Exploring the impact of PDGFD in osteosarcoma metastasis through single-cell sequencing analysis

PURPOSE

The overall survival rate for metastatic osteosarcoma hovers around 20%. Responses to second-line chemotherapy, targeted therapies, and immunotherapies have demonstrated limited efficacy in metastatic osteosarcoma. Our objective is to validate differentially expressed genes and signaling pathways between non-metastatic and metastatic osteosarcoma, employing single-cell RNA sequencing (scRNA-seq) and additional functional investigations. We aim to enhance comprehension of metastatic mechanisms and potentially unveil a therapeutic target.

METHODS

scRNA-seq was performed on two primary osteosarcoma lesions (1 non-metastatic and 1 metastatic). Seurat package facilitated dimensionality reduction and cluster identification. Copy number variation (CNV) was predicted using InferCNV. CellChat characterized ligand-receptor-based intercellular communication networks. Differentially expressed genes underwent GO function enrichment analysis and GSEA. Validation was achieved through the GSE152048 dataset, which identified PDGFD-PDGFRB as a common ligand-receptor pair with significant contribution. Immunohistochemistry assessed PDGFD and PDGFRB expression, while multicolor immunofluorescence and flow cytometry provided insight into spatial relationships and the tumor immune microenvironment. Kaplan-Meier survival analysis compared metastasis-free survival and overall survival between high and low levels of PDGFD and PDGFRB. Manipulation of PDGFD expression in primary osteosarcoma cells examined invasion abilities and related markers.

RESULTS

Ten clusters encompassing osteoblasts, osteoclasts, osteocytes, fibroblasts, pericytes, endothelial cells, myeloid cells, T cells, B cells, and proliferating cells were identified. Osteoblasts, osteoclasts, and osteocytes exhibited heightened CNV levels. Ligand-receptor-based communication networks exposed significant fibroblast crosstalk with other cell types, and the PDGF signaling pathway was activated in non-metastatic osteosarcoma primary lesion. These results were corroborated by the GSE152048 dataset, confirming the prominence of PDGFD-PDGFRB as a common ligand-receptor pair. Immunohistochemistry demonstrated considerably greater PDGFD expression in non-metastatic osteosarcoma tissues and organoids, correlating with extended metastasis-free and overall survival. PDGFRB expression showed no significant variation between non-metastatic and metastatic osteosarcoma, nor strong correlations with survival times. Multicolor immunofluorescence suggested co-localization of PDGFD with PDGFRB. Flow cytometry unveiled a highly immunosuppressive microenvironment in metastatic osteosarcoma. Manipulating PDGFD expression demonstrated altered invasive abilities and marker expressions in primary osteosarcoma cells from both non-metastatic and metastatic lesions.

CONCLUSIONS

scRNA-seq illuminated the activation of the PDGF signaling pathway in primary lesion of non-metastatic osteosarcoma. PDGFD displayed an inhibitory effect on osteosarcoma metastasis, likely through the suppression of the EMT signaling pathway.

Improving Bond Strength of Translucent Zirconia Through Surface Treatment With SiO2-ZrO2 Coatings

BACKGROUND

Translucent monolithic zirconia ceramics have been applied in dental clinics due to their esthetic translucent formulations and mechanical properties. Considering inherent ceramic brittleness, adhesive bonding with resin composite increases the fracture resistance of ceramic restorations. However, zirconia is a chemically stable material that is difficult to adhesively bond with resin.

OBJECTIVES

To investigate the influences of SiO2-ZrO2 coatings on adhesive bonding of zirconia and the surface characterization of those coatings.

METHODS AND MATERIALS

Translucent zirconia discs were classified into groups based on surface treatments: CT (control), SB (sandblasting), C21(SiO2:ZrO2=2:1), C11(SiO2:ZrO2=1:1), and C12 (SiO2:ZrO2=1:2) (n=10). Surface characterization of coatings on zirconia were analyzed by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), surface roughness assessment (Ra), X-ray diffraction (XRD), water contact angle (WCA), translucency parameter (TP), and shear bond strength (SBS). Two-way ANOVA for shear bond strength results and ANOVA for Ra and WCA were performed.

RESULTS

SEM images revealed SiO2 islands on zirconia disks coated with SiO2-ZrO2. Surface roughness of C12, C11, and C21 groups was significantly larger than those of groups SB and CT (p<0.05). XRD results showed that phase transformation of zirconia disks was detected only in the SB group. In addition, SiO2-ZrO2 coatings reduced WCA. The translucency decreased only in group C21. Group C11 showed the highest shear bond strength under both aging conditions.

CONCLUSION

SiO2-ZrO2 coating is a promising method to enhance the adhesive resin bonding of translucent zirconia without causing phase transformation of translucent zirconia.

Learning Intention-Aware Policies in Deep Reinforcement Learning

Deep reinforcement learning (DRL) provides an agent with an optimal policy so as to maximize the cumulative rewards. The policy defined in DRL mainly depends on the state, historical memory, and policy model parameters. However, we humans usually take actions according to our own intentions, such as moving fast or slow, besides the elements included in the traditional policy models. In order to make the action-choosing mechanism more similar to humans and make the agent to select actions that incorporate intentions, we propose an intention-aware policy learning method in this letter To formalize this process, we first define an intention-aware policy by incorporating the intention information into the policy model, which is learned by maximizing the cumulative rewards with the mutual information (MI) between the intention and the action. Then we derive an approximation of the MI objective that can be optimized efficiently. Finally, we demonstrate the effectiveness of the intention-aware policy in the classical MuJoCo control task and the multigoal continuous chain walking task.

Annexin A1 induces oxaliplatin resistance of gastric cancer through autophagy by targeting PI3K/AKT/mTOR

Resistance to oxaliplatin (OXA) is a major cause of recurrence in gastric cancer (GC) patients. Autophagy is an important factor ensuring the survival of cancer cells under chemotherapeutic stress. We aimed to investigate the role of OXA-related genes in autophagy and chemoresistance of gastric cancer cells. We established OXA-resistant gastric cancer cells and used RNA-seq to profile gene expression within OXA-resistant GC and corresponding parental cells. Immunohistochemistry and RT-qPCR was performed to detect gene expression in tissues of two cohorts of GC patients who received OXA-based chemotherapy. The chemoresistant effects of the gene were assessed by cell viability, apoptosis, and autophagy assays. The effects of the gene on autophagy were assessed with mRFP-GFP-LC3 and Western blotting (WB). Gene set enrichment analysis (GSEA) and WB were performed to detect the activity of PI3K/AKT/mTOR signaling under the regulation of the gene. The OXA-resistant property of GC cells is related to their enhanced autophagic activity. Based on RNA-seq profiling, ANXA1 was selected as a candidate, as it was upregulated significantly in OXA-resistant cells. Furthermore, we found that higher ANXA1 expression before chemotherapy was associated with subsequent development of resistance to oxaliplatin, and overexpression of ANXA1 promoted the resistance of gastric cancer cells to oxaliplatin. So, it may serve as a key regulator in GC chemo-resistance knockdown of ANXA1, via inhibiting autophagy, enhancing the sensitivity of OXA-resistant GC cells to OXA in vitro and in vivo. Mechanically, we identified that PI3K/AKT/mTOR signaling pathway was activated in the ANXA1 stable knockdown AGS/OXA cells, which leads to the suppression of autophagy. ANXA1 functions as a chemoresistant gene in GC cells by targeting the PI3K/AKT/mTOR signaling pathway and might be a prognostic predictor for GC patients who receive OXA-based chemotherapy.

