Saikosaponin a promotes neutrophil extracellular trap formation and bactericidal activity

This study aimed to investigate the effects of SSa, one of the major triterpenoid saponins extracted from Radix bupleuri, on neutrophil extracellular trap (NET) formation and the mechanism associated with this process. Using Sytox green and immunofluorescence assays, we found SSa rapidly induced NET formation, which depended on NADPH oxidase (NOX)-independent ROS production and autophagy. Pharmacologic inhibitor studies indicated that ERK and PI3K/AKT signalling were also required for SSa-induced NET formation, whereas protein arginine deiminase 4 (PAD4) was not required. Furthermore, we found that SSa promoted neutrophil bactericidal activity mainly through NET formation. Based on flow cytometry and the Cell Counting Kit-8 (CCK-8) assays, the results demonstrated that SSa-induced NET formation occurred without neutrophil death. Taken together, these findings indicated that SSa could be a potential natural product to boost innate immune defense against pathogen attack via NET formation.

CD44 is a potential immunotherapeutic target and affects macrophage infiltration leading to poor prognosis

CD44 plays a key role in the communication of CSCs with the microenvironment and the regulation of stem cell properties. UALCAN was used to analyze the expression of CD44 in bladder cancer (BLCA) and normal tissue. The UALCAN was utilized to analyze the prognostic value of CD44 in BLCA. The TIMER database was used to explore the relationship between CD44 and PD-L1; CD44 and tumor-infiltrating immune cells. The regulatory effect of CD44 on PD-L1 was verified by cell experiments in vitro. IHC confirmed the results of the bioinformatics analysis. GeneMania and Metascape were used to analyze protein-protein interaction (PPI) investigations and functional enrichment analysis. We found that BLCA patients with high CD44 expression had worse survival than those with low CD44 expression (P < 0.05). IHC and the TIMER database results showed that CD44 expression was positively correlated with PD-L1 expression (P < 0.05). At the cellular level, the expression of PD-L1 was significantly inhibited after CD44 expression was inhibited by siRNA. Immune infiltration analysis showed that CD44 expression levels in BLCA were significantly correlated with immune infiltration levels of different immune cells. IHC staining results further confirmed that the expression of CD44 in tumor cells was positively associated with the number of CD68⁺ macrophages and CD163⁺ macrophages (P < 0.05). Our results suggest that CD44 is a positive regulator of PD-L1 in BLCA and may be a key regulator of tumor macrophages infiltration and may be involved in M2 macrophage polarization. Our study provided new insights into the prognosis and immunotherapy of BLCA patients through macrophage infiltration and immune checkpoints.

Targeting PYCR2 inhibits intraperitoneal metastatic tumors of mouse colorectal cancer in a proline-independent approach

Whether proline deficiency is a metabolic vulnerability in colorectal tumors is unknown. The aim of this study was to investigate the effects of proline metabolism-related genes and exogenous proline on the progression of colorectal cancer (CRC). We aimed to further clarify the role of pyrroline-5-carboxylate reductase (PYCR) 2, a key enzyme of proline synthesis, in the regulation of colorectal intraperitoneal metastatic tumors. This study was carried out based on The Cancer Genome Atlas (TCGA) data, database analysis, single-cell functional analysis, tissue microarray, cell experiments, and animal models. We found that, PYCR2 mRNA and protein levels were upregulated in CRC. The mRNA level of PYCR2 was closely related to the prognosis and tumor metastasis of CRC patients. The upregulated PYCR2 expression was at least partly due to low promoter methylation levels. The nomogram constructed based on PYCR2 expression and clinical characteristics of CRC showed good accuracy in predicting lymph node metastasis. Pycr2 knockdown inhibited epithelial-mesenchymal transition (EMT) of mouse CRC cells. Proline supplementation did not rescue the inhibition of mouse CRC cell proliferation and migration by Pycr2 knockdown. Proline supplementation also did not rescue the suppression of subcutaneous tumors and intraperitoneal metastatic tumors in mice by Pycr2 knockdown. PYCR2 co-expressed genes in TCGA-CRC were enriched in epigenetic modification-related biological processes and molecular functions. Four small molecules with the lowest binding energy to the PYCR2 protein were identified. Collectively, Pycr2 knockdown inhibited mouse CRC progression in a proline-independent approach. PYCR2 may be a promising tumor metastasis predictor and therapeutic target in CRC.

A novel nomogram for adult primary perihilar cholangiocarcinoma and considerations concerning lymph node dissection

Objective

To construct a reliable nomogram available online to predict the postoperative survival of patients with perihilar cholangiocarcinoma.

