E3 ligase Trim35 inhibits LSD1 demethylase activity through K63-linked ubiquitination and enhances anti-tumor immunity in NSCLC

Targeting lysine-specific histone demethylase 1A (LSD1) can improve tumor immunogenicity of poorly immunogenic tumors, such as non-small cell lung cancer (NSCLC), with elevated T cell infiltration and sensitize tumors to anti-PD-1 therapy. However, the lack of reliable biomarkers limits utilization of LSD1 inhibitors in cancer therapy. Here, we identify an E3 ligase, Trim35, as an effective biomarker for high activity of LSD1 to predict prognosis of LSD1-targeted therapy as well as immunotherapy. Mechanistically, Trim35 represses LSD1 demethylase activity by mediating K63 ubiquitination at lysine site 422 of LSD1. Suppressed LSD1 activity facilitates ERGIC1 transcription, followed by autophagy inhibition and IFNGR1 stabilization to activate IFN-γ signaling, leading to increased MHC class I expression and immune surveillance of NSCLC cells. Furthermore, combinational use of an LSD1 inhibitor and anti-PD-1 therapy can significantly eradicate poorly immunogenic lung cancer with low Trim35. These findings strongly suggest that Trim35 is a promising biomarker for prediction of immunotherapy outcome in NSCLC.

Endothelial RIPK1 protects artery bypass graft against arteriosclerosis by regulating SMC growth

RIPK1 is crucial in the inflammatory response. The process of vascular graft remodeling is also involved in endothelial inflammation, which can influence the behavior of smooth muscle cells. However, the role of endothelial RIPK1 in arterial bypass grafts remains unknown. Here, we established an arterial isograft mouse model in wild-type and endothelial RIPK1 conditional knockout mice. Progressive vascular remodeling and neointima formation occurred in the graft artery, showing SMC accumulation together with endothelial inflammatory adhesion molecule and cytokine expression. Endothelial RIPK1 knockout exacerbated graft stenosis by increasing secretion of N-Shh. Mechanistically, RIPK1 directly phosphorylated EEF1AKMT3 at Ser26, inhibiting its methyltransferase activity and global protein synthesis, which further attenuated N-Shh translation and secretion. Consistently, treatment with the Hedgehog pathway inhibitor GDC0449 markedly alleviated RIPK1 knockout-induced graft stenosis. Our results demonstrated that endothelial RIPK1 played a protective role in arterial bypass graft vascular remodeling, highlighting that targeting Hedgehog pathway may be an attractive strategy for graft failure in the future.

[Applications and challenges of large language models in critical care medicine]

The rapid development of big data methods and technologies has provided more and more new ideas and methods for clinical diagnosis and treatment. The emergence of large language models (LLM) has made it possible for human-computer interactive dialogues and applications in complex medical scenarios. Critical care medicine is a process of continuous dynamic targeted treatment. The huge data generated in this process needs to be integrated and optimized through models for clinical application, interaction in teaching simulation, and assistance in scientific research. Using the LLM represented by generative pre-trained transformer ChatGPT can initially realize the application in the diagnosis of severe diseases, the prediction of death risk and the management of medical records. At the same time, the time and space limitations, illusions and ethical and moral issues of ChatGPT emerged as the times require. In the future, it is undeniable that it may play a huge role in the diagnosis and treatment of critical care medicine, but the current application should be combined with more clinical knowledge reserves of critical care medicine to carefully judge its conclusions.

Identification, validation and biological characterisation of novel glioblastoma tumour microenvironment subtypes: implications for precision immunotherapy

BACKGROUND

New precision medicine therapies are urgently required for glioblastoma (GBM). However, to date, efforts to subtype patients based on molecular profiles have failed to direct treatment strategies. We hypothesised that interrogation of the GBM tumour microenvironment (TME) and identification of novel TME-specific subtypes could inform new precision immunotherapy treatment strategies.

MATERIALS AND METHODS

A refined and validated microenvironment cell population (MCP) counter method was applied to >800 GBM patient tumours (GBM-MCP-counter). Specifically, partition around medoids (PAM) clustering of GBM-MCP-counter scores in the GLIOTRAIN discovery cohort identified three novel patient clusters, uniquely characterised by TME composition, functional orientation markers and immune checkpoint proteins. Validation was carried out in three independent GBM-RNA-seq datasets. Neoantigen, mutational and gene ontology analysis identified mutations and uniquely altered pathways across subtypes. The longitudinal Glioma Longitudinal AnalySiS (GLASS) cohort and three immunotherapy clinical trial cohorts [treatment with neoadjuvant/adjuvant anti-programmed cell death protein 1 (PD-1) or PSVRIPO] were further interrogated to assess subtype alterations between primary and recurrent tumours and to assess the utility of TME classifiers as immunotherapy biomarkers.

RESULTS

TME^High tumours (30%) displayed elevated lymphocyte, myeloid cell immune checkpoint, programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 transcripts. TME^High/mesenchymal+ patients featured tertiary lymphoid structures. TME^Med (46%) tumours were enriched for endothelial cell gene expression profiles and displayed heterogeneous immune populations. TME^Low (24%) tumours were manifest as an 'immune-desert' group. TME subtype transitions upon recurrence were identified in the longitudinal GLASS cohort. Assessment of GBM immunotherapy trial datasets revealed that TME^High patients receiving neoadjuvant anti-PD-1 had significantly increased overall survival (P = 0.04). Moreover, TME^High patients treated with adjuvant anti-PD-1 or oncolytic virus (PVSRIPO) showed a trend towards improved survival.

CONCLUSIONS

We have established a novel TME-based classification system for application in intracranial malignancies. TME subtypes represent canonical 'termini a quo' (starting points) to support an improved precision immunotherapy treatment approach.

SLC3A2 promotes tumor-associated macrophage polarization through metabolic reprogramming in lung cancer

Tumor-associated macrophages (TAMs) are one of the most abundant immunosuppressive cells in the tumor microenvironment and possess crucial functions in facilitating tumor progression. Emerging evidence indicates that altered metabolic properties in cancer cells support the tumorigenic functions of TAMs. However, the mechanisms and mediators the underly the cross-talk between cancer cells and TAMs remain largely unknown. In the present study, we revealed that high solute carrier family 3 member 2 (SLC3A2) expression in lung cancer patients was associated with TAMs and poor prognosis. Knockdown of SLC3A2 in lung adenocarcinoma cells impaired M2 polarization of macrophages in a coculture system. Using metabolome analysis, we identified that SLC3A2 knockdown altered the metabolism of lung cancer cells and changed multiple metabolites, including arachidonic acid, in the tumor microenvironment. More importantly, we showed that arachidonic acid was responsible for SLC3A2-mediated macrophage polarization in the tumor microenvironment to differentiate into M2 type both in vitro and in vivo. Our data illustrate previously undescribed mechanisms responsible for TAM polarization and suggest that SLC3A2 acts as a metabolic switch on lung adenocarcinoma cells to induce macrophage phenotypic reprogramming through arachidonic acid.