Preparation and characterization of a novel triple composite scaffold containing silk fibroin, chitosan, extracellular matrix and the mechanism of Akt/FoxO signaling pathway in colonic cancer cells cultured in 3D

This work examined the physical and chemical properties and biocompatibility in vivo and in vitro of a unique triple composite scaffold incorporating silk fibroin, chitosan, and extracellular matrix. The materials were blended, cross-linked, and freeze-dried to create a composite scaffold of silk fibroin/chitosan/colon extracellular matrix (SF/CTS/CEM) with varying CEM contents. The SF/CTS/CEM (1:1:1) scaffold demonstrated the preferable shape, outstanding porosity, favorable connectivity, good moisture absorption, and acceptable and controlled swelling and degradation properties. Additionally, HCT-116 cells cultivated with SF/CTS/CEM (1:1:1) showed excellent proliferation capacity, cell malignancy, and delayed apoptosis, according to the in vitro cytocompatibility examination. We also examined the PI3K/PDK1/Akt/FoxO signaling pathway and discovered that cell culture using a SF/CTS/CEM (1:1:1) scaffold may prevent cell death by phosphorylating Akt and suppressing FoxO expression. Our findings demonstrate the potential of the SF/CTS/CEM (1:1:1) scaffold as an experimental model for colonic cancer cell culture and for replicating the three-dimensional in vivo cell growth environment.

Single-cell landscape and clinical outcomes of infiltrating B cells in colorectal cancer

B cells constitute a major component of infiltrating immune cells in colorectal cancer (CRC). However, the characteristics of B cells and their clinical significance remain unclear. In this study, using single-cell RNA sequencing and multicolour immunofluorescence staining experiments, we identified five distinct subtypes of B cells with their marker genes, distribution patterns and functional properties in the CRC tumour microenvironment. Meanwhile, we found a higher proportion of IgG plasma cells in tumour sites than that in adjacent normal mucosal tissues. In addition, the CXCL13-producing CD8⁺ T cells in the tumour tissues could promote the formation of tertiary lymphoid structure (TLS) B cells, and the CCL28-CCR10 axis is pivotal for IgG plasma cell migration from the periphery of TLSs to the tumour stroma. Finally, we identified four distinct colon immune classes (CICs: A-D) and found that CD20⁺ B cells within TLSs were enriched in one immune-inflamed or hot tumour group (CIC D). This B cell-rich group, which was characterized by strong antigen presentation, IgG plasma cells accumulation, microsatellite instability-high (MSI-H) and high tumour mutation burden (TMB-H), as well as immunosuppressive property in particular, might become a potential predictive biomarker for future immunotherapy. Additionally, in an immunotherapy cohort, patients with the enrichment of B cells and TLSs were demonstrated to obtain significant therapeutic advantages. Together, our findings provide the detailed landscape of infiltrating B cells and their potential clinical significance in CRC.

Clinical study on risk factors related to postoperative recurrence or metastasis of rectal cancer: a retrospective cohort study

Background

Rectal cancer is usually treated by surgery, but recurrence or metastasis seriously affect the quality of life and survival of patients. Identifying the risk factors for postoperative recurrence or metastasis of rectal cancer has important guiding value for the treatment of rectal cancer. However, the research on risk factors of postoperative recurrence or metastasis of rectal cancer has not been unified.

Methods

The data of all patients undergoing rectal cancer surgery in The Fifth People's Hospital of Shanghai, Fudan University, from 2016 to 2020 were collected and analyzed. A total of 185 patients were included for statistical analysis and were divided into a recurrence or metastasis group and a non-recurrence or metastasis group. Patients were followed up according to National Comprehensive Cancer Network (NCCN) guidelines by enhanced CT or MRI, and colonoscopy. The cut-off of the research was recurrence, metastasis, or death. Logistic regression analysis and Cox regression analysis were used to analyze the risk factors related to postoperative recurrence or metastasis of rectal cancer, and the survival curve was drawn.

Results

Multiple logistic regression analysis showed involvement of the mesorectal fascia (MRF) [OR (odds ratio) =2.9, 95% confidence interval (CI): 1.16-7.29, P=0.023], nerve and vascular invasion (OR =1.7, 95% CI: 1.08-2.59, P=0.022), intraoperative blood transfusion (OR =3.7, 95% CI: 1.45-9.40, P=0.006), and Dukes staging (OR =2.3, 95% CI: 1.26-4.35, P=0.007) were independent risk factors for postoperative recurrence or metastasis of rectal cancer. Involvement of mesenteric fascia infiltration (OR =11.5, 95% CI: 1.49-88.79, P=0.019) and Dukes stage (OR =3.0, 95% CI: 1.46-6.26, P=0.003) were independent risk factors for liver metastasis, while nerve and vascular invasion (OR =2.4, 95% CI: 1.19-5.00, P=0.015) was an independent risk factor for pulmonary metastasis.

Conclusions

Postoperative recurrence or metastasis of rectal cancer is related to many factors. These findings have clinical guiding value and significance for the follow up and prognosis of patients with rectal cancer after surgery. Large-scale prospective clinical studies are needed.

SELENBP1 inhibits progression of colorectal cancer by suppressing epithelial–mesenchymal transition

Selenium-binding protein 1 (SELENBP1) is frequently dysregulated in various malignancies including colorectal cancer (CRC); however, its roles in progression of CRCs and the underlying mechanism remain to be elucidated. In this study, we compared the expression of SELENBP1 between CRCs and colorectal normal tissues (NTs), as well as between primary and metastatic CRCs; we determined the association between SELENBP1 expression and CRC patient prognoses; we conducted both in vitro and in vivo experiments to explore the functional roles of SELENBP1 in CRC progression; and we characterized the potential underlying mechanisms associated with SELENBP1 activities. We found that the expression of SELENBP1 was significantly and consistently decreased in CRCs than that in adjacent NTs, while significantly and frequently decreased in metastatic than primary CRCs. High expression of SELENBP1 was an independent predictor of favorable prognoses in CRC patients. Overexpression of SELENBP1 suppressed, while silencing of SELENBP1 promoted cell proliferation, migration and invasion, and in vivo tumorigenesis of CRC. Mechanically, SELENBP1 may suppress CRC progression by inhibiting the epithelial–mesenchymal transition.

Selenium binding protein 1 inhibits tumor angiogenesis in colorectal cancers by blocking the Delta-like ligand 4/Notch1 signaling pathway

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SELENBP1 localizes to vessels and is suppressed in tumor vessels.

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SELENBP1 inhibits in vivo and in vitro angiogenesis.

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SELENBP1 antagonizes tumor angiogenesis by blocking the DLL4/Notch1 signaling pathway.

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SELENBP1 is a candidate target to treat bevacizumab-resistance in colorectal cancer.

Background

Selenium binding protein 1 (SELENBP1) is frequently downregulated in malignancies such as colorectal cancer (CRC), however, whether it is involved in tumor angiogenesis is still unknown.

Methods

We analyzed the expression and localization of SELENBP1 in vessels from CRC and neighboring tissues. We investigated the in vitro and in vivo activity of SELENBP1 in angiogenesis and explored the underlying mechanism.

Results

SELENBP1 was localized to endothelial cells in addition to glandular cells, while its vascular expression was decreased in tumor vessels compared to that in vessels from neighboring non-tumor tissues. Gain-of-function and loss-of-function experiments demonstrated that SELENBP1 inhibited angiogenesis in vitro, and blocked communications between HUVECs and CRC cells. Overexpression of SELENBP1 in CRC cells inhibited tumor growth and angiogenesis, and enhanced bevacizumab-sensitivity in a mouse subcutaneous xenograft model. Mechanic analyses revealed that SELENBP1 may suppress tumor angiogenesis by binding with Delta-like ligand 4 (DLL4) and antagonizing the DLL4/Notch1 signaling pathway. The inhibitory effects of SELENBP1 on in vitro angiogenesis could largely be rescued by DLL4.