Methods

Data from 1808 patients diagnosed with perihilar cholangiocarcinoma between 2004 and 2015 were extracted from the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) database. They were randomly divided into training and validation sets. The nomogram was established by machine learning and Cox model. The discriminant ability and prediction accuracy of the nomogram were evaluated by concordance index (C-index), receiver operator characteristic (ROC) curve and calibration curve. Kaplan-Meier curves show the prognostic value of the associated risk factors and classification system.

Results

Machine learning and multivariate Cox risk regression model showed that sex, age, tumor differentiation, primary tumor stage(T), lymph node metastasis(N), TNM stage, surgery, radiation, chemotherapy, lymph node dissection were associated with the prognosis of perihilar cholangiocarcinoma patients relevant factors (P < 0.05). A novel nomogram was established. The calibration plots, C-index and ROC curve for predictions of the 1-, 3-, and 5-year OS were in excellent agreement. In patients with stage T1 and N0 perihilar cholangiocarcinoma, the prognosis of ≥4 lymph nodes dissected was better than that of 1- 3 lymph nodes dissected (P < 0.01).

Conclusion

The nomogram prognostic prediction model can provide a reference for evaluating the prognosis and survival rate of patients with perihilar cholangiocarcinoma. Patients with stage T1 and N0 perihilar cholangiocarcinoma have more benefits by increasing the number of lymph node dissection.

The antitumor activity of hPRDX5 against pancreatic cancer and the possible mechanisms

Recombinant human peroxiredoxin-5 (hPRDX5), isolated from anti-cancer bioactive peptide (ACBPs), shows a homology of 89% with goat peroxiredoxin-5 (gPRDX5) and is reported to display anti-tumor activity in vivo. Herein, we explored the effect of hPRDX5 and the responsible mechanism in treating pancreatic cancer. Tumor-bearing mice were randomly divided into normal PBS group and treatment group (n=5; 10 mg/kg hPRDX5). Flow cytometry was employed to examine lymphocytes, myeloid-derived suppressor cell subsets, and the function proteins of natural killer (NK) cells in peripheral blood, spleen, and tumor tissues of mice. Western blot was used to measure the protein expressions of the key nodes in TLR4-MAPK-NF-κB signaling pathway. The rate of tumor suppression was 57.6% at a 10 mg/kg dose in orthotopic transplanted tumor mice. Moreover, the population of CD3+CD4+T cells, NK cells, and CD3+CD8+T cells was significantly increased in the tumor tissue of the hPRDX5 group, while the proportion of granulocytic-myeloid-derived suppressor cells decreased slightly. In addition, after treatment with hPRDX5, the percentage of NK cells in blood increased more than 4-fold. Our findings indicated that hPRDX5 effectively suppressed pancreatic cancer possibly via the TLR4-MAPK-NF-κB signaling cascade; hence hPRDX5 could be a prospective immunotherapy candidate for treating pancreatic cancer.

3,4-dihydroxyphenylethyl alcohol glycoside reduces acetaminophen-induced acute liver failure in mice by inhibiting hepatocyte ferroptosis and pyroptosis

APAP is one of the most commonly used antipyretic and pain medications, but excessive use can cause liver toxicity and damage. 3,4-dihydroxyphenylethyl alcohol glycoside (DAG) is a component isolated from Sargentodoxa cuneata known to have anti-apoptotic, anti-oxidation and anti-inflammatory effects. However, the effects of DAG on acute liver failure (ALF) are largely unknown. The purpose of this study is to study the protective effects and mechanism of DAG on APAP-induced ALF in mice. We established an ALF model in adult male pathogen-free C57BL/6 mice treated with APAP (300 mg/kg) by intraperitoneal injection and resolved by 24 h. Hematoxylin and eosin (HE) staining was used to evaluate the pathological changes in mouse liver tissue. The infiltration of neutrophils in liver tissue and reactive oxygen species (ROS) in AML12 cells were analyzed by flow cytometry. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), glutathione (GSH), malondialdehyde (MDA), catalase (CAT), and superoxide dismutase (SOD) were analyzed using relevant kits. Our results show that DAG reduced APAP-induced serum ALT and AST levels, histopathological changes, liver neutrophil infiltration and proinflammatory cytokines production, also attenuated the accumulation of MDA and the exhaustion of GSH, CAT and SOD. In vitro experiment indicated that DAG dose-dependently inhibited APAP-induced the levels of pro-inflammatory factors (IL-1β and IL18), and reactive oxygen species (ROS) and preventing GSH depletion in mouse AML12 hepatocytes. More interestingly, DAG inhibited the expression of ERK, HO-1, NLRP3, Caspase1 (p20) and Gasdermin-D and upregulated the expression of GPX4 in liver tissues and AML12hepatocytes. Therefore, our results indicate that DAG may act as a potential agent to treat ALF induced by APAP by inhibiting hepatocyte ferroptosis and pyroptosis.

