Use of glioma to assess the distribution patterns of perfluoroalkyl and polyfluoroalkyl substances in human brain.

Human brain has a complex structure and is able to perform powerful functions. Blood-brain barrier blocks the entry of foreign substances and maintains the homeostasis of the brain. However, some exogenous substances are still able to pass through the blood-brain barrier, with distribution patterns yet to be clarified. Perfluoroalkyl and polyfluoroalkyl substances (PFASs), including perfluoroalkyl carboxylic acids (PFCAs), perfluoroalkyl sulfonic acids (PFSAs), a precursor (perfluorooctane sulfonamide that can be degraded to other substances), and emerging PFASs, were analyzed for the first time in living human brain glioma. The target compounds were detected and quantified in 25 out of 26 glioma samples. The concentration range of ∑PFAS was < RL-51 ng g-1 wet weight (applied to all reported concentrations), with a median of 2.9 ng g-1. The most abundant compound was PFCAs (40%), followed by PFSAs (28%), emerging PFASs (22%), and perfluorooctane sulfonamide (10%). Abundant alternatives PFASs, including short-chain PFCAs, short-chain PFSAs, and emerging PFASs (52% of ∑PFAS), were found in the glioma samples, supporting the notion that low molecular weight exogenous compounds have high permeability to cross the blood-brain barrier and accumulate in brain tissue. Gender difference was not significant (p > 0.05) in the concentrations of PFASs in the glioma samples. Concentrations of PFASs increased with increasing age, from 0.61 ng g-1 (0-14 years old) to 1.6 ng g-1 (>48 years old), with no significant linear correlation with age. The present study suggested that glioma is an effective indicator for monitoring exogenous contaminants in brain tissues.

Residual cancer is a strong predictor of survival in T3 incidental gallbladder cancer.

BACKGROUND AND PURPOSE: Index cholecystectomy is insufficient for curing T3 incidental gallbladder cancer (IGC), and once residual cancer (RC) is found, the prognosis is often poor. The purpose of this study was to investigate the effect of RC on the prognosis and the optimal choice of adjuvant therapy for R0 reresection patients with T3 IGC. METHODS: We retrospectively reviewed data from patients with T3 IGC who underwent radical reresection from January 2013 to December 2018. RC was defined as histologically proven cancer at reresection. Demographics and tumour treatment-related variables were analysed in correlation with RC and survival. Adjuvant (Adj) chemoradiotherapy (CRT) was correlated with overall survival (OS) and disease-free survival (DFS). RESULTS: Of the 167 patients with IGC who underwent surgery, 102 underwent radical extended resection. Thirty-two (31.4%) RCs were found. Hepatic side tumours (T3h) and both side tumours (T3h + T3p) were associated with the presence of RC. In multivariate analysis, RC and lymph node metastasis were independent prognostic factors for DFS and OS (P < 0.05). RC was associated with a significantly shorter median OS (20 vs. 53 months; P < 0.01) and DFS (11 vs. 40 months; P < 0.001) despite R0 resection. For R0 reresection patients with RC and/or lymph node metastasis, Adj CRT significantly improved OS (P = 0.024). CONCLUSION: Residual cancer and lymphatic metastasis are important factors for the poor prognosis of T3 IGC despite R0 resection, and these patients should actively receive adjuvant therapy.

Dimethyl fumarate ameliorates endotoxin-induced acute kidney injury against macrophage oxidative stress.