Conclusion

These results revealed a novel role of SELENBP1 as a potential tumor suppressor that antagonizes tumor angiogenesis in CRC by intervening the DLL4/Notch1 signaling pathway.

Down Syndrome Candidate Region 1 Isoform 1L regulated tumor growth by targeting both angiogenesis and tumor cells

Angiogenesis is critical for solid tumor growth beyond its minimal size. Previously, we reported that Down Syndrome Candidate Region 1 isoform 1L (DSCR1-1L) was one of the most up-regulated genes in endothelial cells induced by VEGF and histamine, and regulated endothelial cell proliferation, migration and angiogenesis. However, it was not known whether DSCR1-1L played a role in tumor growth. In this study, we found that DSCR1-1L shRNAs significantly inhibited the growth of transplanted melanoma in mice and its associated tumoral angiogenesis. In the gain of function assay, overexpression of DSCR1-1L cDNA in mouse endothelium is sufficient to significantly increase the tumor initiation induced by carcinogen, the growth of xenografted tumor, and the tumor metastasis in our endothelially-expressed DSCR1-1L transgenic mice, in which angiogenesis was induced. It was the first time to find that DSCR1-1L was also expressed in various tumor cells. DSCR1-1L shRNAs inhibited, but overexpression of DSCR1-1L cDNA increased, the tumor cell proliferation and migration. Most recently, we reported that DSCR1-1L modulated angiogenesis by down-regulation of VE-cadherin expression. Here, we found that DSCR1-1L down-regulated the expression of E-cadherin. Hence, DSCR1-1L is an excellent therapeutic target for cancers by regulation of both the endothelial and tumor cells through down-regulating (V)E-cadherin. DSCR1-1L shRNAs have the potential to be developed for clinical application.

A Hierarchical Bayesian Latent Class Model for the Diagnostic Performance of Mini-Mental State Examination and Montreal Cognitive Assessment in Screening Mild Cognitive Impairment Due to Alzheimer's Disease

BACKGROUND

The Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) are low costing and noninvasive neuropsychological tests in screening Mild Cognitive Impairment (MCI) due to Alzheimer's disease (AD). There is no consensus on which test performs better in detecting MCI due to AD based on the different imperfect reference standards. Therefore, we conducted a meta-analysis to assess the diagnostic performance of MMSE and MoCA for screening MCI due to AD in the absence of a gold standard.

METHODS

Six electronic databases were searched for relevant studies until April, 2022. A hierarchical Bayesian latent class model was used to estimate the pooled sensitivity and specificity of MoCA and MMSE in the absence of a gold standard.

RESULTS

90 eligible studies covering 21273 individuals for MMSE, 26631 individuals for MoCA were included in this meta-analysis. The pooled sensitivity was 0.71(95%CI: 0.67-0.74) for MMSE and 0.85(95%CI: 0.83-0.88) for MoCA, while the pooled specificity was 0.71(95%CI: 0.68-0.74) for MMSE and 0.79(95%CI: 0.76-0.81) for MoCA. MoCA was useful to "rule in" and "rule out" the diagnosis of MCI due to AD with higher positive likelihood ratio (4.07; 95%CI: 3.60-4.62) and lower negative likelihood ratio (0.18; 95%CI: 0.16-0.22). Moreover, the diagnostic odds ratio of MoCA was 22.08(95%CI: 17.24-28.29), which showed significantly favorable diagnostic performance.

CONCLUSIONS

It suggests that MoCA has greater diagnostic performance than MMSE for differentiating MCI due to AD when the gold standard is absent. However, these results should be taken with caution given the heterogeneity observed.

A Nomogram for Predicting the Cancer-Specific Survival of Patients with Initially Diagnosed Metastatic Gastric Cancer

Background:

There are few models to predict the survival of patients of different ethnicities initially diagnosed with metastatic gastric cancer (mGC). Therefore, the aim of this study was to construct a nomogram to predict the cancer-specific survival (CSS) of these patients.

Methods:

Data for 994 patients initially diagnosed with mGC between 2000 and 2013 were extracted from the Surveillance, Epidemiology, and End Results database. Patients were randomly classified into a training (n = 696) or internal validation (n = 298) cohort, and a cohort of 133 patients from Fudan cohort was used for external validation. A nomogram to predict the CSS of mGC patients was derived and validated using a concordance index (C-index), calibration curves, and decision-curve analysis (DCA).

Results:

Multivariate Cox regression indicated that five factors were independent predictors of CSS: differentiation grade, T stage, N stage, metastatic site at diagnosis, and with or without chemotherapy. Thus, these factors were integrated into the nomogram model. The C-index value of the nomogram model was 0.63 (95% CI: 0.60–0.65), and those of the internal and external validation cohorts were 0.60 (95%: CI 0.55–0.64) and 0.63 (95%: CI 0.57–0.69), respectively. The calibration curves showed good consistency between the actual and predicted survival rates in both the internal and external validation cohorts. The DCA also showed the clinical utility of the nomogram model.

Conclusions:

We established a practical nomogram to predict the CSS of patients initially diagnosed with mGC. The nomogram can be used for individualized prediction of survival and to guide clinicians in making treatment decisions.

A novel transcriptional complex on the VE-cadherin promoter regulated the downregulation of VE-cadherin in the Down Syndrome Candidate Region 1 isoform 1L-mediated angiogenesis

Angiogenesis is critical for many diseases. Previously, we reported that Down Syndrome Candidate Region 1 isoform 1L (DSCR1-1L) was one of the most up-regulated genes in endothelial cells induced by VEGF and histamine, and regulated endothelial cell proliferation and Matrigel angiogenesis in mice. However, it was not known whether DSCR1-1L regulated angiogenesis in vivo and what was the molecular mechanism underlying it. In this study, gene knockdown and overexpression models were established to study the role of DSCR1-1L in angiogenesis in vivo. Further, the downstream regulatory target of DSCR1-1L was explored with molecular biological methods in vascular endothelial cells. We found that DSCR1-1L shRNAs significantly inhibited angiogenesis induced by VEGF in mice (p < 0.0001). In the gain-of-function assay, overexpression of DSCR1-1L cDNA in mouse endothelium of EC-FH-DSCR1-1L transgenic mice was sufficient to induce angiogenesis significantly (p < 0.01). DSCR1-1L regulated angiogenesis in the early stage by down-regulation of the VE-cadherin expression through targeting its transcription, but not mRNA stability. Three DSCR1-1L-targeted DNA elements in the VE-cadherin promoter were identified by promoter reporter assays, among which, a novel specific transcriptional complex was found. The DNA sequence (CTTCTG) in the VE-cadherin promoter was identified to directly interact with proteins by Electrophoresis Mobility Shift Assays and DNase I footprint assay. Hence, DSCR1-1L is an excellent therapeutic target for angiogenic diseases through down-regulating the formation of a novel transcriptional complex on the VE-cadherin promoter. DSCR1-1L shRNAs and cDNA have the potential to be developed for clinical application. Our results also contribute significantly to the field of mechanistic studies.

GJA1 promotes hepatocellular carcinoma progression by mediating TGF-β-induced activation and the epithelial-mesenchymal transition of hepatic stellate cells

Introduction

Gap junction protein, alpha 1 (GJA1), which is correlated with recurrences and unfavorable prognoses in hepatocellular carcinomas (HCCs), is one of the specific proteins expressed by activated hepatic stellate cells (HSCs).