[Effect of Xuanfu Daizhe decoction on stemness of esophageal cancer cells]

Objective: To investigate the effect of Xuanfu Daizhe decoction on the stemness of esophageal cancer cells. Methods: The BALB/c nude mice were randomly divided into the control group and experimental group, 5 mice in each group, which were continuously administered with normal saline and Xuanfu Daizhe decoction (9.89 g/kg) by gastrogavage, respectively. Human esophageal carcinoma cells ECA-109 (5×10⁶) were subcutaneously injected into the mice on the 8th day. Tumor volume was measured twice a week. The mice were sacrificed 4 weeks after injection, and the tumor tissue and mouse serum were collected. The expressions of the major stemness-regulating transcription factors, i.e., NANOG, OCT4 and SOX2, were detected by RT-qPCR, Western Blot and immunohistochemistry. ECA-109 cells were treated with 10% fetal bovine serum and serum from the above two groups of mice for 48 hours respectively, and three replicate wells were set in each group, and the expressions of NANOG, OCT4, SOX2 and the levels of AKT and p-AKT were detected by RT-qPCR and Western Blot, respectively. ALDH activity in tumor cells was detected by flow cytometry; the number of spheroids of tumor cells was detected by the spheroidization experiment. Results: Compared with the control group, the growth and size of esophageal cancer tumors were significantly inhibited by Xuanfu Daizhe Decoction; the expressions of NANOG, OCT4, SOX2, the ALDH activity, the number of spheroids, and the levels of AKT and phosphorylated AKT (p-AKT) in esophageal cancer cells were significantly reduced by Xuanfu Daizhe Decoction both in vivo and in vitro. Conclusion: Xuanfu Daizhe Decoction inhibits the stemness of esophageal cancer cells, it may be a potentially effective drug for the treatment of esophageal cancer and provides a theoretical basis for the exploration of new effective drugs for the treatment of esophageal cancer.

Hydroxytyrosol Inhibits MDSCs and Promotes M1 Macrophages in Mice With Orthotopic Pancreatic Tumor

The poor immunotherapy of pancreatic cancer is mainly due to its complex immunosuppressive microenvironment. The Mediterranean diet contributes to low cancer incidence. Hydroxytyrosol (HT) derived from olive oil has multiple health-promoting effects, but its therapeutic effect on pancreatic cancer remains controversial. Here, we evaluated the inhibitory effect of HT on mouse pancreatic cancer, and the effect of HT on the immune microenvironment. We found that HT can inhibit the proliferation of Panc 02 cells through signal transducer and activator of transcription (STAT) 3/Cyclin D1 signaling pathway. In the tumor-bearing mice treated with HT, the orthotopic pancreatic tumors were suppressed, accompanied by a decrease in the proportion of myeloid-derived suppressor cells (MDSCs) and an increase in the proportion of M1 macrophages. In addition, we found that HT inhibited the expression of immunosuppressive molecules in bone marrow (BM)-derived MDSCs, as well as down-regulated CCAAT/enhancer-binding protein beta (C/EBPβ) and phosphorylation of STAT3. Moreover, HT enhanced the anti-tumor effect of anti-CD47 antibody in vivo. HT combined with plumbagin (PLB) induced more Panc 02 cells death than HT or PLB alone. This combination therapy not only inhibited the accumulation of MDSCs, but also promoted the infiltration of CD4⁺ and CD8⁺ T cells in the tumors. In summary, HT is a potential immunomodulatory drug for the treatment of pancreatic cancer.

FTY720 induces neutrophil extracellular traps via a NADPH oxidase-independent pathway

FTY720 is an immunosuppressive agent which has been approved to treat multiple sclerosis (MS). The main object of the present study is to investigate whether FTY720 has the potential to induce the formation of neutrophil extracellular traps (NETs) in vitro. Using Sytox Green assay and fluorescence microscopy, our results showed that FTY720 trigged the NET formation. In contrast to classic NET formation induced by Phorbol 12-myristate 13-acetate (PMA), FTY720-induced NETs were detected earlier and independent of NADPH oxidase (NOX) activity. Pharmacological inhibitor experiments indicated that autophagy was also required for the NET formation induced by FTY720. Moreover, p38 and AKT inhibitor significantly suppressed the NET formation by FTY720, whereas ERK inhibitor had no effect, suggesting that FTY720-induced NETs depended on the activation of p38 and AKT. We further found that citrullination of histone H3 and peptidylarginine deiminase 4 (PAD4) did not mediated FTY720-induced NET formation. Interestingly, necroptosis signaling activation was involved in the vital NET formation by FTY720, however, plasma membrane rupture resulting from necroptosis was not a major component of NET formation described here. Collectively, these findings indicated that FTY720 could be a potential antibacterial drug to protect host against pathogen infection.