BACKGROUND: Characterized by macrophage infiltration, renal inflammation during septic acute kidney injury (AKI) reveals a ubiquitous human health problem. Unfortunately, effective therapies with limited side effects are still lacking. This study is aiming to elucidate the role of Dimethyl fumarate (DMF) in macrophages against oxidative stress of septic AKI. METHODS: Balb/c mice were gavaged by 50 mg/kg DMF then injected with 10 mg/kg LPS by i.p. We examined LPS-induced renal dysfunction and histological features in murine kidneys. Raw264.7 macrophage cells were also treated with DMF and then induced by LPS. The mitotracker staining was used to follow mitochondria integrity by confocal microscopy. Flow cytometry measured the production of ROS by DCF-HDA and the expression of iNOS. Western blot detected the expression of Nrf-2 and Sirt1. Co-IP measured the interaction between Sirt1 and Nrf-2. Confocal microscopy observed the colocalization of Sirt1 and Nrf-2 in LPS-treated Raw264.7 macrophage cells. RESULTS: DMF ameliorated murine LPS nephritis with reduced blood urea nitrogen and serum creatinine, as well as decreased the histological alterations compared to the normal control. DMF significantly inhibited the expression of iNOS and reduced the production of nitrite in Raw264.7 cells following LPS treatment. Our study also revealed the role of DMF in protecting against intracellular ROS accumulation and mitochondria dysfunction in LPS-induced nephritis. DMF facilitated colocalization and interaction between Sirt1 and Nrf-2 in LPS-treated cells. CONCLUSIONS: This study showed that DMF alleviated LPS-induced nephritis, indicating protective effects of DMF on macrophage against oxidative stress induced by LPS potentially involving Nrf-2-mediated pathway.

A Mixed-Methods Study to Evaluate Depression and Anxiety Among Undergraduate Nursing Students.

INTRODUCTION: As the backbone of future healthcare delivery, the mental health of undergraduate nursing students can have a direct impact on patients' perceptions of health and the quality of their healthcare learning. However, there has been little qualitative research on the factors influencing the mental health of undergraduate nursing students. AIM: This study investigated the current status and factors influencing depression and anxiety in undergraduate nursing students. METHODS: Questionnaires were administered to third-year nursing students at a medical college university using the Self-Assessment Scale for Anxiety (SAS) and the Self-Depression Scale (SDS). The students who suffered from anxiety or depression were selected for qualitative interviews and the results of the interviews were analysed by using the seven-step Koretz analysis. RESULTS: (1) SAS and SDS scores of undergraduate nursing students were higher than the national average. (2) The qualitative interviews revealed that five themes, including childhood experience, body image, interpersonal relationships, professional identity and career planning, influenced mental health. DISCUSSION: Undergraduate nursing students exhibited a high prevalence of anxiety and depression. The colleges should establish a proactive educational model centred on teaching quality, professional identity, career planning and mental health. IMPLICATION FOR PRACTICE: This study found that the mental health of undergraduate nursing students was influenced by a variety of factors, which require diverse and constant interventions. School, family and social resources should collaborate to develop a systematic approach for better mental health education in undergraduate nursing students.

Virtual screening and network pharmacology-based synergistic coagulation mechanism identification of multiple components contained in compound Kushen Injection against hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is a primary liver malignancy commonly encountered in the setting of chronic liver disease and cirrhosis. Compound Kushen Injection (CKI) has been widely used in HCC, however, the underlying mechanisms are scarce. OBJECTIVE: To explore the molecular mechanisms of CKI for HCC.To explore the molecular mechanisms of CKI for HCC. MATERIALS AND METHODS: The chemical ingredients of CKI were reviewed from published articles and the potential targets were got from Herbal Ingredients' Targets Platform. Coagulation-related targets were from Kyoto Encyclopedia of Genes and Genomes and HCC-related targets were from Therapeutic Target Database, Gene Expression Omnibus, and The Cancer Genome Atlas. Then the CKI-Herb-Target and CKI-Herb-Target-HCC networks were built. The shared targets between CKI and HCC were used for functional enrichment through Metascape and the shared coagulation-related target was used for molecular docking and survival analysis. RESULTS: A total of 23 chemical ingredients and 41 potential targets shared between CKI and HCC were obtained. The results of functional enrichment indicated that several canonical pathways of CKI mostly participated in the treatment of HCC. Furthermore, a chemical ingredient of CKI formed a stable hydrogen bond link with the ASN-189 on PLG, with a best binding energy of -4.7 kcal/mol. Finally, PLG was confirmed as the shared coagulation-related target and interrelated with the prognosis of HCC. CONCLUSION: CKI probably improves HCC prognosis through PLG. Our research undoubtedly deepened the understanding of the molecular mechanism of CKI anti-HCC.