Methods

Expression of GJA1 was compared between HCCs and nontumor tissues (NTs), between hepatic cirrhosis and NTs, and between primary and metastatic HCCs using transcriptomic datasets from the Gene Expression Omnibus and the Integrative Molecular Database of Hepatocellular Carcinoma. The in vitro activities of GJA1 were investigated in cultured HSCs and HCC cells. The underlying mechanism was characterized using Gene Set Enrichment Analysis and validated by western blotting.

Results

The expression of GJA1 was significantly increased in HCCs and hepatic cirrhosis compared to that in NTs. GJA1 was also overexpressed in pulmonary metastases from HCCs when compared with HCCs without metastasis. Overexpression of GJA1 promoted while knockdown of GJA1 inhibited proliferation and transforming growth factor (TGF)-β-mediated activation and migration of cultured HSCs. Overexpression of GJA1 by lentivirus infection promoted proliferation and migration, while conditioned medium from HSCs overexpressing GJA1 promoted migration but inhibited proliferation of Hep3B and PLC-PRF-5 cells. Lentivirus infection with shGJA1 or conditioned medium from shGJA1-infected HSCs inhibited the proliferation and migration of HCCLM3 cells that had a high propensity toward lung metastasis. Mechanistically, GJA1 induced the epithelial–mesenchymal transition (EMT) in HSCs and HCCLM3 cells.

Conclusion

GJA1 promoted HCC progression by inducing HSC activation and the EMT in HSCs. GJA1 is potentially regulated by TGF-β and thus may be a therapeutic target to inhibit HCC progression.

Characterizing the air pollution of the cities in the closure of corona virus disease 2019 in China

With the rapid development of industrialization and urbanization in China, energy and vehicle consumption have continued to increase in recent years and air pollution has become serious. In early 2020, Corona Virus Disease 2019 broke out in Wuhan, China. From January 29, 2020, several sources of the air pollution almost all stopped working, including gasoline burning vehicles, dust producing building sites, coal-fired factories, etc. Five indicators of the atmospheric environmental quality were observed from December 19, 2019 to April 30, 2020 in nine cities and 1-h average concentrations, 24-h average concentrations and Air Quality Index were assessed. The 1-h average concentrations of the nitrogen dioxide, the ozone and the sulfur dioxide showed obvious difference though the closure did not change the sequence of the five pollutants' concentrations in the air at diverse sampling moments. The changing of the 24-h average concentrations of the five pollutants indicated the amount of pollutants in the air were greatly affected by human activities. The nitrogen dioxide, the sulfur dioxide and the particulate matters decreased obviously in the closure. The air in the metropolis and the south-east cities were relatively clean and the pollutants' concentrations decreased slightly during the closure period. The northern and the heavy industrial cities showed significant drop on air pollution indicators and the air quality of the two city groups could be greatly improved if some effective measures could be taken of environmental management and regional development.

GABRD promotes progression and predicts poor prognosis in colorectal cancer

Little is known about the functional roles of gamma-aminobutyric acid type A receptor subunit delta (GABRD) in colorectal cancer (CRC). The expression of GABRD between CRCs and adjacent normal tissues (NTs), metastasis and primary tumors was compared using public transcriptomic datasets. A tissue microarray and immunohistochemical staining (IHC) were used to determine the clinical and prognostic significance of the GABRD in CRC. We used gain-of-function and loss-of-function experiments to investigate the in vitro roles of GABRD in cultured CRC cells. We characterized the potential mechanism of GABRD’s activities in CRC using a Gene Set Enrichment Analysis (GSEA) with The Cancer Genome Atlas Colon Adenocarcinoma (TCGA-COAD) dataset. We found that the GABRD expression was significantly increased in CRCs compared to that in NTs, but was similar between metastasis and primary tumors. Overexpression of GABRD was significantly associated with later pTNM stages and unfavorable patient survival. Overexpression of GABRD accelerated while knock-down of GABRD inhibited cell growth and migration. Mechanistically, the function of GABRD might be ascribed to its influence on major oncogenic events such as epithelial–mesenchymal transition (EMT), angiogenesis, and hedgehog signaling. Collectively, GABRD could be a novel prognostic predictor for CRC that deserves further investigation.

PRELP has prognostic value and regulates cell proliferation and migration in hepatocellular carcinoma

Purpose: Hepatocellular carcinoma (HCC) is an aggressive and prevalent tumor threatening human health. A previous study suggested low PRELP (proline/arginine-rich end leucine-rich repeat protein) expression was associated with poor patient survival in pancreatic ductal adenocarcinoma (PDAC). However, the role of PRELP in HCC has not yet been illuminated. Methods: PRELP expression analyses were carried out using transcriptomic datasets from the Integrative Molecular Database of Hepatocellular Carcinoma (HCCDB). The correlations between PRELP expression and clinicopathological features, and prognostic analyses were performed with a tissue microarray (TMA) and immunohistochemistry (IHC). The endogenous expression and in vitro roles of PRELP were investigated in cultured HCC cell lines. The potential mechanisms were characterized by a Gene Set Enrichment Analysis (GSEA) and gene-gene correlation analyses. Results: We found that PRELP mRNA expression was dramatically decreased in HCCs in comparison with that in adjacent normal tissues (NTs) or hepatic cirrhosis. IHC staining showed that PRELP was down-regulated in HCCs, which mainly located in cytoplasm, and was also found in nuclei. The correlation analyses revealed that PRELP expression was relevant to later p-stages (p= 0.028) and tumor size (p= 0.001). The overall survival (OS) and relapse free survival (RFS) time was shorter in HCC patients with lower PRELP expression levels than that with higher PRELP expression levels. Overexpression of PRELP inhibited, while knockdown of PRELP promoted proliferation and migration of HCC cells. For potential mechanisms, PRELP may inhibit progression of HCCs by interacting with integrin family members and the extracellular microenvironment. Conclusion: Our findings demonstrated that overexpression of PRELP correlates with better patient survival and inhibits both cell proliferation and migration in HCC. Therefore, PRELP can serve as a potential prognostic biomarker and therapeutic target which deserves further investigation.

Preparation and Characterization of a Novel Triple Composite Scaffold Containing Silk Fiborin, Chitosan, and Alginate for 3D Culture of Colonic Carcinoma Cells In Vitro

BACKGROUND Three-dimensional (3D) cell-culture scaffolds are ideal in vitro models to bridge the gap between two-dimensional cell culture in vitro and in vivo cancer models. Construction of 3D scaffolds using two kinds of biomaterials has been reported, but there are still many defects. To improve the performance of the scaffolds for 3D cell culture of colonic carcinoma (CC) cells in vitro, we attempted to construct triple composite scaffolds using silk fibroin (SF), chitosan (Cs), and alginate (Alg). MATERIAL AND METHODS We explored the suitability of triple composite scaffolds of SF/Cs/Alg at ratios of 1: 1: 0.5, 1: 1: 1, and 1: 1: 2 for 3D culture of CC cells, and used the dual composite scaffold of SF/Cs (1: 1) as a control group. We analyzed the physicochemical characteristics of these scaffolds and studied cell adhesion, cell proliferation, migration, colony-forming ability, microstructure and ultrastructure, and spheroid-forming capacity of the commercially available CC cell line HCT-116 on the prepared scaffolds. RESULTS Our results show that SF/Cs/Alg (1: 1: 1) scaffolds demonstrated the best profile, the highest uniform porosity and connectivity, and excellent hydroscopicity, and also exhibited appropriate and controlled swelling and degradation characteristics. The adhesion, proliferation, colony-forming, and wound-healing assays, green fluorescent protein-labeled HCT116 cell imaging, 4',6-diamidino-2-phenylindole and DY-554-phalloidin staining, scanning electron microscopy, and haematoxylin and eosin staining revealed that the triple composite scaffolds of SF/CS/Alg (1: 1: 1) supported cell adhesion, proliferation, migration, colony-forming ability, and spheroid formation far better than the dual composite scaffold of SF/CS (1: 1). CONCLUSIONS This study successfully demonstrated the potential of SF/Cs/Alg (1: 1: 1) scaffold as an alternative for the 3D in vitro culture of CC cells.