Identification of tumour-infiltrating myeloid subsets associated with overall survival in lung squamous cell carcinoma

Lung squamous cell carcinoma (LUSC) is a primary subtype of lung cancer with limited therapeutic options and poor prognosis, and tumour-infiltrating myeloid cells (TIMs) are key regulators of LUSC. However, the correlation between the abundance of TIM subtypes and clinical outcomes of LUSC remains unexplored. This study aimed to develop and validate a prognostic model for low- and high-risk patients with LUSC based on myeloid cell microenvironments. TIM markers in the tumoural (T) and stromal (S) regions were quantified using immunohistochemistry for 502 LUSC patients. L1-penalized Cox regression was used to develop a myeloid survival score (MSS) model based on the training cohort, followed by validation in distinct cohorts from multiple centres. RNA sequencing and immunostaining were used to examine the mechanisms of myeloid cells in LUSC progression and predict potential drug targets and therapeutic agents. Of the 12 myeloid markers, CD163T, CD163S, and S100A12T were highly associated with overall survival (OS) in LUSC patients. The MSS of the three myeloid signatures accurately categorized LUSC patients into risk categories, with an observable difference in OS between the training and validation cohorts. Tumours with high MSS were associated with enhanced antioxidative ability and hedgehog signalling and a shift to a more pro-tumorigenic microenvironment, accompanied by a reduced tumour cell immunogenicity and increased CD8⁺ T cell exhaustion patterns. Additionally, in high-risk patients, potential drug targets and compounds regulating hedgehog signalling were identified. Our study provides the first prognostic myeloid signature for LUSC, which may help advance precision medicine. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Girdin Promotes Tumorigenesis and Chemoresistance in Lung Adenocarcinoma by Interacting with PKM2

Girdin, an Akt substrate, has been reported to promote tumorigenesis in various tumors. However, the role of Girdin in a spontaneous tumor model has not yet been explored. Here, we studied the role of Girdin in lung adenocarcinoma (LUAD) using the autochthonous mouse model and found that Girdin led to LUAD progression and chemoresistance by enhancing the Warburg effect. Mechanistically, Girdin interacted with pyruvate kinase M2 (PKM2), which played a vital role in aerobic glycolysis. Furthermore, Girdin impaired Platelet Derived Growth Factor Receptor Beta (PDGFRβ) degradation, which in turn, promoted PKM2 tyrosine residue 105 (Y105) phosphorylation and inhibited PKM2 activity, subsequently promoting aerobic glycolysis in cancer cells. Taken together, our study demonstrates that Girdin is a crucial regulator of tumor growth and may be a potential therapeutic target for overcoming the resistance of LUAD cells to chemotherapy.

POS1368 DIVERSITY OF HEMODYNAMIC TYPES IN CONNECTIVE TISSUE DISEASE ASSOCIATED PULMONARY HYPERTENSION: MORE THAN A SUBGROUP OF PULMONARY ARTERIAL HYPERTENSION

Background

Connective tissue disease (CTD) associated pulmonary hypertension (PH) is classified as a subgroup of WHO group 1 PH, also called pulmonary arterial hypertension (PAH). However, not all CTD-PH fit the hemodynamic definition of PAH. This study investigates the diversity of hemodynamical types of CTD-PH, their different clinical characteristics and outcomes.

Objectives

This study investigates the diversity of hemodynamical types of CTD-PH, their different clinical characteristics and outcomes.

Methods

We performed a retrospective cohort study. CTD-PH patients underwent right heart catheterization (RHC) were enrolled and divided into WHO group1 PH, WHO group 2 PH and high output PH (PVR<3WU and PAWP<15mmHg) according to hemodynamic features. Patients with obvious lung diseases, left heart disease and pulmonary embolism were excluded. Baseline characteristics, inflammatory markers, autoantibodies, cardiac function status, echocardiogram parameters, hemodynamics and survival rates were compared.

Results

207 CTD-PH patients were included, including 139 in WHO group 1 PH, 36 in WHO group 2 PH and 32 in high output PH. Incidence of anti-ribonucleoprotein antibody was lower in WHO Group 2 PH. High output PH is less severe, presenting lower NT-proBNP level, better WHO functional class, lower mPAP and PVR, higher cardiac output, and less cardiac remodeling. Among patients with elevated PAWP, combine pre& post-capillary PH had higher mPAP and larger right ventricle diameter. Association of mild to moderate interstitial lung disease didn’t show significant difference in disease characteristics. Short-term survival was significantly worse in WHO group 2 PH, yet 5-year survival rates didn’t differ between groups.

Conclusion

Pre-capillary PH is not the only hemodynamic type of CTD-PH. Different types of CTD-PH present different clinical phenotypes and outcome. Carefully phenotyping PH in CTD-PH patients is important.

Disclosure of Interests

None declared

Pharmacologic conversion of cancer-associated fibroblasts from a protumor phenotype to an antitumor phenotype improves the sensitivity of pancreatic cancer to chemotherapeutics

Previous therapeutic attempts to deplete cancer-associated fibroblasts (CAFs) or inhibit their proliferation in pancreatic ductal adenocarcinoma (PDAC) were not successful in mice or patients. Thus, CAFs may be tumor suppressive or heterogeneous, with distinct cancer-restraining and -promoting CAFs (rCAFs and pCAFs, respectively). Here, we showed that induced expression of the glycosylphosphatidylinositol-anchored protein Meflin, a rCAF-specific marker, in CAFs by genetic and pharmacological approaches improved the chemosensitivity of mouse PDAC. A chemical library screen identified Am80, a synthetic, nonnatural retinoid, as a reagent that effectively induced Meflin expression in CAFs. Am80 administration improved the sensitivity of PDAC to chemotherapeutics, accompanied by increases in tumor vessel area and intratumoral drug delivery. Mechanistically, Meflin was involved in the suppression of tissue stiffening by interacting with lysyl oxidase to inhibit its collagen crosslinking activity. These data suggested that modulation of CAF heterogeneity may represent a strategy for PDAC treatment.

Diagnostic accuracy of lung ultrasonography in childhood pneumonia: a meta-analysis

This meta-analysis aimed to assess the diagnostic accuracy of lung ultrasonography in pneumonia-affected pediatric patients. Literature search of published articles in Medline, Web of Science, Scopus, Embase and Journal of Web till September 2020 were reviewed for the predescribed accuracy assessors. In compliance with the inclusion and exclusion criteria, two researchers independently screened the literature, collected the results and assessed the risks of bias using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. The pooled sensitivity and specificity, pooled positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio were estimated for the meta-analysis. The overall efficiency of lung ultrasonography (LUS) was evaluated using a summary receiver operating characteristic curve. Q and I2 statistics were used to determine heterogeneity. Meta disc software was used for the analysis of the study. Out of 1182 studies, only 29 articles were chosen; 25 of them were prospective studies and 4 studies were retrospective. The overall pooled sensitivity was 0.83 [95% confidence intervals (CI), 0.81-0.84] and specificity was 0.84 (95% CI, 0.81-0.86), depicting good diagnostic performance. LUS is an efficient imaging technique for detecting childhood pneumonia with a high accuracy rate. It is an appealing alternative to chest X rays to detect and follow-up pneumonia in children because it is simple to do, widely available, comparatively cheap and free of radiation hazards.

