/STAT6 pathway, offering a potential therapeutic strategy for nerve injury.

Immunotherapy has brought new hope to gastric cancer (GC) patients. Exploring the immune infiltration pattern in GC and the key molecules is critical for optimizing the efficacy of immunotherapy. Aldo-keto reductase family 1 member B10 (AKR1B10) is an inflammatory regulator and is closely related to the prognosis of patients with GC. However, the function of AKR1B10 in GC remains unclear. In the present study, the CIBERSORT algorithm was used to analyze the immune infiltration pattern in 373 samples in the Cancer Genome Atlas (TCGA) database. Differentially expressed genes (DEGs) were seared by combing the TCGA database and the Gene Expression Omnibus (GEO) database, and the key molecule AKR1B10 was identified by weighted gene coexpression network analysis (WGCNA). The biological functions of AKR1B10 in stomach adenocarcinoma (STAD) were investigated in vitro. Macrophage polarization was the main immune infiltration pattern in GC, and the state of macrophage polarization was closely related to the pathological grading of GC and the clinical stage of patients. AKR1B10, MUC5AC, TFF2, GKN1, and PGC were significantly down-regulated in GC tissues. Low AKR1B10 expression induced M2 macrophage polarization and promoted the malignant phenotype of GC. M2 macrophage polarization is the main immune infiltration pattern in GC. Low AKR1B10 expression induces M2 macrophage polarization and promotes the malignant transformation of GC.

The USP8/CEP55/CHMP6 Axis Orchestrates Triple-Negative Breast Cancer Progression by Regulating Ferroptosis and Macrophage M2 Polarization.

Colorectal cancer (CRC) is prone to metastasis, leading to a poor prognosis. miR-411-3p exhibits a tumor-suppressive function in CRC, but its exact mechanism is unclear. The malignant biological properties of CRC cells were detected by Carboxyfluorescein diacetate succinimidyl ester (CFSE) staining, scratch-wound and transwell assay. Levels of markers associated with macrophage polarization were evaluated by flow cytometry and ELISA kits. Bioinformatics analysis to screen whether the downstream target mRNA of miR-411-3p is matrix metalloproteinase 7 (MMP7), and Dual-Luciferase reporter assay verified the targeting relationship between the two. qRT-PCR tested miR-411-3p and MMP7 levels. MMP7 level was quantified by Western blot. Additionally, a nude mouse subcutaneous graft tumor model was constructed, Ki-67 expression was detected by immunohistochemistry, and the impact of miR-411-3p/MMP7 on the polarization of M2 macrophages was explored. miR-411-3p expression is downregulated in CRC. Knockdown of miR-411-3p elevated the amount of CFSE-positive, migrating, and invading cells, decreased apoptosis, and elevated the levels of M2 macrophage polarization markers. After overexpression of miR-411-3p, all of the above metrics were reversed in CRC cells. miR-411-3p targeted negative regulation of MMP7 expression, and MMP7 overexpression further enhanced the promotional effect of knockdown of miR-411-3p on the malignant progression of CRC and M2 macrophage polarization. Furthermore, knockdown of miR-411-3p upregulated the MMP7 level, elevated Ki-67-positive cells count, and induced M2 macrophage polarization in vivo. Knockdown of miR-411-3p upregulates MMP7 and induces M2 macrophage polarization, which in turn promotes malignant biological progression of CRC.

Exosome circ_0076611-mediated macrophage M2 polarization to improve triple-negative breast cancer metastasis and the intervention of baicalin nano prodrugs.

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype and chemotherapy is the cornerstone treatment for TNBC. Regrettably, emerging findings suggest that chemotherapy facilitates pro-metastatic changes in the tumour microenvironment. Extracellular vesicles (EVs) have been highly implicated in cancer drug resistance and metastasis. However, the effects of the EVs released from dying cancer cells on TNBC prognosis and corresponding therapeutic strategies have been poorly investigated. This study demonstrated that paclitaxel chemotherapy elicited CXCL1-enriched EVs from apoptotic TNBC cells (EV-Apo). EV-Apo promoted the chemoresistance and invasion of co-cultured TNBC cells by polarizing M2 macrophages through activating PD-L1 signalling. However, baohuoside I (BHS) remarkably sensitized the co-cultured TNBC cells to paclitaxel chemotherapy via modulating EV-Apo signalling. Mechanistically, BHS remarkably decreased C-X-C motif chemokine ligand 1 (CXCL1) cargo within EV-Apo and therefore attenuated macrophage M2 polarization by suppressing PD-L1 activation. Additionally, BHS decreased EV-Apo release by diminishing the biogenesis of intraluminal vesicles (ILVs) within multivesicular bodies (MVBs) of TNBC cells. Furthermore, BHS bound to the LEU104 residue of flotillin 2 (FLOT2) and interrupted its interaction with RAS oncogene family member 31 (RAB31), leading to the blockage of RAB31-FLOT2 complex-driven ILV biogenesis. Importantly, BHS remarkably chemosensitised paclitaxel to inhibit TNBC metastasis in vivo by suppressing EV-ApoCXCL1-induced PD-L1 activation and M2 polarization of tumour-associated macrophages (TAMs). This pioneering study sheds light on EV-ApoCXCL1 as a novel therapeutic target to chemosensitise TNBC, and presents BHS as a promising chemotherapy adjuvant to improve TNBC chemosensitivity and prognosis by disturbing EV-ApoCXCL1 biogenesis.

tsRNA-10105-enriched migrasomes mediate hepatocellular carcinoma immunosuppressive microenvironment by inducing M2 Macrophage polarization.