TAFA5 promotes proliferation and migration in gastric cancer

TAFA chemokine like family member 5 (TAFA5), a TAFA family member that encodes small secreted proteins in the central nervous system, has been demonstrated to have increased expression in human malignancies. However, the expression and function of TAFA5 in gastric cancer (GC) remains unclear. In the present study, public datasets and human GC samples were used to determine the TAFA5 expression levels. The results revealed that TAFA5 was upregulated in GC when compared with adjacent normal tissues. Overexpression of TAFA5 in GC was associated with poor differentiation, and worse tumor, nodal and metastasis stages. In addition, high TAFA5 expression was correlated with unfavorable patient prognoses. In vitro experiments indicated that downregulation of TAFA5 inhibited the proliferation and migration of GC cell lines. Finally, the results from gene set enrichment analysis using data from The Cancer Genome Atlas revealed that TAFA5 expression was significantly correlated with genes associated with epithelial-mesenchymal transition, which was further confirmed by western blot analysis. In conclusion, the results of the present study suggested that TAFA5 had significant effects on GC progression, suggesting that it may serve as a potential therapeutic target for GC therapy.

Overexpression of CPXM2 predicts an unfavorable prognosis and promotes the proliferation and migration of gastric cancer

Carboxypeptidase X, M14 family member 2 (CPXM2), has been associated with several human disorders such as developmental diseases. However, whether CPXM2 is involved in oncogenesis or tumor progression remains unclear. In the present study, we used clinical samples from gastric cancer (GC) patients to investigate potential roles of CPXM2 in GC. We also analyzed datasets from the Oncomine database, The Cancer Genome Atlas (TCGA), and the Kaplan‑Meier Plotter to validate these results. We found that CPXM2 was overexpressed in GC and that the overexpression was associated with an unfavorable prognosis, regardless of the Lauren classification and tumor node metastasis staging. In addition, knockdown of CPXM2 in cultured GC cells significantly impeded cell proliferation and migration, as indicated by the cholecystokinin octapeptide, colony formation assay, scratch wound healing assay, and Transwell® migration assay. Furthermore, gene set enrichment analysis using RNA‑seq data from TCGA indicated that high CPXM2 expression in GC patients was positively correlated with the HALLMARK_APICAL_JUNCTION and HALLMARK_EPITHELIAL_MESENCHYMAL_TRANSITION gene sets. Finally, western blotting results revealed that several key molecules involved in the epithelial mesenchymal transition were regulated by CPXM2. Taken together, these results imply an active role for CPXM2 in promoting tumor aggressiveness via epithelial to mesenchymal transition (EMT) modulation in GCs.

DLL4 and Jagged1 are angiogenic targets of orphan nuclear receptor TR3/Nur77

Pathological angiogenesis is a hallmark of many diseases. Previously, we reported that orphan nuclear receptor TR3/Nur77 was a critical mediator of angiogenesis to regulate tumor growth and skin wound healing via regulating the expression of the junctional proteins and integrins. However, the molecular mechanism, by which TR3/Nur77 regulates angiogenesis is not completely understood. Here, we were the first to find that TR3/Nur77, via its various amino acid fragments, regulated the expression of DLL4 and Jagged 1 in cultured endothelial cells. DLL4 and Jagged1 mediated TR3/Nur77-induced angiogenic responses and signaling molecules, but not the expression of integrins. Instead, integrins regulated the expressions of DLL4 and Jagged1 induced by TR3/Nur77. Further, DLL4, Jagged1 and integrins α1, α2, β3 and β5 were regulated by TR3/Nur77 in animal sepsis models of lipopolysaccharide (LPS)-induced endotoxemia, and cecal ligation and puncture (CLP), in which, TR3/Nur77 expression was significantly and tranciently increased. Mouse survival rates were greatly increased in Nur77 knockout mice bearing both CLP and LPS models. The results elucidated a novel axis of VEGF/histamine ➔ TR3/Nur77 ➔ integrins ➔ DLL4/Jagged1 in angiogenesis, and demonstrated that TR3/Nur77 was an excellent target for sepsis. These studies supported our previous findings that TR3/Nur77 was an excellent therapeutic target, and further our understanding of the molecular mechanism, by which TR3/Nur77 regulated angiogenesis.

Effect of Age on Prognosis of Gastric Signet-Ring Cell Carcinoma: A SEER Database Analysis

Background

Age is a prognostic factor for multiple malignancies. In this study, we aimed to assess the effect of age on the cancer-specific survival (CSS) of patients with gastric signet-ring cell carcinoma (SRC).

Material/Methods

Information on patients with gastric SRC was extracted from the Surveillance, Epidemiology, and End Results database. Chi-squared tests were used to demonstrate distribution differences, and Kaplan-Meier analysis and Cox regression models were used to analyze the impact of age on CSS.

Results

A total of 4596 patients were enrolled and divided into 3 subgroups according to age (<45, 45–74, and >74 years old). Higher percentages of T4, N2, and M1 disease were observed in the <45-year-old group (all P<0.001). Kaplan-Meier plots showed that the youngest group had the most favorable 5-year CSS rate (36.3%), which remained true after stratification according to tumor stage. Multivariate Cox regression models demonstrated a poorer survival outcome for >74-year-old than for <45-year-old patients (hazard ratio 1.841, 95% confidence interval 1.636–2.071; P<0.001).

Conclusions

Young age is associated with improved survival, even though younger patients generally present with a more advanced-stage disease.

Overexpression of FNDC1 in Gastric Cancer and its Prognostic Significance

Objectives: The aims of this study were to compare the expression of fibronectin type III domain containing 1 (FNDC1) in gastric cancer (GC) and normal gastric tissue, to explore the prognostic significance of FNDC1 expression in patients with gastric adenocarcinoma, and to analyze FNDC1-related signaling pathways. Methods: The expression level of FNDC1 was initially predicted using the Oncomine and Cancer Genome Atlas databases. A Kaplan-Meier plotter database was mined to examine the clinical prognostic significance of FNDC1 mRNA in patients with GC. Subsequently, immunohistochemistry was used to measure FNDC1 protein expression levels in tissue from 90 cases of GC and paired adjacent normal tissue. Kaplan-Meier univariate and Cox multivariate survival analyses were used to determine the prognostic role of FNDC1 expression. Results: Bioinformatic data indicated that FNDC1 mRNA expression levels were significantly highly expressed in GC compared with normal gastric tissue (all P < 0.05), and patients with GC with high FNDC1 mRNA expression levels had remarkably lower overall survival (all P < 0.01). Immunohistochemical results revealed that expression levels of FNDC1 protein were significantly increased in GC compared with normal gastric tissue (P < 0.001). Additionally, Kaplan-Meier univariate and Cox multivariate survival analyses indicated that increased expression of FNDC1 was an independent predictor of poor prognosis in patients with GC (all P < 0.05). Conclusions: FNDC1 was highly expressed in GC, and high expression of FNDC1 was an independent predictor of poor prognosis in patients with GC. FNDC1 co-expressed genes were largely enriched in extracellular matrix-receptor interactions, which are closely related to tumor metastasis.