The Correlation of Centromere Protein Q with Diagnosis and Prognosis in Hepatocellular Carcinoma.

Introduction: Hepatocellular carcinoma (HCC) is one of the major types of liver cancer. Previous studies have shown that the centromere protein family is associated with malignant biological behaviors such as HCC proliferation. As a member of the centromere protein family, centromere protein Q (CENPQ) is closely associated with immunotherapy and immune cell infiltration in various tumors. However, the role and mechanism of CENPQ in HCC remain unclear. Methods: Multiple public databases and RT-qPCR were used to study the expression of CENPQ in HCC. Based on TCGA data, the correlation between CENPQ and clinicopathological characteristics and prognosis of HCC patients was analyzed, and its diagnostic value was evaluated. The potential biological functions of CENPQ in HCC were explored by functional enrichment analysis of differentially expressed genes. The distribution of tumor-infiltrating immune cell types was assessed using single-sample GSEA, and immune checkpoint gene expression was analyzed using Spearman correlation. Subsequently, loss-of-function experiments were performed to determine the function of CENPQ on the cell cycle and proliferation of HCC cells in vitro. Results: CENPQ was found highly expressed in HCC and correlated with weight, BMI, age, AFP, T stage, pathologic stage, histologic grade, and prothrombin time (all p < 0.05). ROC and Kaplan-Meier analyses indicated that CENPQ may be potentially used as a diagnostic marker for HCC (AUC = 0.881), and its upregulation is associated with decreased OS (p = 0.002), DSS (p < 0.001), and PFI (p = 0.002). Functional enrichment analysis revealed an association of CENPQ with biological processes such as immune cell infiltration, cell cycle, and hippo-merlin signaling deregulation in HCC. Furthermore, knockdown of CENPQ manifested in HCC cells with G0/1 phase cycle arrest and decreased proliferative capacity. Conclusion: CENPQ expression was higher in HCC tissues than in normal liver tissues. It was significantly associated with poor prognosis, immune cell infiltration, cell cycle, and proliferation. Therefore, CENPQ may become a promising prognostic biomarker for HCC patients.

Calcite carbonate sinks low-density plastic debris in open oceans.

The vertical settling of plastic debris in oceans is poorly understood. A large share of low-density microplastics (LDMPs) are largely absent from sea surfaces. The present study employs a model that considers the potential of an overlooked microbially induced calcium carbonate precipitation (MICP) process and new motion equations for irregular LDMPs. Here we show that the motion of LDMPs in the present model, exhibiting a damped oscillation pattern, is quite different from that in biofouling models. Furthermore, LDMPs in the size range of 10-200 µm are most likely to gain sufficient density at the biofouling/MICP stage to independently sink to the ocean floor with relatively small drag coefficients, potentially explaining the selective enrichment of LDMPs in the oceanic sediment. The size and shape exhibit strong non-linear effects on the settling patterns of LDMPs. Overall, the present study highlights the importance of calcite-mediated sinking of LDMPs in open oceans.

CENPL accelerates cell proliferation, cell cycle, apoptosis, and glycolysis via the MEK1/2-ERK1/2 pathway in hepatocellular carcinoma.