SIK2 maintains breast cancer stemness by phosphorylating LRP6 and activating Wnt/β-catenin signaling

Breast cancer stem cells (BCSCs) are the main drivers of recurrence and metastasis. However, commonly used drugs rarely target BCSCs. Via screenings, we found that Salt-inducible kinase 2 (SIK2) participated in breast cancer (BC) stemness maintenance and zebrafish embryos development. SIK2 was upregulated in recurrence samples. Knockdown of SIK2 expression reduced the proportion of BCSCs and the tumor initiation of BC cells. Mechanistically, SIK2, phosphorylated by CK1α, directly phosphorylated LRP6 in a SIK2 kinase activity-dependent manner, leading to Wnt/β-catenin signaling pathway activation. ARN-3236 and HG-9-91-01, inhibitors of SIK2, inhibited LRP6 phosphorylation and β-catenin accumulation and disturbed stemness maintenance. In addition, the SIK2-activated Wnt/β-catenin signaling led to induction of IDH1 expression, causing metabolic reprogramming in BC cells. These findings demonstrate a novel mechanism whereby Wnt/β-catenin signaling pathway is regulated by different kinases in response to metabolic requirement of CSCs, and suggest that SIK2 inhibition may potentially be a strategy for eliminating BCSCs.

Assessment of causal effects of visceral adipose tissue on risk of cancers: a Mendelian randomization study

BACKGROUND

Despite the established association between obesity and cancer risk, it remains unclear whether visceral obesity is causally related to cancer risk and whether it is more pro-oncogenic than total body fat.

METHODS

We conducted two-sample Mendelian randomization (MR) analysis to assess the causal effects of visceral adipose tissue (VAT) on six common cancers. For exposure data, 221 genetic variants associated with the predicted volume of VAT in 325 153 Europeans from UK Biobank were used as instrumental variables. Genetic association data of six common cancers (breast, lung, colorectal, ovarian, pancreatic and prostate cancers) were obtained from large-scale consortia with an average of 19 576 cases and 43 272 controls. We performed univariable MR with five MR methods [inverse-variance weighted (IVW), MR-Egger regression, weighted median, MR-Pleiotropy Residual Sum and Outlier (MR-PRESSO) and Radial MR] and multivariable MR to estimate the effect of VAT independent of body mass index (BMI). Finally, we performed a series of sensitivity analyses as validation of primary MR results.

RESULTS

Two associations survived the false discovery rate correction for multiple testing (q-value < 0.05): in IVW, the odds ratios (95% CIs) per unit increase in genetically determined VAT were 1.65 (1.03 to 2.62) for pancreatic cancer and 1.47 (1.20 to 1.82) for lung squamous-cell carcinoma, respectively, which showed the same directions and overlapped confidence intervals with MR-Egger regression and weighted median results. There were no outlier variants identified by MR-PRESSO and no evidence supporting the presence of heterogeneity and pleiotropy in sensitivity analyses, although with wider confidence intervals that included the null, multivariable MR results for these two cancers showed the same directions and similar effect sizes as in IVW, which were independent of the effect from BMI. There was no evidence for a causal effect of VAT on the risk of other types of cancer.

CONCLUSION

Our findings suggest that lifelong exposure to elevated volumes of VAT might increase the risk of pancreatic cancer and lung squamous-cell carcinoma, highlighting the importance of revealing the underlying mechanisms for intervention targets.

Association between trauma exposure and respiratory disease-A Mendelian randomization study

BACKGROUND

Trauma is a well-known risk factor for many disease, but the effect of trauma on respiratory disease is unclarified. In the present study, we aimed to evaluate the association between trauma and respiratory disease.

METHOD

Using both United Kingdom biobank and Finnish biobank genome-wide association study data (GWAS), we performed a two-sample Mendelian randomization (MR) analysis to evaluate the relationship between trauma and respiratory disease. We used four methods including inverse-variance weighted (IVW), weighted median, Maximum likelihood, and MR-Egger in this MR analysis. The IVW MR was selected as the main method. We also performed multivariable Mendelian randomization (MVMR) to simultaneously assess the independent impact of trauma exposure on respiratory disease.

RESULTS

In the main two-sample MR analysis, trauma exposure was significantly associated with increased risk of respiratory disease (OR 1.15, 95%CI: 1.05-1.25). Besides, there was no heterogeneity and horizontal pleiotropy observed in the sensitivity analysis. After adjusting for pack years of smoking and body mass index (BMI), trauma exposure retained its association with respiratory disease (OR, 1.13, 95%CI, 1.04-1.23 adjusted by pack years of smoking; and OR, 1.11, 95%CI, 1.04-1.18 adjusted by BMI).

CONCLUSION

Our study discovered the association between trauma exposure and the increased risk of respiratory disease, suggesting the prevention and treatment with trauma to reduce the risk of respiratory disease.

SNAIL1: Linking Tumor Metastasis to Immune Evasion

The transcription factor Snail1, a key inducer of epithelial-mesenchymal transition (EMT), plays a critical role in tumor metastasis. Its stability is strictly controlled by multiple intracellular signal transduction pathways and the ubiquitin-proteasome system (UPS). Increasing evidence indicates that methylation and acetylation of Snail1 also affects tumor metastasis. More importantly, Snail1 is involved in tumor immunosuppression by inducing chemokines and immunosuppressive cells into the tumor microenvironment (TME). In addition, some immune checkpoints potentiate Snail1 expression, such as programmed death ligand 1 (PD-L1) and T cell immunoglobulin 3 (TIM-3). This mini review highlights the pathways and molecules involved in maintenance of Snail1 level and the significance of Snail1 in tumor immune evasion. Due to the crucial role of EMT in tumor metastasis and tumor immunosuppression, comprehensive understanding of Snail1 function may contribute to the development of novel therapeutics for cancer.

Dvl2 facilitates the coordination of NF-κB and Wnt signaling to promote colitis-associated colorectal progression

Colitis‐associated colorectal cancer (CAC) arises due to prolonged inflammation and has distinct molecular events compared with sporadic colorectal cancer (CRC). Although inflammatory NF‐κB signaling was activated by pro‐inflammatory cytokines (such as TNFα) in early stages of CAC, Wnt/β‐catenin signaling later appears to function as a key regulator of CAC progression. However, the exact mechanism responsible for the cross‐regulation between these 2 pathways remains unclear. Here, we found reciprocal inhibition between NF‐κB and Wnt/β‐catenin signaling in CAC samples, and the Dvl2, an adaptor protein of Wnt/β‐catenin signaling, is responsible for NF‐κB inhibition. Mechanistically, Dvl2 interacts with the C‐terminus of tumor necrosis factor receptor 1 (TNFRI) and mediates TNFRI endocytosis, leading to NF‐κB signal inhibition. In addition, increased infiltration of the pro‐inflammatory cytokine interleukin‐13 (IL‐13) is responsible for upregulating Dvl2 expression through STAT6. Targeting STAT6 effectively decreases Dvl2 levels and restrains colony formation of cancer cells. These findings demonstrate a unique role for Dvl2 in TNFRI endocytosis, which facilitates the coordination of NF‐κB and Wnt to promote CAC progression.