Orphan nuclear receptor TR3/Nur77 differentially regulates the expression of integrins in angiogenesis

Pathological angiogenesis is a hallmark of many diseases. Previously, we reported that orphan nuclear receptor TR3/Nur77 (human homolog, Nur77, mouse homolog) is a critical mediator of angiogenesis to regulate tumor growth and skin wound healing via down-regulating the expression of the junctional proteins and integrin β4. However, the molecular mechanism, by which TR3/Nur77 regulated angiogenesis, was still not completely understood. In this report by analyzing the integrin expression profile in endothelial cells, we found that the TR3/Nur77 expression highly increased the expression of integrins α1 and β5, decreased the expression of integrins α2 and β3, but had some or no effect on the expression of integrins αv, α3, α4, α5, α6, β1 and β7. In the angiogenic responses mediated by TR3/Nur77, integrin α1 regulated endothelial cell proliferation and adhesion, but not migration. Integrin β5 shRNA inhibited cell migration, but increased proliferation and adhesion. Integrin α2 regulated all of the endothelial cell proliferation, migration and adhesion. However, integrin β3 did not play any role in endothelial cell proliferation, migration and adhesion. TR3/Nur77 regulated the transcription of integrins α1, α2, β3 and β5, via various amino acid fragments within its transactivation domain and DNA binding domain. Furthermore, TR3/Nur77 regulated the integrin α1 promoter activity by directly interacting with a novel DNA element within the integrin α1 promoter. These studies furthered our understanding of the molecular mechanism by which TR3/Nur77 regulated angiogenesis, and supported our previous finding that TR3/Nur77 was an excellent therapeutic target for pathological angiogenesis. Therefore, targeting TR3/Nur77 inhibits several signaling pathways that are activated by various angiogenic factors.

Graphene enhanced field emission from InP nanocrystals

We report the observation of field emission (FE) from InP nanocrystals (NCs) epitaxially grown on an array of p-Si nanotips. We prove that FE can be enhanced by covering the InP NCs with graphene. The measurements are performed inside a scanning electron microscope chamber with a nano-controlled W-thread used as an anode. We analyze the FE by Fowler-Nordheim theory and find that the field enhancement factor increases monotonically with the spacing between the anode and the cathode. We also show that InP/p-Si junction has a rectifying behavior, while graphene on InP creates an ohmic contact. Understanding the fundamentals of such nanojunctions is key for applications in nanoelectronics.

Electron holography on HfO2/HfO2-x bilayer structures with multilevel resistive switching properties

Unveiling the physical nature of the oxygen-deficient conductive filaments (CFs) that are responsible for the resistive switching of the HfO₂-based resistive random access memory (RRAM) devices represents a challenging task due to the oxygen vacancy related defect nature and nanometer size of the CFs. As a first important step to this goal, we demonstrate in this work direct visualization and a study of physico-chemical properties of oxygen-deficient amorphous HfO_2-x by carrying out transmission electron microscopy electron holography as well as energy dispersive x-ray spectroscopy on HfO₂/HfO_2-x bilayer heterostructures, which are realized by reactive molecular beam epitaxy. Furthermore, compared to single layer devices, Pt/HfO₂/HfO_2-x /TiN bilayer devices show enhanced resistive switching characteristics with multilevel behavior, indicating their potential as electronic synapses in future neuromorphic computing applications.

Puerarin prevents inflammation and apoptosis in the neurocytes of a murine Parkinson's disease model

The aim of this study was to investigate Parkinson's disease (PD) using a murine model of PD. Specifically, we aimed to explore the mechanism by which puerarin prevents inflammation and apoptosis in neurocytes. Eighty healthy male C57/BL6 mice were randomly selected and divided into four groups (N = 20 each): control group; PD group; PD+puerarin group; and puerarin group. At the end of the treatment period, the animals' brains were removed after perfusion and decollation. The protein expression levels of tyrosine hydroxylase (TH) in the murine brains were assessed by immunohistochemistry and the protein expression levels of TH, glial fibrillary acidic protein (GFAP), inducible nitric oxide synthase (iNOS), cleaved Caspase-3, and Bax in the substantia nigra and corpus striatum of the animals were assessed by western blotting. The spontaneous activity of the PD mice was found to be significantly higher after puerarin treatment and the distance traveled by mice in an open field assessment was 1700 cm further in puerarin-treated PD mice than in PD mice. Immunohistochemistry and western blotting analyses indicated that the expression of TH was significantly higher (2.63-fold) in puerarin-treated PD mice than in untreated PD mice and that the expression of GFAP in PD mice was significantly reduced (~45%) by puerarin treatment. These findings lead us to conclude that puerarin significantly alleviates 1-methyl-4-phenyl- 1,2,3,6-tetrahydropyridine-induced injury in dopaminergic neurons. Puerarin mediates anti-apoptotic and anti-inflammatory activities and plays a neuroprotective role.

Vitamin D prevents articular cartilage erosion by regulating collagen II turnover through TGF-β1 in ovariectomized rats

OBJECTIVE

To explore the effect of vitamin D on turnover of articular cartilage with ovariectomy (OVX) induced OA, and to investigate transforming growth factor-β1 (TGF-β1) as a possible underlying mechanism mediated by 1α,25(OH)2D3.

DESIGN

Sixty-six rats were randomly allocated into seven groups: sham plus control diet (SHAM+CTL), OVX+CTL diet, sham plus vitamin D-deficient (VDD) diet, OVX+VDD diet, and three groups of ovariectomized rats treated with different doses of 1α,25(OH)2D3. The cartilage erosion and the levels of serum 17β-estradiol, 1α,25(OH)2D3 and C-telopeptide of type II collagen (CTX-II) were measured. TGF-β1, type II Collagen (CII), matrix metalloproteinases (MMP)-9,-13 in articular cartilage were assessed by immunohistochemistry. TGF-β1 and CTX-II expression were measured in articular cartilage chondrocytes treated with/without tumor necrosis factor (TNF-α), 1α,25(OH)2D3, and TGF-β receptor inhibitor (SB505124) in vitro.

RESULTS

Cartilage erosion due to OVX was significantly reduced in a dose-dependent manner by 1α,25(OH)2D3 supplementation, and exacerbated by VDD. The expressions of TGF-β1 and CII in articular cartilage were suppressed by OVX and VDD, and rescued by 1α,25(OH)2D3 supplementation. The expression of MMP-9,-13 in articular cartilage increased with OVX and VDD, and decreased with 1α,25(OH)2D3 supplementation. In vitro experiments showed that 1α,25(OH)2D3 increased the TGF-β1 expression of TNF-α stimulated chondrocytes in a dose-dependent manner. 1α,25(OH)2D3 significantly counteracted the increased CTX-II release due to TNF-α stimulation, and this effect was significantly suppressed by SB505124.

CONCLUSION

VDD aggravated cartilage erosion, and 1α,25(OH)2D3 supplementation showed protective effects in OVX-induced OA partly through the TGF-β1 pathway.

Post deposition annealing of epitaxial Ce1−xPrxO2−δfilms grown on Si(111)

In this work the structural and morphological changes of Ce_1−xPr_xO_2−δ(x= 0.20, 0.35 and 0.75) films grown on Si(111) due to post deposition annealing are investigated by low energy electron diffraction combined with a spot profile analysis.