Centromere protein L (CENPL) is involved in the mitotic process of eukaryotic cells and the development of various types of cancer. However, its role in hepatocellular carcinoma (HCC) remains unclear. This study aimed to investigate the expression and clinical significance of CENPL in HCC, and explore its involvement in regulating HCC cell proliferation, apoptosis, cell cycle, and glycolysis both in vivo and in vitro. CENPL expression was analyzed in HCC and normal liver tissues using The Cancer Genome Atlas, Gene Expression Omnibus mining, real-time quantitative polymerase chain reaction, and immunohistochemistry. Functional assays were used to assess the role of CENPL in HCC cell proliferation, apoptosis, cell cycle, and glycolysis. The potential pathways underlying the regulatory effects of CENPL, as well as the expression of mitogen-activated protein kinase (MAPK) signaling pathway-related molecules and markers of proliferation and glycolysis were investigated. CENPL was significantly upregulated in HCC tissue and associated with multiple clinicopathological features and poor patient prognosis. Univariate and multivariate analyses demonstrated that CENPL may serve as an independent prognostic factor for HCC. Upregulation of CENPL in HCC regulated tumor proliferation and glycolytic processes. Mechanistic studies revealed that differentially expressed genes between the CENPL-overexpressing and control groups were mainly concentrated in the MAPK signaling pathway. Pathway inhibition analysis indicated that CENPL activated the MEK1/2-ERK1/2 signaling pathway to promote proliferation and glycolysis in HCC cells. This study elucidated the role of CENPL in regulating cell proliferation, apoptosis, cell cycle, and glycolysis in HCC. CENPL may represent a therapeutic target and prognostic biomarker for HCC.

Establishment and validation of a predictive nomogram for severe pleural effusion in liver cancer patients after hepatectomy.

This study aims to develop and validate a predictive nomogram for severe postoperative pleural effusion (SPOPE) in patients undergoing hepatectomy for liver cancer. A total of 536 liver cancer patients who underwent hepatectomy at the Department of Hepatobiliary Surgery I of the Affiliated Hospital of North Sichuan Medical College from January 1, 2018, to December 31, 2022, were enrolled in a retrospective observational study and comprised the training dataset. Lasso regression and logistic regression analyses were employed to construct a predictive nomogram. The nomogram was internally validated using Bootstrapping and externally validated with a dataset of 203 patients who underwent liver cancer resection at the Department of General Surgery III of the same hospital from January 1, 2020, to December 31, 2022. We evaluated the nomogram using the receiver operating characteristic curve, calibration curve, and decision curve analysis. Variables such as drinking history, postoperative serum albumin, postoperative total bilirubin, right hepatectomy, diaphragm incision, and intraoperative blood loss were observed to be associated with SPOPE. These factors were integrated into our nomogram. The C-index of the nomogram was 0.736 (95% CI: 0.692-0.781) in the training set and 0.916 (95% CI: 0.872-0.961) in the validation set. The nomogram was then evaluated using sensitivity, specificity, positive predictive value, negative predictive value, calibration curve, and decision curve analysis. The nomogram demonstrates good discriminative ability, calibration, and clinical utility.

Per- and polyfluoroalkyl substances (PFAS) exposure in plasma and their blood-brain barrier transmission efficiency-A pilot study.

Per- and polyfluoroalkyl substances (PFAS) have been shown to penetrate the blood-brain barrier (BBB) and accumulate in human brain. The BBB transmission and accumulation efficiency of PFAS, as well as the potential health risks from human co-exposure to legacy and emerging PFAS due to differences in transport efficiency, need to be further elucidated. In the present pilot study, 23 plasma samples from glioma patients were analyzed for 17 PFAS. The concentrations of PFAS in six paired brain tissue and plasma samples were used to calculate the BBB transmission efficiency of PFAS (RPFAS). This RPFAS analysis was conducted with utmost care and consideration amid the limited availability of valuable paired samples. The results indicated that low molecular weight PFAS, including short-chain and emerging PFAS, may have a greater potential for accumulation in brain tissue than long-chain PFAS. As an alternative to perfluorooctane sulfonic acid (PFOS), 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA) exhibited brain accumulation potential similar to that of PFOS, suggesting it may not be a suitable substitute concerning health risk in brain. The BBB transmission efficiencies of perfluorooctanoic acid, PFOS, and 6:2 Cl-PFESA showed similar trends with age, which may be an important factor influencing the entry of exogenous compounds into the brain. A favorable link between perfluorooctane sulfonamide (FOSA) and the development and/or progression of glioma may be implicated by a strong positive correlation (r2 = 0.94; p < 0.01) between RFOSA and Ki-67 (a molecular marker of glioma). However, a causal relationship between RFOSA and glioma incidence were not established in the present study. The present pilot study conducted the first examination of BBB transmission efficiency of PFAS from plasma to brain tissue and highlighted the importance of reducing and/or controlling exposure to PFAS.