Comparisons of Underlying Mechanisms, Clinical Efficacy and Safety Between Anti-PD-1 and Anti-PD-L1 Immunotherapy: The State-of-the-Art Review and Future Perspectives

Over the past decade, diverse PD-1/PD-L1 blockades have demonstrated significant clinical benefit in across a wide range of tumor and cancer types. With the increasing number of PD-1/PD-L1 blockades available in the market, differences between the clinical performance of each of them started to be reported. Here, we provide a comprehensive historical and biological perspective regarding the underlying mechanism and clinical performance of PD-1/PD-L1 blockades, with an emphasis on the comparisons of their clinical efficacy and safety. The real-world evidence indicated that PD-1 blockade may be more effective than the PD-L1, though no significant differences were found as regards to their safety profiles. Future head-to-head studies are warranted for direct comparison between them. Finally, we summarize the yet to be elucidated questions and future promise of anti-PD-1/PD-L1 immunotherapy, including a need to explore novel biomarkers, novel combinatorial strategies, and their clinical use on chronic infection.

CD109 regulates in vivo tumor invasion in lung adenocarcinoma through TGF-β signaling

Stromal invasion is considered an important prognostic factor in patients with lung adenocarcinoma. The mechanisms underlying the formation of tumor stroma and stromal invasion have been studied in the lung; however, they are still unclear. CD109 is a glycosylphosphatidylinositol-anchored glycoprotein highly expressed in several types of human malignant tumors including lung cancers. In this study, we investigated the in vivo functions of CD109 protein in malignant lung tumors. Initially, we identified an association between higher expression of CD109 protein in human lung adenocarcinoma and a significantly worse prognosis, according to immunohistochemical analysis. We also showed that CD109 deficiency significantly reduced the area of stromal invasive lesions in a genetically engineered CD109-deficient lung adenocarcinoma mouse model, which correlated with the results observed in human lung adenocarcinoma. Furthermore, we identified latent TGF-β binding protein-1 (LTBP1) as a CD109-interacting protein using mass spectrometry and confirmed their interaction by co-immunoprecipitation. Importantly, increased CD109 expression enhanced stromal TGF-β activation in the presence of LTBP1. Therefore, these data suggest the significance of the regulation of TGF-β signaling through CD109 and LTBP1 interaction in tumor stroma and also reveal the importance of CD109 expression levels in promoting lung cancer cell proliferation, migration, and invasion, and thus predicting the outcome of patients suffering from lung adenocarcinoma. Therefore, CD109 protein could be a potential therapeutic target for this disease.

Complex roles of the actin-binding protein Girdin/GIV in DNA damage-induced apoptosis of cancer cells

The actin‐binding protein Girdin is a hub protein that interacts with multiple proteins to regulate motility and Akt and trimeric G protein signaling in cancer cells. Girdin expression correlates with poor outcomes in multiple human cancers. However, those findings are not universal, as they depend on study conditions. Those data suggest that multiple aspects of Girdin function and its role in tumor cell responses to anticancer therapeutics must be reconsidered. In the present study, we found that Girdin is involved in DNA damage‐induced cancer cell apoptosis. An esophageal cancer cell line that exhibited high Girdin expression showed a marked sensitivity to UV‐mediated DNA damage compared to a line with low Girdin expression. When transcriptional activation of endogenous Girdin was mediated by an engineered CRISPR/Cas9 activation system, sensitivity to DNA damage increased in both stationary and migrating HeLa cancer cells. High Girdin expression was associated with dysregulated cell cycle progression and prolonged G₁ and M phases. These features were accompanied by p53 activation, which conceivably increases cancer cell vulnerability to UV exposure. These data highlight the importance of understanding complex Girdin functions that influence cancer cell sensitivity to therapeutics.

Glutamine Synthetase Promotes Radiation Resistance via Facilitating Nucleotide Metabolism and Subsequent DNA Damage Repair

Radiation resistance is a critical problem in radiotherapy for cancer. Radiation kills tumor cells mainly through causing DNA damage. Thus, efficiency of DNA damage repair is one of the most important factors that limits radiotherapy efficacy. Glutamine physiologically functions to generate protein and nucleotides. Here, we study the impact of glutamine metabolism on cancer therapeutic responses, in particular under irradiation-induced stress. We show that radiation-resistant cells possessed low glycolysis, mitochondrial respiration, and TCA cycle but high glutamine anabolism. Transcriptome analyses revealed that glutamine synthetase (GS), an enzyme catalyzing glutamate and ammonia to glutamine, was responsible for the metabolic alteration. ChIP and luciferase reporter assays revealed that GS could be transcriptionally regulated by STAT5. Knockdown of GS delayed DNA repair, weakened nucleotide metabolism, and enhanced radiosensitivity both in vitro and in vivo. Our data show that GS links glutamine metabolism to radiotherapy response through fueling nucleotide synthesis and accelerating DNA repair.

Structural and Functional Insight Into the Glycosylation Impact Upon the HGF/c-Met Signaling Pathway

Upon interactions with its specific ligand hepatocyte growth factor (HGF), the c-Met signal is relayed to series of downstream pathways, exerting essential biological roles. Dysregulation of the HGF-c-Met signaling pathway has been implicated in the onset, progression and metastasis of various cancers, making the HGF-c-Met axis a promising therapeutic target. Both c-Met and HGF undergo glycosylation, which appears to be biologically relevant to their function and structural integrity. Different types of glycoconjugates in the local cellular environment can also regulate HGF/c-Met signaling by distinct mechanisms. However, detailed knowledge pertaining to the glycosylation machinery of the HGF-c-Met axis as well as its potential applications in oncology research is yet to be established. This mini review highlights the significance of the HGF-c-Met signaling pathway in physiological and pathological context, and discusses the molecular mechanisms by which affect the glycosylation of the HGF-c-Met axis. Owing to the crucial role played by glycosylation in the regulation of HGF/c-Met activity, better understanding of this less exploited field may contribute to the development of novel therapeutics targeting glycoepitopes.