miR-3065-3p promotes stemness and metastasis by targeting CRLF1 in colorectal cancer

BACKGROUND

Colorectal cancer is one of the most common malignancy in the world. It has been reported that cancer stem cells (CSCs) serve as the primary drivers of tumorigenesis and tumor progression. There is an urgent need to explore novel molecules that regulate CSCs or their signatures. Increasing evidence has shown that miRNAs are involved in tumorigenesis and progression. Here, we aim to explore the regulatory effect and mechanism of miR-3065-3p on the stemness of colorectal cancer.

METHODS

The expression of miR-3065-3p in colorectal cancer and the association of miR-3065-3p expression with prognosis of patients with colorectal cancer were analyzed using TCGA dataset or clinical cases. Gain or loss of function in different models, including colorectal cancer cell lines and orthotopic xenograft or liver metastatic mouse model, were used to investigate the effects of miR-3065-3p on colorectal cancer stemness and metastasis in vitro and in vivo. Cancer stemness was analyzed by detecting the ability of migration and invasion, NANOG, OCT4, and SOX2 expression, ALDH activity and sphere formation. In addition, the interaction of miR-3065-3p and cytokine receptor-like factor 1 (CRLF1) was analyzed theoretically and identified by the luciferase reporter assay. Moreover, the correlation between CRLF1 expression and miR-3065-3p was analyzed in colorectal cancer tissues. Finally, the effect of CRLF1 on the stemness and metastasis of colorectal cancer in vitro and in vivo was assessed.

RESULTS

In this report, we found that miR-3065-3p was overexpressed in colorectal cancer and that its high expression was associated with poor prognosis of patients with colorectal cancer. miR-3065-3p promotes the stemness and metastasis of colorectal cancer. Furthermore, CRLF1 was the downstream target of miR-3065-3p and inhibited the stemness of colorectal cancer. In addition, CRLF1 expression was negatively correlated with miR-3065-3p in colorectal cancer tissues. And, CRLF1 mediated the effects of miR-3065-3p on promoting stemness of colorectal cancer cells.

CONCLUSION

Our data suggest that miR-3065-3p promoted the stemness and metastasis of colorectal cancer by targeting CRLF1. miR-3065-3p might serve as a promising prognostic marker as well as a therapeutic target for colorectal cancer.

Effects of different corticosteroid therapy on severe COVID-19 patients: a meta-analysis of randomized controlled trials

Background

To assess the efficacy and safety of corticosteroids in COVID-19 patients compared with standard care or placebo.

Methods

Electronic databases were searched to identify relevant studies. The mortality, adverse events, and other data from studies were pooled for statistical analysis.

Results

Ten randomized clinical trials were eligible for inclusion. Corticosteroid treatment in COVID-19 patients did not significantly reduce the risk of death (RR: 0.93; CI: 0.82, 1.05) and the need for mechanical ventilation (RR: 0.82; CI: 0.62, 1.08). No mortality reduction was also observed in the subgroup of patients requiring mechanical ventilation (RR: 0.90; CI: 0.79–1.03). The use of corticosteroids increased mortality in the subgroup of patients not requiring oxygen support (RR: 1.24; CI: 1.00–1.55). The survival benefit was observed in a low dosage of corticosteroids (RR: 0.90; CI: 0.84–0.97) and dexamethasone (RR: 0.90; 95% CI: 0.79–1.04). There was no difference in the rates of adverse events (RR: 1.13; CI: 0.58, 2.20) and secondary infections (RR: 0.87; CI: 0.66, 1.15).

Conclusion

Corticosteroid treatment did not convincingly improve survival in severe COVID-19 patients. Low-dose dexamethasone could be considered as a drug for the treatment of COVID-19 patients. More high-quality trials are needed to further verify this conclusion.

Expert Opinion: The effect of corticosteroids on patient survival highly depended on the selection of the right dosage and type and in a specific subgroup of patients. This meta-analysis, which included more RCTs, evaluated the safety and efficacy in severe COVID-19 patients and analyzed the effects of different types of corticosteroid treatments. Corticosteroid treatment did not convincingly improve survival in severe COVID-19 patients. But the low dose dexamethasone appear to have a role in the management of severe COVID-19 patients.