Insufficient evidence to link human exposure to heavy metals with biomarkers of glioma.

Information on molecular mechanisms has implicated potential association between the concentrations of heavy metals and incidences of glioma, but experimental data on human brain tissue remain sparse. To address this data gap, 13 heavy metals were measured in 137 glioma and 35 non-glioma samples collected from 161 alive patients in Guangdong Province, China in 2019 - 2020. All target heavy metals were detected, suggesting they could cross the blood-brain barrier. Concentrations of Mn, Cu, and Zn were higher in glioma than in non-glioma samples, while those of Ni and Se were higher in non-glioma samples, probably suggesting that these five heavy metals are more prone to be altered by changing pathological conditions. In addition, Cu/Zn, Cr/Mn, Cr/Se, Ni/Se, Pb/Mn, and Pb/Se were statistically different between glioma and non-glioma samples by a difference test and a multiple logistic regression model. These concentration ratios may serve as chemical markers to assist pathological analysis for differentiating between tumor and healthy tissues. However, no direct link between heavy metal concentrations or concentration ratios and biomarkers of glioma (i.e., tumor grade, P53, and Ki-67) was observed. No sufficient evidence was obtained to implicate the role of heavy metals in inducing glioma, largely caused by the limited number of samples. Different concentrations and concentration ratios of heavy metals may be the consequence rather than the cause of pathological changes in brain tumors.

Glioma is associated with exposure to legacy and alternative per- and polyfluoroalkyl substances.

Data on the occurrences of legacy and alternative per- and polyfluoroalkyl substances (PFASs) in glioma are scarce. It remains unclear if PFASs exposure is related to the prevalence of glioma. A total of 137 glioma and 40 non-glioma brain tissue samples from patients recruited from the Nanfang Hospital, South China were analyzed for 17 PFAS compounds. Perfluorohexanoic acid, perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorooctane sulfonamide (FOSA), and 6:2 chlorinated polyfluorinated ether sulfonate were frequently detected (> 60 %) in glioma. The total concentrations (range; median) of 17 PFASs in glioma (0.20-140; 3.1 ng g-1) were slightly higher than those in non-glioma (0.35-32; 2.2 ng g-1), but without statistical significance. The PFAS concentrations in males were statistically higher (p < 0.05) than those in females. Elevated glioma grades were associated with higher concentrations of PFOA, PFOS, and FOSA. Positive correlations were observed between PFAS concentrations (especially for PFOA) and Ki-67 or P53 expression, pathological molecular markers of glioma. Our findings suggested that exposure to PFASs might increase the probability to develop glioma. This is the first case study demonstrating associations between PFASs exposure and brain cancer. More evidences and potential pathogenic mechanisms warranted further investigations.

Biobased plastic: A plausible solution toward carbon neutrality in plastic industry?

Biobased plastic exhibits unique benefits for achieving carbon neutrality, a key step toward reducing atmospheric greenhouse gases, due to its stability, high carbon content, and origin of carbon by photosynthesis. Herein we evaluate the role and potential of biobased plastic as an alternative carbon reservoir which is completely artificial, since most plastic polymers are synthetic and massively produced after the 1950 s. Model simulation indicates that plastic, under usage, burial, and littering, forms a growing carbon reservoir, sinking 6.82 gigatons of carbon (GtC) in 2020. Plastic-formed carbon is estimated to stack up to 19.4-23.2 GtC in 2060 under various production scenarios. However, only 18-40% of carbon stored in plastic is biobased carbon, equivalent to approximately 31-48 gigatons of carbon dioxide. Without any low carbon energy upgrade, carbon neutrality is difficult to achieve even with 90% biobased plastic substitution and 50% recycling ratio. Because extra GHG emissions are generated as a result of increasingly using incineration as a post-treatment strategy in response to increasing waste generation, the annual net GHG emission continues to rebound after the bio-based plastic substitution and plastic recycling approach their upper limits. Additional strategies are therefore needed to achieve complete carbon neutrality.