[Evaluation of human milk feeding in hospitalized very low and extremely low birth weight infants]

Objective: To investigate the current situation of human milk (HM) feeding in hospitalized very low and extremely low birth weight infants. Methods: The study retrospectively extracted the data of 601 infants with birth weight <1 500 g, and admitted within 24 hours after birth to the Neonatal Intensive Care Unit of Nanjing Maternity and Child Health Care Hospital from January 2016 to December 2018. The infants were grouped into exclusive mother's-own-milk (MOM) group, donor human milk (DHM) group (partial or none MOM), and mixed (HM and formula) feeding group according to the feeding strategy. Qualitative and quantitative variables in the three groups were compared with One-way ANOVA, Kruskal-Wallis test, Chi-square test or Fisher exact test. Kappa and McNemar test were used for consistency testing. Results: Among the 601 infants (309 boys and 292 girls), 6 (1.0%) infants had never been fed with MOM. The gestational age and birth weight were (29.3±1.9) weeks and 1 260(1 115, 1 400) g in 601 infants. A total of 8 (1.3%) infants were grouped into MOM group, 542 (90.2%) were grouped into DHM group, and 51 (8.5%) were grouped into mixed feeding group. The percentage of enteral feedings with MOM in the stage of hospitalization 1-7 d, 8-14 d and 15-28 d were 73.6% (42.9%, 86.7%), 97.5% (78.6%, 100.0%) and 99.3% (93.0%, 100.0%), respectively (H=414.95, P<0.01), and the pairwise comparison suggested that the stage of hospitalization 1-7 d was the lowest (adjusted both P<0.05). The average weight adjusted daily dose of MOM were 9.7 (4.3, 18.2), 59.1 (26.5, 93.5) and 116.0 (60.3, 142.6) ml/(kg·d) in the stage of hospitalization 1-7 d, 8-14 d and 15-28 d, respectively (H=759.75, P<0.01), and the pairwise comparison suggested that the stage of hospitalization 1-7 d was the lowest (adjusted both P<0.05). The weight adjusted daily dose of MOM in exclusive MOM group, DHM and Mixed feeding group were 95.2 (40.0, 117.2), 82.9(53.6, 103.1) and 55.7 (16.6, 97.5) ml/(kg·d), respectively (H=10.78, P=0.005).Additionally, the percentage and weight adjusted daily dose of MOM showed a general consistency of 0.703 (P>0.05, Kappa=0.408). Conclusions: The rate of exclusive MOM feeding is low, especially during the first 7 days of hospitalization. The percentage of total enteral feedings with MOM and the average weight adjusted daily dose of MOM can well evaluate the situation of HM feeding during hospitalization quantitively.

ADORA1 Inhibition Promotes Tumor Immune Evasion by Regulating the ATF3-PD-L1 Axis

Here, we show that tumor ADORA1 deletion suppresses cell growth in human melanoma cell lines in vitro and tumor development in vivo in immune-deficient xenografts. However, this deletion induces the upregulation of PD-L1 levels, which inactivates cocultured T cells in vitro, compromises anti-tumor immunity in vivo, and reduces anti-tumor efficacy in an immune-competent mouse model. Functionally, PD-1 mAb treatment enhances the efficacy of ADORA1-deficient or ADORA1 antagonist-treated melanoma and NSCLC immune-competent mouse models. Mechanistically, we identify ATF3 as the factor transcriptionally upregulating PD-L1 expression. Tumor ATF3 deletion improves the effect of ADORA1 antagonist treatment of melanoma and NSCLC xenografts. We observe higher ADORA1, lower ATF3, and lower PD-L1 expression levels in tumor tissues from nonresponders among PD-1 mAb-treated NSCLC patients.

Meflin-Positive Cancer-Associated Fibroblasts Inhibit Pancreatic Carcinogenesis

Cancer-associated fibroblasts (CAF) constitute a major component of the tumor microenvironment. Recent observations in genetically engineered mouse models and clinical studies have suggested that there may exist at least two functionally different populations of CAFs, that is, cancer-promoting CAFs (pCAF) and cancer-restraining CAFs (rCAF). Although various pCAF markers have been identified, the identity of rCAFs remains unknown because of the lack of rCAF-specific marker(s). In this study, we found that Meflin, a glycosylphosphatidylinositol-anchored protein that is a marker of mesenchymal stromal/stem cells and maintains their undifferentiated state, is expressed by pancreatic stellate cells that are a source of CAFs in pancreatic ductal adenocarcinoma (PDAC). In situ hybridization analysis of 71 human PDAC tissues revealed that the infiltration of Meflin-positive CAFs correlated with favorable patient outcome. Consistent herewith, Meflin deficiency led to significant tumor progression with poorly differentiated histology in a PDAC mouse model. Similarly, genetic ablation of Meflin-positive CAFs resulted in poor differentiation of tumors in a syngeneic transplantation model. Conversely, delivery of a Meflin-expressing lentivirus into the tumor stroma or overexpression of Meflin in CAFs suppressed the growth of xenograft tumors. Lineage tracing revealed that Meflin-positive cells gave rise to α-smooth muscle actin-positive CAFs that are positive or negative for Meflin, suggesting a mechanism for generating CAF heterogeneity. Meflin deficiency or low expression resulted in straightened stromal collagen fibers, which represent a signature for aggressive tumors, in mouse or human PDAC tissues, respectively. Together, the data suggest that Meflin is a marker of rCAFs that suppress PDAC progression. SIGNIFICANCE: Meflin marks and functionally contributes to a subset of cancer-associated fibroblasts that exert antitumoral effects.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/20/5367/F1.large.jpg.

[Acute respiratory failure due to Pneumocystis pneumonia in connective tissue disease patients: clinical manifestation and prognostic factors related to hospital mortality]

Objective: To investigate the clinical manifestations and prognostic factors of hospital death in connective tissue disease patients with acute respiratory failure caused by pneumocystis pneumonia (PCP) admitted to two medical intensive care units(MICU). Methods: A retrospective review was conducted for all connective tissue disease (CTD) patients with acute respiratory failure from PCP in MICU of 2 academic medical centers between 2010 and 2015. The patients were divided into survivors and non-survivors. Demographic and clinical data, including laboratory, radiological and microbiological findings, as well as therapy, clinical course, mortality and prognostic factors of hospital mortality were included in the analysis. Logistic regression models were used to determine the effect of prognostic factors on hospital death after adjusting for covariates of which the p values were less than 0.1. Results: A total of 41 patients with connective tissue disease were identified. The PaO(2)/FiO(2) ratio (PFR) on ICU admission was 120 mmHg(55-180 mmHg, 1 mmHg=0.133 kPa). Common clinical features included dyspnea (90.2%, 37/41), fever (87.8%, 36/41) and dry cough(65.9%, 30/41). 58.5%(24/41) and 17.1%(7/41) patients were co-infected by CMV and aspergillus, respectively. The overall mortality rate was 75.6%(31/41). Compared with survivors, the age, APACHEⅡ score and incidence of barotrauma in non-survivors were higher (39±17 vs 58±15, t=3.018, P=0.002), (15±6 vs 19±5, t=2.528, P=0.019), (0/10 vs 12/31, χ(2)=5.473, P=0.021), while PFR on ICU admission was lower in non-survivors (172±68 vs 116±49, t=-1.893, P=0.007). Logistic analysis showed that PFR on ICU admission was the independent risk factor for hospital death (OR=1.004, 95%CI: 1.002-1.006, P=0.048). Conclusions: Mortality rate among patients with acute respiratory failure secondary to CTD related PCP is still high, and the poor prognostic factors of hospital mortality included PFR on ICU admission and barotrauma.