Orphan nuclear receptor TR3/Nur77 improves wound healing by upregulating the expression of integrin β4

Tissue repair/wound healing, in which angiogenesis plays an important role, is a critical step in many diseases including chronic wound, myocardial infarction, stroke, cancer, and inflammation. Recently, we were the first to report that orphan nuclear receptor TR3/Nur77 is a critical mediator of angiogenesis and its associated microvessel permeability. Tumor growth and angiogenesis induced by VEGF-A, histamine, and serotonin are almost completely inhibited in Nur77 knockout mice. However, it is not known whether TR3/Nur77 plays any roles in wound healing. In these studies, skin wound-healing assay was performed in 3 types of genetically modified mice having various Nur77 activities. We found that ectopic induction of Nur77 in endothelial cells of mice is sufficient to improve skin wound healing. Although skin wound healing in Nur77 knockout mice is comparable to the wild-type control mice, the process is significantly delayed in the EC-Nur77-DN mice, in which a dominant negative Nur77 mutant is inducibly and specifically expressed in mouse endothelial cells. By a loss-of-function assay, we elucidate a novel feed-forward signaling pathway, integrin β4 → PI3K → Akt → FAK, by which TR3 mediates HUVEC migration. Furthermore, TR3/Nur77 regulates the expression of integrin β4 by targeting its promoter activity. In conclusion, expression of TR3/Nur77 improves wound healing by targeting integrin β4. TR3/Nur77 is a potential candidate for proangiogenic therapy. The results further suggest that TR3/Nur77 is required for pathologic angiogenesis but not for developmental/physiologic angiogenesis and that Nur77 and its family members play a redundant role in normal skin wound healing.

Differential regulation of orphan nuclear receptor TR3 transcript variants by novel vascular growth factor signaling pathways

Angiogenesis is a hallmark of many diseases, including cancer, ischemic heart disease, inflammation, and others. It is well known that vascular endothelial growth factor (VEGF) is the most important angiogenic factor. Recently, we demonstrated that orphan nuclear receptor TR3 (mouse Nur77 and rat NGFI-B) plays critical roles in tumor growth and angiogenesis induced by VEGF-A in vitro and in vivo. However, the signaling pathways that mediate the expression of TR3 induced by VEGF are still not completely understood. Here we reported that 3 TR3 transcript variants (TR3-TVs) are expressed at differential levels, and regulated differentially in endothelial cells. While the expression of TR3-TV1 is relatively low, the expression of TR3-TV2 is up-regulated markedly, and the expression of TR3-TV3 is up-regulated moderately in endothelial cells induced by VEGF-A. The kinetics of the induction of these TR3-TVs is different. We also found that several signaling pathways, including calcium-PLC-PKC-PKD1 pathway, NF-κB pathway, and MAP kinase (ERK, p38, and JNK) pathways are important for VEGF-A-induced TR3-TV2 and TR3-TV3 mRNA induction. More important, we found that VEGF-A or VEGF-E, but not VEGF-B, nor placenta growth factor (PlGF), induces the phosphorylation of insulin-like growth factor-1 receptor (IGF-1R) and the interaction of VEGF receptor 2/kinase insert domain receptor (VEGFR2/KDR) with IGF-1R, which mediates the expression of TR3-TV2, but not TR3-TV3. Taking together, we demonstrate that TR3-TVs are differentially regulated by VEGF-A and identify a novel signaling pathway by which VEGF-A and VEGF-E, but neither VEGF-B, nor PlGF, induce the interaction of VEGFR2/KDR with IGF-1R, resulting in IGF-1R transactivation to induce the high level expression of TR3-TV2. Our data not only elucidate the signaling pathways by which TR3-TVs are regulated, but extend the molecular mechanism, by which VEGF-A-induced angiogenesis. These studies should permit the development of screening assays for compounds that inhibit VEGF signaling.

Dual roles of orphan nuclear receptor TR3/Nur77/NGFI-B in mediating cell survival and apoptosis

As a transcriptional factor, Nur77 has sparked interests across different research fields in recent years. A number of studies have demonstrated the functional complexity of Nur77 in mediating survival/apoptosis in a variety of cells, including tumor cells. Conflicting observations also exist in clinical reports, in that TR3 behaves like an oncogene in tumors of the GI tract, lung, and breast, that is negatively associated with tumor stage and patient prognosis; while functions as a tumor suppressor gene in malignancies of the hematological and lymphatic system, skin, and ovary whose malfunction results in carcinogenesis. This chapter summarizes the apparent opposing effects of Nur77 on cells and explicates the mechanisms that determine the functional preference of Nur77. We conclude that in addition to cell type and agent context, other factors such as cellular localization, signaling pathway, and posttranslational modification also determine the final effects of Nur77 on cells.

Structural transitions of epitaxial ceria films on Si(111)

The structural changes of a (111) oriented CeO2 film grown on a Si(111) substrate covered with a hex-Pr2O3(0001) interface layer due to post deposition annealing are investigated. X-ray photoelectron spectroscopy measurements revealing the near surface stoichiometry show that the film reduces continuously upon extended heat treatment. The film is not homogeneously reduced since several coexisting crystalline ceria phases are stabilized due to subsequent annealing at different temperatures as revealed by high resolution low energy electron diffraction and X-ray diffraction. The electron diffraction measurements show that after annealing at 660 °C the ι-phase (Ce7O12) is formed at the surface which exhibits a (√7 × √7)R19.1° structure. Furthermore, a (√27 × √27)R30° surface structure with a stoichiometry close to Ce2O3 is stabilized after annealing at 860 °C which cannot be attributed to any bulk phase of ceria stable at room temperature. In addition, it is shown that the fully reduced ceria (Ce2O3) film exhibits a bixbyite structure. Polycrystalline silicate (CeSi(x)O(y)) and crystalline silicide (CeSi1.67) are formed at 850 °C and detected at the surface after annealing above 900 °C.

Insulator-metal transition of VO₂ ultrathin films on silicon: evidence for an electronic origin by infrared spectroscopy

We report on the first simultaneous observations of both electronic and structural temperature-induced insulator-to-metal transition (IMT) in VO2 ultrathin films, made possible by the use of broad range transmission infrared spectroscopy. Thanks to these techniques, the infrared phonon structures, as well as the appearance of the free carrier signature, were resolved for the first time. The temperature-resolved spectra allowed the determination of the temperature hysteresis for both the structural (monoclinic-to-rutile) and electronic (insulator-to-metallic) transitions. The combination of these new observations and DFT simulations for the monoclinic structure allows us to verify the direct transition from monoclinic (M1) to rutile and exclude an intermediate structural monoclinic form (M2). The delay in structural modification compared to the primer electronic transition (325 K compared to 304 K) supports the role of free charges as the transition driving force. The shape of the free charge hysteresis suggests that the primer electronic transition occurs first at 304 K, followed by both its propagation to the heart of the layer and the structural transition when T increases. This study outlines further the potential of VO2 ultrathin films integrated on silicon for optoelectronics and microelectronics.

Meta-analysis of temporary ileostomy versus colostomy for colorectal anastomoses

BACKGROUND/AIMS

Defunctioning stoma is a common surgical procedure, it is now generally acknowledged that defunctioning stoma significantly reduce the rates of complications in colorectal surgery, but the choice of temporary ileostomy or temporary colostomy for defunctioning colorectal anastomoses remains controversial. This meta-analysis evaluated two types of defunctioning stoma to determine whether one is superior to the other.

METHODOLOGY

Studies and relevant literatures comparing temporary ileostomy with temporary colostomy for defunctioning colorectal anastomoses were searched though PubMed, Embase and The Cochrane Library. The rates of complications were pooled and compared using a meta-analysis. The risk ratios were calculated with 95% confidence intervals to evaluate the safety and efficacy of each technique.