CENPO is Associated with Immune Cell Infiltration and is a Potential Diagnostic and Prognostic Marker for Hepatocellular Carcinoma.

Purpose: To examine the expression, clinical significance, and potential regulatory mechanism of centromere protein O (CENPO) in hepatocellular carcinoma (HCC). Methods: CENPO expression in pan-cancer was studied using the TCGA-GTEx database, in HCC and normal liver tissues using the GEO and TCGA databases, and in clinical HCC samples by RT-qPCR. The diagnostic value of CENPO was assessed using receiver operating characteristic curves. Univariate and multivariate regression analyses of factors associated with HCC prognosis were performed. CENPO function and its mechanism in HCC were explored using GO, KEGG, and GSEA analyses of differentially expressed genes (DEGs). Association of CENPO expression with immune cell infiltration and immune checkpoint-associated molecules was conducted using TCGA data and the TIMER2.0 database. Relationships between CENPO expression and DNA methylation were analyzed using the UALCAN and cBioPortal databases. CENPO expression in HCC cell lines was detected using RT-qPCR. Results: CENPO is upregulated in most cancers, including HCC and cell lines, and is a potential biomarker for HCC diagnosis (AUC = 0.936, 95% CI: 0.911-0.960). Higher CENPO expression was associated with poorer outcomes in patients with HCC (OS, p = 0.004; DSS, p = 0.002; PFI, p < 0.001), and CENPO was an independent predictor of factors influencing overall survival in HCC. DEGs between samples with high and low CENPO levels were enriched in various biological processes, including activation of the G2M checkpoint and other signaling pathways, while CENPO expression correlated with HCC immune cell infiltration and immune checkpoint-associated molecules, as well as CENPO promoter methylation (p < 0.001). Conclusion: In HCC and cell lines, CENPO is overexpressed, a potential diagnostic marker and an indicator of poor prognosis. CENPO may regulate HCC development by influencing nuclear division and tumor immune infiltration and is regulated by methylation, making it a potential target for HCC immunotherapy.

Increasing temperature can modify the effect of straw mulching on soil C fractions, soil respiration, and microbial community composition.

Straw mulching has been widely adopted in dryland cropping but its effect on soil respiration and microbial communities under warming are not well understood. Soil samples were collected from a corn field with straw mulching (SM) for nine years and without straw mulching (CK), and incubated at 15°C, 25°C, and 35°C for 60 days. Soil respiration, C fractions and bacterial and fungal community structure were measured SM had greater soil organic carbon and potential C mineralization and a similar microbial biomass carbon throughout the incubation when compared with CK. Soil respiration increased with increasing temperature and its temperature sensitivity (Q10) was lower with SM than CK. Similar microbial community composition was found in the soils with SM and CK before incubation. However, SM had a greater bacterial richness and the relative abundances of Proteobacteria, Acidobacteria, Nitrospirae, Planctomycetes, Bacteroidetes, and Basidiomycota, but lower relative abundances of Actinobacteria, Chloroflexi, and Ascomycota than CK after incubation. Bacterial richness and diversity were greater at 15°C and 25°C than 35°C, but there was no difference in fungal richness and diversity among the incubation temperatures. As temperature increased, the relative abundances of Chloroflexi, Acidobacteria, and Bacteroidetes decreased, but Gemmatimonadetes and Ascomycota increased, and were significantly correlated with soil C fractions and respiration. These findings indicated that the effect of straw mulching on soil C cycling and microbial community structure can be highly modified by increasing temperature.