Girdin/GIV regulates collective cancer cell migration by controlling cell adhesion and cytoskeletal organization

Pathological observations show that cancer cells frequently invade the surrounding stroma in collective groups rather than through single cell migration. Here, we studied the role of the actin-binding protein Girdin, a specific regulator of collective migration of neuroblasts in the brain, in collective cancer cell migration. We found that Girdin was essential for the collective migration of the skin cancer cell line A431 on collagen gels as well as their fibroblast-led collective invasion in an organotypic culture model. We provide evidence that Girdin binds to β-catenin that plays important roles in the Wnt signaling pathway and in E-cadherin-mediated cell-cell adhesion. Girdin-depleted cells displayed scattering and impaired E-cadherin-specific cell-cell adhesion. Importantly, Girdin depletion led to impaired cytoskeletal association of the β-catenin complex, which was accompanied by changes in the supracellular actin cytoskeletal organization of cancer cell cohorts on collagen gels. Although the underlying mechanism is unclear, this observation is consistent with the established role of the actin cytoskeletal system and cell-cell adhesion in the collective behavior of cells. Finally, we showed the correlation of the expression of Girdin with that of the components of the E-cadherin complex and the differentiation of human skin cancer. Collectively, our results suggest that Girdin is an important modulator of the collective behavior of cancer cells.

Abstract 3160: The actin-binding protein Girdin/GIV regulates collective cancer cell migration by controlling cell adhesion and cytoskeletal organization

Pathological observations show that cancer cells frequently invade the surrounding stroma in collective groups rather than through single cell migration. The identification of genes and proteins that are specifically involved in the collective behavior of cancer cells has thus far been limited. Here, we studied the role of the actin-binding protein Girdin in collective cancer cell migration. This protein is a specific regulator of collective migration of neuroblasts born in the subventricular zone of the postnatal and adult brains and participates in the progression of cancer. We found that Girdin was essential for the collective migration of the skin cancer cell line A431 on collagen gels as well as their fibroblast-led collective invasion in an organotypic culture model. We provide evidence that Girdin binds to β-catenin that plays important roles in the Wnt signaling pathway and in E-cadherin-mediated cell-cell adhesion. Girdin-depleted cells displayed scattering and impaired E-cadherin-specific cell-cell adhesion. Importantly, Girdin depletion led to impaired cytoskeletal association of the β-catenin complex, which was accompanied by changes in the supracellular actin cytoskeletal organization of cancer cell cohorts on collagen gels. Although the underlying mechanism is unclear, this observation is consistent with the established role of the actin cytoskeletal system and cell-cell adhesion in the collective behavior of cells.

Citation Format: Xiaoze Wang, Atsushi Enomoto, Liang Weng, Hisashi Haga, Sumire Ishida, Masahide Takahashi. The actin-binding protein Girdin/GIV regulates collective cancer cell migration by controlling cell adhesion and cytoskeletal organization [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3160.

[Pigmented extramammary Paget's disease accompanied with condyloma acuminatum: a case report]

Pigmented extramammary Paget's disease (PEMPD) is an uncommon intraepithelial adenocarcinoma and a rare variant of Paget's disease, characterized as a superficial pigmented scaly macule clinically and an increased number of melanocytes scattered between the Paget's cells histologically. So it may be confused clinically and histologically with melanocytic tumors, dermatitis and other dermatoses. Different therapeutic attitudes are required in this case of adenocarcinoma in situ as opposed to melanoma and dermatitis. Condyloma acuminatum (CA) is a common sexually transmitted disease caused by human papilloma virus infection, which is also called as genital warts. In this article, we first reported a case of a 65-year-old Chinese man who had pigmented extramammary Paget's disease complicated with CA. This patient presented with verrucous papules on the scrotum for 3.5 years, infiltrative erythema with itch on the mons pubis for 3 years, and scrotum and penis involved gradually for 4 months. Physical examination showed a 8 cm×10 cm dark red patch on the upper part of the scrotum, penis and mons pubis, as well as few maculopapules and nodules. Histopathologic examination of the lesion on the scrotum revealed a focus of Paget's disease, characterized by the presence of large round cells with abundant pale or granular/dusty cytoplasm, pleomorphic vesicular nuclei and prominent nucleoli (Paget's cells), while the histology of the verrucous lesion was consistent with CA. Immunohistochemistry was performed, which showed diffuse positive staining with CK, CEA, PAS, CK20, EMA, CK7, and Ki-67 (40%), HER2 in Paget's cells and negative with P53, P16, CK5/6, S100, MelanA, HMB45, estrogen receptor, progesterone receptor, and gross cystic disease flid protein 15 (GCDFP15). Human papillomavirus-11 (HPV-11) was positive by genotyping using gene amplification in the lesion of scrotum. According to clinical features and laboratory findings, a diagnosis of PEMPD complicated with CA was made. Local excision of the lesion was performed and sent for histological examination, with all margins clear of tumor. Both aforementioned diseases often occur in the vulva. Even so, it has been rarely reported coexisting of the above two diseases, of which the clinical significance and association are also unclear. In this article, we also reviewed the literature relating to PEMPD, and on this basis, the profile of this disease is discussed including its pathogenesis, clinical manifestation, diagnosis, treatment and advances. Due to PEMPD occasionally accompanied with an underlying carcinoma, it's essential to make an accurate diagnosis. Besides, review of the literature reveals that pigmented variant of Paget's disease could be initially misdiagnosed as melanocytic tumors and other dermatoses unless the entity is considered in the differential diagnosis and additional confirmatory studies are performed.

Robust, tunable, and high purity triggered single photon source at room temperature using a nitrogen-vacancy defect in diamond in an open microcavity

We report progress in the development of tunable room temperature triggered single photon sources based on single nitrogen-vacancy (NV) centres in nanodiamond coupled to open access optical micro-cavities. The feeding of fluorescence from an NV centre into the cavity mode increases the spectral density of the emission and results in an output stream of triggered single photons with spectral line width of order 1 nm, tunable in the range 640 - 700 nm. We record single photon purities exceeding 96% and estimated device efficiencies up to 3%. We compare performance using plano-concave microcavities with radii of curvature from 25 μm to 4 μm and show that up to 17% of the total emission is fed into the TEM₀₀ mode. Pulsed Hanbury-Brown Twiss (HBT) interferometry shows that an improvement in single photon purity is facilitated due to the increased spectral density.

Negative regulation of amino acid signaling by MAPK-regulated 4F2hc/Girdin complex

Amino acid signaling mediated by the activation of mechanistic target of rapamycin complex 1 (mTORC1) is fundamental to cell growth and metabolism. However, how cells negatively regulate amino acid signaling remains largely unknown. Here, we show that interaction between 4F2 heavy chain (4F2hc), a subunit of multiple amino acid transporters, and the multifunctional hub protein girders of actin filaments (Girdin) down-regulates mTORC1 activity. 4F2hc interacts with Girdin in mitogen-activated protein kinase (MAPK)- and amino acid signaling–dependent manners to translocate to the lysosome. The resultant decrease in cell surface 4F2hc leads to lowered cytoplasmic glutamine (Gln) and leucine (Leu) content, which down-regulates amino acid signaling. Consistently, Girdin depletion augments amino acid-induced mTORC1 activation and inhibits amino acid deprivation–induced autophagy. These findings uncovered the mechanism underlying negative regulation of amino acid signaling, which may play a role in tightly regulated cell growth and metabolism.