Histone demethylase KDM6B inhibits breast cancer metastasis by regulating Wnt/β-catenin signaling

Tumor metastasis remains a major challenge for patients with breast cancer. Aberrant epigenetic factor lysine‐specific demethylase 6B (KDM6B) has been associated with tumor progression. Here, we show that KDM6B is significantly down‐regulated in human breast cancer tissues, and its low expression is associated with poor prognosis of patients with breast cancer. Furthermore, overexpression of KDM6B remarkably inhibited cell proliferation, invasion, migration and epithelial–mesenchymal transition markers of breast cancer cells in vitro and tumor growth and lung metastasis in vivo. Notably, the expression of KDM6B in breast cancer tissues was negatively correlated with that of β‐catenin, and overexpression of KDM6B decreased the expression of β‐catenin and its accumulation in the nucleus of breast cancer cells. Overall, our findings provide novel insights into suppression of metastasis of breast cancer cells by KDM6B via β‐catenin and suggest involvement of the KDM6B‐Wnt/β‐catenin axis in breast cancer progression.

Cancer-derived exosomal miR-138-5p modulates polarization of tumor-associated macrophages through inhibition of KDM6B

Rationale: Differential activation of macrophages correlates closely with tumor progression, and the epigenetic factor lysine demethylase 6B (KDM6B, previously named JMJD3) mediates the regulation of macrophage polarization through an unknown mechanism. Methods: We developed a suspension coculture system comprising breast cancer cells and macrophages and used RT-qPCR and western blotting to measure KDM6B expression. Bioinformatics and luciferase reporter assays were used to identify candidate microRNAs of cancer cells responsible for the downregulation of KDM6B. To determine if exosomes mediated the transfer of miR-138-5p between cancer cells to macrophages, we treated macrophages with exosomes collected from the conditioned medium of cancer cells. The effects of exosomal miR-138-5p on macrophage polarization were measured using RT-qPCR, flow cytometry, and chromatin immunoprecipitation assays. We employed a mouse model of breast cancer, metastatic to the lung, to evaluate the effects on tumor metastasis of macrophages treated with miR-138-5p-enriched exosomes. To develop a diagnostic evaluation index, the levels of exosomal miR-138-5p in samples from patients with breast cancer were compared to those of controls. Results: Coculture of breast cancer cells led to downregulation of KDM6B expression in macrophages. Cancer cell-derived exosomal miR-138-5p inhibited M1 polarization and promoted M2 polarization through inhibition of KDM6B expression in macrophages. Macrophages treated with exosomal miR-138-5p promoted lung metastasis, and the level of circulating exosomal miR-138-5p positively correlated with the progression of breast cancer. Conclusion: Our data suggest that miR-138-5p was delivered from breast cancer cells to tumor-associated macrophages via exosomes to downregulate KDM6B expression, inhibit M1 polarization, and stimulate M2 polarization. Therefore, exosomal miR-138-5p represents a promising prognostic marker and target for the treatment of breast cancer.

Braking process identification of high-speed trains for automatic train stop control

Automatic train stop control (ATSC) is a key function of the automatic train operation (ATO) system. An accurate braking process model can help to improve the control strategy. In this paper, the braking process for stop control of high-speed trains is formulated as a single-point time delay model, based on the principle of practical braking processes. Furthermore, a Picard iteration based identification method is first applied to the time delay system, and a train braking process identification method is proposed. The method is straightforward, and the parameters can be identified based on the principle of ordinary differential equations. The effectiveness of the braking process model and the identification method is illustrated by real-life experimental data.

Data-driven approaches for modeling train control models: Comparison and case studies

In railway systems, the train dynamics are usually affected by the external environment (e.g., snow and wind) and wear-out of on-board equipment, leading to the performance degradation of automatic train control algorithms. In most existing studies, the train control models were derived from the mechanical analyzation of train motors and wheel-track frictions, which may require many times of field trials and high costs to validate the model parameters. To overcome this issue, we record the explicit train operation data in Beijing Metro within three years and develop three data-driven approaches, involving a linear regression-based model (LAM), a nonlinear regression-based model (NRM), and furthermore a deep neural network based (DNN) model, where the LAM and NRM can act as benchmarks for evaluating DNN. To improve the training efficiency of DNN model, we especially customize the input and output layers of DNN, batch normalization based layers and network parameter initialization techniques according to the unique characteristics of railway train models. From the model training and testing results with field data, we observe that DNN significantly enhances the predicting accuracy for the train control model by using our customized network structure compared with LAM and NRM models. These data-driven approaches are successfully applied to Beijing Metro for designing efficient train control algorithms.