RESULTS

Five randomized controlled trials and seven non-randomized studies were included, with 1687 patients in total. The meta-analysis of the RCTs demonstrated a lower risk of stoma prolapse (RR 0.15; 95% CI: 0.04-0.48, p = 0.001) in the temporary ileostomy group. Meta-analysis of the non-randomized studies showed a lower risk of stoma prolapse (RR 0.26; 95% CI 0.10-0.67, p = 0.005) and wound infection after stoma closure (RR 0.28; 95% CI 0.5-0.52, p < 0.0001) in the temporary ileostomy group. No other statistically significant difference was observed for complications.

CONCLUSIONS

Each type of defunctioning stoma has its advantages and disadvantages, and there is not a strong evidence for the superiority of one temporary stoma over another for colorectal anastomoses. According to this, large scale RCTs and high quality studies are needed to conduct.

WE-C-217BCD-04: Multimodality Imaging of Breast Cancer Experimental Lung Metastasis

PURPOSE

Metastatic breast cancer (MBC) is incurable. The clinical gold standard for assessing tumor microvessel density (MVD), an independent prognostic marker in MBC, is CD 105 staining. The goal of this study is to develop a positron emission tomography (PET)/near-infrared fluorescent (NIRF) probe for imaging of CD105 expression in MBC (i.e. non-invasive measurement of MVD), as well as other applications such as early detection of metastasis, intraoperative guidance, etc.

METHODS

TRC105, a chimeric anti-CD105 mAb, was dual-labeled with a NIRF dye and ⁸⁹ Zr to yield ^{8 9} Zr-Df-TRC105-800CW. Luciferase-transfected 4T1 murine breast cancer cells were injected intravenously into female BALB/c mice to establish a lung MBC model. Bio luminescence imaging (BLI) was carried out to non- invasively monitor the lung tumor burden. Comprehensive in vivo/ex vivo studies were performed to investigate ^{8 9} Zr-Df-TRC105-800CW in this MBC model. Cetuximab was used as an isotype-matched control.

RESULTS

Radiolabeled TRC105 has high tumor uptake in many tumor types in addition to MBC (e.g. pancreatic/prostate cancer and brain tumor), revealing broad clinical potential for TRC105-based agents. FACS analysis of HUVECs showed no difference in CD 105 binding between TRC105 and Df- TRC105-800CW. PET imaging revealed that 4T1 lung tumor uptake of ⁸⁹ Zr-Df-TRC105-800CW was 8.7±1.4,10.9±0.5, and 9.7±1.1 %ID/g at 4, 24, and 48 h post-injection (n = 4), with excellent tumor contrast. Bio distribution studies, blocking, control studies with ^{8 9} Zr-Df-cetuximab- 800CW, ex vivo BLI/PET/NIRF imaging, and histology all confirmed CD 105 specificity of the tracer. NIRF imaging-guided removal of 4T1 tumors with Df-TRC105-800CW in a subcutaneous model was also straightforward.

CONCLUSIONS

We report the first PET/NIRF imaging of CD105 expression in a MBC model. Broad clinical potential of TRC105- based agents was shown in many tumor types, which also enabled early detection of small metastases and provided intraoperative guidance for tumor removal.

MR imaging assessment of lumbar intervertebral disk degeneration and age-related changes: apparent diffusion coefficient versus T2 quantitation

BACKGROUND AND PURPOSE

T2 and ADC mappings are 2 quantitative MR imaging tools for assessing IVDD. This study aimed to compare these 2 measures in detecting IVDD and its age-related changes.

MATERIALS AND METHODS

Thirty-seven asymptomatic volunteers and 28 patients with back pain or sciatica were examined, and their lumbar disk T2 and ADC maps were quantified via sagittal imaging protocols at 1.5T. For all participants, the Pfirrmann system was used by 2 radiologists for grading disks. T2 and ADC values in the inner portion of disks were measured, and their variances in different grades were analyzed by 1-way ANOVA testing. The ability of T2 and ADC measures to differentiate IVDD grades was compared on the basis of their ROC curves. For asymptomatic subjects, the correlations between age and the 2 MR imaging measures were assessed by the Pearson correlation test.

RESULTS

Both T2 and ADC values were found to decrease with the increasing Pfirrmann grades except T2 in grade V. Significant T2 differences were seen among grades I-IV, but not between grades IV and V. There were no significant ADC differences among grades I-III. Moreover, the areas under the ROC curves differed significantly (0.95 and 0.67 for T2 and ADC, respectively). Linear regression analysis revealed that T2 yielded more significant correlation with age (r = -0.77) than ADC did (r = -0.37).

CONCLUSIONS

T2 quantitation provides a more sensitive and robust approach for detecting and characterizing the early stage of IVDD and age-related disk changes.

Examination of the hdrRM regulon yields insight into the competence system of Streptococcus mutans

Previous studies have identified the hdrRM operon as a novel regulatory system induced by conditions of high cell density. Little is known about the genes under the control of this system, but a variety of important phenotypes are associated with either hdrR overexpression or mutation of hdrM. To characterize the regulatory function of the HdrRM system in Streptococcus mutans we used a microarray approach to compare the transcriptional profiles of an hdrR overexpression strain with an hdrM mutant. Both strains exhibited almost identical profiles, which included all of the known late competence genes as well as a variety of competence-induced bacteriocins. Through a combination of real-time reverse transcription-polymerase chain reaction (PCR), reporter gene analysis and random amplification of complementary DNA ends PCR, we confirmed the role of comX as a central intermediate regulator of numerous genes in the hdrRM regulon. Through these studies, we also identified novel comX-regulated genes required for natural competence. Taken together, our results suggest that the primary function of the HdrRM system is to regulate the late competence genes together with various bacteriocins. This occurs independently of the ComCDE system, even though both systems regulate nearly identical genes. This suggests that S. mutans has multiple parallel input sensory systems that control the same output response: the induction of natural competence and concurrent production of bacteriocins.

BRSK2 expression as a prognosis marker in pancreatic cancer patients

e15603

Background: The prognosis of pancreatic cancer remains dismal because of difficult early diagnosis, low resection rate and aggressive biological behavior. The research of factors related to oncogenesis, tumor infiltration and metastasis is valuable. AMPK(AMP-activated protein kinase)family is a group of regulators on the cellular energy metabolism which are sensitive to the cytoplasmic change of AMP/ATP ratio. As a member of AMPK, BRSK2 is found to be expressed in human pancreatic cell line and facilitate the tumor cell survival on glucose starving. In order to examine the expression of BRSK2 in human pancreatic cancer and explore the underline clinical implication, human pancreatic tissue was examined immunohistochemically Correlation of tumor biological behavior, prognosis and BRSK2 expression was examined. Methods: Seventy nine resected tumor specimens were collected. Immunochemical staining method was used to examine the expression pattern of BRSK2 translated protein. Semi-quantitative analysis was employed to compare the expression intensity and content of BRSK2 in tumor issues, peri-tumorous tissue and normal pancreatic tissue. Possible relationship of tumors differentiation, TNM stage, presence or absence of vessel and neural infiltration were explored with BRSK2 expression. The correlation of BRSK2 expression profile and patients survival was explored. Results: BRSK2 was weakly expressed in normal pancreatic tissues and peri-tumor tissues, including the islet and minor ducts. BRSK2 was strongly expressed in pancreatic cancer tissues, the expression intensity was correlated with extent of lymphatic metastasis, distant metastasis, TNM staging and neural invasion. Tumors with lymphatic metastasis, distant metastasis, neural invasion and later TNM stages showed stronger expression of BRSK2. The expression of BRSK2 in pancreatic cancer was closely correlated to the prognosis of patients, those with higher expression pattern showed bad prognosis. Conclusions: BRSK2 is up-regulated in pancreatic cancer; the expression of BRSK2 is correlated with tumor biological behavior and patient's prognosis.

No significant financial relationships to disclose.