The mechanistic target of rapamycin complex 1 (mTORC1) protein kinase is a master regulator of cell growth, which senses several extracellular signals, such as growth factors and nutrient levels, to coordinate cell metabolism. The activation of mTORC1 by amino acids requires many proteins such as Rag GTPase, GATOR, and Ragulator. However, how cells negatively regulate amino acid signaling remains largely unknown. In this study, we revealed that an endocytosis-related protein called Girdin negatively regulates amino acid–induced mTORC1 activation via the formation of a complex with 4F2 heavy chain (4F2hc), a subunit of multiple amino acid transporters. We show that Girdin/4F2h complex formation requires growth factor-induced Girdin phosphorylation and amino acid–induced 4F2hc ubiquitination. We also find that the complex promotes the internalization of 4F2hc from the plasma membrane to the lysosomes. The subsequent decrease of 4F2hc in the cell surface results in a lower cytoplasmic glutamine and leucine content, which then down-regulates amino acid–induced mTORC1 activation. These findings uncover the mechanism underlying negative regulation of mTORC1 signaling, which may play a role in tightly regulated cell growth and metabolism.

[Left atrial appendage volume is a valuable predictor of atrial fibrillation recurrence after radiofrequency catheter ablation]

Objective: To investigate the association between the left atrial appendage (LAA) volume and atrial fibrillation (AF) recurrence after radiofrequency catheter ablation. Methods: We prospectively enrolled sixty-two patients with AF (40 cases with paroxysmal AF, 22 cases with persistent AF) who successfully underwent a first AF catheter ablation and had performed contrast-enhanced cardiac computed tomography (CT) prior to the procedure to measure LAA volumes in our hospital from January 2012 to August 2015. Circumferential pulmonary vein isolation was performed under the guidance of three-dimension mapping system (CARTO system). Linear ablation or ablation of complex fractioned atrial electrograms was also undertaken if necessary. All patients were followed up at the 3rd, 6th and 12th months after ablation by 24-hour ambulatory Holter monitoring, and were divided into the non-recurrence group (n=42) and the AF recurrence group (n=20). Univariate and multivariate Cox proportional hazards regression analysis were used to assess the factors related to AF recurrence. The receiver operating characteristic (ROC) curve was calculated to assess the best cut-off value of LAA volume to predict AF recurrence. Kaplan-Meier method was used to evaluate the rate of freedom from AF recurrence. Results: Mean LAA volume in all patients was (9.5±3.6)ml. AF recurrence occurred in 20 patients (32%) during the follow-up period. The LAA volume was significantly larger in the AF recurrence group than in the non-recurrence group ((11.5±3.8)ml vs. (8.3±3.1)ml, P=0.002). In the univariate regression analysis, LAA volume (HR=1.36, 95%CI 1.14-1.82, P<0.001), persistent AF (HR=4.43, 95%CI 1.52-12.06, P<0.001) and hypertension (HR=1.61, 95%CI 1.13-2.04, P=0.041) were risk factors of AF recurrence. However, multivariate regression analysis revealed that LAA volume (HR=1.32, 95%CI 1.12-1.51, P<0.001) and persistent AF (HR=4.22, 95% CI 1.48-11.05, P<0.001) were independent predictors for AF recurrence after ablation. The receiver operating characteristic (ROC) curve analysis revealed that a LAA volume >8.80 ml was associated with AF recurrence after ablation (sensitivity: 94% and specificity: 66%, area under the curve=0.76). Kaplan-Meier analysis showed a lower rate free from AF recurrence in the group with LAA volume >8.80 ml (P<0.001). Conclusion: Larger LAA volume is associated with AF recurrence after catheter ablation in patients with AF. A LAA volume greater than 8.80 ml could be used to predict AF recurrence after ablation.

Therapeutic ultrasound protects HUVECs from ischemia/hypoxia-induced apoptosis via the PI3K-Akt pathway

Background: Previous studies have demonstrated that therapeutic ultrasound (TUS) ameliorates angiogenesis on ischemic hind limb animals and also promotes human umbilical vein endothelial cells (HUVECs) tube formation. Apoptosis plays a key role in post-ischemic angiogenesis pathogenesis. However, the mechanisms underlying the anti-apoptotic effects of TUS are not clear. Therefore we put forward the hypothesis that TUS might promote angiogenesis during ischemia/hypoxia (I/H) by decreasing apoptosis. Methods: We investigated the cytoprotective role of TUS and the underlying mechanisms in I/H-induced HUVEC apoptosis. HUVECs were treated under hypoxic serum-starved conditions for 36 h and then treated with or without TUS (9 minutes, 1 MHz, 0.3 W/cm²). The cell viability was examined by the CCK-8 assay, apoptosis cell rate was determined by TUNEL staining and flow cytometry assay. In addition, the mitochondrial-dependent apoptosis pathway was evaluated by the protein activity of Bax, Bcl-2 and Caspase-3. Results: 1) apoptosis could be induced by I/H in HUVECs. 2) TUS attenuates HUVECs cell apoptosis induced by I/H. 3) TUS inhibits the protein expression of apoptosis modulators and effectors that regulate the mitochondrial pathway of apoptosis in HUVECs. 4) TUS increases the phosphorylation of Akt, which demonstrates the activation of the phosphoinositide 3-kinase (PI3K)- serine/threonine kinase (Akt) signal pathway. Conclusions: The present study indicates that exposure to TUS exerts a protective effect against I/H-induced apoptosis among HUVECs and that this process is mediated through the mitochondrial-dependent intrinsic apoptotic pathway. We also confirm that the PI3K-Akt signal cascade may be taken part in the TUS effects on apoptosis.

[The 455th case: swollen leg, jaundice and mental disturbance]

A 17-year-old young man with a history of swollen leg and intermittent jaundice was presented to Peking Union Medical College Hospital with acute fever and mental disturbance. He developed deep venous thrombosis, acute myocardial infarction and plantar skin necrosis during the past four years, and was presented with an acute episode of fever, thrombocytopenia, acute kidney injury, acute myocardial infarction, mental disturbance, and obstructive jaundice. Laboratory tests showed schistocytes on peripheral blood smear.High titer of antiphospholipid antibodies was detected.Strikingly, the activity of a disintegrin and metalloprotease with a thrombospondin type 1 motif, member 13 (ADAMTS13)was significantly decreased without the production of inhibitors. Images indicated stenosis of the common bile duct, common hepatic duct, and cystic duct, which caused dilation of bile ducts and the gall bladder. Corticosteroids and anticoagulation therapy were effective at first, but the disease relapsedonce the corticosteroids tapered down. Plasma exchange was administrated for 17 times, which was effective temporarily during this episode. Methylprednisolone pulse therapy, intravenous immunoglobulin, rituximab, anticoagulation therapy, and bile drainage, were all tried but still could not control the disease. The patient's family agreed to withdraw treatment after he developed septic shock.