Legumain-deficient macrophages promote senescence of tumor cells by sustaining JAK1/STAT1 activation

Macrophages serve as the first line of communication between tumors and the rest of the immune system, and understanding the interplay between macrophage and tumor cells is essential for developing novel macrophage-based strategy against tumor. Here, we show that deletion of legumain in macrophages activates senescence of tumor cells. Macrophage derived IL-1β mediates the pro-senescent effect of Lgmn^-/- macrophages since blockage of IL-1β reverses the senescence phenotype in both a coculture model of macrophage and tumor cells and an orthotopic mouse model of breast cancer. Sustained activation of JAK1/STAT1 signaling and increased iNOS were found in the tumor cell-cocultured Lgmn^-/- macrophages, which were necessary for IL-1β expression and secretion. Applying a specific STAT1 agonist mimics the inductive effect of legumain deletion on IL-1β expression in macrophages, and the effect can be blocked via inhibition of iNOS. Legumain and integrin αvβ3 interact to prevent STAT1 signaling in macrophages, and blockage of integrin αvβ3 stimulates STAT1 activation. Therapeutically, transplantation of bone marrow from Lgmn^-/- mice suppresses the malignant growth of tumor by upregulating tumor cell senescence. Therefore, our finding highlights legumain in macrophages as a potential therapeutic target for tumors.

PFKFB4 Promotes Breast Cancer Metastasis via Induction of Hyaluronan Production in a p38-Dependent Manner

BACKGROUND/AIMS

The bi-functional enzyme 6-phosphofructo-2-kinase/fructose-2, 6-biphosphatase-4 (PFKFB4) is highly expressed in many types of cancer and its requirement for tumor survival has been demonstrated in glioma, lung, and prostate cancers. However, whether PFKFB4 plays a role in the tumor metastasis remains uncertain. This study explores the role of PFKFB4 in tumor metastasis and its underlying mechanisms in breast cancer cells.

METHODS

The expression of PFKFB4 was first analyzed using the Cancer Genome Atlas (TCGA) dataset, and confirmed by immunohistochemical staining of tissue microarray and breast cancer tissues from patient samples. Gain- and loss-of- function approaches were used to investigate the effects of PFKFB4 on breast cancer cell migration in vitro. Orthotopic xenograft model and experimental metastasis model were used to assess the effects of PFKFB4 on breast cancer cell metastasis in vivo. ELISA and immunofluorescence staining were used to examine HA production. Quantitative RT-PCR and western blotting were used to explore the mRNA and protein levels of HAS2, respectively.

RESULTS

We found that PFKFB4 enhances the migration/invasiveness of breast cancer cells in vitro as well as in vivo. Notably, the effects of PFKFB4 on migration are mediated by induction of HAS2 expression and HA production. Moreover, PFKFB4-induced HAS2 up-regulation depends upon the activation of p38 signaling.

CONCLUSION

PFKFB4 promotes the metastasis of breast cancer cells via induction of HAS2 expression and HA production in a p38-dependent manner. Therefore, the PFKFB4/p38/HAS2 signaling pathway may serve as a potential therapeutic target for metastatic breast cancer.

JMJD3 suppresses stem cell-like characteristics in breast cancer cells by downregulation of Oct4 independently of its demethylase activity

Epigenetic regulator JMJD3 plays an important role in both tumor progression and somatic cell reprogramming. Here, we explored the effect of JMJD3 on the stem cell-like characteristics of breast cancer and its underlying mechanism involving stemness-related transcription factor Oct4. Our data revealed that, in breast cancer cells lines and an orthotopic xenograph mouse model of breast cancer, ectopic overexpression of JMJD3 suppressed stem cell-like characteristics of breast cancer cells, whereas knockdown of JMJD3 promoted these characteristics. Oct4 mediated the suppressive effects of JMJD3 on the stemness of breast cancer cells. The inhibitory effect of JMJD3 on Oct4 was independent of demethylase activity, but mediated via degradation of PHF20. Furthermore, we applied an agonist of the vitamin D receptor, paricalcitol, and found that it induced JMJD3 in breast cancer cells. Our data showed that administration of paricalcitol suppressed stem cell-like characteristics and Oct4 expression. Taken together, JMJD3 inhibits the stem cell-like characteristics in breast cancer by suppression of stemness factor Oct4 in a PHF20-dependent manner. Administration of paricalcitol leads to upregulation of JMJD3 that suppresses Oct4 expression and the stem cell-like characteristics in breast cancer.

Investigation of underlying comorbidities as risk factors for symptomatic human hepatitis E virus infection

BACKGROUND

Symptomatic Hepatitis E virus (HEV) infection occurs in few infected subjects, and the risk factors are not completely known.