[Responses of soil respiration to temperature under different mulching modes in a dryland corn field]. / 不同覆盖方式下旱作玉米田土壤呼吸对温度变化的响应.

Based on a 9-year field experiment, soil samples under straw mulching (SM), plastic film mulching (FM) and no mulching (CK) were incubated at 15, 25 and 35 ℃ for 60 d to investigate the responses of soil respiration to warming and its temperature sensitivity. The results showed that during the whole incubation period, soil respiration rate exhibited a unimodal distribution, while the cumulative soil respiration increased with an "S" curve. The cumulative soil respiration during the first 30 d accounted for about 75%-85% of total during the whole incubation period. The cumulative SM increased by 19.4% compared with CK, whereas no difference was detected between CK and FM. At 25 ℃ and 35 ℃, the mean soil respiration rate increased by 17.0% and 36.8%, and the cumulative CO2 release of soil respiration increased by 13.1% and 33.6%, respectively, compared with 15 ℃. No interaction was detected between mulching method and temperature. 97.7%-99.9% of variation in soil respiration could be explained by temperature change, with soil respiration being positively correlated with organic carbon and total nitrogen content. Compared with no mulching and plastic film mulching, straw mulching could significantly promote soil respiration by increasing the input of organic matter in the soil, but reduced the temperature sensitivity of soil respiration. Straw mulching rather than plastic film mulching would be more efficient at reducing CO2 emission in the Loess Plateau dryland farming area under the context of global warming.

Extracellular ubiquitin promotes hepatoma metastasis by mediating M2 macrophage polarization via the activation of the CXCR4/ERK signaling pathway.

BACKGROUND: Stored red blood cell (RBC) transfusion has been shown to enhance the risk of cancer recurrence. However, the underlying mechanism remains unknown. At our lab, we have demonstrated that the extracellular ubiquitin (eUb) released by aged RBCs could promote tumor metastasis in a melanoma mouse model. This study aimed to confirm the pro-tumor effect of eUb on hepatocellular carcinoma (HCC) and explore the related immunoregulatory mechanisms. METHODS: Forty HCC tissue specimens and the corresponding adjacent nontumor and normal liver tissues were collected. Two human hepatoma cell lines (MHCC-97H and HepG2.2.15), one murine hepatoma cell line (Hepa1-6), and one human monocyte cell line (THP-1) were adopted in this study. The coculture of hepatoma cells with macrophages was initiated with Transwell inserts. Cell migration in vitro was detected by Transwell and wound-healing assays, while in vivo tumor metastasis was measured by luciferase assay and H&E staining. Macrophage polarization was measured by flow cytometry, immunofluorescence, ELISA, qPCR, and Western blot. Protein expression was detected by Western blot, and immunoprecipitation was used to confirm the interaction between Ub and CXCR4 (CXC chemokine receptor type 4). RESULTS: Ub and CXCR4 were significantly upregulated in HCC tissues, and a positive correlation existed between them. In vitro, the migration of hepatoma cells was not affected by eUb directly, but their metastatic abilities were enhanced after coculture with the macrophages pretreated with eUb. Meanwhile, eUb promoted hepatoma cell metastasis in the lung in vivo and increased the ratio of M2 macrophages in the lung tissues and peripheral blood of tumor-bearing mice. Furthermore, the eUb-induced M2 macrophage polarization was related to the activation of the CXCR4/ERK (extracellular regulated protein kinase) signaling pathway. CONCLUSIONS: Extracellular ubiquitin promoted hepatoma metastasis through M2 macrophage polarization via the activation of the CXCR4/ERK signaling pathway, indicating that a personalized transfusion strategy is needed for the treatment of HCC patients. Neutralizing Ub in stored RBC units could lessen the detrimental clinical outcomes induced by the transfusion of stored RBCs.