Urokinase-type plasminogen activator receptor promotes proliferation and invasion with reduced cisplatin sensitivity in malignant mesothelioma

Malignant mesothelioma (MM) is a rare neoplasm associated with asbestos exposure. The prognosis of MM is poor because it is aggressive and highly resistant to chemotherapy. Using a rat model of asbestos-induced MM, we found elevated urokinase-type plasminogen activator receptor (uPAR; Plaur) expression in rat tissues, which was associated with poor prognosis. The proliferation, migration and invasion of MM cells were suppressed by uPAR knockdown and increased by overexpression experiments, irrespective of urokinase-type plasminogen activator (uPA; Plau) levels. More importantly, we found that uPAR expression is associated with sensitivity to cisplatin in MM through the PI3K/AKT pathway, which was demonstrated with specific inhibitors, LY294002 and Akti-1/2. uPAR knockdown significantly increased sensitivity to cisplatin whereas its overexpression significantly decreased cisplatin sensitivity. Furthermore, sera and tissues from MM patients showed significantly high uPAR levels, which suggested the pathogenic role of uPAR in the tumor biology of human MM. In conclusion, our findings indicate that uPAR levels are associated with malignant characteristics and cisplatin sensitivity of MM. In addition to the potential use of uPAR as a prognostic marker, the combination of uPAR abrogation and cisplatin may reveal a promising therapeutic approach for MM.

Identification of Meflin as a Potential Marker for Mesenchymal Stromal Cells

Bone marrow-derived mesenchymal stromal cells (BM-MSCs) in culture are derived from BM stromal cells or skeletal stem cells. Whereas MSCs have been exploited in clinical medicine, the identification of MSC-specific markers has been limited. Here, we report that a cell surface and secreted protein, Meflin, is expressed in cultured MSCs, fibroblasts and pericytes, but not other types of cells including epithelial, endothelial and smooth muscle cells. In vivo, Meflin is expressed by immature osteoblasts and chondroblasts. In addition, Meflin is found on stromal cells distributed throughout the BM, and on pericytes and perivascular cells in multiple organs. Meflin maintains the undifferentiated state of cultured MSCs and is downregulated upon their differentiation, consistent with the observation that Meflin-deficient mice exhibit increased number of osteoblasts and accelerated bone development. In the bone and BM, Meflin is more highly expressed in primitive stromal cells that express platelet-derived growth factor receptor α and Sca-1 than the Sca-1-negative adipo-osteogenic progenitors, which create a niche for hematopoiesis. Those results are consistent with a decrease in the number of clonogenic colony-forming unit-fibroblasts within the BM of Meflin-deficient mice. These preliminary data suggest that Meflin is a potential marker for cultured MSCs and their source cells in vivo.

Pharmacometabolomic Assessments of Atenolol and Hydrochlorothiazide Treatment Reveal Novel Drug Response Phenotypes

Achieving hypertension (HTN) control and mitigating the adverse health effects associated with HTN continues to be a global challenge. Some individuals respond poorly to current HTN therapies, and mechanisms for response variation remain poorly understood. We used a nontargeted metabolomics approach (gas chromatography time-of-flight/mass spectrometry gas chromatography time-of-flight/mass spectrometry) measuring 489 metabolites to characterize metabolite signatures associated with treatment response to anti-HTN drugs, atenolol (ATEN), and hydrochlorothiazide (HCTZ), in white and black participants with uncomplicated HTN enrolled in the Pharmacogenomic Evaluation of Antihypertensive Responses study. Metabolite profiles were significantly different between races, and metabolite responses associated with home diastolic blood pressure (HDBP) response were identified. Metabolite pathway analyses identified gluconeogenesis, plasmalogen synthesis, and tryptophan metabolism increases in white participants treated with HCTZ (P < 0.05). Furthermore, we developed predictive models from metabolite signatures of HDBP treatment response (P < 1 × 10(-5)). As part of a quantitative systems pharmacology approach, the metabolites identified herein may serve as biomarkers for improving treatment decisions and elucidating mechanisms driving HTN treatment responses.

Angiogenesis effect of therapeutic ultrasound on HUVECs through activation of the PI3K-Akt-eNOS signal pathway

Therapeutic angiogenic effects of low-intensity ultrasound have been reported in endothelial cells and animal models of hind limb ischemia. It has been shown that the proliferation, migration, and tube formation of endothelial cells play critical roles in angiogenesis. The purpose of this study was to determine the underlying mechanism of low-intensity continuous therapeutic ultrasound on angiogenesis in endothelial cells. In the present study, human umbilical vein endothelial cells (HUVECs) were simulated of low-intensity therapeutic ultrasound (TUS, 1 MHz, 0.3 W/cm(2), 9 minute per day) for 3 days, and we observed migration, tube formation, and expression of endothelial nitric oxide synthase (eNOS) and serine/threonine kinase (Akt) in HUVECs. Specific inhibitors of eNOS and phosphoinositide 3-kinase (PI3K) were added to the culture medium and TUS-induced changes in the pathways that mediate angiogenesis were investigated. After exposure to TUS, HUVECs tube formation and migration were significantly promoted, which was blocked by the eNOS inhibitor Immunofluorescence assay and Western blotting analysis demonstrated that eNOS expression in the HUVECs was significantly increased after TUS exhibition. Proteins of phosphorylated eNOS and Akt were both up-regulated after TUS stimulation. However, the specific inhibitor of PI3K not only significantly decreased the expression of p-Akt, but also down-regulated the p-eNOS. This suggested that the PI3K/Akt signal pathway might participate in modulating the activity of eNOS. In short, TUS therapy promotes angiogenesis through activation of the PI3K-Akt-eNOS signal cascade in HUVECs.

Pulsed electromagnetic field improves postnatal neovascularization in response to hindlimb ischemia

Pulsed electromagnetic fields (PEMF) have been shown to promote proliferation and regeneration in the damaged tissue. Here, we examined whether PEMF therapy improved postnatal neovascularization using murine model of hindlimb ischemia, and the underlying cellular/molecular mechanisms were further investigated. Hindlimb ischemia was induced by unilateral femoral artery resection using 6-8 week-old male C57BL6 mice. Then, mice were exposed to extracorporeal PEMF therapy (4 cycles, 8min/cycle, 30 ± 3 Hz, 5 mT) every day until day 14. Our data demonstrated that PEMF therapy significantly accelerated wound healing, decreased prevalence of gangrene and increased postnatal neovascularization. Moreover, the levels of vascular endothelial growth factor (VEGF), endothelial nitric oxide synthase (eNOS) and Akt phosphorylation in ischemic muscles were markedly enhanced following PEMF therapy. In vitro, PEMF inhibited the process of hypoxia-induced apoptosis and augmented tube formation, migration and proliferative capacities of human umbilical vein endothelial cells (HUVECs). Additionally, PEMF exposure increased VEGF secretion, as well as the eNOS and Akt phosphorylation, and these benefits could be blocked by either phosphoinositide 3-kinase (PI3K) or eNOS inhibitor. In conclusion, our data indicated that PEMF therapy enhanced ischemia-mediated angiogenesis, through up-regulating VEGF expression and activating the PI3K-Akt-eNOS pathway. Therefore, PEMF should be a valuable treatment for the patients with critical limb ischemia.