AIM

To explore the risk factors for adverse clinical outcomes in acute HEV infections.

METHODS

A large retrospective study was conducted. The baseline characteristics, clinical outcomes, and laboratory data of 512 acute HEV infection cases were analysed using logistic regression models.

RESULTS

All patients exhibited autochthonous sporadic HEV infections, and most were elderly. Their symptoms varied from asymptomatic to severe liver diseases. In all, 215 patients (42.0%) had liver failure and/or decompensation, and 45 (8.2%) patients died within 3 months. Nearly 60% of patients had underlying chronic liver diseases (CLDs), 20% were cirrhotic, and various extrahepatic underlying comorbidities were common. The logistic regression analysis revealed that underlying CLDs, especially cirrhosis, were closely associated with disease severity (OR = 8.78, P < 0.001) but not with mortality in patients with severe liver diseases. In addition to the known factors, including an old age, the male gender and CLDs, we identified pre-existing extrahepatic tumours, diabetes, and chronic respiratory and renal diseases as novel independent predictors for adverse clinical outcomes. Importantly, patients without these four extrahepatic comorbidities showed a much lower mortality rate (4.2%, P < 0.001) than patients with one (18.5%) or more comorbidities (34.5%).

CONCLUSIONS

Previous comorbidities, including tumours, diabetes, and chronic liver, lung and kidney diseases, were independent risk factors for adverse outcomes, especially mortality, in acute HEV infections. This study provides valuable data for improving the prevention and control of HEV infection.

M2 tumour-associated macrophages contribute to tumour progression via legumain remodelling the extracellular matrix in diffuse large B cell lymphoma

Effects of M2 tumour-associated macrophages on the pathogenesis of diffuse large B cell lymphoma (DLBCL) are still controversial. Our data showed that the number of CD163-positive M2 macrophages correlated negatively with DLBCL prognosis. Macrophage depletion by clodronate liposomes significantly suppressed tumour growth in a xenograft mouse model of DLBCL using OCI-Ly3 cells. Moreover, M2 polarization of macrophages induced legumain expression in U937 cells. Exogenous legumain promoted degradation of fibronectin and collagen I, which was abolished by administration of a legumain inhibitor RR-11a. Overexpression of legumain in Raw 264.7 cells also induced tube formation of endothelial cells in matrigel. In the xenograft mouse model of DLBCL, decreased fibronectin and collagen I, as well as increased legumain expression and angiogenesis were found at the late stage tumours compared with early stage tumours. Co-localization of legumain and fibronectin was observed in the extracellular matrix of tumour tissues. Administration of the legumain inhibitor to the xenograft DLBCL model suppressed tumour growth, angiogenesis and collagen deposition compared with the control. Taken together, our results suggest that M2 tumour-associated macrophages affect degradation of the extracellular matrix and angiogenesis via overexpression of legumain, and therefore play an active role in the progression of DLBCL.

Abstract 5086: Legumain-contained exosomes mediate remodeling of tumor extracellular matrix and protumor effects of TAMs

It has been recognized that tumor associated macrophages (TAMs) in tumor microenvironment play a variety of pro-tumor effects during the tumor progression, while the role of extracellular matrix in mediating these effects is still unclear.

In this study, we focus on elucidating the way as well as the underlying mechanism about the involvement of an asparaginyl endopeptidase, legumain in the crosstalk between TAMs and ECM. Our data showed that co-culture of breast cancer cells 4T1 with macrophages Raw 264.7 promoted asparaginyl endopeptidase, legumain, expression with the introduction of markers of M2 - polarized macrophage. Legumain was detected in the condition medium (CM) collected from RAW 264.7 co-cultured with 4T1 cells by western blotting, with the existence of asparagine endopeptide enzyme activity assessed by enzyme activity assay. Result of western blotting showed that adding the CM of RAW 264.7 co-cultured with 4T1 cells depleted extracellular matrix (ECM) contents, fibronectin and collagen I. Transwell assay showed increased infiltration of 4T1 cells through the ECM contents after treatment with the CM of RAW 264.7 co-cultured with 4T1 cells. Furthermore, treatment with CM of RAW 264.7 co-cultured with 4T1 suppressed the adhesion of endothelial cells with ECM, promoting tube formation of endothelial cells compared with control. All the above results could be abolished by synthesized legumain inhibitor, RR-11a. Interestingly, legumain was also detected in the exosomes isolated from CM of RAW 264.7 co-cultured with 4T1. Applying legumain contained exosomes could replicate the effect of CM of RAW 264.7 co-cultured with 4T1 on the depletion of ECM contents, promotion of 4T1 infiltration and suppression of endothelial cell adhesion with ECM.

Altogether, our results suggest that legumain is overexpressed and secreted out by TAMs; TAMs exosomes contain legumain and help delivering legumain to the ECM thus exert its effect on the depletion of ECM, pro-infiltration and angiogenesis.

Citation Format: Long Shen, Yuzhi Shi, Jing Xun, Chuanai Chen, Lingfang Du, Xiaoyue Tan, Rong Xiang. Legumain-contained exosomes mediate remodeling of tumor extracellular matrix and protumor effects of TAMs. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5086.

[Role of calcium desensitization in vascular hyporeactivity in hemorrhagic shock]

OBJECTIVE

To evaluate the role of calcium desensitization of vascular smooth muscle in vascular hyporeactivity following hemorrhagic shock (HS) in rats.

METHODS

The superior mesenteric artery (SMA) from HS model of rat was adopted to assay the vascular reactivity and calcium sensitivity by observing its contractibility initiated by norepinephrine (NE) and Ca2+ under depolarizing conditions (120 mmol/L K+) with the aid of an isolated organ perfusion system. The experiment was conducted in two parts. In the first part, calcium desensitization was present whether or not in the response-decreased blood vessels was observed, and in the second part, whether angiotensin II (Ang II) and insulin which were calcium sensitivity regulating agents, and a relatively selective inhibitor of Rho-kinase, Fasudil, could regulate the vascular reactivity through regulating the calcium sensitivity was tested.

RESULTS

As compared with the normal group, the cumulative dose-response curve of SMA to NE and Ca2+ in shock group was shifted to the right, the maximal contraction (Emax) and -lg(EC50)(pD2) of NE and Ca2+ were decreased significantly(P<0.05 or P<0.01). Ang II shift the cumulative dose-response curve of NE and Ca2+ to the left, and increased the contractile response of NE and Ca2+ (P<0.05 or P<0.01). On the contrary, insulin rendered the cumulative dose-response curve of NE and Ca2+ shift to the right and decreased the contractile response of NE and Ca2+ (P<0.05 or P<0.01). Pretreatment with Fasudil abolished the enhancing effect of Ang II on vascular contraction produced by NE, and reduced the calcium sensitivity.

CONCLUSION

Calcium desensitization is a physiological condition which exists in the vascular smooth muscle of HS rat, and it plays an important role in vascular hyporeactivity, which is one of the important mechanism of the abnormal condition of vascular hyporeactivity.

CD44ICD promotes breast cancer stemness via PFKFB4-mediated glucose metabolism

CD44 is a single-pass cell surface glycoprotein that is distinguished as the first molecule used to identify cancer stem cells in solid tumors based on its expression. In this regard, the CD44^high cell population demonstrates not only the ability to regenerate a heterogeneous tumor, but also the ability to self-regenerate when transplanted into immune-deficient mice. However, the exact role of CD44 in cancer stem cells remains unclear in part because CD44 exists in various isoforms due to alternative splicing.

Methods: Gain- and loss-of-function methods in different models were used to investigate the effects of CD44 on breast cancer stemness. Cancer stemness was analyzed by detecting SOX2, OCT4 and NANOG expression, ALDH activity, side population (SP) and sphere formation. Glucose consumption, lactate secretion and reactive oxygen species (ROS) levels were detected to assess glycolysis. Western blot, immunohistochemical staining, ELISA and TCGA dataset analysis were performed to determine the association of CD44ICD and PFKFB4 with clinical cases. A PFKFB4 inhibitor, 5MPN, was used in a xenograft model to inhibit breast cancer development.

Results: In this report, we found that the shortest CD44 isoform (CD44s) inhibits breast cancer stemness, whereas the cleaved product of CD44 (CD44ICD) promotes breast cancer stemness. Furthermore, CD44ICD interacts with CREB and binds to the promoter region of PFKFB4, thereby regulating PFKFB4 transcription and expression. The resultant PFKFB4 expression facilitates the glycolysis pathway (vis-à-vis oxidative phosphorylation) and promotes stemness of breast cancer. In addition, we found that CD44ICD and PFKFB4 expressions are generally up-regulated in the tumor portion of breast cancer patient samples. Most importantly, we found that 5MPN (a selective inhibitor of PFKFB4) suppresses CD44ICD-induced tumor development.

Conclusion: CD44ICD promotes breast cancer stemness via PFKFB4-mediated glycolysis, and therapies that target PFKFB4 (e.g., 5MPN therapy) may lead to improved outcomes for cancer patients.